Chiari Malformation

Chiari malformations are structural abnormalities of the cerebellum, typically characterized by downward herniation of the cerebellar tonsils through the foramen magnum. Clinical manifestations include headache, neck pain, vertigo, ataxia, dysphagia, and, in severe cases, hydrocephalus or syringomyelia. Etiology is congenital, though acquired forms can result from spinal CSF leakage or trauma. Diagnosis is made with MRI demonstrating cerebellar tonsillar herniation and associated abnormalities. Management ranges from conservative observation to posterior fossa decompression surgery; prognosis is variable depending on severity and surgical response.