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Biomedical subjects

Y Stern

Publications and source records attributed to Y Stern.

At least 271 records · Page 15Linked to original sources
PubMed1986

Correlates of early disability in Huntington's disease.

Functional disability in Huntington's disease usually results from a combination of the movement disorder, intellectual decline, and psychopathological changes, but the unique contribution of each element has never been investigated. The Shoulson-Fahn functional capacity rating scale measures independence in such daily activities as eating, dressing, and managing personal finances, and is used to stage the illness and follow its progression. To determine which problems contribute most to reduced functional capacity as the disease evolves, we reviewed the records of 48 consecutive patients who were evaluated for intellectual and emotional status and motor disability. Each patient was staged and rated for functional capacity at the time of the examinations. Thirty-three of these patients were followed over several years with repeat evaluations at 6-month intervals. Intellectual impairment and depression correlated significantly with reduced functional capacity. However, when the somatic symptoms of depression were eliminated from the analysis, its relationship to functional capacity was no longer significant. Duration of illness, motor disability, and age at onset also had little impact. Neuropsychological test performance and functional capacity deteriorated over time. Our data suggest that intellectual impairment is a major factor in reducing functional capacity in the early stages of Huntington's disease.

Activities of Daily Living↗
PubMed1986

Clinical and biochemical features of depression in Parkinson's disease.

Among 49 consecutive patients with Parkinson's disease, 40% were depressed according to DSM-III; they had major depression or dysthymic disorder accompanied by sleep disturbance, fatigue, psychomotor retardation, loss of self-esteem, and excessive guilt. During a 10-day dopamine-free period, lumbar puncture was performed to measure the metabolites of dopamine, serotonin, and norepinephrine. Patients were given an overnight dexamethasone suppression test, and the effects of thyrotropin-releasing hormone and L-dopa on plasma growth hormone and prolactin were examined. Level of CSF 5-hydroxyindoleacetic acid was lowest in parkinsonian patients with major depression and was related to psychomotor retardation and loss of self-esteem.

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PubMed1985

Reappraisal of temporary levodopa withdrawal ("drug holiday") in Parkinson's disease.

Transient withdrawal of therapy has been advocated as a method of dealing with the complications of long-term use of levodopa in the treatment of Parkinson's disease. We retrospectively examined the effect of a 10-day period of levodopa withdrawal, or "drug holiday," in 28 patients. We then compared the subsequent clinical course of these patients over one year with that of 30 other randomly selected, similar patients with Parkinson's disease. In both groups the disease progressed; there was no difference in disease severity, capacity for daily living activities, or total amounts of dopamine agonists eventually used. For some patients, it was possible to reduce dopamine agonists used immediately after the drug holiday without causing deterioration, but a pulmonary embolus and other complications occurred. Subsequent complications related to long-term dopamine-agonist therapy during the follow-up period were similar in the two groups. this investigation indicates that a drug holiday carries some risk and does not improve the efficacy of levodopa therapy or prevent the problems that occur with long-term administration.

Activities of Daily Living↗
PubMed1985

Intellectual changes in patients with MPTP-induced parkinsonism.

We studied six patients with MPTP-induced parkinsonism to assess intellectual function, attention, reaction time, and depression. Eight controls with a similar history of drug abuse also participated. General intellectual function, construction, category naming, and frontal lobe function were worse in the patients; other aspects of performance were comparable. All affected women but none of the men were depressed, usually before onset of parkinsonism. The pattern of intellectual deficit in the MPTP patients was similar to that of idiopathic Parkinson's disease. Since MPTP-induced parkinsonism probably represents a purely dopaminergic deficiency, these findings suggest that changes in the dopamine system are responsible for at least some of the intellectual changes of idiopathic Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1985

Heterogeneity in dementia of the Alzheimer type: evidence of subgroups.

We reviewed records of 121 consecutive patients with dementia of the Alzheimer type. Patients with myoclonus or extrapyramidal signs had greater intellectual decline and functional impairment in daily activities. Among patients studied over 4 years, there were four groups: benign--little to no progression; myoclonic--severe intellectual decline and frequent mutism after younger onset; extrapyramidal--severe intellectual and functional decline and frequent psychotic symptoms; typical--a gradual progression of intellectual and functional decline, but without other distinguishing features. Except for the group with myoclonus, no subgroup was segregated by age at onset or other demographic variables. This study suggests that dementia of the Alzheimer type is heterogeneous, and that certain clinical manifestations may be useful in predicting outcome.

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PubMed1984

Reaction time and vigilance in Parkinson's disease. Possible role of altered norepinephrine metabolism.

Delayed reaction time and diminished vigilance have been observed in Parkinson's disease (PD) but have not been related to biochemical changes in the disease. As norepinephrine is reduced in the brain in PD and this neurotransmitter has been related to attention and learning, we investigated the relationship of neuropsychological measures, including those of reaction time and vigilance, to the norepinephrine metabolite 3-methoxy - 4 - hydroxyphenethyleneglycol (MHPG) in 39 patients with idiopathic PD. The MHPG levels correlated with a measure of general intellectual ability and with performance on reaction time and continuous performance tasks. Our data suggest that altered norepinephrine metabolism may contribute to some aspects of intellectual dysfunction in PD.

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PubMed1984

Contribution of perceptual motor dysfunction to construction and tracing disturbances in Parkinson's disease.

Patients with Parkinson's disease and controls traced patterns of increasing complexity presented on a vertical transparent screen. Some patterns were presented with missing segments which subjects were required to fill in. Digitising equipment quantitated movements for computer analysis. Subjects also completed a brief test of general intellectual function, a construction test and an assessment for depression, and the severity of patients' Parkinsonian signs and symptoms was rated. Patients performed more poorly than controls on complete patterns, and their errors increased more sharply than controls on patterns with missing segments. Patients' errors, but not those of controls, in filling in missing segments were uniquely related to performance on construction tasks. Other aspects of patients' tracing performance correlated with the severity of their Parkinsonian symptoms. These findings suggest that there is an underlying perceptual motor deficit in Parkinson's disease that affects performance on both tracing and construction tasks.

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PubMed1984

Pergolide therapy for Parkinson's disease: neurobehavioral changes.

Pergolide mesylate, a long-acting dopamine agonist, is effective in treating Parkinson's disease. Behavioral change is said to be one adverse effect. We therefore studied 19 parkinsonian patients with neuropsychological tests before and after initiating pergolide therapy. Intellectual and behavioral changes were also monitored clinically for up to 2 years. There was no decline in performance on the neuropsychological tests. Six patients had transient psychiatric or intellectual changes that were controlled by reducing drug dosage. These changes were similar to those seen with other dopamine agonists.

Adult↗
PubMed1984

Altered serotonin metabolism in depressed patients with parkinson's disease.

Depression is a common symptom in patients with Parkinson's disease. It is not related to the severity of the motor symptoms or changes in dopamine metabolism and does not improve on treatment with dopamine agonists. Alterations in serotonin metabolism are found in primary (endogenous) depression. The brain content of serotonin in Parkinson's disease is also reduced, but this has not been related to any manifestation of the disorder. We found that the CSF content of the major metabolite of serotonin, 5-hydroxyindoleacetic acid, was lower in depressed than in nondepressed parkinsonians. The data suggest that the alterations in serotonin metabolism in Parkinson's disease identify a subgroup of patients who are prone to depression.

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PubMed1983

Functional asymmetry of the amine transporter from chromaffin granules.

The studies presented in this communication describe the existence of a pH-dependent kinetic barrier in amine translocation in membrane vesicles isolated from chromaffin granules from bovine adrenal medulla. This barrier prevents efflux of amines previously accumulated in the membrane vesicles. In these preparations, once the amine is accumulated, there is no further need for ATP. This would suggest a low permeability of the membrane, both to ions and to the amine. In addition, we show that under conditions which thermodynamically favour efflux this is kinetically blocked. This block is due to a rapid protonation of the transporter in the interior of the vesicle. Net efflux can be induced by agents that bring upon an alkalinization of the internal pH such as ammonium salts or nigericin. On the other hand, the rate of exchange with extravesicular substrate is almost identical at the various pH values tested. The physiological implications of this mechanism are discussed.

Adenosine Triphosphate↗
PubMed1983

Is "subcortical dementia" a recognizable clinical entity?

The concept of "subcortical dementia" is controversial, lacking clinical validation and having only a questionable pathological basis. Over 100 patients with Alzheimer's, Parkinson's or Huntington's disease, subdivided into three functional disability stages, were given a brief quantitative neuropsychological assessment. Patients with Huntington's or Parkinson's disease were less intellectually impaired than those with Alzheimer's disease at each functional stage. Criteria for dementia were present in all of the Alzheimer's patients but in only half of the Huntington's and Parkinson's disease groups. Patients with similar overall intellectual function scores had no distinct pattern of neuropsychological test performance. Depression, absent in patients with Alzheimer's disease, was present in half the patients with Huntington's and Parkinson's disease and was correlated with intellectual decline. The concept of subcortical dementia is misleading. The pattern of neuropsychological impairment is not distinct, and the neuropathological basis of dementia in these diseases may result from a combination of cortical and subcortical degeneration.

Adult↗
PubMed1983

Perceptual motor dysfunction in Parkinson's disease: a deficit in sequential and predictive voluntary movement.

We studied the ability of Parkinsonian patients and controls to generate voluntary movements on a tracing task. Subjects were videotaped while tracing designs of increasing complexity, presented on a vertical, transparent screen. Some designs were presented in a degraded form and subjects filled in their missing sections. Subjects also received a constructional task and a test of general intellectual ability. The quality of errors on the tracing task differed in the Parkinsonian and control groups. Parkinsonian patients made two distinct types of errors. One probably related to the motor disorders of the disease, but another seemed to be related to a higher level of control over sequential and predictive movements. The latter correlated with performance on the constructional and general intellectual tasks. These results suggest that Parkinson's disease may affect basal ganglia structures that are necessary for voluntary movements which require sequencing or planning. Clinically this may be observed in perceptual motor tasks since they require both voluntary movement and sequential organisation of behaviour.

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