Shunt dependency syndrome and acquired Chiari malformation secondary to cerebrospinal fluid diversion procedures: a 9-year longitudinal observation

Background Shunt dependency syndrome is a rare long-term complication of cystoperitoneal (CP) shunting for intracranial arachnoid cysts, which is characterized by acute intracranial hypertension with normal-sized or small ventricles. Additionally, acquired Chiari type I malformations (ACIM) could be infrequently secondary to extrathecal shunt drainage of cerebrospinal fluid. Case report We described a 12-year-old boy who developed shunt dependency syndrome following a CP shunting for treating a temporal arachnoid cyst. To manage this rare complication, we placed a lumboperitoneal (LP) shunt. During the follow-up period, shunt-induced ACIM and concomitant syringomyelia were noted. Conclusion Shunt dependency syndrome is a rare complication secondary to CP shunting in the treatment of temporal arachnoid cysts, and LP shunting is an effective option to relieve the intracranial hypertension. However, the clinicians should be alert to the ACIM as a rare late complication of cerebrospinal fluid diversion procedures, and the potential protecting effect of the programmable valve should be emphasized.