Chiari Malformation

Snapshot

• An infant boy presents with trouble swallowing, bilateral arm and leg weakness, and stridor. The infant was born to a 28-year-old woman who did not seek prenatal care. On physical exam, the infant barely moves his arms and legs and has stridor. A meningomyelocele is appreciated in the lumbosacral area. Magnetic resonance imaging of the head shows downward displacement of the cerebellar vermis and tonsils through the foramen magnum. (Chiari II malformation)

Introduction

• Clinical definition
  • Chiari malformations describes a
    • heterogenous group of neurological anatomic anomalies involving the
      • cerebellum, brainstem, and craniocervical junction along with
        • the cerebellum being downwardly displaced
• Epidemiology
  • incidence
    • Chiari malformation type I is
      • the most common type
• Pathogenesis
  • unclear
• Associated conditions
  • meningomyelocele 
  • spinal cavitations
  • Robin sequence
  • neurofibromatosis type I
  • Noonan syndrome