Posterior fossa hydrocephalus syndrome in children

Introduction to posterior fossa hydrocephalus syndrome in children The posterior fossa hydrocephalus syndrome, which is non-communicating hydrocephalus, is a congenital malformation of the posterior cranial fossa, mainly due to the accumulation of cerebrospinal fluid to the fourth ventricle cyst, and the symptoms of nerve damage occur. Also known as Dandy-Walker syndrome, Luschka-Magendie hole (fourth ventricle hole) atresia syndrome, fourth ventricle lateral hole, mesenteric atresia syndrome. basic knowledge The proportion of illness: 0.002% Susceptible people: young children Mode of infection: non-infectious Complications: brain swelling, syringomyelia

The cause of posterior fossa hydrocephalus syndrome in children

(1) Causes of the disease

This symptom is a congenital malformation of the posterior fossa, the cause is unknown, is the early developmental disorder of the embryo, the main lesion is the fourth ventricle Magendie hole and Luschka hole obstruction, also seen in congenital hydrocephalus, intraventricular or external accumulation Cerebrospinal fluid.

(two) pathogenesis

Due to the accumulation of cerebrospinal fluid in the fourth ventricle, the fourth ventricle capsular enlargement occurs; the cerebellar sacral dysplasia and the posterior temporal iliac defect, and the enlarged anterior sac and the cerebellar hemisphere are pushed forward and lateral by the enlarged fourth ventricle; The cerebellum and transverse processes are displaced upwards, causing high sinus and enlarged posterior fossa.

The pathological features of this disease are:

1 fourth ventricle cystic dilatation;

2 The cerebellar vermis is underdeveloped or not developed;

3 There is hydrocephalus that is congenital or later.

Prevention of posterior fossa hydrocephalus syndrome in children

This symptom is a congenital malformation disease with unknown etiology. It is caused by early developmental disorders of the embryo. The preventive measures refer to other birth defects diseases. Prevention should be carried out from pre-pregnancy to prenatal:

Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV) and reproductive system examination (such as screening for cervical inflammation). General medical examinations (such as blood pressure, electrocardiogram) and asking about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.

Complications of posterior fossa hydrocephalus syndrome in children Complications, brain swelling, syringomyelia

Some cases of this disease may be associated with abnormal nervous system, including lumbosacral spinal bulging, simple brain bulging, combined malformation including corpus callosum dysplasia, autopsy can also find organ or tissue ectopic, no cerebral gyrus, multiple cerebellum , stenosis of the aqueduct and syringomyelia.

Symptoms of posterior cranial fossa hydrocephalus syndrome Common symptoms Increased intracranial pressure gait instability Head enlargement Hydrocephalus Eyeball tremor Headache and vomiting intelligence reduction

1. Increased intracranial pressure Most children develop symptoms before the age of 2, such as headache, vomiting, irritability and other symptoms of increased intracranial pressure, anterior and posterior diameter of the skull, occipital protrusion, clinical manifestations mainly hydrocephalus, intracranial pressure Increase symptoms.

2. Neurological damage symptoms Increased cranial pressure caused by cerebellar and cranial nerve damage symptoms, abnormal intelligence and motor function, lack of motor development, cranial nerve damage manifested as nerve palsy, poor head control, cerebellar function impairment Unstable state, nystagmus, etc., can also be manifested as spastic cerebral palsy and mental retardation.

Examination of posterior fossa hydrocephalus syndrome in children

Blood test

When the infection is concurrent, the peripheral blood leukocyte count and neutrophil classification increase, and anemia and other manifestations may occur.

2. Phenol red experiment

In order to identify whether it is a traffic hydrocephalus, phenol red can also be injected into the brain in the clinic, and the time of occurrence of cerebrospinal fluid in the subarachnoid space of the spinal cord is observed.

The specific operation process is as follows: after intracerebroventricular injection of 1 ml of neutral phenol red, lumbar puncture is performed, so that the cerebrospinal fluid is slowly dropped from the puncture needle onto a gauze moistened with 10% sodium hydroxide. When the gauze appears red, it indicates the cerebrospinal fluid. Phenol red is available. Under normal circumstances or 2 to 12 minutes after intraventricular injection of cerebral ventricle, phenol red should appear in the subarachnoid space of the spinal cord. If it does not appear for 20 minutes, it can be considered as obstructive hydrocephalus.

The main pathological changes of the nervous system are not easy to see by -ultrasound and general image examination. The occipital enlargement caused by hydrocephalus is often enlarged, and the posterior cranial fossa is transparent and suspected. CT is applied to the diagnosis of this disease after clinical application. Greatly improved, magnetic resonance (MRI) examinations are more convenient and provide clearer images, including narrowing of the aqueduct.

CT examination

It is of great value for the diagnosis of hydrocephalus. It can also distinguish whether it is traffic hydrocephalus. When non-communicating hydrocephalus (obstructive hydrocephalus), the ventricles are obviously dilated and become blunt, which can be determined according to the expansion of the ventricles. In the obstructed area, unilateral or bilateral interventricular septal obstruction may cause unilateral or bilateral lateral ventricle dilatation, while the third and fourth ventricles are normal, and the stenosis of the aqueduct appears as bilateral ventricle and third ventricle dilatation, while the fourth ventricle is normal. When the middle and side holes of the fourth ventricle are blocked, all the ventricles (including the four ventricles) are dilated.

In the case of traffic hydrocephalus, CT showed a spherical expansion of the ventricle, to a lesser degree, the fourth ventricle was the smallest, the basal pool often expanded, and the cerebral sulcus widened.

In recent years, due to the widespread use of CT, the clinical name of "external hydrocephalus" has appeared. CT shows that the ventricle enlargement is not obvious, while the basal pool, lateral fissure, longitudinal fissure pool and cerebral hemisphere sulcus increase. Wide, subarachnoid enlargement, it was thought that it may be an early manifestation of traffic hydrocephalus, and some people think that these manifestations are benign, self-limited subarachnoid enlargement, not traffic hydrocephalus, because In infants and young children under 2 years old, the growth rate of the skull is faster than that of the brain, and the gap between the brain and the skull is increased, so that the sulcus, the fissure and the pool are relatively wide on the CT. Under normal circumstances, the spider web on the brain surface The sub-membrane cavity can be as wide as 4mm, the longitudinal fissure pool is 6mm, and the lateral fissure pool is 10mm, which are all in the normal range. After 18 months to 2 years old, the brain develops faster, the gap between the brain parenchyma and the skull gradually becomes smaller, and the subarachnoid space The widening situation is no longer obvious.

2. MRI examination

In addition to showing ventricular enlargement, in the obstructive hydrocephalus, spinal fluid can penetrate into the cerebral ventricle through the ependymal membrane, interstitial edema around the ventricle, and there is a high signal around the ventricle in the proton density-weighted image, which has important diagnosis. value.

3. X-ray inspection

X-ray skull radiographs, vertebral angiography and ventriculography are helpful for diagnosis, and all the elderly have visible signs of increased intracranial pressure.

Diagnosis and identification of post-cranial fossa hydrocephalus syndrome in children

diagnosis

The typical clinical manifestations are generally not difficult to diagnose. Repeat the review of the head circumference. If the growth is too fast, it can assist in the diagnosis. When the children have increased intracranial pressure, the possibility of hydrocephalus should be considered. In children with closed cranial sutures, hydrocephalus has no manifestation of head enlargement.

Because the symptoms lack specific signs and symptoms, the diagnosis is more difficult. The case-reported cases reported by Maria range from birth to 34 years old, and most cases are diagnosed at less than 6 months.

Differential diagnosis

In babies, care should be taken to identify the following:

1. Immature children have a faster head enlargement, some are similar to hydrocephalus, but the ventricles are not large.

2. The head enlargement of the disease is mostly square, and there are other symptoms of rickets.

3. Chronic subdural hematoma often has a history of head trauma (sometimes history of trauma is not obvious), vomiting, slower head enlargement, CT shows subdural space widening, subdural puncture has more orange or yellow liquid.

4. Intracranial space-occupying lesions such as tumors, abscesses, etc.

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