Term ‘Hydro’ meaning water and ‘cephalus’ referring to the head.
Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the cavities of the brain.
CSF has 3 crucial functions in our body-
1. It acts as a shock absorber for the brain and spinal cord
2. It acts as a vehicle for transporting nutrients in the brain and removing waste.
3. It flows between the cranium and spine to regulate changes in pressure within the brain.
This accumulation of CSF causes increased pressure inside the skull. Hydrocephalus can occur due to birth defects or can be acquired later in life.
The 4 types of hydrocephalous are communicating, non-communicating, ex-vacuo, and normal pressure.
The signs and symptoms of hydrocephalus may vary by age of onset.
In infants CSF builds up in CNS, causing the signs and symptoms of hydrocephalus in infants include:
· Poor feeding
· Eyes fixed downwards
· Deficits in muscle tone and strength
· Poor response to touch
· Poor growth
CHANGES IN HEAD
· An unusually large head
· A bulging or tense soft spot on the top of the head
· A rapid increase in the size of the head
YOUNG & MIDDLE-AGED ADULTS
Common sign and symptoms in this age group include:
· Loss of coordination
· Decline in memory, concentration, and other thinking skills
· urge of urination
· Impaired vision
· Loss of coordination
· Loss of bladder control
· The progressive of reasoning skills
· Memory loss
There are two types of causes for hydrocephalus-
Congenital hydrocephalus is present in the infant prior to birth in the uterus during fetal development. The most common cause of congenital hydrocephalus is AQUEDUCTAL STENOSIS (narrowing of the aqueduct of Sylvius), which occurs when the narrow passage between 3rd and 4th ventricle in the brain is blocked to allow sufficient CSF to drain. Therefore, fluid accumulates in upper ventricles causing hydrocephalus.
Other possible causes for hydrocephalus are neural tube defects, arachnoid cysts, Dandy-Walker syndrome, and Arnold-Chiari malformation.
About 80-90% of fetuses with spina-bifida often associated with meningocele or myelomeningocele develop hydrocephalus.
This is congenital hydrocephalus.
This condition hydrocephalus is acquired as a consequence of CNS infection, meningitis, brain tumours, head trauma, toxoplasmosis or intracranial haemorrhage (subarachnoid or intraparenchymal) and is usually painful.
Excessive CSF in the ventricles occurs for one of the following reasons:
i) Obstruction- The most common problem is a partial obstruction of the normal flow of CSF, either from one ventricle to another or from the ventricles to other spaces around the brain.
ii) Poor absorption- Less common problem is with the mechanism that enables the blood vessels to absorb CSF. This is often related to inflammation of brain tissue from disease or injury.
iii) Overproduction- Rarely, CSF is created to move quickly then it can be absorbed.
This is Acquired hydrocephalus.
Diagnosis of hydrocephalus is usually based on
· A general physical exam
· Neurological exam
· Brain imaging test
Type of neurological exam depends on a person’s age.
The neurologist may conduct a relatively simple test to judge muscle condition, movement, wellbeing & Senses function.
Brain imaging tests can show enlarged ventricles caused by the accumulation of excess of CSF. It is also used to identify the underlying causes of hydrocephalus.
Imaging test may include:
It is often used for an initial assessment for infants because it’s a relatively simple, low-risk procedure. The ultrasound is placed over the frontanel spot on the top of baby’s head. It can also detect the hydrocephalus prior to birth in the mother’s womb during regular parental examinations.
B. MRI: Magnetic Resonance Imaging
This test is painless, but it is noisy and requires lying still.
Children may need a mild sedative for MRI scans.
C. COMPUTERIZED TOMOGRAPHY (CT SCANS)
Scanning is painless and quick, but this test also requires lying still so the child usually receives a mild sedative.
Drawbacks of CT Scanning include less detailed images than an MRI, and exposure to a small amount of radiation.
There are 2 surgical treatments for hydrocephalus-
The most common treatment for hydrocephalus is the surgical insertion of a drainage tube called shunt between the brain ventricles and abdominal cavity.
A shunt is a flexible narrow tube with a valve that keeps fluids from the brain flowing in the right direction at a proper rate.
One end of the tubing is usually placed in one of the ventricles of the brain, then the tubing is tunnelled under the skin to another part of the body where the excess cerebrospinal fluid can be more easily absorbed such as abdomen or chambers of the heart.
EXTERNAL VENTRICULAR DRAIN (ETV) OR ENDOSCOPIC THIRD VENTRICULOSTOMY
In ETV a surgeon uses a small video camera to have a direct vision inside the brain. Then he makes a hole in the bottom of one of the ventricles or between the ventricles to enable CSF to flow out of the brain.
You also can read about Myasthenia Gravis