title: Hyperekplexia in a patient with a brainstem vascular anomaly.
abstract: OBJECTIVE
  To describe a patient with a clinical picture suggestive of idiopathic hyperekplexia (IH), who was later found to harbour a subtle brainstem vascular anomaly.
  
  
  METHODS
  A 35-year-old man, 4 years earlier, developed sudden jumping and falling in response to unexpected sensory stimuli.
  
  
  RESULTS
  Neurological examination was normal. Electromyography showed an excessively large and non-habituating motor startle response. There were no mutations of the alpha1 subunit of the inhibitory glycine receptor which cause hereditary hyperekplexia. Although all these findings were consistent with a diagnosis of IH, a blink reflex study showed an enhanced recovery curve suggestive of a brainstem lesion. A detailed MRI study revealed a subtle vascular anomaly involving the lower brainstem.
  
  
  CONCLUSIONS
  This is the first report of sporadic hyperekplexia related to a brainstem vascular anomaly. Subtle damage to the brainstem should always be excluded in patients with sporadic hyperekplexia, regardless of the coexistence of additional clear-cut neurological symptoms.
authors.affiliation: Institute of Neurology, School of Medicine, University of Catanzaro, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gambardella
authors.forename: P
authors.initials: P
authors.lastname: Valentino
authors.forename: G
authors.initials: G
authors.lastname: Annesi
authors.forename: R L
authors.initials: RL
authors.lastname: Oliveri
authors.forename: F
authors.initials: F
authors.lastname: Bono
authors.forename: R L
authors.initials: RL
authors.lastname: Mazzei
authors.forename: F L
authors.initials: FL
authors.lastname: Conforti
authors.forename: U
authors.initials: U
authors.lastname: Aguglia
authors.forename: M
authors.initials: M
authors.lastname: Zappia
authors.forename: K
authors.initials: K
authors.lastname: Pardatscher
authors.forename: A
authors.initials: A
authors.lastname: Quattrone
mesh_terms: D000328:Adult; D001767:Blinking / Q000235:genetics / Q000502:physiology; D001933:Brain Stem / Q000098:blood supply*; D002536:Cerebral Arteries / Q000002:abnormalities*; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis* / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D012890:Sleep / Q000502:physiology; D014851:Wakefulness / Q000502:physiology