I. What is normal pressure hydrocephalus
Normal pressure hydrocephalus (normalpressurehydrocephalus), abbreviated as NPH, is a clinical syndrome with normal intracranial pressure and enlarged ventricles, accompanied by memory and mental retardation, unsteady gait, urinary incontinence and other manifestations.
Second, there are several types of normal pressure hydrocephalus?
1. Secondary normal pressure hydrocephalus: It is often caused by subarachnoid hemorrhage, craniocerebral trauma, meningitis, craniotomy and other clear causes.
2. Idiopathic normal cranial pressure hydrocephalus: often without clear etiology.
3. Why does hydrocephalus form?
1. Secondary normal cranial pressure hydrocephalus: often due to meningitis or subarachnoid hemorrhage resulting in impaired cerebrospinal fluid recovery
2. Idiopathic normal cranial pressure hydrocephalus: it may be related to intermittent intracranial pressure increase, brain parenchymal abnormalities, brain elasticity changes, diffuse reduction of cerebral blood flow, etc.
4. What kind of manifestations will be seen in normal cranial pressure hydrocephalus?
1. Most of them have gait instability as the first symptom, which can be manifested as slight walking imbalance, small steps with wide base, repeated falls, but no walking rhythm change, no panic gait, and serious cases cannot walk or stand.
2. About 2/3 may have varying degrees of psychiatric symptoms, mainly cognitive dysfunction, including memory loss (especially near memory), slowed thinking, loss of consciousness, inattention, mild dementia, etc.
3. Half of the patients have urinary incontinence.
V. How can hydrocephalus be diagnosed?
1. CT and MRI can measure the size of the ventricles, determine the degree of ventricular dilatation, partially detect the cause, determine the effect of postoperative treatment and the presence of complications.
Low signal changes around the ventricles on MRIT1WI indicate that hydrocephalus is still progressing. Coronal scans often show a small cerebrospinal fluid gap in the convex surface of the brain due to obstruction (unlike cerebral atrophy).
The reference standard for normal ventricular size is 3.5~112.5px distance between lateral ventricle body and external angle on both sides, 1.5~60px width of lateral ventricle body, 0.2~7.5px width of hyaline septum, 0.5~20px transverse diameter and 2.2~75px longitudinal diameter of third ventricle, and 7.5~250px distance between two temporal angles.
2. Lumbar puncture pressure does not exceed 180 mmH2O, sugar and protein quantification at normal levels; a positive Tap test (symptoms improve significantly after lumbar puncture release of 20-30 ml of cerebrospinal fluid, and the efficacy can last 12-36 hours) is an indication of effective cerebrospinal fluid shunt surgery, and patients who are negative will improve slowly only a few months after shunt surgery.
3. Intracranial pressure monitoring for 24 hours can be seen as scattered high pressure waves.
4. Other tests such as cerebral blood flow, radioisotope, brain pool imaging and electroencephalography can determine the parameters of postoperative changes in cerebrospinal fluid shunt.
VI. How can hydrocephalus be treated? Is there any risk?
1. Minimally invasive ventriculo-abdominal shunt should be performed as soon as possible after diagnosis. It is generally advisable to choose a low-pressure shunt of 60~90mmHg (0.59~0.83kPa), or more preferably, an adjustable pressure shunt.
2. The incidence of postoperative complications is 5%-25%, and the common ones are subdural hematoma, epilepsy and shunt device infection.
VII. Is the prognosis good?
The prognosis is good for those with a clear etiology, those with a short course of disease, and those who are younger.