Retrograde memory in cerebrovascular disease and Alzheimer's disease.

Retrograde memory is frequently tested in the mental status examination of patients with stroke or degenerative dementia. The goal of this experiment was to compare gradients of retrograde memory in patients without neurologic disease (n = 26), patients with cerebrovascular disease (n = 43), and patients with probable Alzheimer's disease (n = 27). Patients were asked to recall and then name photographs of the 6 most recent US presidents.

Constructional ability in two- versus three-dimensions: relationship to spatial vision and locus of cerebrovascular lesion.

Introduction: Clinical evaluation and research on constructional ability have come to rely almost exclusively on two-dimensional tasks such as graphomotor copying or mosaic Block Design (BD). A return to the inclusion of a third dimension in constructional tests may increase the spatial demands of the task, and improve understanding of the relationship between visual perception and constructional ability in patients with cerebral disease.

Method: Subjects were patients (n=43) with focal or multifocal cerebrovascular lesions as determined by CT or MRI.

Single photon emission computerized tomography (SPECT) in detecting neurodegeneration in Huntington's disease.

Single photon emission computerized tomography (SPECT) studies were performed on 34 manifest Huntington's disease (HD) patients at various stages of clinical pathology ranging from early chorea to late dystonia with or without signs of dementia and 12 pre-symptomatic patients with abnormal terminal CAG expansions. Thirty HD patients with obvious clinical signs and seven pre-symptomatic patients without signs or symptoms of HD displayed selective caudate hypoperfusion by direct visual inspection. Such qualitative, selective striatal hypoperfusion patterns can be indicative of early and persistent metabolic changes in striatal neuropathology.

DNA testing and genetic counseling: truth or consequences.

Advances in medical genetics are providing a major clinical challenge to practitioners seeing patients concerned about their risk of developing either inherited disease or susceptibility to acquired disease. Popular information can easily exceed our professional ability to provide services to well-read patients who want answers with scientific certainty. The challenge also involves ethical questions regarding confidentiality and the way that results are disclosed.

Visuospatial judgment and right hemisphere disease.

The performances of patients with stroke-produced unilateral hemispheric lesions on a test requiring the identification of lines were examined in the light of a recent report that contradicted previous observations. The study confirmed the results of earlier studies that patients with lesions of the right hemisphere show a remarkably high frequency of defective performances while those with lesions of the left hemisphere do not. Possible reasons for findings that deviate from this rule are discussed.

Hemisphere asymmetry in decision making abilities. An experimental study in unilateral brain damage.

Thirty control subjects and 60 unilateral brain-damaged patients, 30 with left hemisphere (LH) damage and 30 with right hemisphere (RH) disease, underwent a disjunctive 4-choice reaction time study. Speed of reaction (as defined by the reciprocal of reaction time (RT), movement time (MT) and total response time (TRT] and accuracy of response (as represented by the sum of errors in selecting the correct response key) were investigated comparatively as a function of side of lesion and of performance on Raven's Coloured Progressive Matrices (PM47). In contrast to movement speed (1/MT), reaction speed (1/RT) as well as total response speed (1/TRT) showed a lesion effect independent of side of damage.

Constructional praxis performance of Japanese and American, normal and brain-damaged patients.

Numerous studies have suggested population differences between Japanese and Americans concerning various cognitive functions. Transcultural differences in spatial reasoning, language, and dominance for emotional expression raise important questions concerning current conceptions of hemispheric cerebral dominance for cognitive functioning. If cultural differences in cognition exist, learning may play a greater role in determining laleralizalion of cognitive functions than is presently accepted.

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).

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.

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.

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.

Mental status examination in Alzheimer's disease. The neuropsychologist's role.

The neuropsychologic consultant can offer an objective and comprehensive method of documenting the mental status of patients being evaluated for dementia. The neurobehavioral examination is an extension and elaboration of the bedside mental status examination, with added methods of controlling for various background factors that can influence performance on cognitive testing. In dementia, the cognitive findings appear to have a close association with the underlying neuropathologic changes and mortality.

Prediction of outcome in anorexia nervosa from neuropsychological status.

To evaluate the possibility that subtle brain dysfunction may exist in anorexia nervosa and indicate a poor prognosis, 20 anorexia nervosa patients received neuropsychological assessments covering a broad array of cognitive performances. The patients were examined at admission and again at the end of an inhospital treatment program when they were at normal weight for their age and height. Pretreatment performance on the assessment battery was not associated with outcome 1 year after discharge.

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.

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.

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.

Spontaneous recovery in rabbit eyelid conditioning.

Spontaneous recovery of the classically conditioned rabbit eyelid response increased in a negatively accelerated function with an increase of postextinction rest from .17 to 24 hr. The data were obtained from six groups of male New Zealand rabbits which received an extinction session separated by rest intervals of varying duration from a spontaneous recovery test.

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.

Interactive effects of age and cerebral disease on cognitive performances.

A battery of mental tests was given to groups of younger (16--44 years) and older (48--60 years) control and cerebral diseased patients. Each patient in the younger cerebral diseased group was matched individually with an older cerebral diseased patient for type and site of lesion. Each patient with cerebral disease was matched individually with a control patient for age, educational level and sex.

The reliability of reaction time determinations.

The reliability of simple and two-choice reaction time (RT) as a function of number of trials and measure of central tendency was examined. It was found that, within the particular conditions of the study, 18 trials were sufficient to obtain a highl reliable determination of simple RT but 30 trials were required for a highly reliable determination of two-choice RT. The selection of measure of central tendency was not related to degree of reliability.