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Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
10:59

Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury

Published on: November 19, 2012

Mutism and amnesia following high-voltage electrical injury: psychogenic symptomatology triggered by organic

Nishant K Mishra1, Heike Russmann, Cristina Granziera

  • 1Department of Neurology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland. nishmishra@gmail.com

European Neurology
|September 29, 2011
PubMed
Abstract

Insights

A patient experienced mutism and amnesia after an electric shock, showing transient organic brain impairment. Subsequent mild head trauma resolved mutism but not amnesia, suggesting combined organic and dissociative mechanisms.

Area of Science:

  • Neuroscience
  • Psychiatry
  • Neurology

Background:

  • Mutism and retrograde amnesia can stem from organic or dissociative causes, potentially influenced by right prefrontal activity.
  • A patient (M.R.) developed left hemiparesis, mutism, and retrograde amnesia post-electric shock, with no lasting brain lesions.
  • Dissociative symptoms may be modulated by right prefrontal cortex activity.

Observation:

  • M.R. experienced transient right brain impairment indicated by left hemiparesis, resolving within 90 days.
  • Neuropsychological assessments one year later suggested a dissociative component to the persistent mutism and retrograde amnesia.
  • Extensive investigations including MRI, fMRI, and EEG revealed no abnormalities.

Findings:

  • A subsequent mild head injury 27 months post-injury led to rapid speech recovery (resolution of mutism).
  • Despite speech recovery, the retrograde amnesia remained a persistent symptom.
  • The patient's recovery pattern highlights a dissociation in the time course of different symptoms.

Implications:

  • This case underscores the complex interplay between organic and dissociative mechanisms in neurological and psychiatric conditions.
  • It demonstrates how distinct dissociative symptoms can manifest and resolve independently over time.
  • Understanding these interactions is crucial for accurate diagnosis and treatment of complex amnesic and speech disorders.

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