Pearls & Oy-sters: Spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome.

A 65-year-old woman with no significant medical history was brought to the emergency room after experiencing 2 weeks of band-like occipital headaches and 2 days of progressive mental status changes. Her neurologic examination was significant for decreased alertness, disorientation to time, confabulation, loss of recent and remote memory, diffuse hyperreflexia, and a left Hoffmann sign. MRI of the brain with contrast showed bilateral subdural hygromas, diffuse enhancement of the dura mater, with mild sagging of the brainstem suggestive of intracranial hypotension (figure 1, A and B). MRI of the spine showed a large collection of CSF in the lumbar epidural space (figure 2A); however, the tear site was not identified. EEG also revealed generalized slowing with no evidence of seizure activity. Her mental status continued to deteriorate despite conservative measures such as aggressive hydration, caffeine intake, and bedrest in the Trendelenburg position. A head CT was ordered for worsening mental status and revealed symmetric hypoattenuation of the bilateral parasagittal occipital cortices consistent with PRES (figure 2B), a finding that was not present on the initial MRI. She then received an emergent lumbar epidural blood patch, resulting in dramatic improvement in mental status several hours later. She was discharged without any focal neurologic deficits. An MRI performed 10 days later revealed no evidence of PRES in the occipital region. An MRI of the lumbar spine performed 5 weeks later showed resolution of the fluid collection (figure 3).