Compression of the brain

Compression of the brain is the severest and most dangerous type of crani­ocerebral trauma, noted in 3-5 % of patients with CCT. It is characterized by a rapid growth of general cerebral and focal symptoms in any interval of time after trauma or immediately after it, above all things by dysfunctions of truncal parts, and presents a direct threat for the patient's life.

The principal reasons of compression of the brain in CCT are the formation of intracranial hematomas, subdural hydromas, pneumocephaly, depressed fractures of the bones of the calvarium, foreign bodies and an aggressive edema-swelling of the brain, developing mainly because of contusion of cerebral tissue.

In the clinical picture of compression of the brain (foremost by hematomas), the pathognomonic symptoms are the presence of lucid interval (the period of imagi­nary well-being), anisocoria with midriasis on the side of compression, bradicardia, hemiparesis or hemiplegia on the side opposite to concussion. Often enough in pa­tients with compression of the brain (especially in depressed fractures and chronic hematomas), the episyndrome develops.

One of the principal reasons of compression of the brain in CCT is formation of intracranial hematomas which, according to the classification, happen to be:

• epidural (accumulations of blood between the internal surface of the bones of the skull and dura mater of the brain most frequent within the limits of one bone;
• subdural (accumulation of blood between the internal surface of the dura mater and external surface of the brain limited by the processes of the dura mater;
• intracerebral (accumulation of blood in cerebral tissue);
• intraventricular (accumulation of blood in the ventricles of the brain).

Apart from the formation of hematomas, there is possible hemorrhage under the arachnoid membrane (subarachnoid hemorrhage - SAH) which often accompanies by contusion of the brain and does not lead to compression of the brain.

Depending on the period of formation, hematomas can be: acute -up to 3 days; subacute - up to 2 weeks; chronic - more than 2 weeks. The terms of arising of the symptomatology of compression of the brain in intracranial hematomas mainly depend on their localization and bleeding source. Hematomas can be either plural or bilateral. Sometimes there are variants of "multiply" intracranial hematomas (epi-subdural, subdural, epidural-subperiosteal and others).

On the whole, the clinic of intracranial hematomas depends on the source of bleeding, localization and sizes of hemorrhage, speed of the development of com­pression of the brain, as well as on the severity of concomitant damages of the skull and brain, the patient's age and his individual peculiarities (concomitant diseases, 'former diseases, traumas and others).

A bleeding source in epidural hematomas is usually the trunk or branches of the middle meningeal artery, rarer - the veins of the dura mater, dural sinuses and vessels of diploe. These hematomas arise usually at the site of applying the trau­matizing factor, at times rather insignificant. In this connection many patients do not lose their consciousness at all or note its relatively short-term loss (usually less than an hour approximately in 40 % of cases).The lucid interval is most frequently short-term. Chronic epidural hematomas occur extremely rarely. Diagnosis is made on the basis of CT or MRI, at that hematoma reminds a biconvex lens by appearance. Rather often there are fractures of the bones of the skull at the site of the formation of hematoma (mainly fractures of the temporal bone.

The source of bleeding in the formation of subdural hematomas are veins dam­aged as a result of trauma of the head which flow into the sinuses of the brain, dam­aged superficial vessels of the hemispheres of the brain, venous sinuses. This type of hematomas is most widespread (more than half of the total amount of intracranial hematomas). Unlike epidural haematomas subdural ones can be formed also on the side opposite to the blow and in 10-15% of cases are bilateral. On the performing CT or MRI grams hematoma most often has the appearance of a convexo-concave lens.

The clinical picture of subdural hematomas is characterized by a long-term lucid interval, not infrequently one can come across subacute and chronic variants of the course, focal symptomatology is less apparent than in epidural hematomas and more.

Intracerebral hematomas, as a rule, accompany by severe contusion of the brain, but sometimes they arise also in contusions of the brain with minimal neurological symptomatology. The source of their formation are the veins and arteries of the brain. Intracerebral hematomas occur considerably rarer than other intracranial hematomas, they are more frequently of small sizes. The clinical picture of intracerebral hematoma is characterized by the development of general cerebral, focal and truncal symptoms in early terms after trauma, a subacute course occurs rarer. The final diagnosis is made on the basis of CT or MRI.

Intraventricular hematomas, as a rule, accompany by intracerebral hematomas, as isolated they occur rarely. A bleeding source is damage of the vascular plexus of the ventricles or a break of intracerebral hematoma into the cavity of the ventricle. Neurological symptomatology develops quickly, immediately after trauma, and is characterized by a short period of psychomotor excitation, acutely developing deep disorder of consciousness, appearance of gormeotonia and decerebration rigidity. Apparent vegetative disorders (hyperthermia, deep disorder of breathing arterial hypertension which is replaced by hypotension) quickly.

In the worsening of the state cramps disappear and hypomyotonia appears, tendon reflexes go down and pathological reflexes disappear. The prognosis in intraventricular hematomas is extremely unfavorable.

Subdural hydroma is a local accumulation of liquor in the subdural space (between the dura mater and arachnoid membrane) being formed as a result of tears of the arachnoid membrane with the formation of the valve which only lets liquor one-way. The clinical picture reminds a subacute or chronic subdural hematoma, and the final diagnosis can be only made using additional methods of the investigation, and sometimes intraoperatively.

Pneumocephaly is penetration of air into the cranial cavity. More frequently it arises in fractures of the calvarium with damage of air sinuses and rupture of the dura mater. Pumping the air into the cranial cavity of is facilitated by the valvular mechanism formed at the expense of the mucous membrane of sinuses or of the dura mater. Not infrequently pneumocephaly is accompanied with Iiquorrhea. In not apparent pneumocephaly, not causing compression of the brain, the patients can experience a headache, the feeling of gurgling and transfusion of the liquid in the head. The diagnosis is specified craniographically, as well as in performing CT or MRI. In a well-formed valvular mechanism, the air can arrive in large volumes and cause compression of the brain.

A depressed fracture arises more frequently as isolated, sometimes accompanies splintered fractures in which damage of the dura mater and cerebral tissues is not infrequently noted.

Clinically, one observes symptoms of focal damage in apparent compression of the brain. As a result of irritation of the cortex of the brain by splinters of the bone epileptic attacks can arise. Diagnostic difficulties in determination of the depressed fractures, especially in rough depressions, do not arise. It can be determined palpatorily, and sometimes even by sight. For the final diagnosis it is necessary as well as in other types of craniocerebral trauma, to use additional methods of checkup - craniography (in 2 projections), CT, MRI.

Date: 2015-01-02; view: 1377