Chiari Malformation
What is Chiari Malformation?
Chiari Malformation is a condition in which the lowest part of the brain called the cerebellum, extends into your spinal canal. This occurs when part of your skull is abnormally small or misshapen. This results in crowding at the base of skull which causes pressure on the brainstem and obstructs the flow of cerebrospinal fluid (CSF).
Chiari malformation is categorized into 4 types:
- Type 1 Chiari malformation is the most common type that develops when the skull and brain are still growing. As a result, symptoms may not appear until late childhood or adulthood.
- Type II, III and IV are paediatric forms and are present at birth.
Advanced forms of Chiari Type 1 malformations are associated with syringomyelia which is where there is accumulation of CSF within the spinal cord that causes pressure and dysfunction.
Most importantly, a true Chiari malformation needs to be differentiated from low lying cerebellar tonsils, which is an insignificant anatomical variant. This is commonly reported on MRIs.
What are the Causes of Chiari Malformation?
Chiari malformation that occurs during the foetal stages is also referred to as primary or congenital Chiari malformation.
It may also occur later in life if there is intracranial hypertension or spinal fluid is drained out from the lumbar or thoracic areas of the spine either due to injury. This is referred to as acquired or secondary Chiari malformation.
What are the Symptoms of a Chiari Malformation?
If symptoms do appear it varies among individuals and may include:
- Headache, which is the hallmark sign of Chiari malformation, and occurs especially after sudden coughing, straining or sneezing
- Neck pain
- Balance problems
- Limb weakness
- Numbness or pins and needles in limbs
- Dizziness
- Swallowing problems
- Ringing or buzzing in the ears (tinnitus)
How is Chiari Malformation Diagnosed?
A Chiari malformation is diagnosed with a thorough review of your symptoms, medical history, and a physical examination. In addition, you may need to undergo the following tests:
- MRI scan
- CT scan
What is the Treatment for Chiari Malformation?
The choice of treatment depends on the type and severity of the condition and if you have any symptoms
Medications to control headaches and other related symptoms such as neck pain may be recommended.
Your doctor may recommend surgery if you have headaches typical for Chiari or if you have syringomyelia.
Surgery is aimed at creating space at the base of the skull so as to eliminate pressure and enable circulation of CSF.
