title: Mutism and amnesia following high-voltage electrical injury: psychogenic symptomatology triggered by organic dysfunction?
abstract: BACKGROUND
  Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later.
  
  
  METHODS
  M.R.'s neuropsychological pattern and anatomoclinical correlations were studied through (i) language and memory assessment to characterize his deficits, (ii) functional neuroimaging during a standard language paradigm, and (iii) assessment of frontal and left insular connectivity through diffusion tractography imaging and transcranial magnetic stimulation. A control evaluation was repeated after recovery.
  
  
  RESULTS
  M.R. recovered from the left hemiparesis within 90 days of the accident, which indicated a transient right brain impairment. One year later, neurobehavioral, language and memory evaluations strongly suggested a dissociative component in the mutism and retrograde amnesia. Investigations (including MRI, fMRI, diffusion tensor imaging, EEG and r-TMS) were normal. Twenty-seven months after the electrical injury, M.R. had a very mild head injury which was followed by a rapid recovery of speech. However, the retrograde amnesia persisted.
  
  
  CONCLUSIONS
  This case indicates an interaction of both organic and dissociative mechanisms in order to explain the patient's symptoms. The study also illustrates dissociation in the time course of the two different dissociative symptoms in the same patient.
authors.affiliation: Department of Neurology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland. nishmishra@gmail.com
authors.forename: Nishant K
authors.initials: NK
authors.lastname: Mishra
authors.forename: Heike
authors.initials: H
authors.lastname: Russmann
authors.forename: Cristina
authors.initials: C
authors.lastname: Granziera
authors.forename: Philippe
authors.initials: P
authors.lastname: Maeder
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Annoni
mesh_terms: D000328:Adult; D000647:Amnesia / Q000175:diagnosis / Q000209:etiology*; D001921:Brain / Q000098:blood supply; D004556:Electric Injuries / Q000150:complications*; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009155:Mutism / Q000175:diagnosis / Q000209:etiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood
chemical_list: D010100:Oxygen