Intracranial hypotension as a unique complication of the rupture of an anterior sacral meningocele into a recurrent pilonidal cyst

BACKGROUND: Intracranial hypotension (IH) is an underdiagnosed, but important cause of new-onset, daily persistent headache, especially among the young- and middle-aged population. It results from a cerebrospinal fluid (CSF) leak with subsequent lowered CSF pressure. CASE DESCRIPTION: A 37-year-old female presented to the emergency department with sudden onset severe headaches. Two years earlier, she had undergone surgery for resection of a pilonidal cyst (PC). The night before admission, she had watery discharge from the recurrent PC and severe diffuse positional headaches associated with photophobia and neck pain. The head computed tomography showed pneumocephalus in the posterior fossa and a spine magnetic resonance imaging revealed an anterior sacral meningocele (ASM) in close contact with the recurrent PC. A final diagnosis was made of headaches due to IH. The leakage site was the rupture of the ASM in the PC. The surgical repair of the ASM was achieved suturing two overlapping dural flaps. There was no more CSF leakage from the PC and the headaches disappeared. CONCLUSION: This is a unique case of IH due to the rupture of an ASM into a recurrent PC. The association of an ASM and PC, at the best of our knowledge, is unique. Moreover, the fistulation of the ASM to the PC is exceptional. ASM can be successfully closed with a posterior approach, using two overlapping dural flaps.