Ganser symptoms in a case of frontal-temporal lobe dementia: is there a common neural substrate?

Neuropsychological testing was completed in a patient who showed cognitive decline of mental functions, unusual answers to questions, and other characteristics of what has typically been described in the literature as the "Ganser Syndrome." Clear evidence of malingering on a memory test seemed to confirm that this patient was exaggerating deficits for psychiatric reasons or secondary gain, yet the patient showed evidence of mild organic impairment on MRI and continued to deteriorate in cognitive functions and basic self-care. Although an initial SPECT scan had suggested a pattern inconsistent with dementia, a second scan showed frontal-temporal perfusion deficits. Based on this scan and the clinical picture of progressive deterioration, a diagnosis of frontal-temporal lobe dementia was made. This case illustrates that the seemingly deliberate selection of incorrect responses may occur in the early stages of an organic dementia, and that a diagnosis of frontal-temporal lobe dementia should be considered in cases where symptoms appear to be psychiatric or nonorganic. The case further raises the question of whether the reported symptoms of Ganser Syndrome may be accounted for by frontal-temporal lobe dysfunction, since there appears to be some overlap between symptoms of Ganser Syndrome and frontal-temporal lobe dementia. It is also important to note that many reported cases of Ganser Syndrome had a history of head injury.