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Biomedical subjects

D T Stuss

Publications and source records attributed to D T Stuss.

At least 73 records · Page 4Linked to original sources
PubMed1986

Language functioning after bilateral prefrontal leukotomy.

Three groups of patients with orbital frontal lesions secondary to leukotomy were compared to psychiatric and normal control groups on a series of tasks involving language. The results indicated that chronic orbital frontal lesions, at least in the patients in this study, do not affect language as defined by the tasks used in the study. The frontal lobes, when implicated in language, appear to require dorsal-lateral or medial cortical involvement.

Aphasia↗
PubMed1985

Subtle neuropsychological deficits in patients with good recovery after closed head injury.

This study demonstrates residual mental deficits in patients who have apparently recovered after closed head injury. Twenty closed head injury patients were compared to 20 normal control subjects matched for age, sex, handedness, education, language, and IQ. All received a series of neuropsychological tests. Discriminant function analysis significantly differentiated the two groups. Correct classification of individuals as having suffered a head injury or not was 85%. The head injury patients did have primary impairment on tests of divided attention. Litigation was not a factor. We propose that this impairment of information processing reflects residual brain damage secondary to the closed head injury.

Adult↗
PubMed1984

The effects of prefrontal leucotomy on visuoperceptive and visuoconstructive tests.

Visuoperceptive and visuoconstructive tests were administered to three groups of schizophrenics who had undergone bilateral prefrontal leucotomy approximately 25 years earlier. A nonoperated schizophrenic patient group and a normal subject group served as controls for the effects of schizophrenic symptomatology and for age and education. The results demonstrated that orbital frontal white matter lesions do not disturb simple perceptions and constructions. The nonoperated schizophrenics had significant problems on many of the tests. Only one test, the WAIS Picture Arrangement, revealed deficits in all patient groups, including the good recovery leucotomized patients. This suggests impairment in the higher-order control and organization of perceptual material which may be secondary to orbital frontal white matter lesions or reflect aspects of the underlying schizophrenic disorder.

Frontal Lobe↗
PubMed1983

Event-related potentials during naming and mental rotation.

The biphasic late negative wave (Nx-Ny) evoked during the naming of pictures of objects was investigated in a series of experiments. The monitoring of several possible non-cerebral generators indicated that these components were probably cerebral in origin. The Ny wave differed in scalp distribution from the preceding CNV. It was unaffected by stimulus duration or by stimulus repetition. The Nx-Ny complex occurred in both a naming task and a mental rotation task. The slow waves following the biphasic negative wave differed significantly between these two tasks. In the mental rotation task, there was a large prolonged negativity in both parietal regions. The Nx wave (at approximately 250 msec) of the biphasic complex may represent the initial registration of the stimulus. The Ny wave (at approximately 420 msec) does not appear to be specifically related to semantic processing. Rather it may index some process involved in initiating the further evaluation of a complex stimulus. The slow waves that follow the biphasic negative complex may reflect the actual perceptual processing of the stimulus.

Brain↗
PubMed1983

The involvement of orbitofrontal cerebrum in cognitive tasks.

Although the frontal lobes are frequently associated with high-level cognitive functions, patients with significant frontal damage often maintain normal "intelligence". While recent research has clarified some aspects of this enigma, specific questions remain concerning the nature of the deficit in these patients and its relation to lesion localization within the frontal lobes. A group of psychiatric patients who had undergone prefrontal leucotomy 25 years earlier and whose frontal lesions were bilateral and maximal orbitofrontally were evaluated. Sixteen leucotomized schizophrenics, divided into three groups based upon recovery after psychosurgery, were compared to two control groups: (1) non-leucotomized chronic schizophrenics; (2) normal subjects. Four tests were administered: Wechsler Adult Intelligence Scale, Wisconsin Card Sorting test, Visual Metaphor test, and the Visual Verbal test of abstraction. The results suggest that orbitofrontal pathology does cause impaired performance on certain cognitive tests, which appeared independent of IQ measures.

Cognition↗
PubMed1982

Evidence for the involvement of orbitofrontal cortex in memory functions: an interference effect.

Although it is frequently stated that the frontal lobes play a significant role in memory function, research proof has been ambiguous at best. This problem was addressed by administering a variety of memory tests to 16 schizophrenic patients who had undergone prefrontal leucotomy approximately 25 years earlier. The 16 were divided into three groups on the basis of recovery after surgery. Two comparison groups were established to control for psychiatric symptomatology, years of institutionalization, age, and years of education. The results demonstrate that large bilateral orbitofrontal lesions may not result in amnesia; in fact, the nonoperated schizophrenic control group performed the most poorly. Proactive interference was demonstrated, however, resulting in significant impairment for all patients with prefrontal lobe damage despite normal scores on commonly used memory tests. Ability to maintain consistent and directed attention and to overcome interference is proposed as a role of the frontal lobes in memory function.

Amnesia, Retrograde↗
PubMed1982

Motor abilities after frontal leukotomy.

The effect of bilateral frontal leukotomy on motor function was evaluated by neurologic examination, tests of praxis, and appropriate neuropsychologic tests administered to five groups of subjects. Postleukotomy schizophrenic patients were subdivided into three degrees of recovery. Two nonleukotomized groups served as controls for effects of schizophrenia, age, and education. The results indicate that the size of the bifrontal damage was not significant in the response to the motor tests, whereas the severity of schizophrenia clearly affected results. As tested, bilateral orbitofrontal white matter lesions did not disturb motor competency.

Brain Diseases↗
PubMed1981

Frontal leukotomy size and hemispheric asymmetries on computerized tomographic scans of schizophrenics with variable recovery. Northampton Veterans Administration study.

The computerized tomographic (CT) scans of 17 schizophrenic men who had had bilateral prefrontal leukotomy performed 25 years earlier were examined to determine the relationship among leukotomy site, size, hemispheric asymmetries, and recovery. Six cases of good recovery (GR), five of moderate recovery (MR), and six of no recovery (NR) were studied; 16 of 17 patients were right-handed. Results showed that the GR cases had significantly larger lesions in the low orbitofrontal region (especially on the left) than did the other MR and NR cases. Also, five of six of the GR cases had significantly greater lesion size asymmetry in the low orbitofrontal region and overall than did the other MR and NR cases. There was no consistent asymmetry of lesion size (larger right or left) that was associated with recovery. Significant differences were observed in the hemispheric asymmetries of the right-handed schizophrenics vs normal subjects. Only half the cases had the expected increased left occipital width, and half had unexpected equal or increased right occipital widths. All of the GR cases had either an increased left or right occipital width; none had equal widths. Additional observation of long-standing leukotomy sites on CT scans in schizophrenia cases is recommended.

Aged↗
PubMed1981

The long-term effects of prefrontal leukotomy.

To explore the long-term effects of bilateral prefrontal destruction, 16 schizophrenics who had undergone prefrontal leukotomy approximately 25 years earlier were studied by neurologic examination, psychiatric outcome, EEG, computerized tomography (CT), and a battery of neuropsychological tests. Five nonleukotomized chronic schizophrenics and five age-matched normal subjects served as controls. We report details on the subjects, outline the test procedures, and offer an overview of the long-term residua. In general, the larger the frontal lesion demonstrated by CT, particularly if asymmetric, the better the psychiatric outcome and the better the performance on psychological testing, but there was no correlation between frontal lesion size and either neurological or EEG abnormality.

Brain Diseases↗
PubMed1981

Long-term effects of prefrontal leucotomy--an overview of neuropsychologic residuals.

A battery of neuropsychologic tests was administered to 16 schizophrenics who had undergone prefrontal leucotomy approximately 25 years earlier. The 16 were divided into three groups based on their recovery after surgery. Five non-leucotomized chronic schizophrenics and five normal subjects served as controls. This paper presents a description of the subject population, a listing of the neuropsychologic battery administered, as well as main results from each major psychologic function tested. This information serves as an introduction and an overview for later detailed results.

Adult↗
PubMed1981

Leucotomized and nonleucotomized schizophrenics: comparison on tests of attention.

Deficits in attention have been strongly linked with both schizophrenia and pathology in the prefrontal cortex. This observation was tested by administering a battery of commonly used tests of attention, sustained mental activity, and tracking to 16 patients who had undergone prefrontal leucotomy approximately 25 years earlier. Presurgical diagnosis in each patient was schizophrenia. The 16 were divided into three groups based on their recovery after surgery. A control group of nonleucotomized schizophrenics was established to control for psychiatric symptomatology. A second control group consisted of subjects without history of psychiatric or CNS disorder. In general, there was no statistically significant impairment of performance in attention tests between the patients with prefrontal psychosurgery and the normal control subjects. The nonoperated schizophrenic control group performed most poorly. Lesion chronicity, interaction of leucotomy and presurgical psychiatric state, and conditions of test administration are suggested as possible explanations for the unexpected results.

Attention↗
PubMed1979

Naming to picture versus description in three aphasic subgroups.

Twenty-three male aphasics, classified as Broca's, Wernicke's and anomic, were tested on their ability to name objects to either visual confrontation or oral associative description. For the Broca's and Wernicke's aphasics, naming to visual confrontation was significantly better than to oral description. Broca's aphasics tended to produce more correct names than both other groups in both conditions, although significance was reached only in oral description. Differences were not significantly affected by the comprehension deficit or severity of aphasia. With picture naming, all groups tended to name immediately or not al all. For oral description, there was a greater proportion of long latency responses for the posterior patients. When given phonemic or visual cues to assist naming, Broca's aphasics benefited the most, the anomics performing most poorly. All these results suggest qualitative differences in naming ability in aphasic subgroups.

Anomia↗