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Biomedical subjects

E V Sullivan

Publications and source records attributed to E V Sullivan.

At least 109 records · Page 6Linked to original sources
PubMed1991

Neuropsychological deficits accompanying striatonigral degeneration.

This study presents a structural and functional description of a case of striatonigral degeneration (SND) and emphasizes neuropsychological findings. The patient, a 55-year-old woman with progressive and relatively intractable rigidity and bradykinesia, particularly of the right side, was studied with brain MR scans and with a wide variety of sensory, motor, and cognitive tests known to be subserved by specific brain regions. T2-weighted MR images revealed curvilinear areas of high signal in the lateral putamen at low magnetic field strength (0.3T) and adjacent regions of marked low signal in the posterior-lateral putamen at high magnetic field (1.5T). High signal changes in the insular cortex were also noted on the high field images. Letter fluency and short-term memory as well as motor speed, strength, and sequencing were selectively impaired. Taken together, the data of this case suggest that structural involvement of the putamen resulted in dysfunctions usually associated with the primary motor cortex and orbitofrontal cortex, while sparing functions of other frontal regions as well as temporal and parietal cortices.

Brain Diseases↗
PubMed1991

Double dissociation of short-term and long-term memory for nonverbal material in Parkinson's disease and global amnesia. A further analysis.

The traditional concept of memory disorder is deficiency of the long-term (LTM) but not short-term (STM) component of memory. STM impairment with LTM sparing is seldom reported. The present study investigated STM and LTM for nonverbal material in three neurological conditions associated with memory impairment: bilateral medial temporal lobe lesions (patient H.M.), Parkinson's disease (PD) and Alzheimer's disease (AD). Subjects received 3 tests of nonverbal memory: forward block span, immediate and delayed recall of the Wechsler Memory Scale drawings, and immediate and delayed recognition of abstract designs. Compared with the normal control group, the patient groups displayed different patterns of sparing and loss of the two components of memory: in PD, only STM was impaired; in medial temporal lobe amnesia, only LTM was impaired; and in AD, STM and LTM were both impaired. The contrasting patterns of sparing and loss of STM and LTM in PD and global amnesia were present for both recognition and recall. These results provide evidence that STM and LTM are dissociable processes and are served by separate neurological systems: STM depends upon intact corticostriatal systems, whereas LTM depends upon intact medial temporal lobe systems.

Aged↗
PubMed1991

Cognitive impairment in early, untreated Parkinson's disease and its relationship to motor disability.

Current knowledge of cognitive dysfunction in Parkinson's disease (PD) has largely been obtained from studies of chronically treated patients in whom effects of disease chronicity, treatment, depression and dementia are confounding factors. Studies of untreated patients have examined few cognitive domains and relationships between cognition, depression and motor disability have been incompletely explored. Accordingly, we studied 60 consecutive patients with newly diagnosed, untreated, idiopathic PD and 37 matched, healthy control subjects; no subject had clinical dementia or depression. All subjects received tests of specific processes of memory and cognition, including working memory, verbal and non-verbal short- and long-term memory, language, visuospatial capacity, set-formation and shifting and sequencing. Patients also received quantitative global clinical measures of severity of dementia, depression and motor disability. The PD group as a whole showed deficits in immediate recall of verbal material, language production and semantic fluency, set-formation, cognitive sequencing and working memory and visuomotor construction. However, this group was unimpaired in immediate memory span, long-term forgetting, naming, comprehension and visual perception. Language deficits and more severe frontal lobe impairments were confined to those PD patients scoring abnormally on a Mini Mental State examination. Motor disability correlated strongly with severity of depression but weakly with cognitive impairment. Cognitive sequencing, set-formation and set-shifting deficits tended to associate with depression, but otherwise there was no association between cognition and depression. The results indicate dissociation of cognition and motor control in early PD which suggests that cognitive dysfunction is largely independent of frontostriatal dopamine deficiency underlying motor disability. Some, but not all, of the frontal lobe deficits of chronic disease are detectable in early, untreated PD. The pathogenesis of the cognitive deficits shown here appears to involve extrastriatal dopamine systems or non-dopaminergic pathology. Longitudinal study is necessary to determine whether increasing disease duration exacerbates the early cognitive deficits and affects new cognitive domains, in addition to producing increasing motor disability.

Adult↗
PubMed1990

A quantitative analysis of CT and cognitive measures in normal aging and Alzheimer's disease.

Patients with presumptive Alzheimer's disease (AD) and healthy community volunteers received computed tomographic (CT) brain scans and cognitive tests. The CT scans were quantitatively analyzed with a semiautomated thresholding technique to derive volumetric measures of cerebrospinal fluid (CSF)-to-tissue ratios in six regions of interest (ROIs): lateral ventricles; vertex sulci, frontal sulci, Sylvian fissures, parieto-occipital sulci, and third ventricle. Regression analysis was performed on CT data from 85 older volunteers (ages 51-82) to generate age norms for each ROI. Within this group, tissue loss, as measured by the % CSF in each ROI, was highly correlated with age, although each ROI showed different rates of change over age. For all ROIs, the AD group had significantly more tissue loss than expected in normal aging. In addition, AD patients with a presenescent onset (before age 65) tended to have greater vertex sulcal and frontal sulcal tissue reduction than AD patients with a senescent onset (age 65 or after). When regional tissue reduction, corrected for age, was correlated with cognitive test scores, two sets of double dissociations emerged within the AD group: large CT z scores (i.e., decreased tissue and increased CSF) of frontal sulci, but not of the third ventricle, correlated with low Comprehension and Boston Naming Test scores, whereas large CT z scores of the third ventricle, but not of the frontal sulci, correlated with low scores on Digit Symbol and Picture Arrangement. These results suggest that heterogeneity of structural and functional integrity exists among patients with AD.

Adult↗
PubMed1990

Recency and frequency discrimination in the amnesic patient H.M.

Temporal contextual memory and event memory were compared across retention intervals in the patient H.M. who is amnesic following bilateral medial temporal lobectomy. Memory for temporal context was assessed using verbal and nonverbal recency discrimination tasks and a frequency task in which subjects made discriminations between words repeated 1, 3 or 5 times. The tests evaluated event memory under parallel conditions by two-choice content recognition tasks. In both recency and frequency tests, H.M. showed above-chance and often normal temporal contextual memory under conditions of impaired and even chance-level content recognition. These results show that temporal contextual memory does not require intact content recognition and is independent of medial temporal lobe structures. Furthermore, the amnesia of bilateral medial temporal lobe resection does not manifest primary loss of temporal contextual memory.

Amnesia↗
PubMed1989

Hemispheric asymmetry in tactile forgetting induced by tactually-guided movement.

Asymmetries in tactile short-term memory related to differential specialization of the cerebral hemispheres were studied in normal human adults using the Brown-Peterson distractor task. When the distractor was an auditory arithmetic task, no difference emerged between the two hands for the retention of touches to the fingers; however, when the distractor was a tactual maze task executed by the right hand, asymmetry in favor of the left hand was observed. Specifically, when the right hand performed the tactual maze, there was greater interference with tactile memory than when the left hand performed the maze, independent of which hand received the memory material. The results support a characterization of short-term memory as embracing multiple, limited storage capacities divided along the lines of processing demands, arising from different classes of material, placed on the two cerebral hemispheres.

Adult↗
PubMed1989

Different cognitive profiles on standard behavioral tests in Parkinson's disease and Alzheimer's disease.

Patients with Parkinson's disease (PD) displayed a different pattern of cognitive deficit from patients with dementia resulting from Alzheimer's disease (AD). Specifically, PD patients, whether or not impaired on a mental status examination, had deficient Picture Arrangement but normal Vocabulary test scores whereas AD patients were impaired on both measures. Furthermore, PD patients with impaired mental status examination scores showed a deficit in set formation on Picture Arrangement not seen in the AD patients. Finally, when recent memory performance, as measured by the Wechsler Memory Scale, was predicted from an estimated IQ, 71% of PD patients who had normal mental status examination scores were seen to have at least a mild memory impairment.

Aged↗
PubMed1989

Nonverbal recognition and recency discrimination deficits in Parkinson's disease and Alzheimer's disease.

In a study of verbal temporal ordering, patients with Parkinson's disease (PD) were impaired in making judgements of the relative recency of serially-presented words but were normal in word recognition; by contrast, patients with Alzheimer's disease (AD) were impaired on both verbal tasks (Sagar et al., 1985, 1988b). The present study used a nonverbal analogue of the verbal temporal ordering task to examine whether the deficit in recency discrimination of the PD patients transcended material-specific bounds or was specific to verbal material. The nonverbal task was administered to the patients with PD, patients with AD and normal control subjects studied with the verbal task. The results showed that the retention functions for the recognition of verbal and nonverbal material differed qualitatively from each other and this difference was present in all three subject groups. For verbal and nonverbal recency discrimination and verbal content recognition, performance declined with increasing retention intervals; for nonverbal content recognition, however, performance was essentially unchanging across retention intervals. As on the verbal test, recency discrimination on the nonverbal test was impaired in both patient groups. In contrast to the results with the verbal task, both groups were impaired on content recognition. The patterns of impairment, however, differed between the two patient groups in a parallel way to those of the verbal task: performance of the AD group was impaired at the longest retention intervals but not at the shortest intervals, whereas the performance of the PD group was impaired at the shortest but not at the longest intervals. This deficit in nonverbal short-term recognition memory was present even in PD patients who scored within the normal range on a quantitative test of dementia. These results show that deficits in recency discrimination and short-term memory processing in PD extend to nonverbal as well as verbal material and imply bilateral frontal lobe dysfunction in the genesis of these deficits.

Aged↗
PubMed1989

Penetrating head injury in young adulthood exacerbates cognitive decline in later years.

Few investigators have studied whether the behavioral effects of brain insult in adulthood are stable after the period of maximum recovery. We addressed this issue in a 30-year longitudinal study of 84 veterans of World War II, 57 with penetrating head injury (HI) and 27 with peripheral nerve injury (PNI), matched with respect to age, premorbid intelligence, and premorbid education. Each subject was examined during the 1950s and during the 1980s; each examination included the largely verbal Army General Classification Test (AGCT) (with Vocabulary, Arithmetic, and Block Counting subscales) and the Hidden Figures Test (which measures figure-ground discrimination). HI exacerbated decline in performance over time, irrespective of lesion site or cognitive test. HI and PNI subjects differed significantly (p less than 0.05) in AGCT Total and Arithmetic change scores, and means were in the same direction for all other measures. In analyses contrasting subjects in each of the eight lesion groups to PNI subjects, those with left parietal lobe injuries showed significantly greater decline from the 1950s to the 1980s on the Vocabulary and Arithmetic subscales of the AGCT, as did those with left temporal lobe injuries on the Arithmetic subscale, whereas subjects with right parietal lobe injuries showed significantly greater decline on the Hidden Figures Test. We hypothesize that the observed reduction of cognitive capacities late in life was due to some combination of HI in young adulthood, secondary effects of the injury occurring with time, effects of stress on remaining brain tissue caused by functioning for decades in a compromised state, and changes in the brain occurring with age. Although the HI subjects were not demented, follow-up studies must assess whether exacerbated decline is a harbinger of dementia.

Adult↗
PubMed1988

Remote memory function in Alzheimer's disease and Parkinson's disease.

Remote memory for public and personal events was evaluated in Alzheimer's disease (AD) and Parkinson's disease (PD), using a series of recall and recognition tests. Information related to content and date of past events was assessed separately. In recall of the content of personal and public events, both groups showed a gradient of deficit in which remote events were affected less than recent ones; the magnitude and temporal extent of the retrograde loss was related to severity of dementia. By contrast, gradient effects were not evident in the recall of date and were less marked in the recognition of content or date. In public and personal events tests, patients with PD showed a relative impairment in dating capacity, compared with their memory for the content of events, which was independent of dementia. These results suggest that dementia affects the recall of distant events less than recall of recent ones. Furthermore, the selective gradient effects in recall of content suggest that memory for date is served by cognitive processes independent of memory for event content. In PD, dating capacity is a sensitive measure of remote memory function that may be disrupted independently of dementia.

Alzheimer Disease↗
PubMed1988

Temporal ordering and short-term memory deficits in Parkinson's disease.

Previous studies of remote memory function have indicated a dissociability between memory for the content and date of past events and suggested selective deficits of dating capacity in Parkinson's disease (PD). The present study examined the hypothesis that poor dating in PD is linked to a specific deficit in temporal contextual memory which also affects new learning. Patients with PD and patients with Alzheimer's disease (AD) were compared in their ability to perform tasks of content recognition and recency discrimination of words presented sequentially. Compared with AD patients, PD patients were disproportionately impaired in recency discrimination relative to content recognition. When performance was analysed as a function of retention interval, AD patients showed impairment in both tasks at all intervals. PD patients, by contrast, showed deficits in content recognition at the short stimulus-test intervals only, possibly reflecting the clinical phenomenon of bradyphrenia. These results suggest that recency discrimination deficits and impaired short-term memory processing are specific cognitive deficits in PD that may be linked to subcortical deafferentation of the frontal lobes.

Alzheimer Disease↗
PubMed1984

Prognostic factors for life expectancy after penetrating head injury.

Survival curves were made for 190 World War II veterans with penetrating head injuries, and for 106 WW II veterans with peripheral nerve injuries who matched the subjects with head injuries with respect to age at injury, years of formal education, and preinjury intelligence-test score. The results indicated that penetrating head injury coupled with posttraumatic epilepsy shortened life expectancy in subjects who survived the early postinjury period, but that head injury alone did not. Educational level was also a significant variable independent of seizures: subjects with more education survived longer than those with less education. Age at injury and the difference between preinjury and postinjury intelligence-test scores did not predict survival status.

Adolescent↗
PubMed1984

Selective subject attrition in a longitudinal study of head-injured veterans.

Recent longitudinal studies of aging have suggested that intellectually inferior subjects selectively drop out during the course of the investigation. This issue of subject attrition was addressed in a neuropsychological study of 314 veterans who had sustained head or peripheral nerve injuries in World War II. These men were examined originally by Teuber and his colleagues at New York University in the 1940s and 1950s, and the veterans' participation was sought for a 40-year follow-up study at the Massachusetts Institute of Technology. In the current follow-up study, the veterans were subdivided according to their response to recent recruitment letters: those who agreed to be retested, those with whom recent contact was established but who declined to participate, those who did not reply to our correspondence, and those who were deceased. Those who agreed to be retested in the 1980s had significantly more education and achieved significantly higher Army General Classification Test scores both before and after injury than did the untested cohort. Even with the selective subject attrition, however, the remaining sample represented a broad range of intellectual competence.

Craniocerebral Trauma↗