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

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.