Abstract
A subset of the diffuse cerebral changes and psychometric deficits found in chronic alcoholics is similar to that seen in the frontal lobe syndrome. Certain features of alcoholic Korsakoff's syndrome (AKS) also point to cortical involvement, and this may have a basis in alcohol neurotoxicity. Twenty-five patients with AKS and 24 non-Korsakoff alcoholic controls were compared using an automated CT brain scan program. In addition to evidence of their diencephalic lesions (wide third ventricles), AKS patients revealed widespread cerebral damage with greater Sylvian and interhemispheric fissure (IHF) size than alcoholics. Korsakoffs were also inferior to alcoholics in performance on a category sorting test, in which non-perseverative error scores correlated significantly with IHF size. The principle of distinguishing between selective memory decline and global intellectual decline (GID) was applied to 38 patients with AKS. Indices were developed for each type of deficit and much variation found in their distributions. The degree of GID correlated significantly with IHF size, showing similar trends with other cortical measures. These results suggest a cortical substrate for the degree of GID and a frontal substrate for category sorting deficits; with a probable basis in alcohol neurotoxicity rather than thiamine deficiency, which is not known to impair cortical structure. A new model is proposed of the pathophysiology of alcoholic brain damage and AKS which includes recent work on neurotransmitter sources and thalamo-frontal connections.
Highlights
The frontal lobes have been at the centre of debate and controversy concerning cognitive processing and the regulation of complex behaviour in humans, brain evolution and the mind--body problem
Several issues are raised, including the relative contributions of alcoholism and thiamine deficiency to alcoholic Korsakoff's syndrome (AKS), and those of cortical disorder and sub-cortical disorder to AKS. These issues are relevant to the confusion surrounding the term alcoholic dementia and its overlap with Korsakoff's syndrome which has been documented on neuropsychological (Cutting, 1978; Jacobson and Lishman, 1987) and neuropathological grounds (Harper, 1983; Torvik et at., 1982)
After out-partialling the National Adult Reading Test (NART) IQ, the two groups do not differ significantly on the block design tests whereas Korsakoffs reveal poor performance on both the category sorting test (CST) and a test of alternating verbal fluency, the number of pairs of alternating birds and colours produced in one minute-thought to be sensitive to frontal lobe function (Newcombe, 1969) (Table 2)
Summary
The frontal lobes have been at the centre of debate and controversy concerning cognitive processing and the regulation of complex behaviour in humans, brain evolution and the mind--body problem. Sir Aubrey Lewis (1952) wrote of "deficiencies of memory and judgement, laziness, indifference, facile euphoria and lability of mood with failure to observe responsibilities, mendacity, gross lack of self-control and general demoralization." In Horvath's (1975) series of 100 deteriorated alcoholics, behavioural abnormalities, apathy, emotional lability, perseveration and lack of insight were common features. Many of these symptoms are present in mild form in the clinically unimpaired alcoholic (Parsons, 1987). In reviewing the neuro-psychological evidence, Tarter and Edwards (1986) concluded that the impairments of alcoholics were very similar to those found in patients with anterior-basal brain lesions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
