Intracranial hypotension-like syndrome after a spinal tap test performed for idiopathic normal pressure hydrocephalus.

It is somewhat unexpected to have headaches in patients with idiopathic normal pressure hydrocephalus (INPH) for which the treatment is drainage of cerebrospinal fluid (CSF) using shunt. Moreover, intracranial hypotension syndrome (IHS) can be a challenging diagnosis, as CSF leak may be difficult to confirm as imaging findings can be normal. This report describes a woman with INPH who developed symptoms of IHS after a spinal tap test. There might be cases with IHS, like our case, who do not completely fulfill the current diagnostic criteria in terms of not having any objective evidence of intracranial hypotension but who also could not be explained by other conditions and recovered totally after classical IHS treatment. Current diagnostic criteria for IHS might be revised for those having normal neuroimaging and not accepting lumbar puncture. Nevertheless, when the history, signs, and symptoms strongly suggest IHS even with normal imaging, treatment should be started immediately.