Beware of frontal lobe deficits in hippocampal clothing

The Wisconsin card-sorting test (WCST) is a commonly used clinical tool for the detection of frontal lobe dysfunction, specifically executive dysfunction. Patients with lesions outside the frontal lobes sometimes show deficits on the WCST, however, and some researchers have implicated hippocampal dysfunction as the cause of the deficit. But a critical role for the hippocampus seems to be untenable because amnesic patients with bilateral medial temporal lobe (MTL) lesions perform the WCST normally. In the case of epileptic patients, an alternative explanation of the card-sorting impairment is the propagation of abnormal discharges from MTL to frontal lobe structures, causing remote interference with executive circuits.