Hydrocephalus (腦水腫)

其實腦水腫並唔係太多 "水"係個腦到, 宜係由腦脊液既不平衡所造成, 甘究竟咩係腦水腫呢?

禁"閱讀更多" 啦

What is Hydrocephalus?

Hydrocephalus is a condition in which the flow of the cerobrospinal fluid (CSF) (腦脊液) in the Central Nervous System (CNS) (中樞神經系統) is interrupted or blocked. CSF is the liquid that circulates between the layers of tissue that cover the brain, within the four ventricles of the brain, and around the spinal cord(脊髓) . In normal circumstances, the CSF moves within the ventricles in the brain, exits through closed spaces at the base of the brain, flows over the surface of the brain and spinal cord, and is then reabsorbed into the bloodstream. Hydrocephalus develops when there is an imbalance between the production of CSF and its reabsorption or when its flow is blocked.

The cerebrospinal fluid builds up inside the brain, putting pressure on the tissues of the central nervous system and causing symptoms ranging from visual disturbances and headache to mental disturbances and difficulty walking.

Categories of Hydrocephalus

• Congenital (先天性). This type of hydrocephalus is present at birth and may be caused by genetic disorders or problems that occur during the baby’s development before birth.

• Acquired (後天性). Acquired hydrocephalus develops later in life as the result of brain tumors, head injuries, infections of the brain, or other brain disorders.

• Noncommunicating or obstructive(非交通性腦積水). In this type of hydrocephalus, the CSF cannot flow freely among the ventricles inside the brain.

• Communicating(交通性腦積水). This type of hydrocephalus is one in which the CSF can flow between the ventricles of the brain but is blocked from leaving the brain.

          - Normal pressure hydrocephalus (NPH).This is a form of communicating hydrocephalus most                                                                   commonly found in the elderly. It is a condition in which CSF builds up within the ventricles of the brain.

An MRI scan(磁力共振掃描) of a brain with Normal Pressure Hydrocephalus (NPH)  (left) and a normal MRI scan (right). The large dark area on the left is the ventricles, made bigger by a build-up of CSF.

Symptoms

• Infants: Enlargement of the skull;  veins (靜脈) in the scalp (頭皮) are enlarged; baby feeds poorly, vomits, has seizures (癲癇) , sleeps a great deal, or has eyes that look downward much of the time (“sunsetting”).

Infants with "sunset eye".

• Children: Headache; nausea (反胃) ; vomiting; fever; blurred (模糊) or double vision; unstable balance; irritability (情緒化); sleepiness (嗜睡); delayed progress in walking or talking; poor coordination; change in personality; difficulty staying awake or waking from sleep.

• Adults: Headache; constant drowsiness (嗜睡); loss of ability to think clearly or concentrate; difficulty walking; personality changes and loss of social skills. Job performance is often affected.

• Elderly adults: Loss of coordination or balance; shuffling gait (步履不穩) , memory loss; headache; or bladder control problems.

Treatment

• The surgical insertion of a shunt system (分流系統)

A shunt is a flexible plastic tube that carries

extra CSF away from the brain. The shunt system consists of the shunt 

itself, a valve (

瓣膜

) that keeps the CSF flowing in the correct direction, and a 

long thin tube called a catheter (導管). The shunt is inserted into one of the 

brain’s ventricles. The catheter and valve are attached to it, and 

the catheter tubing is threaded (紉) underneath the skin to another part of the 

body (usually the heart or the abdomen) where the excess CSF can be 

absorbed. The shunt system needs periodic replacement in children as 

they grow or in adults if the tubing becomes blocked or infected.

Diagram of Shunt System

• Surgery on the third of the brain’s four ventricles (For noncommunicating hydrocephalus)

In this procedure, 

the surgeon uses a miniature camera (微型攝像頭) and instrument to locate the third

ventricle and cut a small hole in its floor. This hole allows the CSF to

bypass the blockage between the ventricles and flow toward its normal 

outlet from the brain.

Location of the Third Ventricles