TB meningitis cerebrospinal fluid. Features of diagnosing meningeal tuberculosis
Lumbar cerebrospinal fluid is normal.
Table 17
Purulent meningitis
Serous meningitis
Tuberculous meningitis.
Epidemic encephalitis.
Traumatic brain injury
Tumor of the central nervous system.
1) red a) normal
3) yellow c) blood stagnation
d) purulent meningitis.
1) norm a) 0.033
4. Terms for inflammation:
d) arachnoiditis
d) meningitis.
2) reactions of Pandey b) Samson
d) sulfosalicylic acid
e) azure-eosin.
2) cytosis b) in the counting chamber
d) Nonne-Apelt.
Date of publication: 2014-11-02; Read: 16554 | Page copyright infringement
Cerebrospinal fluid is involved in the nutrition of brain cells, in creating osmotic balance in brain tissue and in regulating metabolism in brain structures. Various regulatory molecules are transported through the cerebrospinal fluid, changing the functional activity of different parts of the central nervous system.
Maintains a certain concentration of cations, anions and pH, which ensures normal excitability of the central nervous system (for example, changes in the concentration of Ca, K, magnesium change blood pressure, heart rate).
Introduction.
Cerebrospinal fluid (cerebrospinal fluid, cerebrospinal fluid) is a fluid constantly circulating in the ventricles of the brain, cerebrospinal fluid tracts, subarachnoid (subarachnoid) space of the brain and spinal cord
The role of cerebrospinal fluid in the functioning of the central nervous system is great. Cerebrospinal fluid protects the brain and spinal cord from mechanical influences, ensures the maintenance of constant intracranial pressure and water-electrolyte homeostasis. Supports trophic and metabolic processes between blood and brain.
List of used literature.
- Human Anatomy / Ed. M.G. Gain - 9th ed., p. 542.
- Kozlov V.I. Anatomy of the nervous system: A textbook for students / V.I. Kozlov, T.A. Tsekhmistrenko. — M.: Mir: ACT Publishing House LLC, 2004. — 206 p.
- Human Anatomy: Textbook in 2 volumes / Ed. M.R. Sapina.
- Anatomy of the central nervous system. Reader. (Tutorial for students). Authors and compilers: T.E.Rossolimo, L.B.Rybalov, I.A.Moskvina-Tarkhanova.
- Reader on the anatomy of the central nervous system: Textbook. manual / Ed.-comp. OK. Khludova. -M.
Composition of cerebrospinal fluid in various nasologies
: Ross. psychologist. society, 1998. - 360 p. - Decree. anatomist. terms: p. 342-359.
- http://knowledge.allbest.ru; http://www.kazedu.kz; http://medbiol.ru.
- Cerebrospinal fluid (CSF), its composition, functions, circulation paths.
- Composition of cerebrospinal fluid (CSF).
- Pathways of circulation of cerebrospinal fluid (CSF).
Karaganda State Medical University
Department of Anatomy.
Topic: Circulation of cerebrospinal fluid.
Completed by: student of group 246 OMF
Kosilova E.Yu.
Checked by: teacher G.I. Tugambaeva
Karaganda 2012.
Pages:← previous12
Lumbar cerebrospinal fluid is normal. In healthy people, the liquor obtained by lumbar puncture is a colorless and transparent, like water, liquid of a slightly alkaline reaction (pH 7.35-7.4) with a relative density of 1.003-1.008. Contains 0.2-0.3 g/l protein; 2.7-4.4 mmol/l glucose; 118-132 mmol/l chlorides. Microscopic examination reveals 0-5 cells in 1 μl (mainly lymphocytes).
In a number of diseases of the central nervous system, the cerebrospinal fluid has similar properties, which made it possible to distinguish three laboratory syndromes of pathological cerebrospinal fluid: serous cerebrospinal fluid syndrome, purulent cerebrospinal fluid syndrome and hemorrhagic cerebrospinal fluid syndrome (Table 17).
Table 17
Main syndromes of pathological cerebrospinal fluid
Purulent meningitis can be caused by meningococci, streptococci and other pyogenic cocci. It often develops as a complication of purulent otitis, with skull injuries. On the second or third day of the disease, pronounced pleocytosis appears (up to 2000-3000·106/l), which increases very quickly. The liquor becomes cloudy and purulent. When settling, a rough fibrinous film is formed. The vast majority of formed elements are neutrophils. The protein content increases sharply (up to 2.5-3.0 g/l or more). Globulin reactions are positive. The content of glucose and chlorides has been reduced since the first days of the disease.
Serous meningitis can cause tuberculous mycobacteria, Coxsackie and ECHO viruses, mumps, herpes, etc. The most severe form of serous meningitis is tuberculous meningitis.
Tuberculous meningitis. A characteristic sign is an increase in cerebrospinal fluid pressure. Normally, cerebrospinal fluid is released at a rate of 50-60 drops per minute; with increased pressure, cerebrospinal fluid flows out in a stream. The liquid is often transparent, colorless, and sometimes opalescent. In most patients, a thin fibrinous mesh forms in it. Cytosis at the height of the disease reaches 200·106/l or more, lymphocytes predominate. The protein level is increased to 0.5-1.5 g/l. Globulin reactions are positive. The concentration of glucose and chlorides is noticeably reduced. Decisive in the diagnosis of tuberculous meningitis is the detection of Mycobacterium tuberculosis in the fibrinous film.
Epidemic encephalitis. Cerebrospinal fluid is often transparent and colorless. Pleocytosis is moderate, up to 40·106/l, of a lymphoid nature. Protein levels are normal or slightly elevated. Globulin reactions are weakly positive.
Traumatic brain injury. One of the leading signs of traumatic brain injury is the presence of blood in the CSF (red color of varying intensity). An admixture of blood can be a symptom of other lesions of the central nervous system: rupture of a cerebral aneurysm, hemorrhagic stroke, subarachnoid hemorrhage, etc. On the first day after hemorrhage, the liquid after centrifugation becomes colorless, on the second day xanthochromia appears, which disappears after 2-3 weeks. The increase in protein content depends on the amount of blood shed. With massive hemorrhages, the protein content reaches 20-25 g/l. Moderate or severe pleocytosis develops with a predominance of neutrophils, which are gradually replaced by lymphocytes and macrophages. Normalization of cerebrospinal fluid occurs 4-5 weeks after injury.
Tumor of the central nervous system. Changes in the cerebrospinal fluid depend on the location of the tumor, its size and contact with the cerebrospinal fluid space. The fluid may be colorless or xanthochromic when the subarachnoid space is blocked. The protein content increases slightly, but with a block of the cerebrospinal fluid tract or spinal cord tumors, a sharp increase in protein content is detected, and globulin tests are positive. Cytosis does not exceed 30·106/l, mainly lymphoid. If the tumor is located far from the cerebrospinal fluid pathways, the CSF may be unchanged.
5.4. CHECK QUESTIONS FOR THE CHAPTER “RESEARCH OF CEREBROSPRINAL FLUID”
Match the elements in the columns. One element in the left column corresponds to only one element in the right column.
1. The amount of liquor (ml), which:
1) produced per day a) 8-10
2) circulates simultaneously b) 15-20
3) removed during puncture c) 100-150
2. Color of cerebrospinal fluid in normal and pathological conditions:
1) red a) normal
2) colorless b) subarachnoid hemorrhage (1st day)
3) yellow c) blood stagnation
d) purulent meningitis.
1) norm a) 0.033
2) spinal cord tumor b) 0.2-0.3
2.4 Methods for laboratory testing of cerebrospinal fluid
Terms for inflammation:
1) brain a) pleocytosis
2) dura mater b) stroke
3) arachnoid c) encephalitis
d) arachnoiditis
d) meningitis.
5. Reagents used for:
1) counting cytosis a) ammonium sulfate
2) reactions of Pandey b) Samson
3) determining the amount of protein c) carbolic acid
d) sulfosalicylic acid
e) azure-eosin.
6. The predominant type of cellular elements in the cerebrospinal fluid in diseases of the central nervous system:
1) neutrophils a) tuberculous meningitis
2) red blood cells b) purulent meningitis
c) hemorrhage (first day).
7. Methods for determination in liquor:
1) ratio of protein fractions a) with sulfosalicylic acid
2) cytosis b) in the counting chamber
3) amount of protein c) in colored preparations
d) Nonne-Apelt.
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Product catalog
| 38.02 | Clinic-Blood No. FSR 2008/03535 dated 10/29/2008 Kit for conducting a general blood test using standardized methods: fixation and staining of blood smears (4000 samples), erythrocyte count (4000 samples), leukocyte count (4000 samples), platelet count (4000 samples), ESR using the Panchenkov micromethod (4000 samples) |
— |
| 38.03 | Clinic-Cal. Set No. 1 (general) No. FSR 2010/09420 dated 12/08/2010 Set of reagents for clinical analysis of stool: Occult blood (1000 samples), Stercobilin (50 samples), Bilirubin (200 samples), Microscopic examination (neutral fat, fatty acids, soaps, starch, helminth eggs) (2000 samples) |
— |
| 38.03.2 | Clinic-Cal. Kit No. 2 Determination of occult blood |
1000 |
| 38.03.3 | Clinic-Cal. Set No. 3 Determination of stercobilin Reagent kit for clinical stool analysis |
50 |
| 38.03.4 | Clinic-Cal. Kit No. 4 Determination of bilirubin Reagent kit for clinical stool analysis |
200 |
| 38.03.5 | Clinic-Cal. Set No. 5 Microscopic examination | 2000 |
| 38.04 | Clinic-Uro. Set No. 1. |
Kit for clinical urine analysis No. FSR 2010/09509 dated 12/17/2010
Acidity (pH) (1000 sample), Glucose (1000 sample), Ketones (1000 sample), Bilirubin (400 sample), Urobilinoids (1000 sample), Total protein: - qualitative sample. (1000), — quantitative definition. (330)
- qualitative definition (1000) - quantitative definition. (330)
Set of reagents for clinical sputum analysis: Acid-fast mycobacteria (AFB) (200 samples), Alveolar macrophages with hemosiderin (reaction to Prussian blue) (100 samples), Malignant neoplasm cells (300 samples)
Set for analysis of cerebrospinal fluid: Cytosis (Samson's reagent) (200 samples), Total protein: qualitative Pandey reaction (200 samples), quantitative test. (sulfosalicyl compounds and sodium sulfate) (200 samples), globulins (200 samples)
A kit for detecting helminths and their eggs in feces using a thick smear method. Kato reagent - 1 bottle (50 ml.) Cellophane cover plates - 500 pcs. Silicone rubber plug - 1 pc.
A set of reagents for determining the protein content in urine and cerebrospinal fluid with pyrrogalol red. The reagent is a solution of pyrogallic red in succinate buffer. Calibrator 1 - Protein Calibration Solution
100 ml
set of reagents for supravital staining of urine sediment (modification of the Sternheimer method)
Microscopic examination (Quantity and morphological structure of cellular elements)
The number and morphological structure of cellular elements are essential for establishing the nature of inflammatory processes in the brain and its membranes.
Based on the nature of changes in the cerebrospinal fluid, purulent and serous meningitis (meningoencephalitis) are differentiated. Serous include meningitis (meningoencephalitis), in which the cerebrospinal fluid is transparent, sometimes slightly cloudy, and opalescent; the number of cellular elements is increased to 500 - 600 in 1 μl, lymphocytes predominate.
Purulent ones include meningitis (meningoencephalitis), in which the number of leukocytes exceeds 0.5 - 0.6 * 109/l and can reach 20 * 109/l or more. Colorless, transparent or opalescent cerebrospinal fluid should be specially examined to identify the fibrin film (“mesh”) specific to tuberculous meningitis, which can form in a test tube after 12–24 hours.
Very often, tuberculosis bacilli are detected microscopically in such a film.
MICROSCOPIC STUDY OF CSF
With meningitis, meningoencephalitis, septic thrombosis of the cerebral sinuses, changes in the cerebrospinal fluid are inflammatory in nature.
The number of cellular elements (mainly neutrophils) increases to a much greater extent than the protein content increases - cell-protein dissociation.
In pathological processes accompanied by cerebral edema, increased intracranial pressure and leading to blockage of the liquor pathways, a significant increase in protein content with a slightly increased or normal number of cellular elements (protein-cell dissociation) is more typical.
Such ratios are observed in acutely manifested brain tumors, large epidural and subdural hematomas and some other pathological processes that cause swelling and dislocation of the brain.
As a result of microscopic examination of cerebrospinal fluid smears, it is not always possible to determine the causative agent of meningitis (bacteria, fungi, protozoa, tumor cells) - in 35 - 55% of cases. Thus, the role of microscopy in establishing the etiology of inflammatory lesions of the meninges is limited.
This equally applies to the possibilities of bacteriological diagnosis of the etiology of meningoencephalitis, brain abscesses and septic thrombosis of the cerebral sinuses. The sugar content in the cerebrospinal fluid decreases in many pathological processes due to a decrease in its transport through the blood-brain barrier.
“Emergency conditions in neuropathology”, B.S. Vilensky
The review presents changes in laboratory parameters of cerebrospinal fluid in major severe diseases of the central nervous system.
MENINGITIS
Cerebrospinal fluid testing is the only method that can quickly diagnose meningitis. The absence of inflammatory changes in the cerebrospinal fluid always allows one to exclude the diagnosis of meningitis. The etiological diagnosis of meningitis is established using bacterioscopic and bacteriological methods, virological and serological studies.
Pleocytosis is the most characteristic feature of CSF changes. Based on the number of cells, serous and purulent meningitis are distinguished. With serous meningitis, cytosis is 500-600 in 1 μl, with purulent meningitis - more than 600 in 1 μl. The study must be carried out no later than 1 hour after receiving it.
According to the etiological structure, 80-90% of bacteriologically confirmed cases are Neisseria meningitides, Streptococcus pneumoniae and Haemophilus. Bacterioscopy of CSF, due to the characteristic morphology of meningococci and pneumococci, gives a positive result at the first lumbar puncture 1.5 times more often than culture growth.
CSF in purulent meningitis ranges from slightly cloudy, as if whitened with milk, to densely green, purulent, sometimes xanthochromic. In the initial stage of development of meningococcal meningitis, there is an increase in intracranial pressure, then mild neutrophilic cytosis is noted in the cerebrospinal fluid, and in 24.7% of patients the CSF is normal in the first hours of the disease. Then, in many patients, already on the first day of the disease, cytosis reaches 12,000-30,000 in 1 μl, neutrophils predominate. A favorable course of the disease is accompanied by a decrease in the relative number of neutrophils and an increase in lymphocytes. Occurring cases of purulent meningitis with a typical clinical picture and relatively little cytosis can probably be explained by a partial blockade of the subarachnoid space. There may not be a clear correlation between the severity of pleocytosis and the severity of the disease.
The protein content in the CSF during purulent meningitis is usually increased to 0.6-10 g/l and decreases as the cerebrospinal fluid is sanitized. The amount of protein and cytosis are usually parallel, but in some cases with high cytosis the protein level remains normal. A high protein content in the CSF is more common in severe forms with ependymitis syndrome, and its presence in high concentrations during the recovery period indicates an intracranial complication (block of the cerebrospinal fluid tract, dural effusion, brain abscess). The combination of low pleocytosis with high protein content is a particularly unfavorable prognostic sign.
In most patients with purulent meningitis, from the first days of illness there is a decrease in glucose levels (below 3 mmol/l); in case of death, the glucose level was in the form of traces. In 60% of patients, the glucose level is below 2.2 mmol/l, and the ratio of glucose level to that in the blood in 70% is less than 0.31. An increase in glucose level is almost always a prognostically favorable sign.
In tuberculous meningitis, bacterioscopic examination of the CSF often gives a negative result. Mycobacteria are more often found in fresh cases of the disease (in 80% of patients with tuberculous meningitis). The absence of mycobacteria in lumbar punctate is often noted when they are detected in the cisternal CSF. In case of negative or questionable bacterioscopic examination, tuberculosis is diagnosed by culture or biological test. In tuberculous meningitis, the CSF is clear, colorless, or slightly opalescent. Pleocytosis ranges from 50 to 3000 in 1 μl, depending on the stage of the disease, amounting to 100-300 in 1 μl by the 5-7th day of illness. In the absence of etiotropic treatment, the number of cells increases from the beginning to the end of the disease. There may be a sudden drop in cytosis with a repeat lumbar puncture performed 24 hours after the first. The cells are predominantly lymphocytes, but often at the onset of the disease mixed lymphocytic-neutrophilic pleocytosis occurs, which is considered typical for milliary tuberculosis with seeding of the meninges. Characteristic of tuberculous meningitis is the diversity of the cellular composition, when, along with the predominance of lymphocytes, there are neutrophils, monocytes, macrophages and giant lymphocytes. Later, pleocytosis acquires a lymphoplasmacytic or phagocytic character. A large number of monocytes and macrophages indicates an unfavorable course of the disease.
Total protein in tuberculous meningitis is always increased to 2-3 g/l, and earlier researchers noted that protein increases before the onset of pleocytosis and disappears after its significant decrease, i.e., in the first days of the disease, protein-cell dissociation takes place. Modern atypical forms of tuberculous meningitis are characterized by the absence of typical protein-cell dissociation.
With tuberculous meningitis, an early decrease in glucose concentration is observed to 0.83-1.67 mmol/l and below. In some patients, a decrease in chloride levels is detected. In viral meningitis, about 2/3 of cases are caused by the mumps virus and a group of enteroviruses.
In serous meningitis of viral etiology, the CSF is transparent or slightly opalescent. Pleocytosis is small (rarely up to 1000) with a predominance of lymphocytes. In some patients, neutrophils may predominate at the onset of the disease, which is typical for a more severe course and a less favorable prognosis. Total protein is within 0.6-1.6 g/l or normal. In some patients, a decrease in protein concentration is detected due to overproduction of cerebrospinal fluid.
CLOSED CRANIO BRAIN INJURY
The permeability of cerebral vessels in the acute period of traumatic brain injury is several times higher than the permeability of peripheral vessels and is directly dependent on the severity of the injury. To determine the severity of the lesion in the acute period, a number of liquorological and hematological tests can be used. These include: the severity and duration of the presence of hyperproteinorachia as a test characterizing the depth of dysgemic disorders in the brain and the permeability of the blood-cerebrospinal fluid barrier; the presence and severity of erythroarchia as a test that reliably characterizes ongoing intracerebral bleeding; the presence of pronounced neutrophilic pleocytosis within 9-12 days after the injury, which serves as an indication of the unresponsiveness of the tissues limiting the cerebrospinal fluid spaces and the inhibition of the sanitizing properties of the arachnoid cells or the addition of an infection.
Concussion: CSF is usually colorless, clear, and contains little or no red blood cells. On days 1-2 after injury, cytosis is normal; on days 3-4, moderately pronounced pleocytosis appears (up to 100 in 1 μl), which decreases to normal numbers on days 5-7. In the liquorogram, lymphocytes with the presence of a small number of neutrophils and monocytes, macrophages, as a rule, are absent. The protein level on days 1-2 after injury is normal, on days 3-4 it rises to 0.36-0.8 g/l and returns to normal by days 5-7.
Brain contusion: the number of red blood cells ranges from 100 to 35,000 and with massive subarachnoid hemorrhage reaches 1-3 million. Depending on this, the color of the CSF can be from grayish to red. Due to irritation of the meninges, reactive pleocytosis develops. For bruises of mild and moderate severity, pleocytosis on days 1-2 is on average 160 in 1 μl, and in severe cases it reaches several thousand. On days 5-10, pleocytosis significantly decreases, but does not reach normal in the next 11-20 days. In the cerebrospinal fluid there are lymphocytes, often macrophages with hemosiderin. If the nature of pleocytosis changes to neutrophilic (70-100% neutrophils), purulent meningitis has developed as a complication. The protein content in mild to moderate cases is on average 1 g/l and does not return to normal by 11-20 days. With severe brain damage, protein levels can reach 3-10 g/l (often fatal).
With traumatic brain injury, the energy metabolism of the brain switches to the path of anaerobic glycolysis, which leads to the accumulation of lactic acid in it, and, ultimately, to brain acidosis.
The study of parameters reflecting the state of brain energy metabolism allows one to judge the severity of the pathological process. A decrease in the arteriovenous difference in pO2 and pCO2, an increase in glucose consumption by the brain, an increase in the venoarterial difference in lactic acid and an increase in it in the cerebrospinal fluid. The observed changes are the result of disruption of the activity of a number of enzyme systems and cannot be compensated by the blood supply. It is necessary to stimulate the nervous activity of patients.
HEMORRHAGIC STROKE
The color of the cerebrospinal fluid depends on the admixture of blood. In 80-95% of patients, during the first 24-36 hours the CSF contains an obvious admixture of blood, and later it is either bloody or xanthochromic. However, in 20-25% of patients with small lesions located in the deep parts of the hemispheres, or in the case of blockage of the cerebrospinal fluid pathways due to rapidly developing cerebral edema, red blood cells are not detected in the CSF. In addition, red blood cells may be absent during lumbar puncture in the very first hours after the onset of hemorrhage, while the blood reaches the spinal level. Such situations are a reason for diagnostic errors - the diagnosis of “ischemic stroke”. The largest amount of blood is found when blood breaks through into the ventricular system. The removal of blood from the cerebrospinal fluid tract begins from the very first day of the disease and continues for 14-20 days in case of traumatic brain injury and stroke, and in case of cerebral aneurysms up to 1-1.5 months and does not depend on the massiveness of the hemorrhage, but on the etiology process.
The second important sign of CSF changes in hemorrhagic stroke is xanthochromia, detected in 70-75% of patients. It appears on the 2nd day and disappears 2 weeks after the stroke. With a very large number of red blood cells, xanthochromia may appear within 2-7 hours.
An increase in protein concentration is observed in 93.9% of patients and its amount ranges from 0.34 to 10 g/l and higher. Hyperproteinorachia and increased bilirubin levels can persist for a long time and, along with liquorodynamic disorders, can cause meningeal symptoms, in particular headaches, even 0.5 - 1 year after subarachnoid hemorrhage.
Pleocytosis is detected in almost 2/3 of patients, it is increasing over 4-6 days, the number of cells ranges from 13 to 3000 in 1 μl. Pleocytosis is associated not only with the breakthrough of blood into the cerebrospinal fluid pathways, but also with the reaction of the meninges to the shed blood. It seems important to determine the true cytosis of the cerebrospinal fluid in such cases. Sometimes, with hemorrhages in the brain, the cytosis remains normal, which is associated with limited hematomas without a breakthrough into the cerebrospinal fluid space, or with the unresponsiveness of the meninges.
With subarachnoid hemorrhages, the admixture of blood can be so large that the cerebrospinal fluid is visually almost indistinguishable from pure blood. On the 1st day, the number of red blood cells, as a rule, does not exceed 200-500 x 109/l, later their number increases to 700-2000 x 109/l. In the very first hours after the development of small-volume subarachnoid hemorrhages, a lumbar puncture can produce clear cerebrospinal fluid, but by the end of the 1st day an admixture of blood appears in it. The reasons for the absence of blood in the CSF may be the same as for a hemorrhagic stroke. Pleocytosis, mainly neutrophilic, over 400-800x109/l, is replaced by lymphocytic by the fifth day. Within a few hours after hemorrhage, macrophages may appear, which can be considered markers of subarachnoid hemorrhage. An increase in total protein usually corresponds to the degree of hemorrhage and can reach 7-11 g/l and higher.
ISCHEMIC STROKE
CSF is colorless and transparent, in 66% the cytosis remains within the normal range, in the rest it increases to 15-50x109/l, in these cases characteristic cerebral infarctions are detected, located close to the cerebrospinal fluid pathways. Pleocytosis, predominantly lymphoid-neutrophilic, is caused by reactive changes around extensive ischemic foci. In half of the patients, the protein content is determined within the range of 0.34-0.82 g/l, less often up to 1 g/l. The increase in protein concentration is due to necrosis of brain tissue and increased permeability of the blood-brain barrier. Protein content can increase by the end of the first week after a stroke and last for over 1.5 months. Quite characteristic of ischemic stroke is protein-cell (increase in protein content with normal cytosis) or cell-protein dissociation.
BRAIN ABSCESS
The initial phase of abscess formation is characterized by neutrophilic pleocytosis and a slight increase in protein. As the capsule develops, pleocytosis decreases and its neutrophilic character is replaced by lymphoid, and the greater the development of the capsule, the less pronounced the pleocytosis. Against this background, the sudden appearance of pronounced neutrophilic pleocytosis indicates a breakthrough of the abscess. If the abscess was located near the ventricular system or the surface of the brain, the cytosis will be from 100 to 400 in 3 μl. Minor pleocytosis or normal cytosis may occur when the abscess was delimited from the surrounding brain tissue by a dense fibrous or hyalinized capsule. The zone of inflammatory infiltration around the abscess in this case is absent or weakly expressed.
CNS TUMORS
Along with protein-cell dissociation, which is considered characteristic of tumors, pleocytosis may occur with normal protein content in the cerebrospinal fluid. With gliomas of the cerebral hemispheres, regardless of their histology and location, an increase in protein in the cerebrospinal fluid is observed in 70.3% of cases, and in immature forms - in 88%. A normal or even hydrocephalic composition of the ventricular and spinal fluid can occur both with deep-seated and with gliomas growing into the ventricles. This is mainly observed in mature diffusely growing tumors (astrocytomas, oligodendrogliomas), without obvious foci of necrosis and cyst formation and without gross displacement of the ventricular system. At the same time, the same tumors, but with gross displacement of the ventricles, are usually accompanied by an increase in the amount of protein in the cerebrospinal fluid. Hyperproteinorachia (from 1 g/l and above) is observed in tumors located at the base of the brain. With pituitary tumors, the protein content ranges from 0.33 to 2.0 g/l. The degree of shift in the proteinogram is directly dependent on the histological nature of the tumor: the more malignant the tumor, the more severe the changes in the protein formula of the cerebrospinal fluid. Beta lipoproteins appear that are not normally detected, and the content of alpha lipoproteins decreases.
In patients with brain tumors, regardless of their histological nature and location, polymorphic pleocytosis quite often occurs. The cellular reaction is determined by the peculiarities of the biological processes occurring in the tumor at certain stages of its development (necrosis, hemorrhage), which determine the reaction. The brain tissue and membranes surrounding the tumor. Tumor cells of the cerebral hemispheres in the fluid from the ventricles can be detected in 34.4%, and in the spinal cerebrospinal fluid - from 5.8 to 15% of all observations. The main factor determining the entry of tumor cells into the cerebrospinal fluid is the nature of the structure of the tumor tissue (poor connective stroma), the absence of a capsule, and the location of the tumor near the cerebrospinal fluid spaces.
CHRONIC INFLAMMATORY DISEASES (arachnoiditis, arachnoencephalitis, periventricular encephalitis)
Meningitis is a dangerous brain disease that leads to disability and, in the absence of medical care, death. Since cerebrospinal fluid changes its properties during meningitis, the doctor, after examining it, can make an accurate diagnosis and immediately prescribe the necessary treatment. Cerebrospinal fluid is taken using a lumbar puncture (puncture). There is no need to be afraid of this procedure, because it helps you choose the most effective treatment method.
Cerebrospinal fluid controls the functionality of the nervous system. To obtain it, the doctor performs a lumbar puncture on the patient. Functions of cerebrospinal fluid:
- protect the brain from damage and exposure to mechanical factors;
- maintain optimal pressure inside the skull;
- promote metabolic processes between the brain and the fluid environment of the body;
- evacuate metabolic products;
- maintain the functioning of parts of the brain.
The total volume of spinal fluid ranges from 140 to 270 cubic meters. cm. It is formed by secretion by cells located in the vascular connections of the ventricles of the brain. Approximately 700 cubic meters are produced every day. see cerebrospinal fluid.
Normal indicators
Normally, cerebrospinal fluid has the following indicators:
- density - from 1.005 to 1.009;
- the pressure should be within 100-200 millimeters of water;
- there should be no coloring;
- cytosis (per 1 microliter): ventricular fluid - up to 1, cisternal fluid - up to 1, lumbar fluid - within 2-3);
- alkaline index - from 7.31 to 7.33;
- total protein - from 0.16 to 0.33 grams per liter;
- glucose indicator - from 2.8 to 3.9 mmol per liter;
- chlorine (ions) - 120-128 millimoles.
Meningitis is an absolute indication for lumbar puncture. This procedure is prohibited if:
- severe swelling of the brain tissue (the procedure can cause great harm);
- a sharp jump in cerebrospinal fluid pressure;
- the presence of a large formation inside the brain;
- dropsy.
Carrying out a puncture procedure for hydrocephalus and in the event of a pressure surge inside the skull can lead to a condition where a piece of brain tissue extends into the opening of the head. At the same time, the work of the most important human life support centers is disrupted.
During the puncture, the person lies on his side, tilts his head to his chest and brings his legs bent at the knee joint to his stomach. This position ensures optimal accessibility at the puncture site. It is located between the 3rd and 4th vertebrae in the lower back. There is no longer a spinal cord in this place.
Alcohol is applied to the puncture site, and an anesthetic is injected under the skin. The skin is pierced with a special needle with a tip. If it is inserted correctly, cerebrospinal fluid begins to be released through the needle.
Features of analysis
Cerebrospinal fluid during meningitis is examined according to certain rules. The first drops of it do not fall into the test tube and are carefully removed because they contain an admixture of blood. The liquid must be in a sterile and chemically clean tube. It is collected in two vessels: one is sent for chemical and general clinical analysis, and the other for bacteriological.
All liquor samples are carefully protected from overheating and cooling. To determine bacterial bodies, they are additionally heated.
Liquid analysis is carried out in several stages:
- assessment of color, volume, measurement of relative density;
- counting cells in the sample (calculated per 1 ml);
- microscopic examination of the sample;
- cytological examination of the stained sample;
- biochemical analysis;
- microscopy.
Deviations from normal indicators - video
In the presence of brain diseases, the cerebrospinal fluid changes its characteristics:
- If pathogenic microorganisms are present in it, it turns greenish-gray. A large number of leukocytes are found in the fluid.
- The red color of the cerebrospinal fluid indicates the presence of red blood cells. It happens with intense inflammatory damage or after injury.
- With the development of inflammatory processes in the body, the cerebrospinal fluid becomes yellow and even brown, and hemoglobin decomposition products are found in it. This condition is called xanthochromia.
- False coloration of the cerebrospinal fluid is also possible. It occurs with prolonged use of certain medications.
- The green color of the liquor occurs with purulent inflammation of the lining of the brain.
- A cyst rupture turns it dark.
- When protein elements are cytosed, the cerebrospinal fluid becomes opalescent.
- The disease process in the meninges increases the density of the spinal fluid to 1.015.
- Increased amounts of fibrinogen promote the growth of fibrosis clots and films. Typically, such phenomena occur during the development of the tuberculosis process.
Sometimes enzymes are found in the liquor. Normally, it should contain few enzymes. An increase in the content of these substances may indicate a disruption in brain activity.
In meningitis, counting the number of microbial cells is of particular importance.. This number is critical for determining an accurate diagnosis and selecting a treatment method. The following calculation methods are used:
- determination of the number of cells that are stained using the Romanovsky Giemsa or Nokhtu method);
- counting liquor elements using a Fuchs and Rosenthal chamber. In its absence, a Goryaev chamber is used.
The increase in cells in the cerebrospinal fluid during meningitis is called pleocytosis. It is often diagnosed during inflammatory diseases. This phenomenon is most pronounced in the tuberculous form of meningitis.
Staining with Samson's solution makes it possible to accurately differentiate microbial and other cells. With meningitis, the number of lymphocytes, neutrophils, monocytes, eosinophils, and basophils increases. The doctor is interested in the quantity of all these elements.
Slow leakage of cerebrospinal fluid, the impossibility of obtaining it, pronounced coloring, discrepancy between the patient’s serious condition and the composition of the fluid, pronounced coagulation of the cerebrospinal fluid indicates that the patient is developing blocked types of meningitis.
The presence of atypical cells in the fluid while maintaining its transparency and the absence of increased protein content does not confirm the diagnosis of meningitis. The patient is referred for additional studies, since this sign may indicate the progression of a malignant process in the brain.
The liquor in this case is heterogeneous. A feature of the disease process is that the number of pathologically altered cells and microorganisms in the cerebrospinal fluid rapidly increases. If the patient is suspected of developing purulent meningitis, then a general examination should be carried out no later than 60 minutes after the lumbar puncture.
The fluid in the spinal canal with purulent meningitis is usually opaque and green or milky in color. Laboratory studies confirm the growth of neutrophils, the spread of indicators of all formed elements.
If the number of neutrophils in the spinal fluid decreases significantly, this indicates that the outcome of the disease is favorable. Analysis of cerebrospinal fluid during meningitis helps determine the severity of the pathological process.
In the presence of purulent formations, the amount of protein increases, but with timely sanitation it begins to decrease. The combination of pleocytosis and elevated protein indicates an unfavorable prognosis for meningitis.
With the purulent variety of the disease, there is a decrease in glucose in the cerebrospinal fluid. If its quantity increases, then this indicates regression of the disease.
Laboratory tests for microorganisms for the tuberculous type of meningitis do not show positive results. A more thorough study of the cerebrospinal fluid helps to detect the presence of a pathogen in it.
Precipitation can be noticed no earlier than 12 hours after analysis. The sediment looks like a fibrin network in the form of a web or flakes. A large number of Mycobacterium tuberculosis can be found in it.
During the tuberculous process, the cerebrospinal fluid remains transparent, without noticeable coloring. Cytosis occurs in a fairly wide range and differs depending on the stage of meningitis. In the absence of etiotropic treatment, the number of cells always increases. Repeated cerebrospinal fluid sampling after the start of therapy noted a decrease in the number of cells.
A characteristic feature of the development of pathology is the presence of lymphocytes in the cerebrospinal fluid. If the level of monocytes and macrophages in it increases, this is a bad sign. Neutrophils and giant lymphocytes can be found in large quantities in the cerebrospinal fluid. Protein in this pathology usually increases, its level can reach 3 grams per liter.
The glucose level in the cerebrospinal fluid with tuberculous meningitis drops sharply to 0.8 mmol. Sometimes the chloride level also decreases. A favorable indicator is an increase in the level of these cerebrospinal fluid indicators.
Bacterial examination of the cerebrospinal fluid is mandatory to establish the type of pathogen. If the analysis was carried out on the first day after hospitalization, then in almost all cases pathological microorganisms are detected. On the 3rd day of disease development, the number of microbes decreases significantly.
Changes in cerebrospinal fluid go through several stages:
- increased level of intracranial pressure;
- development of neutrophilic type of cytosis;
- the appearance of changes indicating the development of a purulent type of meningitis.
If meningitis is not treated or is not treated correctly, bacteria are found in the patient’s cerebrospinal fluid. The amount of protein and neutrophils increases. The more protein, the more severe the disease.
In the pneumococcal form of meningitis, the fluid is cloudy, purulent, and sometimes turns green. The number of neutrophils is moderate. Proteins can be up to 10 grams per liter or even more.
In serous meningitis, the cerebrospinal fluid is usually clear with the presence of a small number of lymphocytes. At the initial stage of the disease, some accumulation of neutrophils is observed. This indicates a complicated course of the disease and usually indicates an unfavorable prognosis for meningitis.
Most often, protein levels fluctuate within normal limits. Among some patients, the amount of this substance in the cerebrospinal fluid decreases slightly, which is caused by an increase in the production of cerebrospinal fluid. Pleocytosis is increased only in the case of meningitis caused by the Coxsackie virus. With herpes, on the contrary, it is almost absent.
During the recovery stage, the patient exhibits lymphocytosis. In mild cases, it is noted already on the third day of illness. With serous meningitis caused by the mumps virus, the cerebrospinal fluid is usually clear and without color. It reveals the presence of lymphocytes, and the level of chloride ions and glucose increases slightly.
Examination of the spinal fluid during meningitis is mandatory: this is the only way to determine whether a patient has inflammation of the meninges and choose the most appropriate therapy. You should not be afraid of damage to the spinal cord, since there is no spinal cord at all at the puncture site. After receiving the biological material, the laboratory assistant immediately studies it. This must be done as quickly as possible, because some forms of meningitis progress quickly, and every second is precious for the patient’s recovery.
Liquor (cerebrospinal or cerebrospinal fluid, CSF) – biological fluid necessary for the functioning of the central nervous system. Its research is one of the most important types of laboratory research. It consists of a preanalytical stage (preparation of the subject, collection of material and its delivery to the laboratory), analytical (the actual implementation of the study) and postanalytical (decoding the result obtained). Only the correct execution of all manipulations at each of these stages determines the quality of the analysis.
Cerebrospinal fluid (CSF) is formed in the choroid plexuses of the ventricles of the brain. In an adult, 110–160 ml of cerebrospinal fluid circulate simultaneously in the subarchnoid spaces and in the ventricles of the brain, and 50–70 ml in the spinal canal. CSF is formed continuously at a rate of 0.2–0.8 ml/min, which depends on intracranial pressure. A healthy person produces 350–1150 ml of cerebrospinal fluid per day.
Liquor is obtained by puncture of the spinal canal, more often - lumbar - in accordance with a technique well known to neurologists and neurosurgeons. The first drops of it are removed (“travel” blood). Then the cerebrospinal fluid is collected into at least 2 tubes: into a regular tube (chemical, centrifuge) for general clinical and chemical analysis, and into a sterile one for bacteriological examination. On the referral form for a CSF study, the doctor must indicate not only the patient’s name, but also the clinical diagnosis and purpose of the study.
It should be remembered that cerebrospinal fluid samples delivered to the laboratory must be protected from overheating or cooling, and samples intended for the detection of bacterial polysaccharides in serological tests should be heated in a water bath for 3 minutes.
The actual laboratory study of cerebrospinal fluid (analytical stage) is carried out according to all the rules accepted in clinical laboratory diagnostics when analyzing any biological fluids and includes the following stages:
Macroscopic analysis - assessment of physical and chemical properties (volume, color, character),
- counting the number of cells,
- microscopy of the native specimen and cytological examination of the stained specimen;
- biochemical research,
- microbiological examination (if indicated).
We find it appropriate and informative in some cases to supplement the study of CSF with immunological and, possibly, other tests, the significance of which is discussed in the specialized literature.
Decoding of cerebrospinal fluid indicators
Normal CSF is colorless and transparent (like distilled water, in comparison with which the physical properties of cerebrospinal fluid are usually described).
The grayish or gray-green color of the cerebrospinal fluid is usually due to the admixture of microbes and leukocytes. The red color of the CSF of varying intensity (erythrochromia) is due to the admixture of red blood cells found in recent hemorrhages or brain injury. Visually, the presence of red blood cells is detected when their content is more than 500-600 per μl.
In pathological processes, the liquid may be xanthochromic - colored yellow or yellow-brown by the breakdown products of hemoglobin. It is also necessary to remember about false xanthochromia - the coloring of the cerebrospinal fluid caused by medications. Less commonly, we see a greenish color in the CSF (purulent meningitis, brain abscess). The literature also describes a crusty color of the cerebrospinal fluid - when a craniopharyngioma cyst breaks through into the cerebrospinal fluid tract.
The turbidity of the cerebrospinal fluid may be due to the admixture of blood cells or microorganisms. In the latter case, turbidity can be removed by centrifugation. When the CSF contains an increased amount of coarse proteins, it becomes opalescent.
The relative density of cerebrospinal fluid obtained by lumbar puncture is 1.006–1.007. With inflammation of the meninges and brain injuries, the relative density of the cerebrospinal fluid increases to 1.015. It decreases with overproduction of cerebrospinal fluid (hydrocephalus).
With an increased content of fibrinogen in the cerebrospinal fluid, the formation of a fibrinous film or clot occurs, which is observed more often with tuberculous meningitis. Sometimes a test tube with liquid is left at room temperature for a day (if it is necessary to accurately determine whether a film has formed?). If a fibrinous film is present, it is transferred with a dissecting needle onto a glass slide and stained with Ziehl-Neelsen or another method to identify mycobacteria. Normal CSF is 98-99% water.
Nevertheless, the study of its chemical composition is an important task. It includes determination of the level of protein, glucose and chlorides, and in some cases is supplemented by other indicators.
Protein in liquor
More than 80% of CSF protein comes from plasma by ultrafiltration. The protein content is normal in different portions: in the ventricular – 0.05-0.15 g/l, cisternal 0.15-0.25 g/l, lumbar 0.15-0.35 g/l. To determine the protein concentration in the cerebrospinal fluid, any of the standardized methods can be used (with sulfosalicylic acid and ammonium sulfate, and others). An increased protein content in the cerebrospinal fluid (hyperproteinarchy) can be caused by various pathogenetic factors (Table 1).
The study of cerebrospinal fluid proteins allows not only to clarify the nature of the pathological process, but also to assess the state of the blood-brain barrier. Albumin can serve as an indicator for these purposes, provided that its level in the cerebrospinal fluid is determined by immunochemical methods. The determination of albumin is carried out due to the fact that it, being a blood protein, is not synthesized locally and therefore can be a “marker” of immunoglobulins that have penetrated from the bloodstream due to impaired permeability of barriers. Simultaneous determination of albumin in blood serum (plasma) and CSF allows one to calculate the albumin index:
With an intact blood-brain barrier, this index is less than 9, with moderate damage - 9-14, with noticeable damage - 14-30, with severe damage - 30-100, and an increase of more than 100 indicates complete damage to the barrier.
In recent years, there has been increasing interest in CNS-specific cerebrospinal fluid proteins - neuron-specific enolase, protein S-100, myelin basic protein (MBP) and some others. MBP seems to be one of the most promising among them for clinical purposes. It is practically absent in normal cerebrospinal fluid (its concentration does not exceed 4 mg/l) and appears only under pathological conditions. This laboratory sign is not specific to certain nosological forms, but reflects the size of the lesion (associated mainly with the destruction of white matter). Some authors consider the determination of MBP in the cerebrospinal fluid to be promising for monitoring neurospeed. Unfortunately, today there are still problems associated with the direct determination of the concentration of this protein.
Glucose in cerebrospinal fluid
Glucose is contained in normal cerebrospinal fluid in a concentration of 2.00-4.18 mmol/l. This value is subject to significant fluctuations even in a healthy person, depending on the diet, physical activity, and other factors. To correctly assess the level of glucose in the cerebrospinal fluid, it is recommended to simultaneously determine its level in the blood, where it is normally 2 times higher. Elevated blood glucose levels (hyperglycoarchia) occur in diabetes mellitus, acute encephalitis, ischemic circulatory disorders and other diseases. Hypoglycoarchia is observed with meningitis of various etiologies or aseptic inflammation, tumor damage to the brain and membranes, less often with herpes infection, subarachnoid hemorrhage.
Lactate (lactic acid) has some advantage over glucose as a diagnostic marker, since its concentration in the cerebrospinal fluid (1.2-2.1 mmol/l) does not depend on that in the blood. Its level increases significantly in various conditions associated with energy metabolism disorders - meningitis, especially those caused by gram-positive flora, brain hypoxia and some others.
Chlorides in cerebrospinal fluid
Chlorides - content in normal cerebrospinal fluid - 118-132 mmol/l. An increase in concentration in the CSF is observed when their elimination from the body is impaired (kidney disease, heart disease), with degenerative diseases and tumors of the central nervous system. A decrease in chloride content is observed in encephalitis and meningitis.
Enzymes in liquor
Liquor is characterized by low activity of the enzymes it contains. Changes in the activity of enzymes in the cerebrospinal fluid in various diseases are mainly nonspecific and parallel to the described changes in the blood in these diseases (Table 2). The interpretation of changes in creatine phosphokinase (CPK) activity deserves a different approach. This enzyme is presented in tissues in three fractions, characterized not only by molecular differences, but also by the nature of distribution in tissues: CPK-MB (myocardium), CPK-MM (muscles), CPK-BB (brain). If the total activity of CPK in the cerebrospinal fluid has no fundamental diagnostic value (it can be increased in tumors, cerebral infarction, epilepsy and other diseases), then the CPK-BB fraction is a rather specific marker of damage to brain tissue and its activity in the CSF correlates with the Glasgow scale.
Cell count and cerebrospinal fluid cytogram
When studying biological fluids, including CSF, the number of cells and the cytogram in smears stained with asureosin are usually counted (according to Romanovsky-Giemsa, Nocht, Pappenheim). The counting of cellular elements in the cerebrospinal fluid (determination of cytosis) is carried out using a Fuchs-Rosenthal chamber, after diluting it 10 times with Samson's reagent. Using this particular dye, and not any other. allows you to stain cells within 15 minutes and keep cells unchanged for up to 2 hours.
The number of cells in the entire chamber is divided by 3, so a cytosis of 1 μl is obtained. For greater accuracy, cytosis is counted in three chambers. In the absence of a Fuchs-Rosenthal chamber, you can use the Goryaev chamber by counting cells throughout the entire grid also in three chambers, the result is multiplied by 0.4. There are still discrepancies in the units of measurement of cytosis - the number of cells in the chamber, in 1 µl or 1 liter. It is probably advisable to express cytosis by the number of cells per μl. Automated systems can also be used to count the number of white blood cells and red blood cells in the CSF.
An increase in the content of cells in the CSF (pleocytosis) appears more often with inflammatory diseases, and to a lesser extent with irritation of the meninges. The most pronounced pleocytosis is observed with bacterial infection, fungal lesions of the brain and tuberculous meningitis. In epilepsy, arachnoiditis, hydrocephalus, degenerative processes and some other diseases of the central nervous system, cytosis remains normal.
Staining the cells of the native preparation with Samson's reagent makes it possible to differentiate the cells quite reliably. But their more accurate morphological characteristics are achieved after fixation and staining of prepared cytological preparations. The modern approach to the preparation of such drugs involves the use of a cytocentrifuge. However, even in the USA, only 55% of laboratories are equipped with them. Therefore, in practice, a simpler method is used - deposition of cells onto a glass slide. The preparations must be well dried in air and then painted.
Cellular elements are counted in the stained preparation. They are represented predominantly by blood cells (more often - lymphocytes and neutrophils, less often - monocytes, eosinophils, basophils), plasma and mast cells, macrophages, granular balls (degenerative forms of a special type of macrophages - lipophages in a state of fatty degeneration), arachnoendothelial cells, epindymas can be found . The morphology of all these cellular elements is usually well known to laboratory diagnosticians and is described in detail in many manuals. The level of pleocytosis and the nature of the cerebrospinal fluid cytogram make it possible to clarify the nature of the pathological process (Table 3).
Neutrophilic leukocytosis often accompanies acute infection (local and diffuse meningitis). CSF eosinophilia is observed quite rarely - with echinococcosis of the brain, eosinophilic meningitis. CSF eosinophilia does not usually correlate with the number of eosinophils in the blood. Lymphocytic pleocytosis in the cerebrospinal fluid occurs in viral meningitis, multiple sclerosis, in the chronic phase of tuberculous meningitis, after operations on the meninges. In pathological processes of the central nervous system, polymorphism of lymphocytes is observed, among which activated ones are found. They are characterized by the presence of abundant pale cytoplasm with single azurophilic granules; some cells have lacing or fragmentation of the cytoplasm (clasmatosis). Plasma cells appear in the cytogram during viral or bacterial meningitis, low-grade inflammatory processes, and during the recovery period for neurosyphilis. Monocytes, which undergo degeneration in the cerebrospinal fluid faster than lymphocytes, are observed in multiple sclerosis, progressive panencephalitis, and chronic sluggish inflammatory processes. Macrophages are the “orderlies” of the cerebrospinal fluid; they appear during hemorrhages, infections, traumatic and ischemic necrosis.
Sometimes atypical cells are found in the CSF - elements that, due to their morphological characteristics, cannot be classified as specific cellular forms. Atypical cells are found in chronic inflammatory processes (tuberculous meningitis, multiple sclerosis, etc.), and they are often tumor cells. The probability of finding tumor cells in the cerebrospinal fluid of brain tumors is low (no more than 1.5%). The detection of blast cells in the CSF in hemoblastosis suggests neuroleukemia.
When analyzing the composition of the cerebrospinal fluid, it is important to evaluate the ratio of protein and cellular elements (dissociation). With cell-protein dissociation, pronounced pleocytosis is observed with normal or slightly increased protein content. This is typical for meningitis. Protein cell dissociation is characterized by hyperproteinarchy with normal cytosis. This condition is typical for stagnant processes in the cerebrospinal fluid tract (tumor, arachnoiditis, etc.).
Clinical situations sometimes require counting the number of red blood cells in the bloody cerebrospinal fluid (to objectify the volume of hemorrhage). Red blood cells are counted in the same way as in blood. As mentioned above, the color of the cerebrospinal fluid changes if 1 μl contains more than 500-600 red blood cells, noticeable staining occurs when there are about 2000, and it becomes hemorrhagic when the level of red blood cells is more than 4000/μl.
Microbiological examination of cerebrospinal fluid
One of the common diseases of the central nervous system is purulent meningitis. In such cases, mycorobiological research becomes particularly relevant. It includes an indicative test - bacterioscopy of preparations and classical cultural techniques. CSF bacterioscopy has limited diagnostic value, especially when obtaining clear CSF. A smear prepared from the cerebrospinal fluid sediment obtained by centrifugation is stained with methylene blue or Gram stain, although some authors believe that the latter staining option “injures” the formed elements and creates artifacts. With meningitis and abscesses, a diverse flora is found, corresponding to the nature of the disease. Regardless of the results of microscopy, the diagnosis of bacterial meningitis must be confirmed by culture, which becomes decisive in the diagnosis of this group of diseases and the choice of adequate therapy. It is carried out in accordance with Order No. 375 of the Ministry of Health of the Russian Federation dated December 23, 1998 “On measures to strengthen epidemiological surveillance and prevention of meningococcal infection and purulent bacterial meningitis.” The most common cause of bacterial meningitis is the gram-negative diplococcus Neisseria meningitidis, which in 80% of cases can be detected by bacterioscopy.
CSF microscopy
Normally, only lymphocytes and monocytes are present in the cerebrospinal fluid. In various diseases and pathological conditions, other types of cells may appear in the cerebrospinal fluid.
Lymphocytes are similar in size to erythrocytes. Lymphocytes have a large nucleus and a narrow, unstained rim of cytoplasm. Normally, the cerebrospinal fluid contains 8-10 lymphocyte cells. Their number increases with tumors of the central nervous system. Lymphocytes are found in chronic inflammatory processes in the membranes (tuberculous meningitis, cysticercosis arachnoiditis).
Plasma cells in the cerebrospinal fluid. The cells are larger than lymphocytes, the nucleus is large, eccentrically located, a large amount of cytoplasm with a relatively small nucleus size (cell size - 6-12 microns). Plasma cells in the cerebrospinal fluid are found only in pathological cases with long-term inflammatory processes in the brain and membranes, with encephalitis, tuberculous meningitis, cysticercosis arachnoiditis and other diseases, in the postoperative period, with sluggish wound healing.
Tissue monocytes in the cerebrospinal fluid. Cell size is from 7 to 10 microns. In normal liquids they can sometimes occur as single specimens. Monocytes are found in the cerebrospinal fluid after surgery on the central nervous system, during long-term inflammatory processes in the membranes. The presence of tissue monocytes indicates an active tissue reaction and normal wound healing.
Macrophages in the cerebrospinal fluid. They may have nuclei of various shapes; more often the nucleus is located at the periphery of the cell, the cytoplasm contains inclusions and vacuoles. Macrophages are not found in normal cerebrospinal fluid. The presence of macrophages with a normal number of cells in the cerebrospinal fluid is observed after bleeding or during an inflammatory process. As a rule, they occur in the postoperative period, which has prognostic significance and indicates active cleansing of the cerebrospinal fluid.
Granular balls in the liquor. Cells with fatty infiltration are macrophages with the presence of fat droplets in the cytoplasm. In stained cerebrospinal fluid preparations, the cells have a small peripherally located nucleus and large-cellular cytoplasm. The size of the cells varies and depends on the included drops of fat. Granular balls are found in pathological fluid obtained from brain cysts in areas of decay of brain tissue, in tumors.
Neutrophils in the cerebrospinal fluid. The cells in the chamber are identical in appearance to peripheral blood neutrophils. The presence of neutrophils in the cerebrospinal fluid, even in minimal quantities, indicates either a former or existing inflammatory reaction. The presence of altered neutrophils indicates the attenuation of the inflammatory process.
Eosinophils in the cerebrospinal fluid. Determined in the cerebrospinal fluid by the existing uniform, shiny granularity. Eosinophils are found in subarachnoid hemorrhages, meningitis, tuberculous and syphilitic brain tumors.
Epithelial cells in the cerebrospinal fluid. Epithelial cells limiting the subarachnoid space are quite rare in the cerebrospinal fluid. These are large round cells with small round or oval nuclei. They are found during neoplasms, sometimes during inflammatory processes.
Tumor-like cells and complexes in the cerebrospinal fluid. They are found in the chamber and in the colored liquor preparation. Malignant cells can belong to the following types of tumors:
- meduloblastoma;
- spongioblastoma;
- astrocytoma;
Crystals in the liquor. Rarely found in the cerebrospinal fluid, in case of tumor disintegration.
Echinococcus elements in the cerebrospinal fluid - hooks, scolex, fragments of the chitinous membrane - are rarely found in the cerebrospinal fluid.
PCR diagnostics of cerebrospinal fluid
In recent years, certain prospects in the etiological diagnosis of neuroinfections have been associated with the development of molecular genetic technologies for detecting nucleic acids of pathogens of infectious diseases in the cerebrospinal fluid (PCR diagnostics).
Thus, cerebrospinal fluid is a medium that clearly responds to pathological processes in the central nervous system. The depth and nature of its changes are related to the depth of pathophysiological disorders. Correct assessment of laboratory liquorological symptoms allows you to clarify the diagnosis and evaluate the effectiveness of treatment.
V.V. Bazarny Professor of USMA, Deputy Chief Physician of OKB No. 1
CSF analysis is a specific testing format that is prescribed if there are suspicions of many severe pathological conditions. Due to the complexity of the procedure, especially in children, the doctor will issue a referral to the diagnostic room only after indirect confirmation of the preliminary diagnosis. This allows you to avoid traumatic manipulation with unjustified risks.
The presented analysis involves laboratory testing of cerebrospinal fluid. Usually it is sent for testing for meningitis of any type, encephalomyelitis, as well as a number of other narrow-profile infectious diseases. Despite the fact that the intervention itself is safe with the proper skills of medical personnel, the patient should prepare in advance for standard side effects.
Functions of cerebrospinal fluid
To understand how this biological material is taken for study, and also why it can provide complete information about infection with relatively rare infections, you need to understand the composition of the spinal cord.
CSF, sometimes also called cerebrospinal fluid and shortened to CSF, is a type of human biological fluid. It circulates in the following physiological pathways: the subarachnoid membrane of the brain and spinal cord, as well as the ventricles of the brain.
Its main functional responsibilities were to ensure the internal balance of one of the most important centers of the body - the brain and spinal cord. Due to the composition of CSF, it is able to protect these organs from various mechanical damage. In the event of an impact or similar injury, the biological material will simply absorb most of the negative impact coming from the outside.
It is also designed to ensure the saturation of neurons with oxygen and incoming nutrients during the exchange between blood and brain cells. An established connection works according to an identical principle in the release by neurons of a product processed into carbon dioxide, as well as other decay residues and toxins.
The norm of such an environment contains a sufficient number of vital elements capable of maintaining the chemical indicators of the centers’ activity at the proper level. The auxiliary function of cerebrospinal fluid is to support intracranial pressure, protecting the brain from its possible unexpected surges.
To support the protective forces aimed at protecting the brain environment from infectious processes, the fluid must be constantly renewed, following a direct current. As soon as she ceases to perform at least one duty assigned to her, the well-being of the victim worsens. He is sent to undergo a clinical analysis of spinal fluid material, designed to determine the exact composition indicators.
Key indicators
The interpretation of the examination results is based on a comparison of the results obtained with those that are considered to be the standard in medicine. If a person has some kind of pathology, then the laboratory assistant will definitely detect a corresponding deviation from the template during the assessment of the material.
So, a healthy fluid level should range from 130 to 160 ml. The exact amount depends on the individual physiology of each patient. Moreover, the collected contents should not have any cells, as is typical for lymph or blood.
Most of the composition, which is about 90%, comes from . All other components are distributed in unequal quantities between:
- in an amount of about 50 mg;
- lipids;
- ammonia;
- urea;
- remnants of cellular particles;
- trace concentration of nitrogenous compounds.
All of the above must be in a hydrated state. This allows the composition to wash both brains in order to have time to nourish them, as well as remove waste substances that can quickly turn into full-fledged toxins.
The main physiological load falls on water. But protein, nitrogen and other particles are just by-products that are washed out of neurons, representing already waste material.
The SWS is updated without interruption, which allows it to regularly receive new components. Their fluid is taken from the cerebral ventricles, which are special vascular plexuses. Also, some of the useful elements enter during direct penetration through the physiological walls that carry blood.
Typically, 80% of the volume of cerebrospinal fluid is renewed due to the functioning of the brain. If the body has a surplus of it, then it gets rid of unnecessary milliliters through processing, followed by removal naturally - through the blood and lymphatic system.
Against this background, it becomes clear why sampling this component of the body is so valuable for diagnosis. Even dogs or other pets are sometimes subjected to the procedure when veterinarians suspect serious abnormalities.
The price of the examination depends on the specific laboratory, as well as the need to conduct auxiliary tests. The latter are often prescribed by the doctor immediately, so that the patient does not have to come to the clinic several times. Results are issued over the next few days. Moreover, decoding should be done by the treating specialist, and not by the patient himself.
The latter can find information about the standards for the main components of the content, but he does not need to fully know the table corresponding to various ailments with the indicators prescribed for them. It is enough to simply hand over the laboratory extract to a specialist so that he can figure it out himself and then explain the diagnosis in detail to his ward.
When is analysis necessary?
Manipulation is allowed regardless of age. It is even allowed to take samples from newborns if the percentage of benefit from the intervention significantly outweighs the possible harm.
The main medical indications for sending a patient to the diagnostic room were:
- neoplasms of any location and nature;
- traumatic brain injury, regardless of the cause;
- suffered a heart attack, stroke;
- conditions preceding heart attack and stroke;
- inflammation localized in the brain, which is caused by infectious pathogens;
- epilepsy;
- hernias located in the intervertebral discs;
- cerebral hematomas.
But often people are familiar with such research because of the need to rule out the risks of developing meningitis, especially in children or during an outbreak of the disease.
Many ordinary people, having learned about how the manipulation is done, get scared and refuse to follow medical recommendations. In fact, although the sampling does cause some discomfort, it is not particularly painful if the doctor has the proper skills. The basis is the classic lumbar puncture, which means puncture of tissue with a special needle.
The lumbar region is chosen as the needle insertion point, since it is the area that is safest for health. Sometimes this approach is used not only for diagnosing possible lesions, but also for therapeutic purposes. The last point involves the introduction of drugs such as antibiotics into the subarachnoid space.
Having understood how CSF is taken, you need to understand that after such a short-term, but still traumatic intervention, the patient may experience side effects:
- headache;
- discomfort in the lumbar region;
- malaise.
Usually all of the above goes away within the next day. If this does not happen, then you should immediately report the symptoms of complications to your treating specialist.
The doctor will usually reveal the places where you can get tested during your appointment. But since patients in the hospital’s inpatient department are usually sent to the diagnostic room, the required laboratory will be found in the same building.
Clinical norm
The presented biochemical test has a strict range of normal values. Any deviations from them indicate developing pathologies. Moreover, each disease has its own clinical picture, which allows you to quickly distinguish the result of syphilis from other diseases.
The general standard for a healthy person is as follows:
Cytosis is considered separately. The unit studied is 1 µl. The average statistical parameters should be from 0-1 units in terms of the level of ventricular and cisternal fluid. And the lumbar fluid should increase by 2-3 units per 1 µl.
Explanations of common pathologies
There are about two dozen of the most common diagnosed diseases, identified by studying the results of a cerebrospinal fluid examination. They all have their own clinical features. Thus, biological fluid with tuberculous meningitis will have a faint yellowish tint. Its structure will look like a small cobweb. The main parameters of the composition elements include:
- protein from 45 to 500 units depending on the severity;
- glucose is less than 45, but in approximately 20% of clinical cases the parameter can remain healthy;
- leukocytes range from 25-100, with a particularly severe form the value exceeds the threshold of 500.
To be on the safe side, doctors often send the victim to undergo an acid-resistant paint test and culture on a nutrient medium.
If the patient is suspected of acute gonorrheal meningitis, then the appearance of the collected cerebrospinal fluid will vary from opalescent to purulent. The texture will include clumps and the color will have a yellowish tint. Here you should be especially careful, since when the composition is stained with blood, there is a risk of infection not with meningitis, but with anthrax.
In this case, the protein can vary in the range from 50 to 1500, but most often the radius narrows to 100-500. Glucose does not fall above 45, and the leukocyte boundaries rise to 1000-5000. For the most part we are talking about band neutrophils.
Aseptic meningitis is characterized by completely different distinctive features, which include clear, cloudy or xanthochromic CSF. Protein limits range from 20 to 200, but glucose remains normal.
Leukocytes are first represented by band neutrophils, and then by monocytes. Their level rarely exceeds 500 units, but some victims recorded almost a record 2000.
The most difficult type to deal with is the viral type of meningitis. This is explained by the presence of a typical clear liquid, as well as normal values of glucose and protein. The latter is rarely elevated. White blood cells show from 10 to 1000, with the majority being lymphocytes.
Almost always, the attending physician uses the results of other tests to make an accurate verdict. This may be a myelogram, PCR, bacteriological culture, IgM with specific antigens. The specific additional analysis depends on the suspicion, so what is relevant for multiple sclerosis may not be useful for mumps or acute polio.
