HYDROCEPHALUS

                                                     HYDROCEPHALUS

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.

SYMPTOMS

The signs and symptoms of hydrocephalus may vary by age of onset.

Infants

In infants CSF builds up in CNS, causing the signs and symptoms of hydrocephalus in infants include:

·        Vomiting

·        Sleepiness

·        Irritability

·        Poor feeding

·        Seizures

·        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 size of the head

YOUNG & MIDDLE-AGED ADULTS

Common sign and symptoms in this age group include:

·        Headache

·        Loss of coordination

·        Decline in memory, concentration, and other thinking skills

·        Frequent urge of urination

·        Impaired vision

·        Lethargy

OLDER ADULTS

·        Loss of coordination

·        Loss of bladder control

·         loss of reasoning skills

·        Memory loss

CAUSES

There are two types of causes for hydrocephalus- i) CONGENITAL ii) ACQUIRED

CONGENITAL

Congenital hydrocephalus is present in the infant prior to birth in the uterus during fetal development. Most common cause of congenital hydrocephalus is AQUEDUCTAL STENOSIS (narrowing of the aqueduct of Sylvius), which occurs when the narrow passage between the 3^rd and 4^th 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 a meningocele or myelomeningocele develop hydrocephalus.

ACQUIRED

This condition hydrocephalus is acquired as a consequence of CNS infection, meningitis, brain tumors, head trauma, toxoplasmosis or intracranial hemorrhage (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 the brain tissue from disease or injury.

iii)               Overproduction- Rarely, CSF is created to move quickly than it can be absorbed.

DIAGNOSIS

Diagnosis of hydrocephalus is usually based on

  ·        A general physical exam

  ·        Neurological exam

  ·        Brain imaging test

NEUROLOGICAL EXAM

Type of neurological exam depends on a person’s age.

Neurologist may conduct a relative simple test to judge muscle condition, movement, wellbeing & Senses function.

BRAIN IMAGING

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:

a.     ULTRASOUND-

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 fontanel spot on the top of the 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 child usually receives mild sedative.

Drawbacks of CT Scanning includes less detailed images than an MRI, and exposure to small amount of radiation.

TREATMENT

There are 2 surgical treatments for hydrocephalus-

SHUNT

Most common treatment for hydrocephalus is the surgical insertion of a drainage tube called shunt between the brain ventricles and abdominal cavity.

The shunt is a flexible narrow tube with a valve that keep 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 tunneled 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 heart.

EXTERNAL VENTRICULAR DRAIN (ETV) OR ENDOSCOPIC THIRD VENTRICULOSTOMY

In ETV  the 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.

Departments that treat this condition is-  NEUROLOGY

                                                                          NEUROSURGERY