Neuropsychology and neuroimaging of alcohol dependence

Responsible : Hélène Beaunieux, Anne-Lise Pitel and François Vabret

Chronic alcohol consumption results in neuropsychological deficits and brain abnormalities, ranging from mild-to-moderate cognitive disorders in alcohol-dependent patients without neurological complications (AL) to severe disturbances in patients with Korsakoff’s syndrome (KS). The main aim of our studies on alcoholism is to gain a better knowledge of the harmful effects of chronic alcohol consumption on the brain and cognition.

In a previous research program launched in 2007 (KORSAKOL), we conducted an extensive neuropsychological assessment of AL patients, combined with morphological brain examinations. Our data highlighted a metamemory deficit in AL patients (Le Berre AP, Pinon K, Vabret F, Pitel AL, Allain P, Eustache F, Beaunieux H (2010). Study of metamemory in patients with chronic alcoholism using a feeling-of-knowing episodic memory task. Alcohol Clin Exp Res 34:1888-98.), with a tendency to overestimate memory abilities. AL also exhibited decision-making impairments, which correlated with brain regions involved in cognitive and emotional processes (Le Berre et al., submitted). We examined the contribution of those cognitive functions to the motivation process to stop drinking and found that a set of complementary cognitive abilities seemed to be needed to achieve awareness and resolve ambivalence towards alcohol addiction (Le Berre AP, Vabret F, Cauvin C, Pinon K, Allain P, Pitel AL, Eustache F, Beaunieux H. Cognitive Barriers to Readiness to Change in Alcohol-Dependent Patients. Alcohol Clin Exp Res. 2012 Mar 28. doi: 10.1111/j.1530-0277.2012.01760.x.). Further analyses revealed that the little motivation to modify inappropriate drinking behavior observed in some alcohol-dependent patients at treatment entry could be related to macrostructural brain abnormalities in regions involved in cognitive, emotional and social abilities. These regional volume deficits may prevent some patients to resolve their ambivalence and to apply ‘processes of change’, which are yet essential to move towards a healthier lifestyle according to The Transtheoretical Model (Le Berre et al., submitted). Finally, comparison of gray matter damage in KS and UA showed graded effects of volume deficits in the thalami, mammillary bodies and left insula, those brain regions being damaged in both patient groups, but more severely in KS than in UA (Figure 1; A.L. Pitel, G. Chetelat, A.P. Le Berre, B. Desgranges, F. Eustache, H. Beaunieux. (2012). Macrostructural abnormalities in Korsakoff’s syndrome compared to uncomplicated alcoholism. Neurology, 78(17):1330-3).

 

Figure 1 : Gray matter regions more severely damaged in KS than in AL.

A new research program (ALCOBRAIN) is currently conducted in the laboratory (2011-2015). This ambitious research project includes neuropsychological and multimodal neuroimaging (structural, metabolic, functional) examinations of patients with AL and KS. ALCOBRAIN aims at (1) specifying the physiopathological processes resulting in alcohol-related brain abnormalities and neuropsychological disorders, (2) identifying the factors explaining the heterogeneity of alcohol-related brain abnormalities and neuropsychological disorders, (3) investigating the neural substrates of ToM deficits in AL patients, and (4) examining the brain mechanisms underlying neuropsychological recovery in AL with abstinence.

From a more clinical perspective, ALCOBRAIN will also enable us to develop and implement a new tool (BEARNI for brief Evaluation of Alcohol Related Neuropsychological Impairment) especially designed to conduct a rapid assessment of the alcoholism-related neuropsychological deficits present at alcohol treatment entry. This tool, usable by non-psychologists, will be brief, sensitive and specific to neuropsychological deficits exhibited by alcoholics. It will allow the physicians or nurses to determine, immediately following withdrawal, whether the patient can attend and gain from a standard alcohol treatment or whether some adjustments or a recovery period are required.

Collaborations : Edith Sullivan and Adolf Pfefferbaum, University of Stanford and SRI International, United States