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Biomedical subjects

B Giordani

Publications and source records attributed to B Giordani.

12 recordsLinked to original sources
PubMed1992

Verbal fluency and positron emission tomographic mapping of regional cerebral glucose metabolism.

Impairment in verbal fluency (VF) has been a consistently reported clinical feature of focal cerebral deficits in frontal and temporal regions. More recent behavioral activation studies with healthy control subjects using positron emission tomography (PET), however, have noted a negative correlation between performance on verbal fluency tasks and regional cortical activity. To see if this negative relationship extends to steady-state non-activation PET measures, thirty-three healthy adults were given a VF task within a day of their 18F-2-fluoro-2-deoxy-D-glucose PET scan. VF was found to correlate positively with left temporal cortical region metabolic activity but to correlate negatively with right and left frontal activity. VF was not correlated significantly with right temporal cortical metabolic activity. Some previous studies with normals using behavioral activation paradigms and PET have reported negative correlations between metabolic activity and cognitive performance similar to that reported here. An explanation for the disparate relationships that were observed between frontal and temporal brain areas and VF might be found in the mediation of different task demands by these separate locations, i.e., task planning and/or initiation by frontal regions and verbal memory by the left temporal area.

Adult↗
PubMed1990

Neuropsychological changes in olivopontocerebellar atrophy.

We used standardized neuropsychological measures of intellectual, cognitive, psychomotor, and emotional functioning to compare 39 patients with olivopontocerebellar atrophy and 25 normal controls of similar age. The patients reflected greater depression, anxiety, and subjective emotional discomfort than did the control subjects. While 4 of the patients had below-normal IQ scores (Wechsler Adult Intelligence Scale [WAIS-R] Full-Scale IQ [FSIQ] less than 80), their clinical histories suggested lifelong functioning at such levels. As a group, the patients were not abnormal in general intellectual functioning and related cognitive abilities (WAIS-R FSIQ, mean [+/- SD], 93.46 +/- 13.19; Wechsler Memory Scale mental quotient, 108.95 +/- 17.43). These scores were lower than those of the normal controls (WAIS-R FSIQ, 113.72 +/- 12.68; mental quotient, 127.80 +/- 12.40); however, the controls were a highly educated group with intelligence levels that were higher than those of the average population. Moreover, when education and motor dysfunction were statistically covaried, no significant differences between the patients and the normal controls were apparent on the cognitive and intellectual tasks. Further analysis of specific memory performance in a subgroup of patients and controls matched for age, sex, and education yielded findings that were comparable with the overall group analysis. We conclude that motor dysfunction and depressed mood could leave patients with olivopontocerebellar atrophy appearing to be impaired in memory, even demented, when they are not.

Adult↗
PubMed1990

Anxiety and cerebral cortical metabolism in normal persons.

The State-Trait Anxiety Inventory (STAI) was administered to 43 normal volunteers immediately before and after a positron emission tomography (PET) procedure with [18F]-2-fluoro-2-deoxy-D-glucose (18F-FDG). High trait-anxious individuals had significantly higher state (situational) anxiety associated with the PET scan procedure than did low trait-anxious persons. State anxiety decreased significantly for all respondents following the PET scan procedure. No significant relationships between global or regional cortical metabolic rates and state anxiety were observed. The direct cortical metabolic effects of heightened anxiety in the scan setting, should they exist, are likely obscured in the normal variance of the 18F-FDG method.

Adolescent↗
PubMed1990

Pharmacologic treatment of noncognitive behavioral disturbances in elderly demented patients.

Fifty-nine elderly residents of long-term care facilities who had DSM-III diagnoses of dementia were studied in an 8-week randomized, double-blind comparison trial of haloperidol, oxazepam, and diphenhydramine to test the efficacy of these agents in the treatment of clinically significant behavioral disturbances in patients with dementia. All three agents demonstrated modest but significant efficacy as measured by clinician ratings of agitated behavior and activities of daily living. The absolute magnitude of improvement was greater for haloperidol and diphenhydramine than for oxazepam, but differences among groups did not approach statistical significance. Frequencies of acute adverse events during the trial were similar across the drug treatment groups. Although these drugs may differ in terms of long-term safety and efficacy, they appear to be equivalent for short-term management of agitated behavior in severely demented patients.

Activities of Daily Living↗
PubMed1990

The utility and generality of Mini-Mental State Examination scores in Alzheimer's disease.

The present study sought to evaluate the validity and generality of the Mini-Mental State Examination (MMSE) and its subsection scores. We gave the MMSE and other neuropsychological tests to 51 patients with probable Alzheimer's disease. On the basis of correlational and factor analyses, overall performance on the MMSE proved to have good concurrent validity with other comprehensive neuropsychological assessment instruments. However, the MMSE subsections should not be viewed as highly specific measures of cognition or memory.

Aged↗
PubMed1988

Fast kinetics analysis of the peroxidatic reaction catalysed by horse liver alcohol dehydrogenase.

The kinetics of the enzymatic step of the peroxidatic reaction between NAD and hydrogen peroxide, catalysed by horse liver alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC 1.1.1.1), has been investigated at pH 7 at high enzyme concentration. Under such conditions no burst phase has been observed, thus indicating that the rate-limiting step in the process, which converts NAD into Compound I, either precedes or coincides with the chemical step responsible for the observed spectroscopic change. Kinetic analysis of the data, performed according to a simplified reaction scheme suggests that the rate-limiting step is coincident with the spectroscopic (i.e., chemical) step itself. Furthermore, the absence of a proton burst phase indicates the proton release step does not precede the chemical step, in contrast with the case of ethanol oxidation. A kinetic effect of different premixing conditions on the reaction rate has been observed and attributed to the presence of NADH formed in the 'blank reaction' between NAD and residual ethanol tightly bound to alcohol dehydrogenase. A molecular mechanism for the enzymatic peroxidation step is finally proposed, exploiting the knowledge of the much better known reaction of ethanol oxidation. Inhibition of this reaction by NADH has been investigated with respect to H2O2 (noncompetitive, Ki about 10 microM) and to NAD (competitive, Ki about 0.7 microM). The effect of temperature on the steady-state reaction state (about 65 kJ/mol activation energy) has also been studied.

Alcohol Dehydrogenase↗
PubMed1988

Memory impairment in schizophrenic patients with tardive dyskinesia.

Memory functioning was contrasted in 40 schizophrenic patients with and without tardive dyskinesia (TD). Visual and verbal memory tests were used to investigate specific types of impairments. The presence of TD was ascertained using the Abnormal Involuntary Movement Scale (AIMS). TD patients scored significantly lower than non-TD patients on two measures of visual learning, though no differences were found for verbal learning or immediate recall. These results are consistent with previous reports that schizophrenic patients with TD demonstrate impaired cognitive functioning. They also raise the possibility that the neurochemical and structural changes underlying TD may produce specific deficits in memory for visual materials. In addition, a significant relationship was found between total score on the Brief Psychiatric Rating Scale (BPRS) and performance on all of the test measures included in the cognitive test battery. This demonstrates the importance of attending to the overall level of schizophrenic symptomatology when evaluating results from experimental learning tasks.

Dyskinesia, Drug-Induced↗
PubMed1988

Positron emission tomographic scan investigations of Huntington's disease: cerebral metabolic correlates of cognitive function.

Fifteen drug-free patients with early to mid-stage Huntington's disease (HD) were evaluated with positron emission tomographic (PET) scans of 18F-2-fluoro-2-deoxy-D-glucose uptake and quantitative measures of neurological function, learning, memory, and general intelligence. In comparison with a group of normal volunteers, the HD patients showed lower metabolism in both caudate (p less than 0.001) and putamen (p less than 0.001) on PET scans. A significant and positive relationship was found between neuropsychological measures of verbal learning and memory and caudate metabolism in the patient group but not in the normal group. Visual-spatial learning did not reflect a similar pattern, but performance intelligence quotient was positively related to both caudate and putamen metabolism in the HD group. Vocabulary level was unrelated to either brain structure. Discussion focuses on these and other observed brain-behavior relationships and on the implications of these findings for general behaviors such as those involved in coping and adaptation.

Adult↗
PubMed1986

PET scan investigations of Huntington's disease: cerebral metabolic correlates of neurological features and functional decline.

Fifteen drug-free patients with early to midstage Huntington's disease were evaluated with quantitative neurological examinations, scales for functional capacity, computed tomographic (CT) scans, and positron emission tomographic (PET) scans of 18F-2-fluoro-2-deoxyglucose (18F-FDG) uptake. All patients had abnormal indices of caudate metabolism on PET scanning, whereas in patients with early disease indices of putamen metabolism and CT measures of caudate atrophy were normal. Indices of caudate metabolism correlated highly with the patients' overall functional capacity (r = 0.906; p less than 0.001) and bradykinesia/rigidity (r = -0.692; p less than 0.01). Indices of putamen metabolism correlated highly with motor functions: chorea (r = -0.841; p less than 0.01), oculomotor abnormalities (r = -0.849; p less than 0.01), and fine motor coordination (r = -0.866; p less than 0.01). Indices of thalamic metabolism correlated positively with dystonia (r = 0.559; p less than 0.05). The data suggest that PET scanning with 18F-FDG is a sensitive measure of brain dysfunction in Huntington's disease and that basal ganglia metabolism is highly correlated with the overall functional capacity of individual patients and with the degree of their motor abnormalities.

Activities of Daily Living↗
PubMed1977

Reading disability: an information-processing analysis.

In a task designed to separate perceptual processes from memory, 12-year-old children with reading disabilities showed no perceptual deficits as compared to their peers. However, they exhibited major deficiencies in memory skills for both labelable and nonlabelable visual information. Reading-disabled children in this age group appear to suffer from a basic information-processing deficiency.

Child↗
PubMedDate not supplied

Zonisamide (CI-912) and cognition: results from preliminary study.

Nine patients with refractory partial seizures were evaluated in a pilot study of a new anticonvulsant compound, zonisamide (1,2-benzisoxazole-3-methanesulfonamide; CI-912). Cognitive functioning was evaluated prior to treatment with zonisamide and repeated after 12 and 24 weeks of treatment with zonisamide. At minimum steady-state plasma concentrations greater than 30 micrograms/ml, zonisamide appeared to affect specific cognitive functions such as acquisition and consolidation of new information. Previously learned material, such as vocabulary, and psychomotor performance were not affected. Verbal learning was affected, while visual-perceptual learning was unimpaired. These cognitive effects were observed in the absence of the usual clinical signs and symptoms of toxicity. A linear relationship was found between impairment of cognitive abilities and the minimum plasma concentration (r = -0.73; p less than 0.05). Findings also suggest the development of tolerance to the adverse cognitive effects.

Adult↗