title: Spondylolysis associated with Arnold-Chiari malformation and syringomyelia. A report of two cases.
abstract: METHODS
  This is a report of two cases.
  
  
  OBJECTIVE
  To document the occurrence and association of spondylolysis and Arnold-Chiari malformation Type I.
  
  
  BACKGROUND
  The association of spinal dysraphism has been reported with Arnold-Chiari Type II, but not with Arnold-Chiari Type I.
  
  
  METHODS
  The senior author was involved in the care of these patients. All medical records, laboratory and radiologic investigations, and related literature were reviewed.
  
  
  RESULTS
  The presence of cephalic and caudal neuropore maldevelopment may be present in various combinations. The presence of spondylolysis, with or without spina bifida occulta, associated with Arnold-Chiari malformation type I and syringohydromyelia, is demonstrated.
  
  
  CONCLUSIONS
  In some patients, the presence of spondylolysis may represent a congenital anomaly and may be associated with cephalic neuropore maldevelopment, such as cerebromedullary malformation syndrome (i.e., Arnold-Chiari malformation Type I).
authors.affiliation: Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Bowen
authors.forename: G A
authors.initials: GA
authors.lastname: Malanga
mesh_terms: D000293:Adolescent; D019412:Anatomy, Cross-Sectional; D001139:Arnold-Chiari Malformation / Q000150:complications* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013131:Spine / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D013169:Spondylolysis / Q000150:complications* / Q000209:etiology / Q000473:pathology; D013595:Syringomyelia / Q000150:complications* / Q000473:pathology; D014057:Tomography, X-Ray Computed