Presidents Test performance in varieties of diffuse and unilateral cerebral disease.

Two studies addressed issues concerning the validity of the Presidents Test. The results of Study 1 substantiated that generalized impairment for recent presidents occurs frequently in the context of multifocal and diffuse cerebral disease. Performances of normal elderly (n = 31) on all four Presidents subtests were superior to those of patients with confusional states (n = 7), uncomplicated dementia (n = 24), and dementia with confusion (n = 20). Overall, 88% of the combined sample was correctly classified (control v. diffuse cerebral disease). In Study 2, generalized memory impairment for recent presidents was found to be rare among samples of patients with unilateral right- and left-hemisphere lesions (n = 40 each). A selective impairment in temporal sequencing was preferentially associated with right-hemisphere disease, whereas verbal deficit patterns were more common in patients with left-sided lesions. These findings further document the validity of the Presidents Test as an efficient, objective method for assessing recent memory impairment due to widespread cerebral disease and suggest that qualitative analysis of performance patterns may be useful for detecting certain nonmnemonic cognitive defects in patients with focal brain disease.

Neuropsychological findings in toxicometabolic confusional states.

Patients with acute confusional states display impaired attention and memory with difficulty following complex verbal commands. In addition to these deficits, we have observed a selective impairment in spatial thinking similar to that present following right-hemisphere lesions. Consequently, we compared patients with acute confusional states (CS) to patients with focal right-hemisphere disease (RHD) and controls on a standard neuropsychological battery. Although impaired relative to controls, both CS and RHD groups did not differ from each other on those tests typically associated with right-hemisphere lesions. These included performance IQ, constructional praxis, spatial judgment, and cancellation tasks. In light of these findings, the neurological correlates of selective deficits in spatial processes include not only unilateral right-hemisphere lesions, but also diffuse disorders such as CS. Thus, there is the potential to misinterpret the neuropsychological test results of patients with diffuse cerebral disorders as indicating focal abnormalities when none exist.

Memory for recent U.S. presidents in patients with cerebral disease.

Four tasks were developed to assess memory for recent U.S. presidents: free recall of presidents' names, naming their photographs, and temporal ordering of their printed names and photographs. The tasks were standardized on a sample of 250 hospital control subjects and administered to 55 patients with cerebral disease. Recall of the presidents' names, a task frequently advocated for mental status examination, was relatively difficult for hospital control patients and was least sensitive to brain disease. None of the brain-damaged patients manifested an isolated retrieval defect. Generalized memory impairment for recent presidents was not found with focal lesions. In the context of a diffuse or bilateral disease, generalized memory impairment for recent presidents was a frequent concomitant of substantial intellectual loss. This brief, multi-task assessment of memory for recent presidents may prove a more useful adjunct to neurobehavioral evaluation than testing simple recall of presidents' names.

Effects of minority status on facial recognition and naming performance.

Found performances on two tests of higher cerebral function, a facial recognition test and a naming test in an aphasia examination, to be influenced differentially by minority status (N = 94). Performance on the facial recognition test was relatively free of racial bias for the purposes of clinical assessment, but this was not the case for visual naming. In fact, straightforward application of the standard criteria for the naming test would have resulted in classification of 22% of a sample of urban black control patients as defective. Revised normative standards are presented for use in this segment of the referral population.

Facial recognition in patients with focal brain lesions.

The performances of patients with radiologically or surgically verified focal lesions on a test requiring the identification of unfamiliar faces were investigated. Nonaphasic patients with posterior right hemisphere lesions and aphasic patients with substantial impairment in language comprehension showed a notably high frequency of defect. The frequency of defective performance in nonaphasic patients with right anterior lesions was higher than normal but less than that of the previously mentioned groups. Nonaphasic patients with left hemisphere lesions and aphasic patients without substantial impairment in language comprehension performed on a level comparable with that of control subjects. It is concluded that the identification of unfamiliar faces is a bihemispheric process, possibly involving linguistic as well as visuoperceptive components.

Visuospatial judgment. A clinical test.

We constructed and developed a brief test assessing capacity for discriminating the direction of lines. Application of the test to patients with unilateral brain disease disclosed a remarkably high frequency of defective performance in those with right hemisphere lesions. The performance of patients with left hemisphere lesions was comparable to that of control patients. Brevity and ease of administration make the test convenient for clinical use.

Depression and hemispheric functions: changes associated with unilateral ECT.

Nine depressed patients received ECT to the dominant (left) side along with nine matched depressed patients who received ECT to the non-dominant (right) side. Neuropsychological tests showed that the right hemispheric functions were more frequently abnormal as compared to left hemispheric (dominant) functions in the pre-ECT tests. ECTs delivered to either the right or left side improved right hemispheric functions when the depression was ameliorated. This study indicates that in depression right hemispheric functions are initially disturbed and ECT, instead of being deleterious to these functions, tends to improve them.

Stereopsis and unilateral brain disease.

Performance on a random-letter stereoscopic task has been reported to be affected by right but not left cerebral disease. Subsequent studies employing a conventional stereoacuity test have challenged these results and proposed that dementia may be the primary determinant of impaired stereopsis in the patients with brain disease. The latter investigators have failed to distinguish between local and global stereopsis. The present study confirms the original findings, rules out dementia as a potential artifact, and attempts to reconcile the conflicting series of reports.