Coma from severe spontaneous intracranial hypotension due to a CSF–venous fistula

Spontaneous intracranial hypotension (SIH) is a debilitating condition characterised by orthostatic symptoms resulting from cerebrospinal fluid (CSF) depletion. It is caused by leakage at the spinal level, causing gravitationally dependent downward displacement of intracranial structures. Rarely, severe brain sagging due to SIH can compromise brainstem function to the point of coma and even death. Effective management of such patients requires awareness about SIH as a possible cause of coma and multidisciplinary collaboration between neurocritical care, neurosurgical and neurointerventional services. The management aims to optimise supportive medical management, with early implementation of emergency treatment by placing the patient in a head-down position, and rapid detection and treatment of the CSF leak. We present a rare case of severe SIH resulting in coma from a spinal CSF-venous fistula and review the status of knowledge on this clinical scenario, emphasising current diagnostic techniques, multidisciplinary management and curative interventions.