SPONDYLOLYSIS ASSOCIATED WITH ARNOLD-CHIARI MALFORMATION AND SYRINGOMYELIA - A REPORT OF 2 CASES

Study Design. This is a report of two cases. Objective. To document th e occurrence and association of spondylolysis and Arnold-Chiari malfor mation Type I. Summary of Background Data. The association of spinal d ysraphism has been reported with Arnold-Chiari Type II, but not with A rnold-Chiari Type I. Methods. The senior author was involved in the ca re of these patients. All medical records, laboratory and radiologic i nvestigations, and related literature were reviewed. Results. The pres ence 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 patien ts, the presence of spondylolysis may represent a congenital anomaly a nd may be associated with cephalic neuropore maldevelopment, such as c erebromedullary malformation syndrome (i.e., Arnold-Chiari malformatio n Type I).