Secondary nocturnal enuresis caused by central sleep apnea from Chiari malformation type 1

Objective: To report a novel cause of nocturnal enuresis (NE) and highlight the literature giving insight into this novel mechanism. Patient: A 12-year-old morbidly obese female with 2-year history of nightly secondary monosymptomatic NE. Results: On evaluation, a history of severe sleep disturbed breathing was elicited. Anticipating obstructive sleep apnea (OSA), polysomnography was performed, detecting severe central sleep apnea (CSA) without OSA. Brain magnetic resonance imaging revealed severe Chiari malformation Type I (CM1) with abnormal cerebrospinal fluid dynamics. She had no other classic signs or symptoms of CM1. Neurosurgical decompression halted the NE and normalized nocturnal breathing and cerebrospinal fluid dynamics, confirming that the CSA was caused by the CM1 and resulted in the NE. A thorough literature review found no prior reports of CSA-induced NE. Since CSA and OSA differ by the absence of negative intrathoracic pressures in CSA, this case suggests that such pressures are not a key mechanistic component of SA-induced NE. Conclusion: This first report of secondary NE caused by CSA from CM1 emphasizes obtaining a sleep history in the enuretic child, introduces a new cause of NE, and challenges hypotheses underlying SA-induced NE.