Profiles of impaired, spared, and recovered neuropsychologic processes in alcoholism

Abstract

Long-term chronic alcoholism is associated with disparate and widespread residual consequences for brain functioning and behavior, and alcoholics suffer a variety of cognitive deficiencies and emotional abnormalities. Alcoholism has heterogeneous origins and outcomes, depending upon factors such as family history, age, gender, and mental or physical health. Consequently, the neuropsychologic profiles associated with alcoholism are not uniform among individuals. Moreover, within and across research studies, variability among subjects is substantial and contributes to characteristics associated with differential treatment outcomes after detoxification. In order to refine our understanding of alcoholism-related impaired, spared, and recovered abilities, we focus on five specific functional domains: (1) memory; (2) executive functions; (3) emotion and psychosocial skills; (4) visuospatial cognition; and (5) psychomotor abilities. Although the entire brain might be vulnerable in uncomplicated alcoholism, the brain systems that are considered to be most at risk are the frontocerebellar and mesocorticolimbic circuitries. Over time, with abstinence from alcohol, the brain appears to become reorganized to provide compensation for structural and behavioral deficits. By relying on a combination of clinical and scientific approaches, future research will help to refine the compensatory roles of healthy brain systems, the degree to which abstinence and treatment facilitate the reversal of brain atrophy and dysfunction, and the importance of individual differences to outcome.

Keywords: MRI; alcoholism; brain; frontocerebellar system; impairments; mesocorticolimbic circuitry; neuropsychology; recovery.

Figure 1

Severe brain atrophy in a 72-year-old alcoholic woman (top row) compared to an age-matched nonalcoholic control woman (bottom row). Most prominent indications of alcoholism-related brain damage include enlarged ventricles, thinning of the corpus callosum, and hippocampal atrophy.

Figure 2

The frontocerebellar system (Cisek and Kalaska, 2010). This figure illustrates interactions among cortical areas, basal ganglia, and the cerebellum. Reproduced with permission of Annual Reviews.

Figure 3

The mesocorticolimbic circuitry (Salloway et al., 2001). This figure highlights the following structures: orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), anterior cingulate (AC), amygdala (AMG), hippocampus (Hipp), thalamus (Thal), ventral striatum (VS), dorsal striatum (DS), and globus pallidus (GP). Adapted with permission from The Frontal Lobes and Neuropsychiatric Illness (Copyright 2001), American Psychiatric Association.

Figure 4

Forms of human memory. Memories are stored for time periods ranging from milliseconds to years. Working memory, a component of executive functions, also is discussed in the section on executive functions. Long-term memory is divided into declarative (explicit) memory and procedural (implicit) memory. Declarative memory can be further subdivided into episodic memory (memory for our experiences) and semantic memory (for facts). Procedural memory is memory of skills and knowing how to do things.