| Patterns of cognitive impairment, such as in executive function or memory, may vary across patient groups with damage to grossly similar brain areas. Experiment I compared patterns of frontal-lobe dysfunction in alcoholics with Korsakoff's syndrome (KS: N = 9), non-Korsakoff alcoholics (AC: N = 28), patients with Parkinson's disease (PD: N = 18), and patients with rupture of the anterior communicating artery (ACoA: N = 4) relative to healthy participants (N = 70). Perseverative errors on the Wisconsin Card Sorting Test (WCST-pe) and errors on object alternation (OA) measured orbitofrontal function. Errors on Trails B, number of words generated on the Controlled Oral Word Association Test, and number of categories completed on the WCST (WCST-cc) measured dorsolateral prefrontal function. KS patients were as impaired on orbitofrontal measures as AC participants and were impaired relative to AC participants, whose performance did not differ from controls, on dorsolateral prefrontal measures. Patients with PD were impaired on OA, WCST-pe, and WCST-cc. For OA and WCST-cc, the effect was driven by the impaired performance of PD patients whose initial symptoms were on the right side of the body. The ACoA patients were significantly impaired on tests of orbitofrontal but not dorsolateral prefrontal function relative to a control group. Based on the findings in the PD group from Experiment I, it was hypothesized in Experiment II that side of symptom onset would affect verbal memory. Because women outperform men on verbal tasks, the effect of gender as well as side of symptom onset was examined using the California Verbal Learning Test (CVLT). The CVLT consists of word lists that participants recall after various delays. Of 20 patients with PD, 11 were right-onset (7 men) and 9 were left-onset (5 men). Analyses revealed an interaction between gender and side of onset for three CVLT test components (acquisition Trials 1 and 5, and short delay free recall). The effect was driven by impaired performance of male right-onset patients. These results describe a range of cognitive deficits in KS, AC, PD, and ACoA patients, and underscore consideration of the role of specific areas of frontal-lobe dysfunction, characteristics of disease manifestation, and general factors, including gender, in the presentation of cognitive symptoms. |
