Misdiagnosis of spontaneous intracranial hypotension

Background: Spontaneous intracranial hypotension is an important cause of "new daily persistent headaches" but is not a well-recognized entity. The misdiagnosis of spontaneous intracranial hypotension can have serious consequences. Methods: The clinical course in 18 consecutive patients with spontaneous intracranial hypotension who were evaluated for definitive surgical treatment of the underlying spontaneous spinal cerebrospinal fluid leak from January 1, 2001, through June 30, 2002, was investigated by correspondence with the patients and physicians. Results: Seventeen patients (94%) initially received an incorrect diagnosis, and the diagnostic delay ranged from 4 days to 13 years (median, 5 weeks; mean, 13 months). Migraine, meningitis, and psychogenic disorder were the most commonly entertained diagnoses. Diagnostic or therapeutic procedures for disorders that mimicked spontaneous intracranial hypotension included cerebral arteriography in 2 patients, craniotomies for Chiari malformation in 2 patients, craniotomy for evacuation of subdural hematomas in I patient, and brain biopsy in I patient. Conclusions: Patients with spontaneous intracranial hypotension are commonly misdiagnosed, causing a significant delay in the initiation of effective treatments and exposing patients to the risks associated with treatment for disorders that mimic intracranial hypotension. Increasing the awareness of this spontaneous type of intracranial hypotension is required to decrease the high rate of misdiagnosis.