Etiology
1, excessive cerebrospinal fluid production: except for papillomas of the choroid plexus in the ventricular system, diffuse villous hyperplasia of the choroid plexus is an extremely rare cause of excessive cerebrospinal fluid production.
2, cerebrospinal fluid absorption disorders: children with intracranial hemorrhage or central nervous system infection, bleeding skull base subarachnoid adhesions, resulting in reduced absorption of cerebrospinal fluid by the arachnoid granules, the vast majority of hydrocephalus is due to cerebrospinal fluid absorption disorders.
3, cerebrospinal fluid circulation channel obstruction: for congenital or acquired factors, cerebrospinal fluid circulation channel obstruction has intracerebroventricular obstruction and extracerebroventricular obstruction.
Clinical manifestations
Most of them start to increase the size of the head a few weeks after birth, and they are usually found gradually after 3-5 months, but there are also those whose heads are enlarged at birth. The clinical manifestations are particularly the progressive and abnormal enlargement of the skull due to increased intracranial pressure, which is disproportionate to the circumferential development. The frontal area protrudes forward, the orbital roof is pressed downward, both eyes look downward, the eyeballs turn downward, the upper part of the sclera becomes white, the fontanelle is enlarged and the tension increases, the other fontanelles may also be enlarged, the skull sutures are separated, and the scalp veins are dilated. The cranial percussion shows “broken pot sound”. In infants and young children, the sutures are not closed, and when the intracranial pressure increases, the skull can compensate for the enlargement, so the symptoms of increased intracranial pressure may not be obvious in the early stage. However, when hydrocephalus is serious and progresses faster, it can also appear, and its symptoms are repeated vomiting. Brain degeneration, brain development disorders, central paralysis of the limbs, especially the lower limbs, often with intellectual changes and developmental disorders. Optic nerve compression and atrophy may lead to blindness. Nystagmus and convulsions are also common. The disease is often complicated by deformities in other parts of the body.
In a few cases, hydrocephalus can stop on its own after a certain period of development, and the skull will not continue to increase, and the intracranial pressure is not high, which becomes “static hydrocephalus”.
Examination
1. The infant’s head is abnormally enlarged, the fontanelle is full and bulging, repeated vomiting and crying, the skull percussion shows “broken can sound”, and both eyes show “sunset sign”.
2.Cranial ultrasound and X-ray examination show that the cranial cavity is enlarged, the skull is thinner, the cranial suture is widened, and the fontanelle is enlarged.
3. Ultrasound examination of the brain shows symmetrical enlargement of bilateral ventricles.
4.CT or MRI examination of the head can show the degree of ventricular enlargement and can measure the thickness of the cortex to understand the site of obstruction and the cause of hydrocephalus.
Diagnosis
During infancy, abnormal enlargement of the head and disproportionate size of the head circumference for age are the main signs of hydrocephalus. Regular measurement of the infant’s head circumference will help to detect hydrocephalus early and allow for a definitive diagnosis and timely treatment before typical signs appear. In newborns, despite ventricular enlargement or hydrocephalus, the fontanelle can still be sunken, especially in infants with low birth weight, who may have a smaller than normal head due to dehydration in sick children. Although abnormal enlargement of head circumference in children is an important sign of hydrocephalus, there is no absolute relationship between the two. Continuous observation of ventricular dilatation and auxiliary examinations are needed to make a clear diagnosis.
Differential diagnosis
1. Chronic subdural effusion or hematoma
There is often a history of birth injury, and the lesion can be unilateral or bilateral, often with optic disc edema and a negative sunset sign. The diagnosis can be clearly made by aspiration of hemorrhagic or yellowish fluid from the subdural cavity by fontanelle puncture. Cerebral angiography, CT or MRI can also be identified.
2.Neonatal intracranial tumor
Neonatal intracranial tumor often has enlarged head circumference or secondary hydrocephalus, ventriculography or CT scan and MRI can confirm the diagnosis.
3.Vitamin D deficiency disease
The head circumference can be enlarged to square cranium with enlarged fontanelle, low tone, and other manifestations of vitamin D deficiency disease.
4.Congenital giant craniosynostosis
No hydrocephalus sign, negative sunset sign, no enlargement of ventricular system, no increase of intracranial pressure, CT scan can confirm the diagnosis.
Treatment
1.The main surgical treatment of this disease can be divided into three categories.
(1) Surgery to remove the cause of obstruction;
(2) Surgery to reduce cerebrospinal fluid secretion;
(3) cerebrospinal fluid shunt.
2. Preoperative intracranial hypertension can be treated with dehydration and lowering of cranial pressure. Correct cerebral edema and lower intracranial pressure with 20% mannitol, tachyphylaxis, dexamethasone as the main drugs, and even human albumin can be used.
3, symptomatic, prevention of infection, nerve nutrition and other treatment.
Prevention
The key to controlling the occurrence of hydrocephalus is to eliminate the risk factors before fetal formation and the constitutive factors in the fetal and perinatal periods. This has its significance in preventing the occurrence of hydrocephalus.
1.Research on etiology
2.Strengthen prenatal early diagnosis
3.Promote knowledge of eugenics and reduce the number of births
4.Advocate appropriate age of childbirth
5.Strengthen eugenics education and improve the cultural quality of the population.
6.Safe delivery, prevent asphyxia and birth injury.