Spondylolysis associated with Arnold-Chiari malformation and syringomyelia. A report of two cases.

STUDY DESIGN

This is a report of two cases.

OBJECTIVE

To document the occurrence and association of spondylolysis and Arnold-Chiari malformation Type I.

SUMMARY OF BACKGROUND DATA

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).