Neurological

The unique presentation of a conversion disorder

Recently, the news has highlighted an odd phenomenon plaguing at least 15 teenage girls in a community in upstate New York. The girls began demonstrating spasms, tics and seizures and the condition appeared to be contagious.  After rigorous amounts of diagnostic testing, experts found …. nothing. The conclusion only conclusion that could be made was that these girls were demonstrating what is known as a conversion disorder, or a disorder in which one exhibits physical symptoms without physical cause.  The DSM-IV classifies it as a psychiatric disorder, formerly known as hysteria.

A recent article published in Brain highlighted why this disorder may occur.  The authors of this study conducted a functional magnetic resonance imaging study and compared functional brain connectivity and reaction to fearful, happy and neutral face stimuli.   A post hox anaylsis revealed that:

  • healthy subjects had greater right amygdala activity to fearful vs. neutral stimuli as compared to happy vs. neutral stimuli.   There was no major differences in patients with conversion disorder.
  • individuals with conversion disorder, had greater right amygdala activity to happy stimuli than healthy subjects.  This suggests that there is possible imparied amygdala habituation in individuals with conversion disorders.
  • individuals with conversion disorder had greater functional connectivity between the right amygdala and right supplementary motor area
Overall, the study indicates that psychological or physiological stressors can trigger or exacerbate conversion disorder in some individuals and the disorder appears to be related to an affected amygdala (psychopathy is thought to also to occur due to a similar mechanism).
In another study, examiners performed a systematic review of reported cases of neurological movement disorders to analyze individuals who are suspectible to developing them.  They found that:
  • these occured more frequently in women
  • the most common abnormality was fixed dystonia
  • In 26% of cases, a nerve injury was identified
  • 1/3 were thought to also have CRPS
  • 15% had been diagnosed with a “psychogenic movement disorder” which is more associated with fixed dysotnia and tremor
Another review found that this disorder is often triggered by a history of abuse as well as a personality that is prone to high suggestibility.  The affected individual often demonstrates signs of disorder after a threatening situation.  It is thought that this is an evolutionary trait that made us biologically non-threatening to combatants during warfare (by showing signs of sickness, we posed little threat to them).
Overall, this disorder is unique and should be made as a diagnosis of exclusion.  It can be debilitating, but if recognized, appropriate referral to a psychiatrist is warranted.

Voon V, Brezing C, et al. Emotional stimuli and motor conversion disorder. Brain 2010: 133; 1526-1536.

Rooijen DE, Geraedts, et al. Peripheral trauma and movement disorders: a systematic review of reported cases. J Neurol Neurosurg Psychiatry 2011;82: 892-898.

Brown, RJ, Cardena, E, et al. Should Conversion Disorder Be Reclassified as a Dissociative Disorder in DSM V?. Psychosomatics 2007: 48;  369–378.

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1 reply »

  1. Joe,

    Very interesting, thanks for sharing. I wonder whether the high suggestibility of people with conversion disorders (coupled with the fact they have no “real” source for their symptoms) makes them far more likely to get “miracle” cures from woo based alternative therapies.

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