What is Chiari 2 malformation?
Chiari 1 Cerebellar tonsils protrude through the foramen magnum
Chiari 2 Cerebellum, brain stem and part of the IV ventricle protrude
Chiari 3 The above associated with an encephalocele
Chiari 4 Incompatible with life
Often asymptomatic but may cause headaches with activities which increase the pressure in the brain . The headache is aggravated with coughing or sneezing. 2%-10% are associated with hydrocephalus and may lead to a syrinx (cavity within the spinal cord). Treatment is indicated only if symptomatic or causing a syrinx.
Treatment of a Chiari 1
If treatment is indicated, treatment progresses in a stepwise manner from least to most invasive. Any hydrocephalus is always treated first (with a shunt) followed by a bony foramen magnum decompression and then a cerebellar tonsillectomy if the bony decompression fails. Any syrinx is treated separately only if it fails to resolve with treatment of the Chiari.
This condition is always associated with an open myelomeningocele (see spina bifida). It may present at birth with respiratory and feeding problems – possibly requiring urgent decompression. In early childhood the condition can cause bulbar problems (problems with feeding and drooling)
Treatment of Chiari 2
Surgical treatment remains controversial as the outcome is often so poor but when offered it is usually a cervical laminectomy.