EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
163. Malformations of The Brain: Hydrocephalus
Review of MEDICAL EMBRYOLOGY Book by BEN PANSKY, Ph.D, M.D.
- Hydrocephalus is a frequent anomaly, but is also compatible with life. It is characterized by an abnormal accumulation of cerebrospinal fluid (CSF) in the cerebral ventricles or in the subarachnoid spaces in the case of external hydrocephalus
- THE 3 MAJOR CAUSES of hydrocephalus are
- Excess production of cerebrospinal fluid (communicating hydrocephalus)
- Obstruction of circulation of cerebrospinal fluid (noncommunicating hydrocephalus)
- Defective resorption of cerebrospinal fluid (communicating hydrocephalus)
- HYDROCEPHALUS IN THE NEWBORN, in most cases, is thought to be the result of an obstruction in the aqueduct of Sylvius due to inflammation, a tumor, or an anomaly
- SOME FORMS OF HYDROCEPHALUS are the result of obliteration of the openings of the fourth ventricle (Dandy-Walker deformity)
- In some cases of spina bifida, the posterior part of the brain sinks into the occipital openin With caudal elongation of the trunk, the spinal cord follows the movement and pulls the brain posteriorly. This results in the Arnold-Chiari syndrome
- HYDROCEPHALUS MAY BE DUE to a recessive, sex-linked genetic anomaly in some cases
- The hydrocephalus does not appear in the female who transmits it, but is seen in 50% of the males
- One usually sees an overproduction of cerebrospinal fluid
- MANIFESTATIONS OF HYDROCEPHALUS
- An increased size of the head
- An enlargement of the cranial sutures
- Progressive thinning of the cranial bones
- Lamination of the cerebral cortex in severe cases
- It is often accompanied by psychologic retardation, often severe enough to cause debility, convulsions, or cerebral motor disability
- HYDROCEPHALUS is often associated with spina bifida cystica, even though the hydrocephalus is not obvious at birth.
- The condition of hydrocephalus after birth usually results from meningitis which causes a postinflammatory obstruction
- SURGICAL TREATMENT: arachnoid-ureterostomy or ventricle-cardiac, ventricle-pleura, or ventricle-vena cava shunt may stabilize the condition by removing the obstruction. This, however, has no effect on the nervous lesions that may have occurred before surgery. Prognosis is guarded
