Chiari malformations are structural defects in the base of the skull and cerebellum, the part of the brain that controls balance. It occurs when part of the skull is misshapen or too small, pressing on the brain and forcing it downward.
Some individuals with chiari malformations may not experience any symptoms. For others, symptoms may include:
Structural defects often cause chiari malformations in the brain and spinal cord during foetal development. This is called primary or congenital chiari malformation. The condition can also be caused later in life if spinal fluid is drained excessively from the lumbar or thoracic areas of the spine, either due to traumatic injury, disease, or infection. This is referred to as acquired or secondary chiari malformation.
Many people with chiari malformations experience no symptoms. Their malformations are discovered only during diagnosis or treatment for another disorder. Dr Shiva will perform a physical exam and check the person’s cognition, balance (functions controlled by the cerebellum), touch, reflexes, sensation, and motor skills (functions controlled by the spinal cord). Dr Shiva may order imaging tests to diagnose a chiari malformation or show hydrocephalus or bone abnormalities that might be associated with the disorder.
Chiari malformations that do not show symptoms and do not interfere with a person’s daily activities may only need regular monitoring by a neurosurgeon. Medications may be prescribed to ease headaches and pain.
In many cases, surgery is the only treatment available to ease symptoms or slow the progression of damage to the central nervous system. Surgery can improve or stabilise symptoms in most individuals. Patients may need more than one surgery to treat the condition. The most common surgery to treat chiari malformation is posterior fossa decompression, which creates more space for the cerebellum. It also relieves pressure on the spinal cord and helps to restore the normal flow of cerebrospinal fluid. It involves making an incision at the back of the head and removing a small portion of the bone at the bottom of the skull (craniectomy).