Intracranial hypotension syndrome

Introduction to low intracranial pressure syndrome Low intracranial pressure syndrome is a clinical syndrome characterized by orthostatic headache caused by various causes of cerebrospinal fluid pressure in the lateral subarachnoid space of the lumbar subarachnoid space below 0.59 kPa (60 mmH2O). Low intracranial pressure syndrome is generally caused by a decrease in brain volume, a decrease in cerebrospinal fluid, or a decrease in blood volume in the brain, resulting in a decrease in total intracranial volume, resulting in a decrease in intracranial pressure and a series of clinical manifestations. Its unique clinical manifestations have recently Gradually attracted attention, but there are many problems that have not yet been elucidated. Clinically, this syndrome is not uncommon. It is often misunderstood if it is not recognized. It is often divided into symptomatic low intracranial pressure and primary low intracranial pressure. Intracranial hypotension can be very rapid, more common in young adults than females, its clinical features are severe headache, full headache or occipital neck frontal pain or no fixed position pain, can be radiated to the shoulder. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: epilepsy

Cause of low intracranial pressure syndrome

Reduced cerebrospinal fluid (35%):

1. Cerebrospinal fluid leakage: Low intracranial pressure can be produced after lumbar puncture due to continuous leakage of cerebrospinal fluid from the pinhole, local choroid plexus reflex spasm, and control of the hypothalamic center of cerebrospinal fluid.

2. Craniocerebral trauma or craniocerebral surgery: due to surgery or trauma caused by decreased cerebral circulation and local choroid plexus reflex sputum caused by intracranial hypotension, often accompanied by conscious disturbance. In addition, brain trauma can cause choroid plexus villus hemorrhage followed by intracranial hypotension in the stage of villus stromal fibrosis, so low intracranial pressure syndrome after brain trauma is often one of the main symptoms in the late stage of brain injury.

3. Infection or infection of allergic anti-celebral chronic meningitis and choroidal ependymitis: due to fibrosis of the choroid plexus matrix in the patient's ventricle, the upper layer of the choroid plexus often shrinks in the villus matrix, collagen fibers and argyrophilic fibers proliferate, The collagen fibers and the small arteries of the hiring hair are transparent, and the lumen of the villus arteries is often narrowed or occluded, and fibrous membranes are formed outside the villus blood vessels. The intracranial hypotension is caused by the reduction of cerebrospinal fluid production due to the above pathological changes.

4. Poisoning: It has been reported that chronic barbiturate poisoning has a low intracranial pressure syndrome, and its pathogenesis is unknown.

5. Primary intracranial hypotension: The etiology and pathogenesis of primary low intracranial pressure are not clear. According to the literature, it may be related to the following factors: reduction or overabsorption of choroid plexus cerebrospinal fluid, abnormal anatomy of nerve roots, choroid plexus vasospasm Hypothalamic dysfunction.

6. Shock state: The shock state caused by any cause can reduce cerebral blood flow, resulting in lower pressure of cerebrospinal fluid.

Reduced volume of the cerebral vascular bed (30%):

When the partial pressure of carbon dioxide in the blood is reduced, the volume of the cerebral vascular bed is reduced, the intracranial pressure is significantly reduced, and the patient is often mentally retarded. This is due to the fact that cerebral blood circulation is inhibited relatively quickly or insufficient blood supply. After the patient inhaled carbon dioxide, the blood partial pressure of carbon dioxide increased, the cerebral blood vessels dilated, the intracranial pressure increased, and the condition improved significantly.

Volume reduction (30%):

Dehydration or cachexia state: At this time, intracranial hypotension is formed by the following three factors: 1 loss of brain parenchyma, brain volume reduction; 2 reduction of cerebrospinal fluid production; 3 blood concentration, increased blood osmotic pressure and thus increased absorption of cerebrospinal fluid .

Low intracranial pressure syndrome prevention

Patients should be rested in bed, head low and high, bed height 20 ° ~ 30 °, encourage patients to drink more water, 3000 ~ 4000ml per day, can add salt, preferably saline.

Low intracranial pressure syndrome complications Complications

Easy to have intracranial oozing or bleeding, subdural hematoma.

Symptoms of low intracranial pressure syndrome Common symptoms Dizziness, mental disorders, muscle tenderness, convulsions, nausea and vomiting, gait, unstable neck, strong straight tinnitus

1, intracranial hypotension can be very urgent, more common in young adults than females, its clinical features are severe headache, full headache or occipital neck frontal pain or no fixed position pain, can be radiated to the shoulder .

2. The headache is aggravated when sitting up and standing, and the headache is alleviated or disappeared when lying down or the head is low. Often accompanied by nausea, vomiting, tinnitus, photophobia, dizziness, gait instability, a small number of transient syncope episodes, mental disorders, convulsions, palpitations, sweating, increased headache when standing may be associated with decreased cerebrospinal fluid pressure and standing brain The pain-sensitive structural displacement of the face is related.

3, elderly patients showed dizziness, accompanied by head weight or dizziness. Occasionally, headache and dizziness may be related to localized insufficient blood supply to the basilar artery, which may be caused by a decrease in cerebrospinal fluid production due to choroid plexus spasm.

4, physical examination part of the erect pulse relaxation, neck stiffness, neck muscle tenderness Kline positive, bilateral or one side abducens nerve insufficiency paralysis of the fundus vaginal vaginal nerve system can also have no positive signs. Intracranial low-pressure neck resistance is less resistant to neck damage than true meningeal irritation.

Examination of low intracranial pressure syndrome

(1) Physical examination

For patients with low intracranial pressure syndrome, attention should be paid to the relationship between some headaches and body position; the relationship between headache and cough to increase abdominal pressure; whether the pulse and blood pressure in the supine position and erect, and the size of the pupil are large and light-responsive; eye movement The fundus has no fundus nipple blur or papilledema edema hemorrhage and exudation; cranial nerve and spinal nerve movement sensation and reflex should pay special attention to bilateral abductor nerve; meningeal stagnation and neck muscle tenderness make timely judgment on the condition Choosing the most appropriate auxiliary examination is extremely helpful for diagnosis and treatment.

(2) Auxiliary inspection

In addition to routine, hematuria, electrocardiogram, chest X-ray and other examinations, patients with increased intracranial pressure should also choose to use auxiliary examination according to medical history and physical examination.

1. Lumbar puncture: The pressure of the cerebrospinal fluid in the lateral position is less than 0.59kPa (60mmH2O) or can not be measured. The negative pressure does not have cerebrospinal fluid outflow, and there is no cerebrospinal fluid out of the abdominal abdomen. Only a small amount of cerebrospinal fluid is obtained by suction with empty needle. The cerebrospinal fluid pressure is lower than 3.432 kPa when sitting, and the protein content of cerebrospinal fluid can be slightly increased. The slight increase in the number of red blood cells is due to the high cerebral edema of the meninges, and then the red blood cells and plasma proteins ooze out into the subarachnoid space; a slight increase in lymphocytes may be an inflammatory reaction or a response to extravasation of red blood cells in the leakage of cerebrospinal fluid.

2. Skull CT: It can show that the cerebral cistern becomes narrower and smaller.

3. Skull MRI enhancement: shows extensive diffuse meningeal thickening.

Diagnosis and diagnosis of low intracranial pressure syndrome

Reliable basis for diagnosis of low intracranial pressure syndrome

1. Headache changes with body position: that is, headaches are relieved when sitting up, and headaches are often limited to the neck and neck with nausea, vomiting and dizziness.

2. When the erect position is slow, the heart rate is slowed down more than 10 times per minute.

3. Under normal breathing, the lumbar cerebrospinal fluid pressure in the lateral position is lower than 0.59 kPa (60 mmH2O), and the symptoms are aggravated after the lumbar puncture.

4. Clinically, the cerebrospinal fluid pressure was reduced due to cistercosis of the cerebellum, obstruction of the occipital foramen or obstruction of the spinal canal.

5. Except for the neck resistance, the external nervous system and the fundus are often abnormal.

6. There are lumbar puncture, traumatic brain infection, poisoning, water loss, hypotension, meningocele with cerebrospinal fluid leakage and other causes of intracranial hypotension, the diagnosis of symptomatic intracranial hypotension; no cause is the primary intracranial Low pressure.

Differential diagnosis

1. High intracranial pressure syndrome: When the intracranial pressure is increased, it can cause headache and vomiting. It is more relieved after standing, and it is aggravated after lying for a long time. Often there are fundus optic nerve head edema, lumbar cerebrospinal fluid pressure is higher than normal. Sometimes the skull X-ray or CT shows a special change in intracranial hypertension.

2. Subarachnoid hemorrhage: due to low intracranial pressure syndrome can also suddenly occur, showing symptoms and signs such as headache, vomiting, neck stiffness and photophobia, especially when the pressure on the lumbar cerebrospinal fluid is zero, it is easy to mistake the puncture Success and repeated punctures caused bleeding and misdiagnosis. The incidence of subarachnoid hemorrhage is more abrupt. There are often incentives before the illness. The relationship between headache and body position is not obvious and often accompanied by disturbance of consciousness. Sometimes it is accompanied by cranial nerve palsy, especially oculomotor nerve paralysis. Fundus examination sometimes has subvitreal hemorrhage. The cerebrospinal fluid pressure is high and uniform. The blood cerebrospinal fluid is placed so that the cerebrospinal fluid is yellowish after the red blood cells are precipitated.

3. Epileptic seizures: should be differentiated from syncope episodes during intracranial hypotension. Generally, epileptic seizures occur frequently and terminate frequently, and EEG often has special changes.

4. Vestibular diseases: especially in elderly patients should be differentiated from primary intracranial hypotension, sometimes by the use of lumbar puncture to measure cerebrospinal fluid pressure.

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