Chiari Decompression

Chiari decompression is a type of craniotomy or surgical operation where a bone flap is temporarily removed to access the brain. This surgical operation is done to create room for herniated cerebellum and entails a shift of the brain across regions due to effects like tumor, trauma, or an infection. Chiari decompression is meant to restore the normal flow of cerebrospinal fluid. Risk factors include strokes, memory loss, balance problems, seizure and even death.

This is a malformation or structural defect of the brain; the organ that controls balance. When the bony space at the lower rear of the skull becomes smaller than normal, the cerebellum can be pushed down leading to pressure, which can block the cerebrospinal fluid.

The cerebrospinal fluid protects the brain and spinal cord. When blocked, symptoms like muscle weakness, dizziness, vision problems and lack of coordination occur. Chiari malformation comes in two forms - Chiari 1 and Chiari 2 malformation - both of which cause brain tissue protrusion to spaces at the back of the skull.

Chiari 1 malformation occurs as a result of developmental abnormality that can affect any child. It affects the lower part of the cerebrum also known as tonsils. Chiari 2 malformation is more specific to children with spina bifida. Spina bifida is a congenital defect that happens to a newborn who has an unprotected spinal cord. Chiari 2 malfunction affects a large amount of brain tissue than Chiari 1 malformation.

Causes of Chiari malformation

Chiari 1 malformation is caused by a mismatch between the rate of growth of the skull and that of the brain. This causes the bottom of the cerebrum to push out the base of the skull into the spinal canal. During fetal development, factors like chemical exposure, infection, insufficient vitamins and nutritive diet, alcohol consumption and illegal drugs can cause this malformation.

Chiari 2 malformation occurs mostly with children who have spina bifida and will require treatment for hydrocephalus. Hydrocephalus is abnormal accumulation of cerebrospinal fluid, which leads to enlargement of the head and in some instances, mental disability.

Signs and symptoms

Chiari 1 symptoms depend on the severity of the condition, which varies considerably. It is only when severe, that symptoms are noted. Symptoms involve: pain in the lower back of the head, swallowing difficulties, dizziness and problems with balance and coordination. Children who experience cough syncope or fainting can lose consciousness for a while due to a simple cough or sneeze.

Chiari 2 symptoms include head pains when you cough, sneeze, do vigorous exercise and even when straining to have bowel movement.


The most effective treatment is through surgery that stops damage to the central nervous system. Depending on the condition, more than one surgery is performed. Although surgery is done, severe conditions can leave a patient with permanent paralysis.

Before surgery, the neurosurgeon will explain about the surgery, its risks, benefits, and one will need to sign a consent form. In addition, one's medical history gets established. Things to avoid prior to the surgery include eating or drinking after midnight, on the eve of the surgery. Other instructions given by the surgeon should also be followed strictly.

It is important to have regular check-ups since Chiari malformations show no symptoms until a later stage and with severe consequences like paralysis.