摘要:

The objective of this study was to examine the structure/function relationship between in vivo cerebellar size and higher cognitive function in a sample of healthy young subjects. The design of the study involved correlation of in vivo cerebellar volume measurements with measures of general intelligence (WAIS-R V FSIQ, Vocabulary, Block Design, and Digit Span subtests), motor dexterity (Halstead-Reitan Finger Tapping), verbal (WMS Logical Memory), and visual (Rey-Osterrieth Figure) memory covaring for cerebrum size. A similar analysis was performed using left temporal lobe volumes as a control region. The sample consisted of 62 healthy subjects (30 females, 32 males) enrolled as controls at the MHCRC at the University of Iowa Hospitals and Clinics. This independent sample does not overlap with the groups studied in our previous report on the relationship between cerebellar and brain size and IQ. Cerebellar and total brain size were estimated through automatic, atlas-based volume measurements using MR images obtained with a T1-weighted three-dimensional SPGR sequence on a 1.5-T GE Signa scanner and locally developed software. Cerebellar volume significantly correlated with Finger Tapping (left hand:r= 0.218, p < 0.05; right hand:r= 0.211, p < 0.05) and with memory retention of complex narrative material (r= 0.27, p < 0.02). Cerebellar volume correlated with general intelligence in the expected direction (r= 0.19, p < 0.07). This study confirms previous work indicating that the cerebellum may make a contribution to several aspects of cognition. Cerebellar volume significantly correlated with the ability to retain already encoded information in the verbal domain and with fine motor dexterity. Cerebellar volume positively correlated with general but the relationship did not reach statistical significance. The structural/functional relationship between cerebellum and verbal memory abilities is consistent with evolutionary theory for the phylogenetical increase in the size of the cerebellum.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

We studied subjects with focal subcortical lesions (SCLs) and investigated the frequency of pallidal lesions in secondary major depression (2°MD) presenting after but not before lesion onset. Forty-five subjects were selected for focal subcortical lesions (SCLs) from 10,000 hospital magnetic resonance imaging (MRI) films. SCLs were ascertained by neuroradiologic criteria. Major depression was ascertained by DSM-III, -III-R, and -IV criteria. We compared subjects with 2° MD to SCL subjects lacking life histories of mood disorders and investigated the lesion distribution among pallidal subregions evident on MRI. We further tested an association between pallidal lesions and 2° MD. Pallidal lesions were present in eight (89%) of nine subjects with 2° MD and 13 (59%) of 22 controls. Left posterior pallidal lesions occurred in four (44%) of the nine subjects with 2° MD and two (9%) of the 22 controls (one-tailed Fisher's exact testp= 0.043). Demographic and other factors did not differ between subjects with 2° MD and controls (using Fisher's exact test or Mann-WhitneyUtest as statistically appropriate). These data, of small sample size and requiring confirmation, suggest the possibility that abnormal pallidal function may contribute to depressive pathophysiology, perhaps by influencing basal gangliathalamocortical mood circuits. Left-lateralized circuits in the posterior pallidum may be of particular relevance. The left pallidal association is compatible with previous findings in poststroke depression. Patients with left pallidal lesions may deserve close monitoring for 2° MD after subcortical lesions.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Saccadic latency of schizophrenics (N = 15) and normal controls (N = 11) was measured to the left and right visual fields with three fixation conditions that differentially affect saccade latency. Fixation was offset either 1) prior to the target (gap condition), 2) simultaneous with the target onset (control condition), or 3) after target onset (overlap condition). Saccade latencies are typically reduced in the gap condition, which is attributed to the fixation offset acting to facilitate attentional disengagement or as a preparatory warning signal. Repeated measures Analysis of Variance (ANOVA) revealed that whereas the saccadic latencies of schizophrenics and normal controls do not differ for right visual field targets, the schizophrenics latencies were prolonged to left visual field targets. This difference was most pronounced in the overlap condition, where normal controls produced faster saccades to the left visual field targets, whereas schizophrenics showed the opposite asymmetry. Because the overlap condition provides no early warning of the upcoming target, the lateralized finding suggests a deficit in the right hemisphere mechanisms responsible for sustained attention.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Although patients with chronic fatigue syndrome (CFS) typically present subjective complaints of cognitive and psychological difficulties, studies to date have provided mixed objective support for the existence of specific cognitive deficits. The present study was designed to examine differences in performance between individuals diagnosed with CFS and matched controls with respect to sustained attention, processing efficiency, learning, and memory. Subjects included 17 patients meeting Centers for Disease Control research criteria for CFS and 17 control subjects. Subjects were administered six measures assessing attention, memory, and word-finding ability and two measures assessing psychological distress. For the most part, the two groups did not differ on measures of neurocognitive functioning. Significant group differences were found on a single measure of attention and incidental memory. However, CFS patients differed markedly from controls with respect to reported psychological distress. The results support previous findings of notable levels of psychological distress among CFS patients. They also suggest the need for alternative research paradigms to assess the cognitive abilities of CFS patients.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The hallmark symptom in probable Alzheimer's disease (PAD) is dramatic difficulty in storing and/or retrieving new information on tests of explicit or direct memory. However, in many studies of implicit or indirect memory, these same patients show repetition-priming magnitudes (i.e., facilitation of performance on the basis of previous experience) similar to that of normal controls. Recent studies of repetition priming have shown that PAD subjects have an intact event-related potential (ERP) repetition effect, which is thought to index indirect memory functioning. The present study was designed to test the effect of multiple repetitions of verbal stimuli on the ERPs of PAD patients. ERPs were recorded from 8 subjects with PAD, 8 age-matched elderly and 16 young healthy controls. Subjects were asked to make speeded but accurate choice responses to infrequently occurring animal words and frequently occurring nonanimal words, some of which repeated across three blocks of trials. All groups of subjects produced ERP activity that was more positive to repeated (i.e., old) than to new items, with no additional enhancement elicited by the third presentation. ERP enhancement to repeated items was associated with reaction time facilitation, which also showed no additional facilitation to the third presentation. Moreover, the scalp distribution of the repetition effect was similar in the PAD and control groups, suggesting that it emanated from similar brain tissue in the three groups. These results indicate that ERP and reaction time repetition-priming effects are relatively intact in subjects who are aging normally and in those with a diagnosis of “mild” Alzheimer's disease.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

In normal aging, an association exists between level of education and verbal abilities. Clinical experience suggests that this relationship may also hold true in Alzheimer's disease (AD). In this study, we examined performance on selected verbal and nonverbal neuropsychological tests in a series of 51 patients with probable AD. Performance on two verbal measures the National Adult Reading Test-Revised (NART-R) and the Vocabulary subtest from the Wechsler Adult Intelligence Scale-Revised (WAIS-R) showed strong correlations with level of education. Scores on three nonverbal tests WAIS-R Block Design, WAIS-R Digit Symbol, and Boston Diagnostic Aphasia Examination clock drawings were unrelated to education. Consistent with our hypothesis, AD patients with higher premorbid education showed better performance on certain measures of verbal competence. These results indicate that, as in normal aging, education is associated with verbal abilities in AD.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

A 65-year-old woman with progressive visuospatial dysfunction for 2 years complained of later-onset associated memory impairment. MRI revealed diffuse cerebrocortical atrophy, which was especially severe in both parieto-occipital regions but spared the calcarine and pericalcarine cortices. Examination 5 years after onset revealed left visual hemi-neglect, oculomotor apraxia, optic ataxia, simultanagnosia, verbal alexia, lexical and spatial agraphia, and anterograde amnesia. This patient's disorder is considered in the context of previous reports on the array of cognitive disturbances associated with posterior cortical atrophy (pCA). Special emphasis is made on her reading and writing disturbances, because their prevalence and range of individual variability have not been established in pCA. This array of neuropsychological manifestations may help to distinguish among different clinical and etiological types of pCA, and to elucidate the pathophysiology of a syndrome that has been associated with conditions as diverse as Alzheimer's disease, subcortical gliosis, and prion diseases. The parameters described in our case may thus help to address these issues in clinico-pathological studies with large numbers of patients with pCA.

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0894-878X    

出版商:OVID    

年代:1997

数据来源: OVID