Chronic subdural hematoma

Introduction to chronic subdural hematoma Chronic subdural hematoma develops symptoms 3 weeks after trauma, between the dura mater and the arachnoid, with a capsule hematoma. Most of the head trauma is mild, some traumatic history is lacking, the onset is slow, there is no characteristic clinical manifestation, the early clinical manifestations are mild, and the symptoms are rapidly aggravated after the hematoma reaches a certain amount. It is easily misdiagnosed as intracranial before clinical diagnosis. Tumor, ischemic or hemorrhagic acute cerebrovascular disease. The time from injury to onset is usually 1 month, and it has been reported in the literature for 34 years. basic knowledge The proportion of illness: 0.02%-0.05% Susceptible people: no specific population Mode of infection: non-infectious Complications: subdural hematoma Chronic epidural hematoma

Causes of chronic subdural hematoma

Cause of trauma (50%):

Most of the causes of chronic subdural hematoma have a history of minor head trauma, especially when the elderly are in front of the anterior or posterior occipital, the brain tissue moves more in the cranial cavity and is most easily torn from the surface of the brain. The bridge vein that merges into the superior sagittal sinus.

Cause of disease (30%):

Second, venous sinus, arachnoid or subdural hematoma impaired bleeding, recent clinical observations found that patients with chronic subdural hematoma in the early head injury, CT often showed a small amount of subarachnoid hemorrhage, which may be related to chronic hard Subchomal hematoma is associated with non-invasive chronic subdural hematoma, which may be associated with aneurysms, vascular malformations or other cerebrovascular diseases.

Causes of child injury (20%):

Chronic subdural hematoma in children is mostly bilateral, often caused by birth injury, less postpartum intracranial injury, generally the highest incidence of children within 6 months, and then gradually reduced, but trauma is not the only cause, the author observed To malnutrition, scurvy, intracranial and extracranial inflammation, and children with hemorrhagic qualities, even severely dehydrated infants, can also occur this disease, the source of bleeding is mostly due to the rupture of the bridge vein into the sagittal sinus of the brain surface, Non-traumatic subdural hematoma may be caused by systemic disease or changes in dural vascular permeability caused by intracranial inflammation.

Pathogenesis

The pathogenesis of chronic subdural hematoma mainly lies in the intrauterine hypertension caused by the occupancy effect, local brain compression, cerebral circulation obstruction, brain atrophy and degeneration, and the incidence of epilepsy is as high as 40%, a long-term hematoma, its envelope Calcification may occur due to vascular embolization, necrosis and connective tissue degeneration, resulting in long-term compression of brain tissue, promotion of epilepsy, aggravation of neurological deficits, and even the formation of subcortical hematoma due to rebleeding of the endometrial rupture.

The source of bleeding in chronic subdural hematoma, many authors believe that the vast majority have a slight history of head trauma, the elderly due to brain atrophy, brain tissue in the cranial cavity is more mobile, easy to tear into the sagittal The bridge vein of the sinus causes chronic subdural hematoma. Most of the hematoma is located on the surface of the front of the frontal ridge. It is located between the dura mater and the arachnoid. The capsule of the hematoma begins to appear 5 to 7 days after the onset, to 2 to 3 The formation of the week is basically yellow, brown or gray connective tissue envelope, electron microscopic observation, the medial membrane of the hematoma is collagen fiber, no blood vessels, the outer membrane contains a large number of capillary network, the fissure of the endothelial blood vessels is large, the basement membrane structure is unclear, Increased permeability, red blood cell debris, plasma protein, platelets in the interstitial cell space, suggesting oozing, leading to continuous expansion of the hematoma. It was previously thought that the blood clot was dissolved, the liquid osmotic pressure in the capsule was high, and the cerebrospinal fluid penetrated the capsule into the hematoma cavity. This theory has been basically denied. The study found that there is a large amount of eosinophil infiltration in the outer membrane of the hematoma, and there is degranulation in the cell division. The bottom contains plasminogen, activates plasmin to promote fibrinolysis, inhibits platelet aggregation, and induces chronic bleeding.

Chronic subdural hematoma in children is more common, mostly caused by birth injury, followed by falls, the head deforms when the child is born, causing the bridge surface of the cerebral sinus to rupture; the balance function of children is not perfect, the head falls Common injuries, children with bilateral chronic subdural hematoma, the incidence of children within 6 months is high, and then gradually reduced, except for injuries, bleeding disorders, malnutrition, intracranial inflammation, hydrocephalus, etc. It is also the cause of subdural hematoma in children.

After CT application, it is gradually found that traumatic subdural hematoma can evolve into a subdural hematoma, and it will expand continuously. It may release a large amount of tissue thrombin into the subdural space due to damaged brain tissue. The reaction results in excessive activation of the blood clotting system and the fibrinolytic system.

Chronic subdural hematoma prevention

Strengthen safety awareness, publicity and education of traffic rules, and prevent accidental trauma; people with epileptic seizures should take medication on time and do not engage in dangerous activities to prevent accidents. If they occur, they should go to the hospital for treatment to prevent blood accumulation. Produces a hematoma. If there is trauma, an auxiliary examination should be performed as soon as possible after the occurrence to confirm the diagnosis. In the past, brain ultrasound, EEG, isotope brain scan or cerebral angiography were used to assist diagnosis.

Chronic subdural hematoma complications Complications subdural hematoma chronic epidural hematoma

1. Brain damage: caused by improper operation techniques when placing the drainage tube, should be carefully operated.

2. Tension gas cranium: If the irrigation and drainage are not performed under closed conditions during surgery, the air may be intracranically formed to form a tension gas cranium.

3. Subdural hematoma: mostly due to incomplete hemorrhage of the hematoma capsule, or a sharp drop in intracranial pressure after hematoma aspiration causes tearing of the bridge vein, and should be treated again in time.

4. Epidural hematoma: Most of the blood vessels between the dura mater and the skull are caused by the tearing and tearing of the blood vessels. After the hemorrhage, the peeling is continuously enlarged, and the hematoma should be cleared in time.

Symptoms of chronic subdural hematoma Common symptoms convulsion dementia consciousness blurred head enlargement quadriplegia coma dream edema insomnia nausea

1. Symptoms of increased chronic intracranial pressure: such as headache, nausea and vomiting, double vision, etc., examination of optic disc edema, occasional epilepsy or stroke-like episodes.

2. Mental retardation and psychiatric symptoms: memory loss, poor understanding, slow response, insomnia, dreams, fatigue, irritability, mental disorders, etc.

3. Focal signs of the nervous system: hemiplegia, aphasia, unilateral hemianopia, numbness of the lateral limbs, focal epilepsy, etc.

4. Young children often have lethargy, enlarged head, prominent sputum, convulsions, retinal hemorrhage and so on.

5. The disease progresses to late stage of drowsiness or coma, quadriplegia, cortical tonic attack, epileptic seizures, and one or both sides of the Babinski sign positive.

Some people in foreign countries have divided the clinical manifestations of chronic subdural hematoma into four grades: Grade I: clear consciousness, mild headache, mild or no neurological deficit; Grade II: poor orientation or confusion, and hemiplegic nerve function Missing; Grade III: Stupor, appropriate response to painful stimuli, severe neurological dysfunction such as hemiplegia; Grade IV: coma, no response to painful stimuli, cortical tonic or decortical state.

Examination of chronic subdural hematoma

1. Skull flat film: can show cerebral gyrus, scoliosis enlargement and bone resorption, local bone plate thinning or even external process, patients with many years of disease, the wall of the hematoma can have arc-shaped strip calcification, infants and young children The patient may have an enlarged frontal sac, a cranial suture separation, and an enlarged head.

2. CT scan: more manifested as a crescent-shaped, half-moon or double-convex lens-shaped low-density area under the skull inner plate, or high-density, equal-density or mixed density, unilateral equal-density hematoma should pay attention to the lateral ventricle Indirect signs such as compression deformation and displacement, ipsilateral sulci disappearance and subarachnoid space migration or disappearance, enhanced scan can show hemorrhagic mass envelope.

3. MRI: For the diagnosis of chronic subdural hematoma, MRI has an advantage over CT scan. MRI T1 weighting, like T1 value is shorter than the high signal of cerebrospinal fluid, due to repeated bleeding, hematoma signal can be inconsistent, morphology and CT scan Its coronal plane is significantly better than CT in showing the occupancy effect.

Diagnosis and diagnosis of chronic subdural hematoma

diagnosis

Because the head injury of these patients is often mild, the bleeding is slow, and the compensation gap of the elderly cranial cavity volume is large, so it often has a period of as short as several weeks, and the intermediate remission period of several months can have no obvious symptoms. When the hematoma enlargement causes symptoms of brain compression and elevated intracranial pressure, the patient has long forgotten the history of head injury or has dementia or comprehension due to existing mental symptoms, and cannot provide a reliable medical history, so it is easy to be misdiagnosed. Therefore, in clinical practice, When you suspect this disease, you should perform an auxiliary examination as soon as possible to confirm the diagnosis. CT scan can not only provide accurate diagnosis, but also estimate the time of formation from the morphology of the hematoma, and can predict the age of the hematoma from the density, generally from the new moon. The hematoma evolved into a biconvex hematoma, which takes about 3 to 8 weeks. The age of the hematoma is high at 3.7 weeks, at 6.3 weeks, and at 8.2 weeks, at low density, but for some MRI has an advantage in patients with no mass effect or bilateral chronic subdural hematoma, and has good image discrimination for hematoma or effusion with equal density of CT.

Differential diagnosis

Chronic subdural hematoma before diagnosis, especially in the history of trauma is not clear, prone to misdiagnosis, timely impact study is the key to reduce misdiagnosis, clinically should be identified with the following diseases:

1. Intracranial tumor: no history of trauma, the symptoms of increased intracranial pressure are mostly slow, according to the location and nature of the tumor, relatively early symptoms of focal stimulation or destruction of the nervous system, such as epilepsy, limb numbness, language Dysfunction, vision loss, cranial nerve symptoms, diabetes collapse and endocrine dysfunction, etc., and progressive aggravation, head CT, MRI examination can identify the two.

2. Cerebral thrombosis: It is also more common in the elderly, but no history of trauma, dysfunction of consciousness is mild and focal symptoms are more severe, mostly acute quiescent onset, slow progression, cranial CT shows cerebral vascular branch supply area Low density shadows.

3. Neurosis: headache, dizziness, memory loss, insomnia and more dreams, inattention, slow response, etc., physical examination without neurological focal signs, no positive changes in brain CT examination.

4. Chronic subdural effusion: also known as subdural hematoma, very similar to chronic subdural hematoma, effusion is light yellow or colorless and transparent, protein content is higher than normal cerebrospinal fluid, lower than hematoma fluid, practice has proved Subdural effusion can evolve into a chronic subdural hematoma, often requiring CT or MRI of the brain to confirm the diagnosis.

5. Other: It should be differentiated from normal intracranial pressure hydrocephalus, brain abscess, schizophrenia, hypertensive cerebral hemorrhage.

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