Objective: This pilot study evaluated hypotheses concerning the relationship between cerebral hypoperfusion and residual deficits in the functioning of frontal brain systems in abstinent long-term alcoholics. Method: The participants (N = 22) were 10 healthy, abstinent alcoholics (9 men) and 12 age-equivalent nonalcoholic controls (10 men). Cerebral blood flow was observed through the use of regionally specific computer-derived quantitative analysis of single photon emission computed tomography (SPECT) perfusion images. Measures of alcohol use, abstinence and neuropsychological functioning were also obtained to relate to SPECT findings. Results: A positive relationship was observed between perfusion levels in the left inferior frontal brain region and years of sobriety. Alcoholics with less than 4 years of sobriety had significantly reduced left inferior frontal perfusion compared with both nonalcoholic controls and alcoholics having longer periods of sobriety. Conclusions: The findings support the hypothesis that frontal brain abnormalities in alcoholics may subside with extended abstinence.
The Test of Memory Malingering (TOMM; T. N. Tombaugh, 1996) is a newly developed visual recognition test that uses pictures of common objects as stimuli. Prior normative research with community-dwelling adults and neurologically impaired patients has shown that the TOMM possesses a high degree of specificity and is not affected by demographic variables such as age and education. The current series of 5 integrated experiments was designed to provide important validation data. Converging evidence from all studies showed that scores on the TOMM are able to detect when an individual is not putting forth maximum effort. Overall, the TOMM's high levels of sensitivity and specificity suggest that it has high promise as a clinical test for detecting malingering of memory impairments.
There has been increasing knowledge of the treatment, diagnosis, and demographics of adults with residual attention deficit/hyperactivity disorder (ADHD). However, less is known about the neuropsychological functioning in adults with residual ADHD. In comparing the clinical neuropsychological test performance of a group of adult clinic patients with residual ADHD (N = 30) with that of normal controls (N = 10), we found the patients performed worse on the Trail Making Test, a visual continuous performance test, and the "Brown-Peterson" Auditory Consonant Trigrams Test, but not on any other neuropsychological measures. This pattern indicated a deficit in the area of executive control type functioning, a functional deficit that could be linked to dysregulation of frontal lobe brain systems. Of equal interest was that patients diagnosed with ADHD/hyperactive impulsive type (ADHD+) and patients diagnosed with ADHD/inattentive type (ADHD-) had different types of executive system deficits. ADHD+ was associated with relative deficiency on the Wisconsin Card Sorting Test. ADHD- was associated with relative deficiency on the "Brown-Peterson" Auditory Consonant Trigrams Test, a measure of working memory, as well as less olfactory identification on a smell identification test. The data are discussed in terms of recent localization theories of frontal lobe function. The preliminary data suggest that the different cognitive weaknesses of ADD subtypes may be linked to dysregulation of separate frontal brain regions and/or neurotransmitter systems.
Assessment of capacity to give informed consent in the general hospital setting usually rests on a clinical judgment made of a patient's understanding and appreciation of his or her illness, a process limited by its subjective nature, interexaminer variability, and relative deficiency of quantitative instruments available to provide collateral information. Inasmuch as identification of associated variables could strengthen this process, this study examines the association of cognitive functions to the capacity to give informed consent. Over a one-year period, 65 patients were evaluated independent of medical or psychiatric diagnoses. The study population consisted of medical and neurology inpatients seen for neuropsychiatric evaluation. All evaluations included assessment of capacity to give informed consent as it related to the reason for the admission to the hospital, followed by administration of the Hopkins Competency Assessment Test, the Mini-Mental Status Examination, the Trail-Making Test, Parts A and B, and the Executive Interview. Of 65 patients, 34 were excluded based on preset criteria. The remaining patients were assigned to either a "competent" or "noncompetent" group based on clinical evaluation. Number of patients, gender, and handedness distributions between groups were similar. The groups did not differ significantly in terms of age or education. Significant between-group differences were found on an empirical measure of competency, a general mental state measure, and on measures of attentional and executive cognitive functions. An analysis of classification rates indicated that a measure of executive cognitive functioning (Executive Interview) had the best sensitivity and specificity in correctly classifying competent and noncompetent patients. The results of this study support the association between the capacity to give informed consent in the hospital setting and measures of cognitive functioning, suggesting that utilization of cognitive function measures may strengthen the competency assessment process.
Tasks sensitive to frontal lobe dysfunction (delayed response, delayed alternation, object alternation, and Wisconsin Card Sort) were administered to 20 patients with post-acute closed-head injury (CHI). Time since injury varied (6 to 280 months; mean, 48 months), as did length of coma (2 hr to 120 days; mean, 38 days). Compared to normal controls, CHI patients showed no deficits on delayed response tasks, but were impaired on delayed alternation, object alternation, and the Wisconsin Card Sort Test. Analyses of the performance profiles of the CHI patients suggested that they may have difficulty in establishing set (a consequence of damage to the orbitofrontal system).