Intracranial hypotension syndrome

Introduction to intracranial hypotension syndrome The range of normal intracranial pressure should be 7.84 to 11.8 kPa (80 to 120 mm H2O) as measured by lumbar puncture. Intracranial hypotension (also known as low CSF pressure headache) is an intracranial pressure disorder in which the intracranial pressure is lower than the normal range (less than 70 mmH20). Because there are no serious consequences in general, it is often not enough, but it is not uncommon in clinical practice. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: nausea and vomiting, syncope, insomnia, disturbance of consciousness

Causes of intracranial hypotension syndrome

(1) Causes of the disease

If the secretion of cerebrospinal fluid is reduced, or the cerebrospinal fluid leaks, it causes intracranial hypotension syndrome. Common causes are choroid plexus injury, lumbar puncture, trauma or meningitis.

The intracranial hypotension syndrome is divided into two types: primary and symptomatic. The symptoms include multiple types. The causes of each type are different, mainly due to the decrease in the volume of the contents of the cranial cavity:

1. The reduction in cerebrospinal fluid volume is most common.

2. Reduction of cerebral blood volume.

3. The volume of brain tissue is reduced.

4. Primary intracranial hypotension syndrome.

(two) pathogenesis

1. Reduction of cerebrospinal fluid volume: Cerebrospinal fluid leakage due to various reasons, causing loss of cerebrospinal fluid, is the most common cause of intracranial hypotension syndrome, and is also the main pathogenesis, more common in lumbar puncture, trauma, obstructive brain A large amount of cerebrospinal fluid is released after the accumulation of water flow and in the brain or spinal cord.

Due to the occurrence of obstacles in the ultrafiltration and active transport of cerebrospinal fluid, the secretion of cerebrospinal fluid is reduced, which is also a common cause of intracranial hypotension syndrome. The mechanism is not very clear. Most of them are considered to be reflective sputum with local choroid plexus, choroid plexus Structural changes (bleeding of the villus matrix, fibrosis and atrophy of the choroid plexus epithelium), control of cerebrospinal fluid secretion of the hypothalamic central disorder and reduction of cerebral blood flow, seen in brain injury or brain surgery, inflammation of the choroid plexus of the ventricles, Meningoencephalitis, bleeding, cranial radiation, and metabolic diseases (such as diabetic coma).

2. Reduction of cerebral blood volume: due to the control of the automatic regulation mechanism, the cerebral blood volume is generally not excessively reduced, but when the partial pressure of CO2 in the blood is lowered, the contraction of the cerebral blood vessels causes the volume of the cerebral vascular bed to decrease. A decrease in cerebral blood volume and an intracranial hypotension headache caused by cerebral arteriosclerosis are presumed to be associated with cerebral vascular dysfunction and reduced cerebral blood flow (Shenkin, Finneson, 1953).

Other reasons such as blood loss, shock, due to the reduction of systemic blood volume, secondary cerebral blood flow slowed down, cerebral blood volume decreased and cerebrospinal fluid secretion rate decreased, resulting in intracranial hypotension.

3. Reduction of brain tissue volume: Excision of large brain tissue or brain tumor rarely causes intracranial hypotension syndrome, severe hyperosmolar dehydration, increased blood osmotic pressure and cachexia state during blood concentration, due to brain parenchyma The reduction in brain volume occurs, causing intracranial hypotension syndrome.

4. Primary intracranial hypotension syndrome: also known as spontaneous intracranial hypotension syndrome, refers to a clinical manifestation of intracranial hypotension syndrome, but a special type of intracranial hypotension without lumbar puncture, trauma and other reasons Syndrome.

There are doubts about its etiology and mechanism. Most scholars believe that the cerebrospinal fluid is rapidly absorbed or abnormally leaked due to choroid plexus vasomotor dysfunction; Schaltenbrand proposed three hypotheses on its pathogenesis in 1938, including reduced cerebrospinal fluid production. Excessive absorption of cerebrospinal fluid and tearing of the lumbosacral nerve root sleeve and leakage of cerebrospinal fluid. With the development of imaging diagnostic techniques, it was found to be associated with some severe exercise, mild trauma and congenital malformation and meningeal leakage.

Prevention of intracranial hypotension syndrome

1. Timely diagnosis and timely treatment.

2. According to the cause, pay attention to prevent secondary intracranial infection.

Complications of intracranial hypotension syndrome Complications, nausea and vomiting, syncope, insomnia

Often combined with brain dysfunction and mental retardation, such as nausea and vomiting, dizziness, dizziness, tinnitus, anorexia, fatigue, insomnia, emotional instability, etc., a small number of patients may have fever, disturbance of consciousness, mental disorders, aphasia, hemiplegia and Passive forgetting and so on.

Symptoms of intracranial hypotension syndrome Common symptoms Awareness disorder Head awesome light Insomnia Dizziness Nausea Tinnitus Anorexia Bedridden positioning signs

1. Mostly acute or subacute onset.

2. Mainly manifested as an upright headache, mostly in the forehead, occipital, sometimes affecting the whole head or the direction, shoulder, back and lower extremity radiation, headache and body position have a significant relationship, sitting or standing, headache severe, supine position It quickly disappears or alleviates, and the patient is forced to stay in bed.

3. Often combined with nausea, vomiting, dizziness or dizziness, photophobia, tinnitus, anorexia, fatigue, insomnia, emotional instability, transient syncope and mental retardation.

4. A small number of patients may have conscious disturbances, mental disorders and fever; the literature reports aphasia, hemiplegia and transient forgetting.

Examination of intracranial hypotension syndrome

1. Cerebrospinal fluid examination pressure is lower than 70mmH2O, and CSF routine laboratory tests are more normal.

2. The necessary selective examination depends on the possible cause to choose blood routine, blood electrolytes, blood sugar, immune project examination, such as abnormalities have differential diagnosis significance.

3. CT or MRI often shows brain atrophy, with Gd-DTPA enhanced scanning MRI, which can show diffuse enhancement of the whole brain dura mater and vertical shift of the brain.

4. The vestibular function measurement also has differential diagnosis significance.

Diagnosis and identification of intracranial hypotension syndrome

diagnosis

If there are clear reasons, according to the characteristics of the headache and the clinical manifestation that the heart rate is slow when standing up, the intracranial pressure is reduced when the lumbar puncture is measured, and the diagnosis can be confirmed.

Differential diagnosis

Generally, it should be differentiated from intracranial hypertension syndrome, subarachnoid hemorrhage, third ventricle gel-like cyst, epileptic seizures and vestibular lesions. Lumbar puncture and CSF examination have differential diagnosis value.

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