What is Hydrocephalus?
In Hydrocephalus, there is an excessive accumulation of fluid in the cranial cavity, and in children this results in deformity of the head shape. It is caused either by an excessive production of brain fluid (called cerebrospinal fluid, or CSF) or interference with its normal flow. There are various causes, and the characteristics of three types are described.
Often a hereditary factor plays a part, and it may affect several family members. It may be associated with other severe nervous system diseases, such as spina bifida, meningocele, and other abnormalities. Also, it may take place in babies with harelip, cleft palate, rectal and testicular anomalies, imperforate anus (no opening being present at birth).
In some instances there is enormous cranial deformity at birth, the skull being considerably enlarged. This tends to occur during fetal development. Sometimes it is so extensive as to make a normal delivery impossible. The forehead is large, rounded and projects forward. The head may not be symmetrical, and the suture lines (where the skull bones join) may be wide and bulging. Hair growth is scanty and vessels are distended. Often general nutrition is poor, and bodily development retarded in contrast to the severity of the disorder upon the nervous system.
Various causes have been cited, such as overexposure to X-rays in the antenatal period, viral infections (probably rubella, measles or other common ones), inadequate oxygen reaching the baby at the time of birth, and others that have been cited before for other cases of brain damage and mental retardation. One day we may know for certain the key reasons and take greater steps to avoid them.
There is a blockage obstruction to the free flow of fluids that normally bathe the brain internally and externally. The child might appear to be normal at birth, but within weeks or months, as the fluid is unable to freely flow, this builds up and causes the head to gradually increase in size, often just two to three months after birth. The rate of head growth is markedly out of proportion to the rest of the body. The infant may become tired, lethargic and irritable, with vomiting, reduced vitality and well-being. There will be gradual deterioration.
Medical attention is necessary, first to try to establish the diagnosis, and then to offer some form of therapy. Many and varied attempts have been dreamed up to try to reinstate the normal fluid circulation in the brain. The success is usually small, and in any event there is usually some degree of mental retardation, irrespective of what measures are implemented.
Children may develop various abnormalities of vision, speech, muscular activity, and peculiar behavioral patterns. Some become spastic, requiring specialized care in institutions. Occasionally, but not often, some are spontaneously cured.
These vary according to the degree of the disorder. There may be convulsions, mental disturbances, paralysis of the extremities, visual deterioration, deafness, abnormal eye movements, headache, visual disturbances (due to papilloedema) and vomiting. There is no consistency with symptoms.
These will depend on the age at which the initiating infection occurs. In infants, the signs and symptoms may be similar to those in congenital hydrocephalus. In older persons, it will give rise to the symptoms of increased intracranial pressure. Headaches, double vision and vomiting, may all occur. Physical weakness and mental deterioration will gradually develop if untreated.
Once more treatment is in the realm of the neurologist, and if surgery is undertaken (which may offer the only hope of a cure), this is done in a well-equipped neurosurgical department.
Acute Acquired Hydrocephalus
This may occur when the flow of CSF is rapidly impeded, and the head cannot expand (as is possible in small children). The most common cause is a tumor in the midline, effectively obstructing CSF flow.
Acute Acquired Hydrocephalus Symptoms
These tend to come on abruptly, with few localizing ones. Chief symptoms are headaches and vomiting. Investigations will often reveal the underlying cause. Treatment consists of dealing with the cause, and this usually requires surgery. Once more it is in the province of the neurosurgeon. The outlook will depend on the nature of the lesion.
Treatment is surgical, involving the use of shunts. Medicinal therapy may give temporary relief before surgery – such as diuretics (to assist in fluid loss). Generally the outlook is not good. As one authority states, “In all severe and progressive cases the prognosis [outlook for the future] is hopeless.” In some milder cases the process may become arrested and the patient has some chance of reaching adult life. However, even with surgery, there are the long-term chances of convulsions and mental retardation. Treatment at all times must be under the expert supervision of the neurologists. The best advice that can be offered to parents and relatives is that the sooner medical treatment is instituted, the better.
Chronic Acquired Hydrocephalus
This may come on after an attack of meningitis, which checks the normal free flow of fluids through the brain spaces (ventricles). It may occur at any age, including childhood or adulthood.