The aim of this study was to objectively evaluate the hypothesis that the neuropsychological presentation of Korsakoff's syndrome, the chronic phase of Wernicke-Korsakoff syndrome (WKS), is invariably a severe, selective amnesia against a background of relatively preserved general intellectual functions in a consecutive clinical sample. An analysis of the neuropsychological profiles of nine cases with a recorded history of WKS was undertaken. All cases were adult males (ages 32 to 70) with a long history of alcohol use disorder. Eight cases were chosen retrospectively on a consecutive basis from patient referrals. One additional case was recruited prospectively. Conventional understanding and some current opinion of Korsakoff's syndrome predicts anterograde memory to be consistently more impaired than other cognitive abilities, but this was not found in this case series. The Mean Wechsler Delayed Memory Index was not significantly different from the Wechsler Full-Scale IQ (FSIQ), p = 0.130. Regression of Delayed Memory on FSIQ produced a non-significant intercept, p = 0.213. The 'hallmark' criterion of anterograde memory score at least 20 points less than intelligence score was observed in four of eight cases with available data, equating to a 'sensitivity' of 50%. Three of eight cases with available data had an FSIQ less than the memory score. Contrary to a common view, general intellectual function was not consistently preserved in Korsakoff's syndrome relative to memory function. This study illustrates one of the specific merits of case series, namely, to critique an established view. Clinicians and researchers should expand their diagnostic criteria for Korsakoff's syndrome to include more variable cognitive phenotypes, including a potentially reversible dementia-like impairment of variable severity, and focus on potential treatment opportunities.
Keywords: Wernicke–Korsakoff syndrome; alcohol-related dementia; alcohol-related disorders; memory disorders; neuropsychology.