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Biomedical subjects

M Serby

Publications and source records attributed to M Serby.

At least 19 recordsLinked to original sources

Hypersensitivity to scopolamine in the elderly.

Scopolamine hydrobromide, 0.43 mg/70 kg, was administered by subcutaneous injection to ten young and ten elderly subjects. A comprehensive neuropsychological test battery was used to assess the effects of scopolamine, as compared to placebo, on cognitive function. As previously reported for this group of young subjects, scopolamine significantly impaired performance on tests of recent memory and visuospatial praxis. The same effects were observed in the elderly subjects, but the magnitude of the effects was much larger. The scopolamine injections produced significant psychomotor slowing in the elderly, whereas higher doses of the drug are required to produce this effect in young subjects. In both young and old subjects scopolamine failed to affect immediate memory, language function, object sorting, and the frequency of intrusion errors (although trends toward an effect were more apparent in the elderly). Remote memory, tested in the elderly only, was also unaffected. The results suggest that scopolamine's cognitive effects are quantitatively more pronounced in elderly subjects than young subjects, but that they are qualitatively similar and do not constitute a valid model for the cognitive dysfunction associated with Alzheimer's disease.

Adolescent

Olfactory identification deficits in HIV infection.

OBJECTIVE: Impaired odor identification is described in a number of CNS disorders, and human immunodeficiency virus (HIV) infects the CNS in a large percentage of patients. To evaluate whether impaired olfaction may indicate CNS disease, the authors measured odor identification in patient groups defined along a continuum of progressive immunodeficiency and in a comparison group. METHOD: Most of the 42 HIV-infected patients in the study were outpatients in a clinic specializing in treatment of HIV-infected individuals. The comparison subjects were 37 healthy age- and sex-matched individuals who were recruited from hospital and medical school personnel. Ten of the patients were HIV-seropositive but had no symptoms, 24 had clinical evidence of immunocompromise, and eight had HIV dementia. All subjects were given the University of Pennsylvania Smell Identification Test, which presents common odorants and requires the subject to identify the odor from a four-item word list. The data were analyzed by using analysis of variance after arc-sine transformation and Scheffé post hoc analysis. RESULTS: All patients scored significantly lower on the Smell Identification Test than did the comparison subjects. The patients with HIV dementia had significantly lower scores than did the other two groups of patients. CONCLUSIONS: Clinically, impaired olfaction might serve as a marker of early CNS HIV involvement. Future studies should attempt to match comparison and experimental populations for socioeconomic status and HIV risk behavior.

AIDS Dementia Complex

The nature and course of olfactory deficits in Alzheimer's disease.

OBJECTIVE: The aim of this study was to determine the specific nature and course of olfactory deficits in Alzheimer's disease. Previous studies had noted impaired odor identification, but there was no unanimity about the presence of odor detection deficits. METHOD: Odor identification was tested in 55 patients with Alzheimer's disease and 57 elderly control subjects by using the University of Pennsylvania Smell Identification Test. Odor detection was assessed in 46 subjects with Alzheimer's disease and 40 control subjects by using a forced-choice threshold test with geraniol as the odorant. RESULTS: Significant deficits in olfactory identification were present in subjects who were in the earliest stages of cognitive impairment, and these deficits increased as Alzheimer's disease progressed. There was some overlap in individual smell identification test scores between cognitively impaired patients and normal elderly subjects. On the other hand, odor detection deficits did not appear until Alzheimer's disease was relatively advanced. Smell identification test scores were correlated with Mini-Mental State scores, but geraniol detection was not. CONCLUSIONS: Odor identification is impaired early in Alzheimer's disease and may be more influenced by cognitive status than is acuity of odor detection, which is not altered until later in the disorder. The pattern of hyposmia in Alzheimer's disease suggests that the disorder may not "begin in the nose," as has been theorized previously. Further refinement of olfactory testing may be useful in the diagnostic evaluation of early dementia.

Aged

Scopolamine effects on memory, language, visuospatial praxis and psychomotor speed.

Scopolamine hydrobromide was administered by subcutaneous injection to 30 young subjects in a dose of 0.22 mg/70 kg, 0.43 mg/70 kg, or 0.65 mg/70 kg. Treatment effects were compared to placebo on an extensive cognitive assessment battery. Almost all tests in the battery had been previously administered to Alzheimer's disease patients and nondemented elderly subjects. Scopolamine produced deficits on tests of verbal recall, visuospatial recall, visual recognition memory, visuospatial praxis, visuoperceptual function, and psychomotor speed. Immediate memory, language function, object sorting, and frequency of intrusion errors were unaffected. The low dose of scopolamine produced some peripheral anticholinergic signs but did not affect the cognitive measures. The results support the conclusion reached in previous studies that the cognitive profile of scopolamine-injected young subjects is more similar to that of the nondemented elderly than to that of Alzheimer's disease patients.

Adolescent

ECT and Parkinson's disease revisited: a "naturalistic" study.

In an open study, seven patients with Parkinson's disease received ECT for major depression. Both the motor dysfunction and the mood impairment of these patients improved following an average of seven ECT sessions. Significant improvement in motor function occurred after only two treatments. All aspects of Parkinson's disease improved significantly after ECT. Older patients showed greater improvement in motor function. The authors conclude that the therapeutic utility of ECT in depressed and nondepressed patients with Parkinson's disease should be further evaluated.

Aged

Clinical stages of dementia and the dexamethasone suppression test.

1. This study was undertaken to evaluate the relationship between clinical aspects of primary degenerative dementia and suppression or non-suppression in the dexamethasone suppression test. 2. We studied 34 male patients with primary degenerative dementia (as diagnosed by DSM-III criteria). Dexamethasone 1 mg p.o. was administered at 11:00 PM and blood was drawn for cortisol determination at 4:00 PM the next day. 3. CLINICAL FACTORS INCLUDED: age, age at onset, duration of dementia, history of psychiatric illness, severity as measured by Global Deterioration Scale (GDS) score, and "malignancy" of dementia (rated by years of onset to institutionalization and as a ratio of Global Deterioration Scale to duration of primary degenerative dementia). 4. RESULTS: 56% of primary degenerative dementia patients failed to suppress. The highest degree of non-suppression was seen in Global Deterioration Scale 5 and 6 subjects (Table). 5. An unexpected finding was that a large number of Global Deterioration Scale 7 patients demonstrated normal post-dexamethasone suppression of the hypothalamic-pituitary-adrenal axis. 6. Some contradictions in previously reported studies may be explained by this pattern.

Aged

Olfaction and hemodialysis: baseline and acute treatment decrements.

The effect of hemodialysis (HD) on olfactory recognition and memory function was investigated in people receiving chronic HD treatment. Fifteen subjects were given an olfactory recognition task 0.5 h before and 0.5 h after a dialysis session in counterbalanced order. Ten dialysis patients received a verbal recall task twice. Ten age-matched normal subjects received the olfactory task twice. Results were: (1) olfactory scores in the HD group were significantly lower than control subjects scores; (2) within the dialysis sample, olfactory identification scores were significantly lower after treatment than before, and (3) there were no parallel decreases in memory performance of the dialysis group after a HD treatment. We therefore conclude that those subjects receiving HD treatment demonstrate acute and chronic deficits in olfactory recognition which are unlikely to be due to fatigue, cognitive disequilibrium, anticoagulant treatment or high levels of uremic toxins.

Adolescent

Dementia in an American-Chinese nursing home population.

Of 58 demented residents in an American-Chinese nursing home, 44 (75.9%) had multi-infarct dementia, seven (12.1%) had possible Alzheimer's disease, four (6.9%) had other dementias, and three 5.2% had unknown disorders. Alzheimer's disease was relatively less prevalent than in U.S. nursing homes overall.

Aged

Olfactory deficits in Alzheimer's disease.

Altered olfactory function may be important clinically and theoretically in Alzheimer's disease (AD). Initial evidence of poor olfactory recognition performance in AD was followed by other reports of hyposmia in this disorder. Although two of these studies have found significantly better performance in other demented groups, the utility of olfactory testing in the differential diagnostic workup of dementia may have limitations. Neuroanatomical and neurochemical studies relevant to AD and olfaction are reviewed. Finally, the effects of aging on olfactory performance is discussed. It is concluded that these effects cannot be adequately assessed without rigorous control for cognitive status in sampled cohorts.

Acetylcholine

Olfaction and Alzheimer's disease.

Disturbances in the sense of smell may be important both clinically and theoretically in Alzheimer's disease. Initial evidence of poor olfactory recognition performance in Alzheimer's and parkinsonian dementias was followed by two reports which corroborated olfactory dysfunction in Alzheimer's disease. The neuroanatomical and neurochemical bases for this disturbance are discussed. Despite an abundance of preclinical and clinical data linking olfaction with acetylcholine, a preliminary study failed to show any effect of scopolamine on olfactory thresholds. Two of the olfaction-Alzheimer's studies found significantly better performance in other demented groups (alcoholics and patients with vascular dementia), suggesting possible utility in the differential diagnostic workup. The effect of aging per se on olfactory performance cannot be assessed without rigorous control for cognitive dysfunction in sampled populations.

Acetylcholine

Naltrexone and Alzheimer's disease.

Naltrexone, an oral opiate antagonist, was administered to nine patients with a diagnosis of Alzheimer's-type dementia (ATD) in a two-phase design: an open dose-ranging phase and a double-blind placebo-controlled trial for patients who showed improvement during the open phase. After a three day placebo (baseline) period, patients received increasing doses of naltrexone over two weeks up to a maximum daily dose of 100 mg. Assessments were made at baseline and at daily dose of 5 mg, 50 mg and 100 mg. Testing was done 2 to 4 hours after medication was administered. Any patient who showed cognitive/behavioral improvement on a given dose of naltrexone was then treated with this dosage in a double-blind crossover comparison to placebo. Criteria for inclusion in the double-blind phase consisted of improvement on three behavioral scales and at least one cognitive test on a given dose of naltrexone. Each double-blind phase followed a one-week washout and was two weeks long. Two of the nine patients demonstrated apparent cognitive enhancement on 100 mg daily of naltrexone and were then tested in the double-blind crossover period. Only one of these patients improved during active naltrexone administration. We conclude that the opiate antagonist naltrexone in a dosage range of 5-100 mg daily is not efficacious in ATD.

Alzheimer Disease