Conversion, dissociative amnesia, and Ganser syndrome in a case of “chameleon” syndrome: Anatomo-functional findings

Abstract

The term “chameleon” was first used in the seventeenth century by Sydenham to describe a patient with a protean semiology. We report a single case of “chameleon” syndrome that challenges the current international criteria for somatoform disorders, dissociative amnesia, and Ganser syndrome. The florid symptoms were as follows: anterograde and retrograde amnesia (including semantic, episodic, and procedural deficits), loss of identity, atypical neuropsychological impairment (approximate answers), left sensitive and motor deficit, and left pseudochoreoathetosis movement disorders. Additional behavioral disorders included the following: anxiety, clouded consciousness, hallucinations, and “belle indifference”. A single photon emission computed tomography examination showed bilateral temporal, frontal and a right caudate (in the head of the caudate nucleus) hypoperfusion concordant with a common mechanism of repression in these disorders.

Keywords:

• Somatoform disorders
• Dissociative disorders
• Dissociative amnesia
• Psychogenic movement disorders
• Ganser syndrome
• SPECT

The authors wish to thank Frances Sheppard of the Clinical Investigation Center of Besançon (CIC Inserm) for correcting and improving the English in the manuscript.

Competing interests: None.

Financial disclosure/conflict: None.

Funding source: None.