Assessment of the state of consciousness

When examining a patient with any disorders of consciousness, first of all, it is necessary to assess the adequacy of the state of vital functions (respiratory and cardiovascular) and take urgent appropriate measures when signs of their violation occur. Pay attention to the depth, frequency, rhythm of breathing, the frequency and rhythm of heartbeats, the intensity of the pulse, the amount of blood pressure.

The examination of a patient with a violation of consciousness is carried out according to general principles, but due to limited contact with the patient or lack of contact, the survey has a number of characteristics.

Anamnesis

When collecting an anamnesis from relatives or witnesses of the development of the disease, it is necessary to find out whether the patient had any previous illnesses and complaints (recent craniocerebral trauma, headaches, dizziness, chronic somatic or mental illness in the anamnesis). It is necessary to find out whether the victim has used any medications. It is necessary to establish what symptoms immediately preceded the change of consciousness, what is the rate of the development of the disease. Sudden rapid development of the coma without any previous factors in young people is more likely in favor of drug intoxication or  subarachnoid hemorrhage. In the elderly, this development is typical of a hemorrhage or a brainstem infarct.

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Inspection

In general, attention is drawn to the presence of signs of trauma to the head, trunk and extremities, bite of the tongue, signs of general disease (color, turgor and skin temperature, nutritional status, skin and mucous membrane rashes, edema, etc.), odor mouth, traces of injections.

When conducting a neurological examination, special attention should be paid to the following groups of symptoms.

The position of the patient. It is necessary to note head tilting, indicating a pronounced meningeal syndrome ( meningitis, subarachnoid hemorrhage), asymmetry of the limb position along the body axis ( hemiparesis ), the position of the arms and legs in the state of flexion and / or extension (decortication, decerebration). Attention is drawn to the presence of seizures (the manifestation of epileptic syndrome, intoxication with eclampsia, uremia), hormometry (indicates bilateral damage to medial structures of the midbrain, typical for intraventricular hemorrhages), fibrillar twitchings in different muscle groups (electrolyte disorders), hyperkinesia, involuntary automatic movements (by type of account of coins, walking, etc.). Chaotic motor excitation (hypoxia), movements such as getting rid of shaking, repelling of imaginary objects (hallucinations), etc.

Speech contact and its features. The patient's speech can vary from expanded, intelligible to complete absence. If you can talk with a patient, evaluate its orientation in place, time, personal situation, pace, connectedness and intelligibility of speech. It is necessary to pay attention to the content of speech ( delirium, hallucinations). It should be remembered that speech disorders can be a local symptom of the lesion of the speech centers of the dominant hemisphere ( aphasia ), the cerebellum (chanted speech), the nuclei of IX, X and XII pairs of cranial nerves in the brain stem (violation of phonation, dysarthria ). In these cases, they can not be used to characterize the state of consciousness.

Implementation of instructions and evaluation of motor reactions. In the presence of a speech contact, the execution of motor instructions is evaluated: correctness, rate of inclusion in the task, rate of execution, exhaustion.

If the patient does not follow the instructions, evaluate the motor reaction to pain irritation. The best response is the reaction, in which it localizes the pain and performs coordinated movements to eliminate the stimulus. The reaction of withdrawal is less differentiated. A pathological reaction should be recognized as a tonic extension in the arm or leg, often of a global nature with the involvement of both sides. The absence of any motor reaction to pain is prognostically unfavorable.

The state of the reflex sphere. Assess the state of physiological reflexes (increase, depression, absence), their dissociation along the axis of the body. Mark the presence of pathological, grasping and defensive reflexes, reflexes of oral automatism. Assessment of the reflex sphere gives important information about the localization, the level of brain damage, the degree of oppression of its functions.

Opening the eyes to sound or pain is one of the most important signs of differential diagnosis of the state of wakefulness. If the opening reaction of the eyes is absent, the condition is regarded as comatose. It should be borne in mind that in some cases, the opening of the eyes is due to special causes, for example, bilateral pronounced edema of the eyelids, local damage to the nuclei of the oculomotor nerves in the brain stem. Sometimes the patient in the unconscious state lies with open eyes (wakeful coma), which can be due to the state of the tone of the corresponding muscles. For these patients, the absence of a blinking reflex and involuntary flashing is typical. In such situations, it is necessary to rely on other cardinal symptoms that distinguish comatose conditions, primarily for verbal contact.

The position and movements of the eyeballs are very important for determining the level of brain damage and differentiation of organic and metabolic lesions. In the presence of a verbal contact, arbitrary eye movements are evaluated, paying attention to the gaze upward, the volume of gaze to the sides, the friendliness with eye movement. In the absence of contact, the reflex movements of the eyes are examined: the reflex gaze upward, the presence of oculocephalic and vestibulocephalic reflexes. With supratentorial processes, it is possible to observe the deviation of the eyeballs towards the focus (defeat of the adversive fields). One-sided ptosis and diverging strabismus testify to the defeat of the oculomotor nerve, which, in combination with the progressive depression of consciousness, is typical for the development of the tentorial wedge. For organic lesions at the level of the midbrain, vertical eyeballs (Magendie's symptom) are common, eyeballs are lowered (Parino's symptom), convergent or divergent strabismus, diagonal or rotational mono- or binocular spontaneous nystagmus. With damage at the level of the trunk, it is possible to observe floating and spasmodic friendly and multidirectional movements of the eyeballs, spontaneous binocular or monocular horizontal or vertical nystagmus. With a normal oculocephalic reflex, a rapid passive turn of the head causes the eye to deviate in the opposite direction with a rapid return to the initial state. With pathology, this reaction may be incomplete or absent. The oculovestibular reaction consists in the appearance of the nystagmus in the direction of the stimulus when the external auditory canal is irrigated with ice water. It changes in the same way as the oculocephalic reflex. Oculocephalic and oculovestibular reactions are highly informative for predicting the outcome of the disease. Their absence is prognostically unfavorable and most often indicates the irreversibility of coma. It should be remembered that the oculocephalic reflex is not examined in the case of a trauma to the cervical spine or suspected of it.

The state of the pupils and their reaction to light. It is necessary to pay attention to the bilateral narrowing of the pupils (may indicate a lesion of the prefectural region and bridge, typical for uremia, alcohol intoxication, use of narcotic substances). The appearance of anisocoria can be one of the first manifestations of the tentorial wedge. Bilateral dilatation of the pupils indicates damage at the midbrain level. It is also typical for the use of anticholinergics (eg, atropine). It is extremely important to investigate the pupils' reaction to light. Bilateral absence of pupillary reactions in combination with the dilatation of the pupils (fixed mydriasis) is an extremely unfavorable prognostic sign.

When examining corneal reflexes, one should be guided by a better reaction, since one-sided lack of it can be caused by a violation of the sensitivity of the cornea within the framework of conductive sensitivity disorders, and not by damage to the trunk.

Instrumental and laboratory studies

With the modern availability of methods of neuroimaging, CT or MRI is mandatory in the examination of a patient with a violation of consciousness, and as soon as possible. Also, studies can quickly confirm or exclude the presence of structural changes in the brain, which is very important, especially in the differential diagnosis of disorders of consciousness of unknown etiology. In the presence of structural changes in the brain, the results of CT and MRI can determine the tactics of patient management (conservative or surgical). In the absence of CT and MRI it is necessary to perform craniography and spondylography of the cervical spine to exclude damage to the bones of the skull and neck, as well as Echo. At the early admission of a patient with suspected ischemic stroke and inaccessibility of special examination methods (CT perfusion, diffusion methods for MRI), repeated studies are necessary, which is due to the timing of the formation of the ischemic focus.

We urgently need to conduct laboratory tests with the determination of at least the following parameters: blood glucose, electrolytes, urea, osmolarity of blood, hemoglobin content , gas composition of blood. Secondly, depending on the results of CT and / or MRI, studies are carried out for the presence of sedative and toxic substances in the blood and urine, examination of the functions of the liver, thyroid gland, adrenal glands, blood coagulation system, blood cultures in case of suspicion of a septic state, etc. If suspected on neyroinfektsiju it is necessary to execute a lumbar puncture (after an exception of stagnant disks of optic nerves at an ophthalmoscopy ) with research of structure of a liquor, definition of the maintenance of glucose, bacterioscopic and bacteriologic research.

An important study of the patient in the unconscious state is EEG. It helps to differentiate the organic, metabolic and psychogenic coma, and also allows to characterize the degree of oppression and disintegration of brain work. EEG is of exceptional importance in detecting brain death. Some help in determining the functional state of the brain is provided by the study of evoked potentials on various kinds of stimulation.

Types of states of consciousness

 Distinguish the following types of states of consciousness:

1. clear consciousness;
2. an unclear consciousness in which the patient, although reasonable, but with a delay in answering questions, is not sufficiently oriented in the environment;
3. stupor - stupor; when you leave this state, the questions do not answer reasonably;
4. sopor - stupor; the patient reacts to the surrounding patient, but the reaction is episodic, far from adequate, it is coherent to explain what has happened or is happening to him, the patient can not;
5. unconsciousness - coma (depression of consciousness, often with muscle relaxation).

Disturbance of consciousness can depend on various pathological processes in the central nervous system, including those associated with a disorder of cerebral circulation, which often occurs in elderly people with a dynamic impairment of blood circulation as a result of spasm of blood vessels, but may be associated with persistent anatomical disorders in the form of hemorrhage or ischemia the brain. In this case, in some cases, consciousness can persist, but speech disorders can be expressed. A congenital condition can develop with infectious brain damage, including meningitis.

Disturbances of consciousness, including coma, occur more often with significant changes in the homeostasis system, which leads to severe damage to the internal organs. Usually, in all cases of such endogenous poisoning, there are some or other respiratory disorders (Cheyne-Stokes respiration, Kussmaul, etc.). The most common are uremic, hepatic, diabetic (and its varieties), hypoglycemic coma.

Uremic coma due to terminal failure of kidney function and due to a delay in the body, primarily nitrogenous slags develops gradually against the background of other signs of usually far-reaching renal damage (anemia, hyperkalemia, acidosis), rarely occurs with acute renal failure.

Hepatic coma with severe liver damage can develop quite quickly. It is usually preceded by changes in the psyche that can be regarded as random phenomena that reflect the characterological characteristics of the patient (nervousness, sleep inversion).

Diabetic (acidotic) coma can develop quite quickly against the background of a satisfactory state of health, although there is often a marked thirst with the release of a large amount of urine, which the patients themselves are unaware of telling the doctor, which is accompanied by dry skin.

Hypoglycemic coma can occur with diabetes mellitus as a result of insulin treatment. Although people with diabetes are well aware of the feeling of hunger - the predecessor of this condition, but a coma can develop and suddenly (in the street, in a vehicle). Then it is important to try to find the patient "Diabetes Book", which indicates the dose of insulin administered. One of the bright signs of this coma, which distinguishes it from the diabetic, is the pronounced moisture of the skin.

It is not so rare that there is an alcoholic coma. With her, you can detect the smell of alcohol from her mouth.

Quite often there are attacks of short-term loss of consciousness. After exiting this state, satisfactory or good health returns quickly enough. Most of these seizures are associated with a temporary decrease in cerebral blood flow or, more rarely, epilepsy.

Reduction of cerebral circulation can develop with the inclusion of various mechanisms.

At the heart of simple (vasovagal) syncope lie reflex reactions, leading to a slowing down of the heart and, at the same time, to vasodilatation, especially in skeletal muscles. As a result, a sudden drop in blood pressure is possible. Apparently, the state of the left ventricular receptors is important, which should be activated with a significant decrease in its systolic ejection. An increase in sympathetic tone (which increases ventricular contraction) in combination with a reduced ventricular filling pressure (as a result of bleeding or dehydration) especially often leads to loss of consciousness. Pain, fear, excitement, the accumulation of people in a stuffy room are very often provoking fainting factors. Loss of consciousness usually occurs in a standing position, rarely sitting and especially lying down. Fainting does not occur during exercise, but it can happen after a lot of physical stress. Before fainting, many often experience weakness, nausea, sweating, a feeling of heat or chills. The patient seems to settle on the ground, looks pale. Consciousness is usually absent for more than a minute.

Orthostatic syncope often occurs when going from a prone position to a standing position as a result of a disorder of vasomotor reflexes, often with the administration of various medications, for example, in the active treatment of hypertension. Orthostatic hypotension occurs in elderly patients, especially in the vascular lesion of the autonomic nervous system, which is especially common with prolonged compliance with bed rest.

Fainting associated with the movements (turning) of the head, is due to the increased sensitivity of the receptors of the carotid sinus or the violation of the vertebrobasilar blood flow, which is confirmed by the appearance of a bradycardia with a short-term pressure on the carotid sinus; vertebrobasilar insufficiency is often accompanied by dizziness or diplopia (double vision).

Fainting with a coughing fit is sometimes observed in chronic bronchitis in full-blooded patients with obesity who abuse alcohol and smoking. This is also due to hyperventilation, which causes peripheral vasodilation and cerebral vasoconstriction.

The reception of the Valsalva (straining with a closed glottis), sometimes used as a functional test in cardiology and pulmonology, can so reduce cardiac output, leading to fainting. Fainting during physical exertion can be in patients with severe heart disease with a difficult (obstructed) ejection of blood from the left ventricle ( aortic stenosis ).

Syncope attacks occur with various heart rhythm disturbances, leading to a decrease in cardiac output and impaired blood supply to the brain, especially in elderly patients. The nature of such seizures is refined by prolonged electrocardiographic observation ( Holter monitoring ).

Epileptic seizures are another important cause of short-term loss of consciousness as a result of disorders of electrical processes in the brain neurons. These disorders occur in a limited area of the brain or are common. Less often, they occur during a period of fever or menstruation in response to a flash of light or sharp noise. With a large attack (grand mal) characterized by a sudden onset, the development of seizures. At the same time, the eyes remain open and beveled in one direction, the legs are straightened, the face is full-blooded. A sudden fall can cause head damage. Often there is an involuntary urination and a biting of the tongue.

With a small fit (petit mal), loss of consciousness is very short-lived, the patient looks as if absent for a few seconds, such seizures can be repeated daily. Sometimes, with epilepsy, consciousness does not completely disappear, although visual hallucinations are possible, accompanied by a subsequent complete loss of consciousness. Most patients do not remember what happened to them during the seizure.

Sometimes such seizures in persons with epilepsy in the family, starting as a child, can be repeated for many years, which indicates the absence of an organic lesion in the brain. Seizures that began in adulthood can be associated with the growth of the brain tumor. The appearance of headaches, another focal cerebral symptomatology confirms these assumptions.

Seizures that occur in the morning on an empty stomach or after prolonged fasting, allow to suspect a tumor secreting insulin (episodes depend on hypoglycemia). Epileptoid seizures can be triggered by certain medications, especially during their rapid cancellation (some sedatives and hypnotics).

Epileptic seizures sometimes imitate narcolepsy and catalepsy. Narcolepsy is characterized by bouts, when the patient feels an overwhelming desire to sleep. Catalepsy is characterized by a fit of severe weakness, from which the patient can fall, without losing consciousness.

Attacks of hysteria are sometimes accompanied by a blackout of consciousness and such manifestations as urinary incontinence and biting of the tongue. However, there is no deviation of the eye in one direction and increased blood filling and cyanosis of the face (as in epilepsy). Attacks of hysteria occur more often in the presence of other people. The limb movements are usually coordinated and often directed aggressively against the surrounding people.

Thus, attacks with loss of consciousness can be associated with different causes, are provoked by various factors, and their nature is recognized as a result of the identification and analysis of their accompanying symptoms.