To report a case of reversible cerebral vasoconstriction syndrome (RCVS) associated with subarachnoid hemorrhage (SAH) that happened due to sudden decreased in intracranial pressure during lumbar puncture (LP) procedure for idiopathic intracranial hypertension (IIH).

RCVS has been associated with various risk factors with different pathophysiologies but no clear causality. Multiple mechanisms have been described before but none of them were directly related to the rapid changes in intracranial pressure. Per our literature review this is the first case in which SAH in the setting of RCVS happened during an LP procedure for IIH.

39-year-old man with history of marijuana use, hypertension, migraine headache, asthma, and recent decongestant use presented with worsening headache and blurry vision. Physical examination was suggestive of bilateral hemorrhagic optic disk edema. Magnetic resonance imaging and venography (MRI/MRV) were normal except for partially empty sella. LP was done which revealed opening pressure of 35 and unremarkable studies. During the LP, patient experienced the worst headache of his life that was followed by frequent brain zaps that were worse in the upright position. A blood patch procedure was done but it did not help the pain. CT head showed left frontal SAH. CT angiography showed multifocal areas of irregular vessel narrowing involving the anterior and posterior circulations suggestive of RCVS. Digital subtraction angiography (DSA) revealed similar findings that responded to verapamil injection with marked improvement in pain in the next day. We suspect that RCVS here was due to sudden decrease in intracranial pressure during LP in the setting of chronic use of marijuana, ibuprofen, acetaminophen, and decongestant.