title: Reversible coma: a rare presentation of spontaneous intracranial hypotension.
abstract: BACKGROUND
  Spontaneous intracranial hypotension (SIH) is a well-recognized neurologic disorder that typically presents with orthostatic headaches, low cerebral spinal fluid pressures and distinct abnormalities on magnetic resonance imaging.
  
  
  METHODS
  We present a case of a rare presentation of SIH.
  
  
  RESULTS
  A 49-year-old man presented with a two week history of orthostatic headaches that rapidly progressed to encephalopathy and coma, requiring intubation. Neuroimaging revealed abnormalities typical of SIH; diffusely enhancing pachymeninges, subdural fluid collections, and descent of the brain. Treatment with an epidural blood patch reversed his coma within minutes. Following a second blood patch, the patient became asymptomatic. No cerebral spinal leak could be identified on magnetic resonance imaging or on a nuclear medicine technetium cerebral spinal fluid flow study. At six month follow-up, he remained symptom free.
  
  
  CONCLUSIONS
  The mechanism of coma in SIH is presumed to be compression of the diencephalon from downward displacement of the brain. Although it is very unusual for patients with SIH to present with coma, it is important to recognize since the coma may be reversible with epidural blood patches.
authors.affiliation: Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Kashmere
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Jacka
authors.forename: Derek
authors.initials: D
authors.lastname: Emery
authors.forename: Donald W
authors.initials: DW
authors.lastname: Gross
mesh_terms: D017217:Blood Patch, Epidural; D001930:Brain Injuries / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D015170:Cerebrospinal Fluid Pressure; D003128:Coma / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D006261:Headache / Q000209:etiology* / Q000628:therapy; D006408:Hematoma, Subdural / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D006801:Humans; D019585:Intracranial Hypotension / Q000150:complications* / Q000175:diagnosis* / Q000628:therapy; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011187:Posture; D016896:Treatment Outcome