Biomedical subjects

C M Cullum

Publications and source records attributed to C M Cullum.

At least 19 recordsLinked to original sources

PubMed1994

Reduced platelet cytochrome c oxidase activity in Alzheimer's disease.

We evaluated a simplified method for preparation and analysis of platelet cytochrome c oxidase activity in Alzheimer's disease (AD) and control patients. Mean cytochrome c oxidase activity in controls (n = 17) was 0.233 sec-1/mg whereas mean cytochrome c oxidase activity in Alzheimer patients (n = 19) was 0.193 sec-1/mg, p = 0.033. Complex III (ubiquinol:cytochrome c oxidoreductase), complex II (succinic dehydrogenase), and citrate synthase were all assayed as internal controls and were not significantly different in controls and Alzheimer patients. There is a relatively specific loss of platelet cytochrome c oxidase activity in Alzheimer disease patients.

Aged↗

PubMed1993

Neuropsychological test performance and MEG-based brain lateralization: sex differences.

Magnetoencephalographic (MEG) auditory evoked fields (EF) were recorded from left and right hemispheres of 9 normal males and 12 normal females. Source location of the 100 ms latency component (M100) was localized to superior temporal lobes bilaterally using an inverse solution algorithm. All subjects also were administered the Wechsler block design and visual reproduction subtests, and the California Verbal Learning Test (CVLT). M100 source locations demonstrated significant sex differences in interhemispheric asymmetry. Males had source locations further anterior than females, with the differences most pronounced in the right hemisphere. Expected sex differences were found in neuropsychological test performance, with males performing better on block design ad visual reproduction, and females performing better on the CVLT. Across both sexes, block design scores correlated significantly with right hemisphere M100 location, with more anterior source locations associated with better performance. CVLT scores were negatively correlated with right hemisphere M100 source locations. These findings suggest MEG-based measures of interhemispheric asymmetry may be related to specific neuropsychological test performance measures.

Acoustic Stimulation↗

PubMed1993

Neurophysiological and neuropsychological evidence for attentional dysfunction in schizophrenia.

The behavior of the P50 wave of the auditory evoked potential in a paired stimulus or conditioning-testing paradigm has been used as a measure of sensory gating disturbance in schizophrenia. Schizophrenics fail to decrement the P50 response to the second stimulus of the pair, so that the ratio of the test to the conditioning amplitude is elevated over normal values. The aim of this study was to compare this neurophysiological measure to neuropsychological measures of attention and memory. As expected, schizophrenics performed worse than controls on most measures. The time to complete a digit cancellation test, a measure of sustained attention, was found to be particularly longer in schizophrenics than in control subjects. Furthermore, the increased time to complete this task correlated with the increased ratio of the amplitude of the test P50 response to the conditioning response in the schizophrenics. Thus, a neurophysiological defect in sensory gating may relate to a disorder in sustained attention in schizophrenia. Although the P50 wave may come from the hippocampus, neuropsychological measures of verbal learning and memory were not correlated with alterations in the P50 ratio.

Adult↗

PubMed1993

Three-word recall as a measure of memory.

Clinical examination of memory functions often includes the administration of simple free recall tasks, such as the recall of several words following a few minutes. Little is known, however, about the normative parameters or psychometric properties of such procedures, and such techniques have rarely been compared with more comprehensive, well-standardized memory indices. To address these issues, two three-word recall tasks were administered to a large group of carefully selected healthy subjects over the age of 50 years. The Mini-Mental State Examination (MMSE) was obtained as an index of global cognitive status, and the California Verbal Learning Test (CVLT) was used to exclude subjects with abnormal memory abilities. Significant but modest relationships were found between two three-word recall tasks and CVLT results. Substantial variability was seen on three-word recall, with a significant proportion of normal subjects recalling zero or one word. Results suggest using caution in interpreting simple recall performance as an index of memory, as great variability in results is seen among healthy (particularly older) individuals.

Aged↗

PubMed1993

The diagnostic utility of savings scores: differentiating Alzheimer's and Huntington's diseases with the logical memory and visual reproduction tests.

Recent research has demonstrated that patients with dementia of the Alzheimer type (DAT) evidence more rapid forgetting than do patients with Huntington's disease (HD). The present study focused on whether such group differences translated into measures with adequate sensitivity and specificity at different stages of these disorders. It was found that measures of forgetting (i.e., savings scores) based upon the Logical Memory and Visual Reproduction tests of the Wechsler Memory Scale--Revised had satisfactory to excellent sensitivity and specificity in differentiating DAT and HD patients from healthy control subjects. Savings scores also had good sensitivity and specificity in differentiating DAT from HD in the early stages of the diseases. However, unsatisfactory specificity may limit the utility of savings scores in differentiating among patients with moderate DAT and HD.

Aged↗

PubMed1991

Short- and long-term psychological status following stroke. Short form MMPI results.

Indices of self-reported depression and psychological adjustment after stroke were evaluated using a short form of the MMPI. Patients with poststroke periods of 2 to 6 and 7 to 24 months were selected, and indices of general intellectual functioning and lesion size/location were obtained. Despite similar levels of intellectual functioning and lesion parameters, the longer duration group showed significantly higher depression scores and significant (T greater than 70) elevations on several other clinical scales of the MMPI. In contrast, the mean overall profile of the short-duration group was roughly within normal limits. These findings have implications for the clinical assessment and treatment of stroke patients and long-term psychological adjustment after stroke.

Adaptation, Psychological↗

PubMed1989

The use of the Halstead-Reitan test battery with older adults.

As with younger individuals, neuropsychological evaluation of the older patient with suspected cognitive decline should be reasonably comprehensive. Only through careful analysis of the overall pattern as well as level of performance across various measures can both the likelihood and nature of cerebral dysfunction be ascertained. A neuropsychological battery such as an expanded HRB appears to be well suited for the comprehensive evaluation of the older individual who may be mildly to moderately impaired, whereas briefer test batteries may be sufficient and more practical in some cases. The HRB is widely used in clinical and research settings, yet only a few published studies have provided reference data with respect to large groups of adults over the age of 60. Preliminary data suggest that the HRB has adequate reliability and validity in older as well as younger age groups. However, information regarding the level and pattern of performance of normal individuals over the age of 75 is lacking for the HRB as well as for virtually all other popular neuropsychological measures. Studies consistently have shown that many of the component HRB measures are quite sensitive to the effects of age (as well as education), and therefore, traditional normative cutoff scores produce an unacceptably high rate of false positive diagnostic predictions in older populations. Until more appropriate older age norms are available, great caution must be used in the interpretation of results.

Adolescent↗

PubMed1988

Short-form MMPI findings in patients with predominantly lateralized cerebral dysfunction. Neuropsychological and computerized axial tomography-derived parameters.

Short-form MMPI profiles of cerebrovascular accident and head injury patients with evidence of predominantly lateralized (N = 94) or diffuse (N = 59) cerebral damage were examined in conjunction with quantified computed axial tomographic and neuropsychological data. Results indicated that all groups tended to produce similar overall MMPI profiles, with primary elevations on Scales 8 (Sc) and 2 (D). Across the sample as a whole, patients with left hemisphere damage displayed somewhat more frequent Scale 2 elevations, although this finding was influenced by etiology effects. Left frontal lesion size among patients with left hemisphere damage was negatively associated with Scale 2 scores, and right posterior lesion size was positively associated with Scale 2 scores among patients with right hemisphere damage. Longer lesion durations generally were associated with increased MMPI scores. Results underscore the complex and multidimensional nature of the interrelationships between affective processes and localized cerebral damage.

Adolescent↗

PubMed1988

Poststroke depression and psychosis.

Stroke is capable of producing a varied spectrum of neurobehavioral syndromes that may come to the attention of the mental health professional evaluating psychiatric symptoms in elderly individuals. The neurobehavioral effects may include affective or psychotic symptoms and may occur immediately after the stroke or months to years later. The presence of underlying (or pre-existing) brain disease may have an adverse effect on the resolution of the neuropsychiatric symptoms. Although there are no treatment response studies in the area of psychosis following stroke, the response of poststroke depression to antidepressants makes attempted pharmacologic treatment of symptoms justified.

Brain↗

PubMed1988

Neuropsychology of late-life psychoses.

The number of published neuropsychological studies of older psychiatric patients have been few. Moreover, almost nothing is known about the neuropsychological status of older individuals who develop psychotic symptoms for the first time later in life. Because of the spectrum of possible diagnostic considerations, careful diagnostic evaluations are of critical importance. Such evaluations should include comprehensive history-taking (using several sources), in addition to medical, psychiatric, neurologic, neuroimaging, and neuropsychological assessments. As the number of older individuals in our population grows, we will be increasingly faced with neuropsychiatric disorders that may arise de novo in the elderly. Multimodal and longitudinal investigations of older patients who develop psychotic or depressive symptoms are needed.

Aged↗

PubMed1988

Clinical presentation of late-onset schizophrenia.

DSM-III-R defines late-onset schizophrenia as schizophrenia that begins after age 45. The authors describe five patients who met DSM-III-R criteria for this disorder. The characteristic features of the disorder include bizarre delusions (usually of a persecutory nature), auditory hallucinations, a history of normal functioning at least until age 45, and a deterioration in personal-social functioning after the onset of illness. Physical examination, routine laboratory tests, neuropsychological evaluation, and magnetic resonance imaging (MRI) scans did not suggest the presence of any diagnosable organic mental disorder. In each of the five cases, mood disorders, delusional (paranoid) disorder, and schizophrenia with onset before age 45 were also considered in the differential diagnosis and ruled out. The authors' case vignettes support the premise that late-onset schizophrenia is a clinically diagnosable entity. Cautions in the diagnosis and treatment of such patients are discussed.

Age Factors↗

PubMed1987

Handedness and dementia.

Some researchers have speculated that left-hand dominance is more prevalent among patients suffering from dementia of the Alzheimer's type which began prior to age 65 yr. and that, in those patients, the disease runs a more rapid course. In the present study, seven left-handed dementia patients were matched with seven right-handed dementia patients on the basis of age and years of education and were compared with regard to neuropsychological compromise. While the left-handed group was somewhat more impaired than the right-handed subjects, the difference between the two groups was not statistically significant.

Aged↗

PubMed1987

Relationship between cognitive and morphological asymmetry in dementia of the Alzheimer type: a CT scan study.

In this study we investigated the association between morphological asymmetry and patterns of cognitive ability in dementia of Alzheimer's type (DAT). Digitized CT scans were used to estimate volumetric parameters of the brain. The volume of the cranium, brain parenchyma, the subarachnoid space, and lateral ventricles was computed. The volume of the subarachnoid space was used as an index of cortical atrophy, while the ventricular volume served as an estimate of subcortical atrophy. Asymmetry indices were computed for all structures as the difference between left and right volume divided by their average and multiplied by 100. Cognitive asymmetry index was computed by dividing the difference between VIQ and PIQ of the Wechsler Adult Intelligence Scale (WAIS) by their average and multiplying by 100. After statistically controlling for cranial asymmetry, hemispheric asymmetry was found to correlate positively with cognitive asymmetry. The correlation was somewhat greater for male than for female patients. Asymmetry of both cortical and subcortical atrophy correlated negatively with cognitive asymmetry.

Aged↗

PubMed1986

Ventricle size, cortical atrophy and the relationship with neuropsychological status in closed head injury: a quantitative analysis.

Forty-eight patients with a history of moderate to severe closed-head injury (CHI) were examined with neuropsychological measures and computerized tomography (CT). CT scans were assessed with computerized techniques to determine estimated ventricular volumes (VV) and the degree of cortical atrophy (ATVOL) in each patient. VV's then were used to determine volumetric ventricle-brain ratios (VBR) to correct for head size. The WAIS, Wechsler Memory Scale (WMS) and Halstead-Reitan Neuropsychological Test Battery (HRNTB) were administered to all patients. Correlational analyses were undertaken between VBR and ATVOL measures. PIQ but not VIQ was negatively correlated with VBR and ATVOL, particularly in terms of right-hemisphere measures. WMS Memory Quotient (MQ) also was negatively correlated with VBR and ATVOL with no lateralization. Several HRNTB measures similarly were correlated with ventricular and atrophy estimates. Correlational results also were analyzed in terms of the influence of higher and lower VBR and ATVOL, and the prior presence of hematoma. Results are discussed in terms of the latent effects of cerebral damage secondary to CHI on neuropsychological functioning.

Adult↗

PubMed1986

The relationship between cortical atrophy and ventricular volume.

Utilizing volumetric measures of brain morphology, the relationship between cortical atrophy and ventricular dilation was examined in a sample of 59 Alzheimer's Disease patients and 48 closed head injury patients. Correlation matrices were constructed and factor analyses performed in order to elucidate the various relationships. In the Alzheimer Disease sample there appeared to be a moderately strong relationship between cortical atrophy and ventricular volume. However, analyses also lent support to the position that cortical atrophy and ventricular dilation reflect processes which are related yet somewhat independent. Results obtained from the closed head injury sample indicated that focal damage effects were more evident in cortical atrophy measures, while generalized effects were relatively more important in ventricular dilation. Finally, the relationships between neuropsychological performance and various combinations of high and low cortical atrophy and ventricular volume measures were modest.

Adolescent↗

PubMed1985

Intellectual and memory impairment in dementia. Computerized axial tomography volume correlations.

Ventricular volume estimates and an index of cerebral atrophy were obtained from computerized axial tomography scans of patients with presenile or senile dementia of probable Alzheimer's type. These measures were used to examine the correlation between morphological brain change and performance on the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Memory Scale (WMS). Despite ventricular volumes in excess of 60% larger than normal, no significant correlations were found between ventricular size and WAIS or WMS performance. The index of pericerebral atrophy did correlate negatively with various WAIS measures, particularly Performance IQ, and some aspects of WMS performance. Results suggest that in Alzheimer's disease, pericerebral atrophy measures, but not ventricular dilation, correlate with intellectual decline and certain aspects of memory impairment.

Aged↗

PubMed1985

Neuropsychological and computerized axial tomography volume characteristics of empirically derived dementia subgroups.

Neuropsychological assessment data from 138 Alzheimer's disease patients were cluster-analyzed to yield five separate subgroups. These clusters are best described as follows. Cluster I is a low-functioning subgroup characterized by severe generalized deficits (N = 25), cluster II is a subgroup characterized by a higher level of visual-spatial skills relative to the other groups (N = 39), cluster III (N = 21) and cluster IV (N = 42) are virtually indistinguishable in terms of verbal ability and memory, but do differ with regard to visual-spatial skills, and cluster V is a subgroup which presented with relatively better preserved verbal abilities (N = 11). Despite their different neuropsychological profiles, the subgroups did not differ significantly with regard to those complaints that were noted early in the course of the disease process. However, they were found to differ significantly with regard to the patients' educational backgrounds, the distribution of males and females, and the age of the patients at the time of onset of the disease. Analysis of the degree and lateralization of cortical atrophy using volumetric techniques suggested little relationship with neuropsychological examination results. Ventricular volume differences among the five subgroups were not found to be statistically significant after the effect of age had been partialled out. Results are discussed in relation to the multiple factors relating to brain structure and cognition in Alzheimer's disease.

Adult↗

PubMed1985

Late effects of hematoma on brain morphology and memory in closed head injury.

In order to examine the late effects of prior hematoma on brain morphology and memory in closed head injury (CHI), 16 patients with a history of hematoma and craniotomy following injury were matched with CHI patients without prior hematoma. Volumetric estimates of cortical atrophy and ventricle size computed from CT scans were obtained in addition to Wechsler Memory scale (WMS) scores. Patients with a history of hematoma demonstrated significantly greater cortical atrophy than nonhematoma CHI patients irrespective of hematoma location. The hematoma group also was found to have greater ventricular dilation, although this difference only approached significance. In terms of memory abilities, the hematoma group was more impaired on WMS Memory Quotient (MQ) and the Associate Learning subtest in particular. Results suggest that hematoma following head injury may promote additional detrimental effects on brain morphology and memory status.

Adolescent↗