MRI CHANGES IN INTRACRANIAL HYPOTENSION

We report seven patients with the syndrome of intracranial hypotension who were referred to Memorial Sloan-Kettering, primarily because of s uspicion of meningeal tumor or infection raised by the finding of meni ngeal enhancement on MRI. In three patients, symptoms occurred after l umbar puncture; in four, there was no clear precipitating event. Lumba r puncture after MRI in six patients revealed low CSF pressure (six pa tients) and pleocytosis or high protein, or both (four patients). Thre e patients had subdural effusions. Six patients had measurable descent of the brain on midsagittal images. Postural headache resolved in all seven patients, six of whom had follow-up MRIs. Meningeal enhancement resolved or diminished in all six. Subdural effusions resolved sponta neously in two and were evacuated (but were not under pressure) in one . Downward brain displacement improved or resolved in all patients. Th e clinical syndrome and MRI abnormalities generally resolve on their o wn. An extensive workup is not helpful and may be misleading. Patients should be treated symptomatically.