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Treatment of coma. Symptoms of cerebral coma Deep cerebral coma

Cerebral coma was formerly known as apoplexy coma, and its main cause is primary or secondary damage to the brain as a result of impaired blood supply to the brain tissue.

Reasons

The cause of cerebral coma is extensive brain damage under the influence of toxic and, less commonly, traumatic factors. Among the toxic factors in the first place are alcohol and drug intoxication, coma due to carbon monoxide poisoning. Closed craniocerebral injuries are the leading traumatic etiology of cerebral coma. Despite the general similarity of pathogenetic processes, disorders that occur in the main parts of the brain differ in different types of comas.

However, with any type and type of coma, there are lesions at the level of the cerebral cortex, reticular formation, basal ganglia and limbic system. It is the extent of such disorders (transient or chronic) that lead to the body losing the ability to coordinate activities, which leads to disorders of almost all functions.

Symptoms

Cerebral coma, first of all, is manifested by loss of consciousness with preservation of basic reflexes, which indicates preserved vitality of the brain. The second group of symptoms is the lack of response to stimuli - primarily tactile. The victim seems to have fallen asleep, especially since a cerebral coma is accompanied by a sleep-like state - the eyes are closed, the person literally “fell” into sleep.

In the first stages of cerebral coma, the patient retains at least a minimal range of movements - he is able to change body position and swallows saliva. The deeper the brain damage, the more pronounced the clinical manifestations of depression of consciousness, up to the shutdown of spontaneous breathing. Convulsions, vomiting, increased body temperature are also signs of cerebral coma.

Diagnosis and treatment

The diagnosis of cerebral coma cannot be established through examination alone, although typical signs of coma may indicate its development. A thorough neurological examination is required, using special rating scales. An electroencephalogram and computed tomography are also necessary to diagnose cerebral coma.

Treatment depends on the cause of the coma, that is, if the cerebral coma is toxic, then the cause that caused it is eliminated and detoxification therapy is carried out. Tracheal intubation, dynamic assessment and maintenance of vital signs, and careful nursing all require admission to the intensive care unit.

Forecast

The prognosis depends entirely on the etiological cause of the coma. Some comas lead to a slow decline of brain function, which is almost impossible to stop and the person switches to a vegetative existence. Brain coma of toxic origin is easier to treat. The overall average mortality rate in the case of cerebral coma can reach 35%. It should be remembered that not a single coma passes without leaving a trace on the body.

Coma is translated from Greek as deep, very sound sleep; this is a condition characterized by a complete loss of consciousness, breathing, reflexes, as well as a complete lack of reactions to any irritants.

Cerebral coma is a complete depression of the nervous system and inhibition of its work without the death of body tissues with medicinal maintenance of basic vital functions: breathing, heartbeat, which can periodically stop, and artificial nutrition directly through the blood.

A comatose state of unconsciousness can develop in a person as a result of any damage to the brain organs, either instantly or in a few hours. A person is able to stay in it in an individual case from several minutes to several years.

Classification of comatose states, their causes:

Emergency care for cerebral coma

In case of coma, only specialists can provide assistance. If there is a suspicion that a person has fallen into a coma, you must immediately call an ambulance. The only thing that can be done before the doctors arrive is to ensure that the victim is able to breathe. Since in a comatose state, muscles relax and the swallowing and breathing reflex decreases, the victim must be checked, turned onto his stomach and, if possible, clear the airways.

The word "coma" translated from Greek means "deep sleep, drowsiness." It is characterized as loss of consciousness, a sharp weakening or loss of reaction to external stimuli, extinction of reflexes, etc.

Coma develops as a result of inhibition in the cerebral cortex, spreading to the subcortex and other parts of the nervous system. As a rule, the main reason for the development of coma is a violation of blood circulation in the brain due to a head injury, inflammation affecting the brain, etc.

Causes of coma

The causes of coma can be very diverse. For example, a person may become immobilized and unconscious due to severe damage to both the head and brain, a serious viral infection such as meningitis, a lack of oxygen to the brain for a long time, or poisoning from any drugs or chemicals. , as a result of alcohol intoxication, etc.

Of course, you should not think that if any event from the specified list occurs, this will immediately lead to the development of a coma. Each person has an individual risk of developing a pathology such as coma.

In general, the mechanism for the appearance of coma as a result of one of these reasons is quite simple: part of the brain cells wipes off and stops functioning, as a result of which the person loses consciousness and falls into a coma.

Types of coma

Coma is divided into several different degrees depending on the severity of the patient's condition. As a rule, it is divided into 3 main types:
- deep;
- just a coma;
- superficial.

In general, coma in medicine is divided into 15 degrees. However, from them, about 5 most basic ones can be distinguished, which as a result are reduced to 3 main states.

In the first case, we are talking about a situation when the patient does not come to his senses at all and does not react in any way to any stimuli. At the same time, he does not make sounds, does not react to the voice or touch of even those closest to him.

In a normal coma, the patient may make some sounds and even open his eyes spontaneously. However, he is not conscious.

Superficial coma is characterized by the fact that the patient, while unconscious, can open his eyes in response to a voice. In some cases, he can even pronounce certain words and answer questions. True, the speech is most often incoherent.

Exit from a comatose state is characterized by a gradual restoration of the nervous system and brain functions. As a rule, they return in the order of their oppression. First the pupils begin to react, then consciousness returns.

Consequences

On average, a coma lasts 1-3 weeks. However, there are often cases when it lasts for a longer time - people can lie unconscious for years.

The patient's return to consciousness occurs gradually. At first he comes to his senses for a couple of hours, then this time increases more and more. As a rule, the body goes through several different stages during this time. And the consequences will depend on how he copes with the load placed on him.

Since the brain is affected during a coma, one should be prepared for the fact that the patient may not recover many vital functions. For example, quite often people cannot walk, talk, move their arms, etc. Naturally, the severity of the damage directly depends on the degree of coma the patient was in. For example, after a superficial coma you can come to your senses an order of magnitude faster than after a normal one. The third degree, as a rule, is characterized by almost complete destruction of the brain. This means that there is no need to expect good recovery results.

Among the most common problems faced by a person who has been in a coma are memory impairment, decreased attention, and various changes in behavior (lethargy, aggressiveness, etc.). Sometimes relatives do not even recognize the person close to them.

Also, after a coma, many patients take a long time to restore everyday skills. For example, they cannot eat on their own, wash themselves, etc.

One of the signs of recovery and recovery of a person after a coma is the desire for some kind of activity. However, in this case, you should not be overly happy and immediately give the patient maximum loads - too abrupt a return to normal life can have a negative impact on his condition and lead to a noticeable deterioration in well-being.

Naturally, you should be prepared for the fact that you will have to spend a lot of effort on recovery. The list of important rehabilitation measures includes gymnastics (to restore motor skills), maintaining hygiene, proper nutrition, walks, adequate sleep, taking medications and regular consultations with a doctor.

Classification of comatose states, their causes:

Coma is not an independent disease - it is a symptom characterized by shutdown of the brain under the influence of other diseases of the central nervous system or its damage of any traumatic nature. There are quite a few types of comatose states, divided according to the causes of development and the nature of their course:

Traumatic coma is one of the most common types caused by traumatic brain injury.
Diabetic - develops if the glucose level of a diabetic patient has critically increased, which can be detected by the rather noticeable aroma of acetone from his mouth.
Hypoglycemic is the opposite of diabetic, which develops due to a critical drop in blood sugar. Its harbinger is severe hunger or a complete lack of satiety until the sugar level rises.
Cerebral coma is a slowly developing condition due to the growth of tumors in the brain, such as tumors or abscesses.
Hungry is a common condition caused by extreme dystrophy and lack of protein in the body due to malnutrition.
Meningeal - due to the development of meningitis - inflammation of the membranes of the brain.
Epileptic coma develops in some people after epileptic seizures.
Hypoxic develops due to cerebral edema or suffocation due to oxygen starvation of central nervous system cells.
Toxic is the result of toxic brain damage due to poisoning, infections, or alcohol or drug abuse.
Metabolic is a rather rare type, caused by a severe failure of vital metabolic processes.
Neurological coma can be called the most difficult type not for a person’s body, but for his spirit, since in this condition the patient’s brain and his thinking do not turn off with complete absolute paralysis of the entire body.

In the common view, coma has a rather cinematic image and looks like a complete loss of independent performance of vital body functions, the absence of any reactions and loss of consciousness with rare glimpses of reactions to the outside world, however, in fact, medicine distinguishes as many as five types of coma, differing in their symptoms:

Perkoma is a rapidly passing condition that lasts from several minutes to several hours and can be characterized by confused thinking, incoordination of movements and sudden changes from calm to agitation, while maintaining basic reflexes. In this case, a person hears and feels everything, including pain.
First-degree coma is accompanied by an incomplete loss of consciousness, but rather by stupor, when the patient’s reactions are inhibited, communication with him is difficult, and the patient’s eyes usually move rhythmically from side to side or squint occurs. A person in a first-degree coma may be conscious, stuporous, or in a sleep-like state. He is able to feel touch and pain, hear, understand.
During a second-degree coma, he may be conscious, but at the same time in a deep stupor. He does not understand what is happening, does not react to light, sound, touch, does not make contact, in general, in any way. At the same time, his pupils narrow, the heart begins to beat faster, and sometimes spontaneous motor activity of the limbs or bowel movements is observed.
A person in a third-degree coma is completely disconnected from the outside world and is in a state of deep sleep without any external reaction to external stimuli. In this case, the body does not feel physical pain, its muscles rarely begin to spasm spontaneously, the pupils dilate, the temperature drops, breathing becomes frequent and shallow, and it is also believed that mental activity is completely absent.
Coma of the fourth degree is the most severe type of coma, when the vital functions of the body are fully provided artificially with the help of ventilation, parenteral nutrition (feeding solutions through a vein) and other resuscitation procedures. The pupils do not react at all, muscle tone and all reflexes are absent, and the pressure is reduced to a critical level. The patient cannot feel anything at all.

Any coma is characterized by a flow from one degree to another relative to changes in the patient’s condition.

In addition to natural comatose states, one more thing can be distinguished - an artificial coma, which is correctly called drug-induced. Such a coma is the last forced measure, during which, with special medications, the patient is plunged into a temporary deep unconscious state with the switching off of all reflex reactions of the body and almost complete inhibition of the activity of both the cerebral cortex and the subcortical structures responsible for ensuring vital functions, which are now supported artificially.

An artificial coma is used if general anesthesia is necessary or when it is impossible to avoid irreversible changes in brain tissue in another way during hemorrhages, edema, pathologies of cerebral vessels, severe injuries accompanied by severe painful shock, and other pathologies that threaten the patient’s life. It inhibits not only the activity of the central nervous system, but also almost all processes in the body, which gives doctors and regeneration processes precious time.

With the help of an artificial coma, cerebral blood flow slows down, as well as the movement of cerebrospinal fluid, which makes it possible to narrow intracranial vessels, relieve or slow down cerebral edema with increased intracranial pressure, and as a result, avoid massive necrosis (death) of brain tissue.

Reasons

The main cause of any coma is a disruption of the central nervous system under the influence of any traumatic, toxic or other factors that can cause severe damage to brain tissue, which is responsible for both the unconscious functioning of the body and for thinking and consciousness. Sometimes coma is not caused by damage to brain neurons, but only by suppression of their activity, as, for example, with artificial coma. The condition can be caused by almost all diseases at the last stage, any severe poisoning or injury, as well as extremely severe pain or shock stress, causing overexcitation of brain neurons, which causes their functioning to malfunction.

There is also a common version that coma, like loss of consciousness, may represent one of the body’s protective reactions, which is designed to protect a person’s consciousness from shocks caused by the state of his body and pain, as well as to protect the body from consciousness when it needs time to recovery.

What happens to a person

During a coma, any brain processes in a person completely stop or are greatly inhibited. During a deep coma, nerve impulses become weak or completely absent, so they are unable to cause even reflex actions of the body. If the brain structures responsible for the sensory organs are damaged, then, accordingly, the brain cannot in any way perceive information from the outside world.

How does a person feel

If the physiological processes occurring inside the body during a coma are quite well studied, then it is not possible to look into the patient’s thoughts.

Almost all people whose loved ones are in a comatose state are primarily interested in how the person feels, whether he can listen to what they say and adequately perceive the speech addressed to him, feel pain and recognize loved ones or not.

A person does not feel pain or feels it poorly, since in comatose and unconscious states this function is turned off primarily for the body’s self-defense.

In the deepest comas, when the activity of neurons is completely absent or is so slowed down that we can talk about brain death, but the body still continues to function, the answer to all questions is of course no, but about other cases there is debate even among doctors.

In a neurological coma, cerebral and, most importantly, rational activity is preserved, but the functioning of those structures that are responsible for the functioning of the body is completely paralyzed, so we can safely say that such patients can think, and as a result, perceive everything that happens around them with the help of hearing and occasionally – vision. With complete paralysis, there is no sensation in the body.

In other cases of coma, some patients say that they felt the presence of their loved ones and heard everything that was said to them, others noted that they could think or saw something like dreams, and still others remembered only a complete shutdown of consciousness and all feelings.

Therefore, all doctors recommend that loved ones communicate with people in a coma as if they were conscious, since, firstly, there is a possibility that they hear and this will support them, encourage them to fight harder for life, and secondly, the positive signals entering the brain can stimulate its activity and speed up the exit from this state. In addition, communication with people in a coma has a beneficial effect on the loved ones themselves, who at this time are under great stress, experiencing separation and are afraid of death: this greatly calms them down.

How to distinguish coma

It would seem that everything is clear here, but in fact it is quite difficult to distinguish a real coma from a simple loss of consciousness or neurological or psychological conditions, especially percoma or coma of the second or third degree.

Sometimes two errors occur:

Who is considered to be a deep loss of consciousness?
Superficial coma is not noticed against the background of symptoms of the underlying disease, since changes in the patient’s behavior are not too noticeable.

To determine a comatose state, as well as its severity, doctors use the Glasgow scale, which is a whole complex of signs: reaction to light, level of reflexes or their deviations, reactions to images, sounds, touches, pain and much more.

In addition to tests according to the Glasgow scale, a comprehensive examination is necessary to identify the causes, level of neuronal damage and disturbances in the functioning of the central nervous system:

General tests, tests for hormones or infections.
Liver tests.
All types of tomography.
An EEG, which shows the electrical activity of the brain.
CSF analysis.
And many others. It is very difficult for a non-medic to diagnose a comatose state.

Emergency care and treatment

Since in coma there is suppression of the vital functions of the body, emergency care will include resuscitation procedures in the form of artificial respiration, possibly starting the heart, as well as help to eliminate the causes of its occurrence: removing intoxication, hypoxia, stopping bleeding, replenishing dehydration or exhaustion, reducing or increased glucose levels, etc.

Treatment of coma is carried out in the intensive care unit and also begins, first of all, with the treatment of its causes, followed by the elimination of cerebral consequences and rehabilitation. The specifics of therapy depend on the underlying cause of the condition and the resulting brain damage.

Forecast

Coma is a severe condition, after which there is the possibility of a huge number of complications.

A short-term artificial one, induced for the purpose of general anesthesia, usually passes without consequences as soon as the person is taken out of it. A long-term medical coma has the same complications as a natural one.

Any prolonged coma slows down and greatly complicates absolutely all metabolic processes in the body, so over time the patient develops encephalopathy - organic damage to brain tissue, which can develop for a variety of reasons: lack of blood supply, which results in a lack of nutrients, oxygen, and in the accumulation of toxic metabolic products in the brain, stagnation of cerebrospinal fluid, etc. In addition to cerebral consequences, muscle atrophy develops, disruption of the activity of internal organs and the activity of the peripheral nervous system, as well as disruption of the entire metabolism. Therefore, even after a short-term coma, the patient cannot immediately regain consciousness and begin to speak, much less get up and walk, as is often shown in films.

Metabolic disorders and the gradual development of encephalopathy lead to the death of the brain, when it stops functioning, but the body does not.

Brain death is diagnosed by the complete absence of the following phenomena:

Pupil reactions to light.
Stopping the cerebrospinal fluid.
Complete absence of all reflex reactions.
The absence of electrical activity directly in the patient’s cerebral cortex, which is recorded using an EEG.

Brain death is declared if these fundamental signs are not present within twelve hours, but to confirm the diagnosis, doctors wait another three days, during which periodic diagnostics are carried out.

It is characteristic that the body does not die immediately, since instead of signals from the central nervous system, life in it is maintained with the help of devices. In addition, the cerebral cortex is the first to die, which means a complete loss of personality and the person as such, and the subcortical structures support the body as an empty shell for some time.

Sometimes the opposite state occurs, when the brain is alive, a person can even come to his senses, but his body refuses to work, because it is accustomed to constant artificial hardware support and some of its functions have time to atrophy.

The third option for the development of the patient’s condition is the onset of a special vegetative state, when he does not come to his senses, but his body begins to be active, respond to pain and move muscles. Most often it ends with recovery and recovery.

The prognosis for the likelihood of a favorable exit from a coma depends on the specific disease or injury that caused it, as well as on the individual ability of the body to recover.

Director of LLC "Clinic of the Brain Institute", Doctor of Medical Sciences, Professor of the Departments of Nervous Diseases and Anesthesiology-Reanimatology of the Ural State Medical Academy, Chairman of the Supervisory Board of the ANO "Clinical Institute of the Brain".

Deputy chief physician for medical work, kmn, neurologist

Head of the neurological department, neurologist

Primary cerebral coma is associated with primary damage to the central nervous system as a result of trauma, epileptic seizure, apoplexy, infectious and inflammatory lesions, tumor growth.

Clinical picture and symptoms

Symptoms of cerebral coma depend on the directly damaging factor. With subarachnoid hemorrhage and traumatic injuries, severe focal neurological symptoms occur. Hemiplegia or tetraparesis may occur. Paralysis occurs throughout the striated skeletal muscles. In hemiplegia, the lesion occurs on the side opposite to the lesion. When the victim is in a comatose state, paralysis is manifested by a complete absence of any kind of sensitivity and reflexes.

Causes of cerebral coma

Cerebral coma occurs as a result of serious organic damage to the brain. In clinical practice, it is customary to distinguish several forms of cerebral comas. Apoplectic form - occurs due to subarachnoid or parenchymal bleeding in the brain tissue, as well as after an ischemic stroke with the formation of encephalomalacia zones. Post-traumatic form - as a result of trauma and coma associated with tumor growth.

Therapy

If a cerebral coma occurs, the victim definitely needs qualified medical care. Such a victim is urgently transferred to the intensive care unit in order to continuously monitor the vital functions of the body. Cerebral comas are difficult to treat and correct; only experienced specialists can cope with this condition. The Clinical Brain Institute is equipped with an advanced intensive care unit and specializes in the treatment of all types of neurological emergencies. The center employs highly qualified specialists who are ready to help the victim at any moment.

First aid

If you suspect a comatose state in a person, first call a specialized ambulance team. Check for vital body functions, namely respiratory and cardiovascular activity. Constantly monitor the condition of the victim until doctors arrive at the scene.

Complications of cerebral coma

Since cerebral coma is often associated with gross violations of brain structures, the consequences of such a coma are irreversible. If the victim manages to emerge from the coma, then in most cases he remains disabled due to persistent paralysis of the skeletal muscles. Such a patient needs constant care.

Coma belongs to pathological conditions that pose a danger to the health and life of the patient. Depending on its varieties, the provoking factors are traumatic, toxic, and other brain injuries. In addition to the list of diseases, you should remember the threat of developing coma after brain surgery. The degree of risk depends on the underlying disease for which surgery is performed, the extent of the operation, age, and concomitant pathology of the patient. Let's look at why coma occurs, how it manifests itself and possible prognoses.

Why does coma occur?

Many factors can provoke a coma. The most common and important causes of cerebral coma include:

traumatic lesions of the head and brain structures;
severe course, extensive brain damage with ischemic and;
infections of the membranes (meningitis), substances () of the brain, especially in children;
pathological effects of poisons, toxins, drugs, alcohol and overdose of certain medications;
brain damage due to carbon monoxide poisoning and prolonged oxygen starvation;
endocrine disorders accompanied by hormonal imbalances with hyperfunction or, conversely, lack of hormones (hypocorticoid, diabetic coma).

Characteristic signs of the disease

Symptoms of cerebral coma depend on the degree of manifestation of the pathological condition.

In the initial stage, it resembles deep sleep. The patient lies with his eyes closed, he is disoriented - where he is, with whom and when, there are minor movements, there is no speech or answers to questions, sometimes there is mooing, muscle tone is slightly increased, reflexes are preserved - he swallows and breathes independently, pathological reflexes of the hands may appear , stop, reacts to touch (tactile sensitivity), pain (pain sensitivity), does not control urination, defecation.
In the second degree, the patient experiences depression of consciousness, there is no reaction to treatment at all, there is no response to pain or touch, he breathes loudly and can swallow on his own, the temperature may rise and there is increased sweating, sometimes vomiting, muscle spasms or cramps, tachycardia, blood pressure are observed unstable, its fluctuation is noted.
In the third degree, there are no reflexes, consciousness is completely “switched off”, there is no reaction of the pupils to light, the patient is unable to breathe independently, the temperature and pressure decrease, the muscles become flaccid, their tone is absent.

The terminal stage is practically incompatible with life. The patient lacks almost all reflexes, the pupils are maximally dilated, spontaneous breathing, blood pressure is not recorded, and the temperature drops critically.

Features of the course of cerebral coma with various etiologies

Primary cerebral comas include pathological conditions that have a neurological origin (genesis). The main diseases that cause coma include:

– cerebrovascular lesions (venous thrombosis, arterial aneurysms, atherosclerosis, systemic damage, hypertension, stroke);
traumatic brain injury;
meningitis and encephalitis of viral, fungal, bacterial origin;
neoplasms, hematomas causing swelling, increased pressure inside the skull.

Important! The most common cause of coma is stroke. Second place goes to people with drug overdoses. Diabetes mellitus complicated by hyperglycemic (high glucose) or hypoglycemic (very low glucose) coma ranks third.

Coma due to a cerebral stroke is characterized by certain features:

occurs suddenly, without any warning signs - the situation can be explained by an instantaneous rupture of a vessel and massive hemorrhage;
basic clinical signs of coma - high blood pressure, sudden loss of consciousness, the patient’s face is red, breathing becomes hoarse and the pulse is tense;
symptoms indicating a stroke are facial distortion, impaired muscle and tactile sensitivity on one side of the body, and the appearance of pathological reflexes.

It is possible to recognize coma due to traumatic brain injury in a patient at the preclinical stage by abrasions and lesions of the skin and bones of the head. Typically, blood flows from the ear, bruises form around the eyes (bruises), and the pupils have different diameters (anisocoria). In addition, neurological symptoms are observed, which depend on the location and severity of the injury.

Important! Traumatic comas include coma after brain surgery. Sometimes putting a patient into a coma by medication after surgery serves as a protective mechanism for maximum gentle treatment and preservation of body functions.

Thus, brain damage and coma often accompany each other. It is necessary to recognize its symptoms and immediately call a doctor to preserve the patient’s health and life.

It is not possible to consider all the neurological (and beyond the scope of neurology) aspects of comatose states in one message (I am sure that there is no need to explain the reason for this, since everyone who studies the above condition knows the reasons for this even without my thoughts on this matter). The purpose of this message is to summarize and briefly outline: the main goals (tasks) of a neurologist when examining a patient in a coma; an examination plan for a patient in a comatose state with a more detailed presentation (explanation) of some of its points (since the lack of systematization - clarity - of the “neurological aspects of a comatose state” leads to an increase in examination time, to diagnostic errors and, accordingly, to incorrect supervision of patients). For those who need it, additional literature on this topic (articles, lectures, methodological guides, presentations) with active links [for reading] will be indicated at the end of the message.

Coma is a pathological condition in which the patient is unconscious and looks asleep (Greek koma - deep sleep). He does not react to anything and is not aware of either external stimuli or internal needs. A patient in a coma is unable to communicate with others. Coma occurs either with bilateral dysfunction of the cerebral hemispheres, or with damage to the reticular activating system (RAS) [more about the structural - neuro-anatomical - basis of coma - ].

Dysfunction of the cerebral hemispheres or RAS of the brain stem can be a consequence of organic or metabolic lesions. Organic lesions of the brainstem RAS are usually accompanied by focal neurological symptoms, since the nuclei of many cranial nerves are located near the brainstem and the ascending and descending tracts begin. As for the cerebral hemispheres, their organic damage must be extensive to cause coma. In the absence of focal neurological symptoms, coma is usually the result of general intoxication or metabolic suppression of the cerebral hemispheres and/or the RAS.

You can read more detailed information on each point of the plan in the book “Neurology” by Marco Mumenthaler, Heinrich Mattle; lane with German; under general ed. O.S. Levin; 2nd ed., 2009 (or 3rd ed., 2011) - M.: MEDpress-inform [read: p.1 - p.2 - p.3 - p.4 - p.5]

PLEASE NOTE :

Eye movements in a comatose patient. In a comatose state, gaze fixation is absent, so any tracking movements and, in most cases, also saccades and nystagmus are absent. Deviation of the eyeballs to the side indicates a pathological focus either in the ipsilateral hemisphere or in the contralateral parts of the pons. Only during epileptic seizures can transient nystagmus and tonic rotation of the eyes in the direction opposite to the focus be observed.

Slow floating eye movements during shallow coma indicate the preservation of the functions of the brainstem. Other spontaneous eye movements, such as bobbing or ping-pong, are always a sign of brain damage.

Ocular bobbing (from the English bobbing - blow or squat) is a quick abduction of the eyeballs down, accompanied by a longer return to the starting position. Reflex eye movements are not caused in this condition. Bobbing usually indicates severe damage to the pons. Reverse bobbing (or ocular dipping - from the English dipping - immersion) is an illogical movement in the opposite direction.

Ping-pong (periodic alternating deviation of gaze in the horizontal plane) - the eyeballs change direction of movement every few seconds, which indicates diffuse bilateral damage to the cortex.

Eye movement study. The only way to assess oculomotor functions in a patient in a coma is to study the vestibulo-ocular and oculocephalic (oculocephalic) reflexes. Based on the study of these two reflexes, we can draw a conclusion about the state of the midbrain, pons, and medulla oblongata. [ !!! ] Before examining the oculocephalic reflex, you need to make sure that there is no trauma with a fracture or subluxation of the cervical vertebrae (in this message the oculovestibular reflex will not be considered, since in the emergency department [and this message is aimed primarily at neurologists working in the emergency department] it is not so “convenient” within the limited time allotted for examining the patient).

Oculocephalic reflex(OCR). The head of a patient in a coma, lying on his back, is covered with both hands and rotated to the sides (in the horizontal plane), while using the thumbs to lift the eyelids to observe eye movements. The normal response is that the eyeballs initially turn slightly passively along with the head, but then move in the opposite direction (positive ORP = doll eye phenomenon). The pathological reaction is the loss of the oculocephalic reflex: the eyeballs remain motionless relative to the orbit and passively follow the turn of the head (negative OCR). Then the patient's head is tilted forward and returned to its original position (moving in the sagittal plane). With the brain stem function intact, the eyeballs in this case also move in the direction opposite to the direction of head movement (doll eye phenomenon). When the midbrain is damaged, the OCR study causes normal eye movements in the horizontal plane, while they cannot be caused in the vertical plane; sometimes only downward eye movements are possible. When the pons is affected, the ORC turns out to be negative or pathological in both planes. Violation of the concordance of eye movements during OCR indicates internuclear ophthalmoplegia or damage to subnuclear structures, for example, the abducens nerve [