NEURAL BASIS OF CONFABULATION

We present a case of acute alcohol-induced Korsakoff amnesia. A severe amnestic-confabulatory syndrome characterized the early clinical stat us. The initial neuropsychological tests demonstrated severe learning deficits plus impaired performance on many, but not all, tests of fron tal lobe function. Single-photon emission CT (SPECT) at this stage sho wed hypoperfusion in the orbital and medial frontal regions and the me dial diencephalic area. Four months later, the patient's amnesia remai ned but there was no confabulation. Repeat neuropsychological tests co nfirmed an ongoing severe amnesia, but performance on the frontal lobe tests now was normal. Repeat SPECT showed a return to normal perfusio n in the frontal brain areas but little improvement in the medial dien cephalic region. These findings along with data from the clinical lite rature suggest that confabulation results from dysfunction of orbital and a medial frontal cortex.