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Biomedical subjects

D Mungas

Publications and source records attributed to D Mungas.

At least 37 records · Page 2Linked to original sources
PubMed2000

Memory failure has different mechanisms in subcortical stroke and Alzheimer's disease.

Patients with extensive subcortical cerebrovascular disease may have impaired memory, often despite the absence of medial temporal or diencephalic strokes. In this group, episodic memory failure may arise from frontal lobe dysfunction based on disruption of frontosubcortical loops caused by lacunae. We tested this idea by studying cognitively impaired subcortical stroke (CIS) patients and Alzheimer's disease (AD) patients with [18F]-fluorodeoxyglucose positron emission tomography using a continuous verbal memory task during the period of tracer uptake. Patients were matched on severity of cognitive impairment and overall memory task performance. As hypothesized, we found a double dissociation in the relations between metabolism and memory in these groups, such that memory in CIS (but not in AD) correlates with prefrontal lobe metabolism, whereas in AD (but not in CIS), memory correlates with left hippocampal and temporal lobe metabolism. Analysis of memory subscores showed that CIS patients made more errors on short-delay trials, which is consistent with working memory failure. It seems that different pathogenic mechanisms underlie episodic memory failure in subcortical cerebrovascular disease and AD.

Aged↗
PubMed1998

Impaired acquisition and rapid forgetting of patterned visual stimuli in Alzheimer's disease.

Whether or not rate of forgetting is accelerated in Alzheimer's disease (AD) is controversial. This study examined recognition of visual patterns in patients with AD and in controls at 10 min relative to a learning baseline measured after a 10-s delay (delayed recognition ratio, DRR). Comparable baseline performances were attained in the two groups by manipulating stimulus exposure times. Comparisons between 25 AD and 48 age-matched controls demonstrated lower DRR in AD when initial recognition, which was statistically worse in AD, was covariated. DRR was also lower in an analysis of subgroups closely matched on initial performance. The findings suggest that forgetting is accelerated in AD because multiple aspects of memory processing, including storage, are impaired.

Aged↗
PubMed1997

Caregiver and clinician assessment of behavioral disturbances: the California Dementia Behavior Questionnaire.

As part of a multicenter project to study noncognitive behavioral disturbances in dementia, the authors developed a comprehensive caregiver-rated questionnaire for these behaviors. The authors determined the reliability of caregiver ratings and compared caregiver ratings with clinician ratings using standard instruments. Caregivers showed good test/retest reliability for ratings of all types of patient behavioral disturbance. Caregiver interrater reliability was highest for depression and lowest for psychosis. The correlation between caregiver reports and professional assessments was highest for agitation, intermediate for psychosis, and lowest for depression. The match between caregiver and clinician assessments of patient behaviors appears to vary significantly by the type of behavior assessed.

Aged↗
PubMed1997

Fluency and memory differences between ischemic vascular dementia and Alzheimer's disease.

This study compared 32 patients with ischemic vascular dementia (IVD) to 32 patients with probable Alzheimer's disease (AD) on select language and verbal memory tests. The IVD and AD patients were individually matched on the basis of age, dementia severity, years of education, and gender. The IVD patients had poorer verbal fluency, but better free recall, fewer recal intrusions, and better recognition memory than the AD patients. Relationships between the neuropsychological measures and radiological indexes of cortical and subcortical pathology were also examined. Number of infarcts, white-matter lucency, and ventricular enlargement correlated with some of the neuropsychological measures; cortical atrophy correlated with most of the measures. The findings suggest that neuropsychological deficits in IVD may be related to dysfunction of frontal-subcortical circuits, although an associated degenerative cortical process may also be involved.

Aged↗
PubMed1996

Age and education correction of Mini-Mental State Examination for English and Spanish-speaking elderly.

Previous research has shown that the Mini-Mental State Examination (MMS) is biased as a measure of cognitive impairment in minority and low-education patients. The purpose of this study was to (1) develop a statistical correction for effects of age and education and (2) test the efficacy of the statistically adjusted MMS (MMSAdj) as a screening test for dementia using different ethnic groups and education levels. We used a population-base community survey sample (n=590) composed of 46.6% Hispanics and 53.4% non-Hispanics to derive the statistical correction, defined as:MMSAdj = Raw MMS - (0.471 X [Education-12]) + (0.131 X [Age-70]). Ethnicity and language of test administration were not significantly related to MMSAdj in the community survey sample, but the raw MMS was strongly influenced by these factors. We used an independent sample (n=2,983) of patients evaluated through the California Alzheimer's Disease Diagnostic and Treatment Centers to test the diagnostic accuracy of the MMS and the MMSAdj across low- and high-education groups and across whites, Hispanics, and blacks. Results showed greater stability of sensitivity and specificity across education levels and ethnic groups for the MMSAdj than for the raw MMS and suggest that the MMSAdj is a preferable measure of cognitive impairment for low- education and minority individuals.

Black or African American↗
PubMed1994

Effects of acute alcohol administration on verbal and spatial learning.

The effects of alcohol and placebo on cognitive functioning in male, Asian-American college students were evaluated with a double-blind, placebo-controlled cross-over design using a multi-trial learning test in which verbal and spatial learning were simultaneously assessed. Verbal recall was impaired consistently across learning trials, while impairment of spatial recall was evident only on later learning trials. Recall of spatial information was influenced by order of presentation and amount of exposure time of items. Results do not support a theory that spatial learning is more impaired by alcohol than verbal learning, and thus do not lend support for the hypothesis that alcohol has a greater effect on right than left hemisphere functioning. Results provide evidence that alcohol increases susceptibility to interference effects.

Adult↗
PubMed1992

Serotonin response in sweet-food craving Alzheimer's disease subjects.

Abnormal sweet-food craving may occur in subjects with Alzheimer's disease. This behavior may be due to abnormalities in the brain serotonin system. Fenfluramine stimulates the brain serotonin neurosystem, producing an increase in systemic prolactin. Using the fenfluramine stimulation test, brain serotonin system response was evaluated in 12 subjects with probable Alzheimer's disease. The subjects' caregivers completed questionnaires concerning subject food preferences and behaviors. Alzheimer's disease subjects with sweet-food craving were found to have a significantly higher response to fenfluramine than non sweet-food craving subjects. This preliminary study is limited by small sample size. Allowing for assumptions concerning central nervous system regulatory processes, the data suggest a possible role for the serotonin system in sweet-food craving in Alzheimer's disease.

Aged↗
PubMed1991

In-office mental status testing: a practical guide.

Elderly patients with dementia often first come to the attention of their primary medical care providers. Evaluation of cognitive functioning is an important part of the diagnostic work-up, since dementia is a disorder defined by problems of mental or cognitive abilities. Mental status examination in the physician's office can provide diagnostically valuable information and prove useful for determining the need for referral for formal neuropsychological testing. This article briefly describes the cognitive changes associated with dementia and explains proper administration and interpretation of the Mini-Mental State Examination, a quantitative screening test of cognitive function.

Activities of Daily Living↗
PubMed1990

Effects of haloperidol on recall and information processing in verbal and spatial learning.

1. Normal male subjects were tested with either a multi-trial word list learning test or a spatial analogue prior to administration of either 4 mg. or 10 mg. of oral haloperidol. Six hours after drug administration subjects who had previously received the verbal test were administered the spatial test, and vice versa, so for each test there was a no-drug control group, a group tested after receiving 4 mg. of haloperidol, and a group tested after a 10 mg. dose. 2. Both the verbal and spatial learning tests yield multidimensional measures of components of memory and learning, including measures sensitive to effort-demanding and more automatic information processing operations. 3. Results showed no differences for either test among the pre-drug control group and the 4 mg. and 10 mg. groups, with only one minor exception. 4. The lack of significant results cannot be attributed to insensitivity of the test instruments used, since previous studies have documented sensitivity to a number of clinical conditions and to aging. 5. Results have implications regarding clinical effects of haloperidol. A theory that links dopaminergic functioning with effortful information processing underlying memory and learning was not supported.

Adult↗
PubMed1990

Dietary preference for sweet foods in patients with dementia.

Using a telephone survey, patients with probable Alzheimer's disease (n = 31) and vascular dementia (n = 14) were compared with elderly normal controls (n = 43) in preferences for different foods. Patients with Alzheimer's disease had a greater preference than normal controls for relatively high-fat, sweet foods and for high-sugar, low-fat foods, but did not significantly differ in preference for other foods, including those high in complex carbohydrates and protein. Vascular dementia patients showed a similar pattern, not significantly different from that for Alzheimer's patients. Results did not consistently support a hypothesis that increased sweet preference is a nonspecific form of disinhibited behavior related to declining mental status, nor was a hypothesis relating sweet preference to serotonin activity within the brain consistently supported. Results provide preliminary evidence that craving for sweet food may be a significant part of the clinical syndrome of dementia, but further research is needed to delineate the psychological and biological mechanisms accounting for it.

Aged↗
PubMed1990

Relation of cognitive status and abnormal behaviors in Alzheimer's disease.

Some studies suggest that abnormal behaviors are associated with increasing cognitive loss in Alzheimer's disease (AD). Other studies do not show this association. We examined the relation of cognitive loss, represented by Folstein Mini-Mental State Examination (MMSE) score, with abnormal behaviors in 680 patients with probable AD. Six behaviors were examined: agitation/anger, personality change, wandering, hallucinations/delusions, insomnia, and depression. All but depression were associated with declining MMSE score. The number of abnormal behaviors present in each patient was also related to declining MMSE score. Several other associations were also found: hallucinations/delusions were associated with age and race; agitation/anger was related to male gender; and wandering was associated with increased age. Although these data support the general notion that five of the six abnormal behaviors studied are more likely to occur with increasing cognitive loss, the correlations are small and it is suggested that other as yet unproven factors may play an as large or greater role than MMSE score in predicting such behaviors.

Age Factors↗
PubMed1989

Effect of haloperidol on a symbol digit substitution task in normal adult males.

Two groups of normal male volunteers were administered oral haloperidol at two dose levels: 4 mg (n = 12), and 10 mg (n = 9). Subjects were administered the Symbol-Digit Substitution Test (SDST) prior to drug administration (0 hours) and at the following intervals after administration: 1, 3, 4, 6, 14, 24, and 36 hours. Overall performance of the 10-mg group was poorer than that of the 4-mg group. Both groups showed a significant time-dependent decrease in performance, with the effects for the 10-mg group being apparent earlier and lasting longer. The time course for this decrease corresponded to the time course of elevation of prolactin by haloperidol in these subjects. Performance on the Flexibility of Closure Test was unimpaired in subjects receiving 10 mg haloperidol, indicating that the impairment in performance on the SDST was not exclusively due to nonspecific factors such as sedation or psychomotor retardation. Extrapyramidal side effects could have contributed to impairment on the SDST, but the time course of these effects was different than that of performance impairment. Results indicate that haloperidol may have dose-dependent differential adverse effects on task performance when administered on a short-term basis, although little is known about the exact nature of these effects and their relationship to antipsychotic activity of the drug. Even though these effects may clear with repeated administration, their presence even for a short time may contribute adversely to the risk-benefit profile of neuroleptic medication.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

AIDS as a cause of dementia in the elderly.

It has been recognized that AIDS can present initially as dementia without other neurological or clinical manifestations. In addition, HIV-contaminated blood transfusions in the elderly seem to be underreported. Because of these findings, dementia in the elderly may be misdiagnosed as Alzheimer's disease or other causes of senile dementia. This paper reports on one patient who presented with a diagnosis of Alzheimer's disease and was later found to have AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Psychometric correlates of episodic violent behaviour. A multidimensional neuropsychological approach.

Three groups of neuropsychiatric out-patients, homogeneous according to parameters of violent behaviour, were identified in a previous study using a cluster analysis procedure and compared in this study on psychometric variables. These groups were (a) a group manifesting frequent, impulsive violence (n = 35), (b) a non-violent group (n = 57), and (c) a group whose violent behaviour was much less frequent and severe than in the first group, and more provoked (n = 31). Impulsively violent patients showed language and visual-perceptual deficits, but no other neuropsychological or intellectual deficits. The MMPI F, K and Ma and MacAndrews Alcoholism scales and a perceptual organisation factor derived from the Holtzman Inkblot Test significantly discriminated groups. Results of this and the initial study have implications regarding psychological aspects of aggression and underlying biological mechanisms.

Adolescent↗
PubMed1985

Successful treatment of psychotic depression with carbamazepine.

A patient with recurrent episodes of major depression with psychotic features was treated successfully with carbamazepine after unsatisfactory response to other interventions. Since psychotic depression is often difficult to treat with medications, carbamazepine may be a useful addition to the clinician's pharmacological armamentarium.

Adult↗
PubMed1984

Hypersomnia in major depressive disorders.

Hypersomnia was experienced by 17 of 102 patients with major depressive disorder. Comparisons between hypersomnic and non-hypersomnic depressives demonstrated significant associations between hypersomnia and increased appetite, weight gain, agitation, headaches, depression in a first-degree relative, and earlier age of illness onset.

Appetite↗