title: Spontaneous intracranial hypotension: case series of rare clinical presentations.
abstract: BACKGROUND
  Spontaneous intracranial hypotension (SIH) is an increasingly described entity, with over 70 cases reported in the literature. The classic triad includes orthostatic headache, diffuse pachymeningeal enhancement on magnetic resonance imaging (MRI) with gadolinium, and low cerebrospinal fluid pressure (CSF) in the lateral decubitus (< 60 mm H₂O) and sitting positions.
  
  
  METHODS
  We present four rare clinical presentations of SIH, two of which have not been previously described in the literature, to the best of our knowledge.
  
  
  RESULTS
  Patient 1 presented with dyspnea, dysphagia, bilateral ptosis, diplopia and seizures. Patient 2 presented with a paradoxical positional pattern of orthostatic hypotension. In Patient 3, bilateral subdural hematomas (SDH) were encountered; while in Patient 4, a recurrent unilateral SDH requiring multiple surgical interventions was demonstrated.
  
  
  CONCLUSIONS
  Although uncommon clinical presentations, all four cases of intracranial hypotension were spontaneous, demonstrated diagnostic MRI findings, and responded favorably to blood patches or saline injections.
authors.affiliation: Division of Neurosurgery, London Health Sciences Center, London, Ontario, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Chaudhary
authors.forename: P
authors.initials: P
authors.lastname: Cooper
authors.forename: S P
authors.initials: SP
authors.lastname: Lownie
authors.forename: W
authors.initials: W
authors.lastname: Ng
authors.forename: N
authors.initials: N
authors.lastname: Duggal
mesh_terms: D000328:Adult; D006801:Humans; D019585:Intracranial Hypotension / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged