Arnold-Chiari malformation type I

Definition

A condition caused by failure of the cerebellum to correctly develop during the antenatal period. This condition is characterised by extension of the cerebellar tonsils into the foramen magnum, without involving the brain stem. This condition may present as asymptomatic. Confirmation is through observation of the cerebellar tonsil extension by imaging.

Exclusions

• Arnold-Chiari malformation type II (LA03)

Also indexed as

Nearby in Structural developmental anomalies of the neurenteric canal, spinal cord or vertebral column

• LA07.0Primary tethered cord syndrome
• LA07.1Diastematomyelia
• LA07.2Amyelia
• LA07.3Primary syringomyelia or hydromyelia
• 4B4YOther specified diseases of the immune system
• 4B4ZDiseases of the immune system, unspecified