Hydrocephalus is a condition in which there is excessive accumulation of fluid in brain and it is mainly caused by an imbalance between how much cerebro spinal fluid is produced and how much is absorbed into the bloodstream.
Cerebrospinal fluid is produced by tissues lining the ventricles of the brain. It flows through the ventricles by way of interconnecting channels and eventually flows into spaces around the brain and spinal column. It’s absorbed primarily by blood vessels in tissues near the base of the brain. Cerebrospinal fluid plays an important role in brain
1) It keeps the brain buoyant, allows heavy brain to float within the skull
2) Act as a cushion for the brain to prevent injury.
3) It helps in the removal of waste products of the brain’s metabolism
4)Flowing back and forth between the brain cavity and spinal column to maintain a constant pressure within the brain — compensating for changes in blood pressure in the brain.
EXCESS CEREBROSPINAL FLUID—
1) Obstruction. The most common cause of excessive CSF is partial obstruction of the normal flow of cerebrospinal fluid, either from one ventricle to another or from the ventricles to other spaces around the brain.
2)Poor absorption. Sometimes there is a problem in the mechanisms that makes the blood vessels to absorb cerebral spinal fluid.This mainly occurs due to inflammation of brain tissues from disease or injury.
3) Overproduction. In some of cases the production of cerebrospinal fluid is more than normal and more quickly than it can be absorbed.
Congenital hydrocephalus occurs at the time of birth or during fetal development . The main Causes include infections (e.g., cytomegalovirus [CMV], toxoplasmosis, rubella) and hemorrhaging or internal bleeding in the brain. Here are some of congenital malformations that are commonly associated with CSF obstruction:
1) Aqueductal stenosis– It is narrowing of the pathway to the fourth ventricle
2)Arnold-Chiari malformations– condition in which small part of the cerebellum protrudes into the spinal canal
3)Dandy-Walker syndrome– There is enlarged fourth ventricle due to obstruction in pathway
4) Spina bifida–portion of the spinal cord is pushed through an abnormal opening between two vertebrae.
Acquired hydrocephalus can occur at any age. Some of the conditions may cause CSF obstruction and leads to acquired hydrocephalus:
2) trauma of brain (i.e., result of injury)
3)tumor in brain
4)Cyst (i.e., a fluid-filled sac)
5)Infection (e.g., cerebral abscess, bacterial meningitis)
Article publié pour la première fois le 14/04/2013