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Biomedical subjects

A Rascol

Publications and source records attributed to A Rascol.

At least 55 records · Page 3Linked to original sources
PubMed1990

Lateral asymmetries in primary degenerative dementia of the Alzheimer type. A correlative study of cognitive, haemodynamic and EEG data, in relation with severity, age of onset and sex.

Cognitive, haemodynamic and EEG lateral asymmetries have been quantified in 20 patients with Primary Degenerative Dementia (PDD) and in 20 age-matched normal volunteers. Normalized asymmetry scores were calculated from the data obtained with a test battery, with SPECT and with quantitative EEG. Significant correlations were found between cognitive, haemodynamic and EEG scores in patients but not in controls. The functional asymmetries correlated to the Mini Mental State (MMS) score, the lowest MMS values being observed in patients with right hemisphere predominant impairment. Besides, in these patients, a significant correlation was observed between age at onset and MMS score so that, in this subgroup only, the earlier the onset the more severe the disease. Finally, the prevalence of pronounced functional asymmetry seemed to be higher in our male patients. Our study shows that lateral asymmetries are frequent in patients with PDD and that preferential lateralization of the abnormalities should be given further attention, especially with regards to age, sex and overall severity.

Adult↗
PubMed1990

Beta-adrenergic sensitivity in Parkinson's disease: effect of levodopa treatment.

The beta-adrenergic sensitivity in never-treated and levodopa-treated patients with Parkinson's disease (PD) was studied through the evaluation of lymphocyte beta-adrenoceptor number ([125I]cyanopindolol binding sites) and chronotropic and metabolic (plasma nonesterified fatty acids--NEFA) responses to isoproterenol. No change was found in Bmax values or affinity constant Kd between never-treated patients, levodopa-treated patients with PD, and controls. At rest, no difference was observed in heart rate, plasma catecholamine, or NEFA levels between the three groups. Isoproterenol sensitivity (chronotropic response and plasma NEFA increase) was similar in never-treated and treated PD. The results suggest that peripheral beta-adrenergic sensitivity is unaffected either by the pathophysiological process of PD or by levodopa treatment.

Aged↗
PubMed1990

Adrenergic supersensitivity in parkinsonians with orthostatic hypotension.

The adrenergic status was studied through evaluation of platelet alpha 2-adrenoceptor number [( 3H]yohimbine binding sites), plasma catecholamine levels and blood pressure response to noradrenaline infusion in three groups of subjects (1) Parkinsonians with orthostatic hypotension; (2) Parkinsonians without orthostatic hypotension; and (3) control subjects. In Parkinsonians with orthostatic hypotension, systolic and diastolic blood pressures significantly (P less than 0.05) decreased from 144 +/- 9 and 76 +/- 6 mmHg in the lying position to 95 +/- 12 and 60 +/- 7 mmHg after 5 min standing. In these patients, noradrenaline plasma levels were significantly low (62 +/- 11 pg ml-1, (P less than 0.05) when compared with controls (219 +/- 13 pg ml-1) whereas no difference was noticed in Parkinsonians without orthostatic hypotension (195 +/- 14 pg ml-1). The noradrenaline dose required for a 25 mmHg increase in systolic blood pressure was significantly (P less than 0.01) lower in Parkinsonians with orthostatic hypotension (0.19 +/- 0.03 microgram kg-1) when compared with Parkinsonians without orthostatic hypotension (0.86 +/- 0.11 microgram kg-1) or with controls (0.68 +/- 0.1 microgram kg-1). Platelet alpha 2-adrenoceptor number was higher in Parkinsonians with orthostatic hypotension (313 +/- 52 fmol mg-1 protein) than in Parkinsonians without orthostatic hypotension (168 +/- 9 fmol mg-1 protein) or in controls (175 +/- 4 fmol mg-1 protein) with no change in Kd. This study demonstrates that in patients with Parkinson's disease, orthostatic hypotension is associated with an increase in both vascular sensitivity to noradrenaline and platelet alpha 2-adrenoceptor number.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Blood pressure and plasma catecholamines in never-treated parkinsonian patients: effect of a selective D1 agonist (CY 208-243).

We found blood pressure (BP), heart rate (HR), plasma norepinephrine (NE), and epinephrine (E) levels in the lying and the standing positions to be similar in never-treated parkinsonian patients (stages 1 and 2) and age-matched controls. CY 208-243, a new centrally active D1 agonist, significantly decreased BP, HR, and NE (but not E) values in the lying position; it elicited orthostatic hypotension and blunted the rise in NE elicited by standing up. These results indicate that the early stages of Parkinson's disease are not accompanied by major changes in autonomic cardiovascular function and suggest the involvement of central D1-receptors in the control of sympathetic tone.

Antiparkinson Agents↗
PubMed1990

[Comparison of bromocriptine and levodopa as first line treatment of Parkinson's disease: results of a 3-year prospective randomized study].

The long term effects of a first line treatment with levodopa or bromocriptine were compared in 36 previously untreated patients with Parkinson's disease in a prospective randomized trial: 18 patients were treated with levodopa alone (mean dose: 485 +/- 71 mg daily) whereas 18 others received bromocriptine alone (mean dose: 55 +/- 6 mg daily) during 36 +/- 3 and 31 +/- 3 months respectively. We observed a similar decrease in the Columbia rating scale but the nature of long term side effects was different in the two groups: patients on levodopa developed peak-dose dyskinesias (5 cases), wearing off akinesia (1 case) and on-off effects (1 case). Under bromocriptine treatment, 2 patients developed severe psychosis whereas one suffered from primary lack of drug effectiveness and 5 others from late decrease of drug effectiveness. These results suggest the potential value of relatively high doses of D2 dopamine agonists (such as bromocriptine) in the first line treatment of Parkinson's disease: however, their use can be limited by their decrease of effectiveness after several years and/or the occurrence of severe neuropsychiatric side-effects.

Bromocriptine↗
PubMed1989

[Antiparkinsonian drugs].

Levodopa (+ dopa decarboxylase inhibitor) is the most active of all drugs used in the treatment of Parkinson's disease. It acts on both akinesia and rigidity and improves the prognosis of the disease by increasing life expectancy. But levodopa also produces late side-effects: it often induces abnormal movements, fluctuations in motor performance, on-off effects, psychotic hallucinations, etc. Since these late side-effects remain difficult to treat, it is always necessary to assess the benefits and risks of the first treatment with levodopa. Anticholinergic drugs, which mainly act on tremor, must be used with caution since they may induce memory alterations and often confusional states in aged parkinsonians. Dopamine agonists are prescribed as adjuvant therapy in the treatment of the late side-effects of levodopa. New drugs (selegiline), new pharmaceutical preparations (sustained release forms), the first treatment of the disease (levodopa alone versus agonists alone versus levodopa + agonists), together with the new pharmacological approaches (brain grafts, drug infusions) are now under clinical evaluation.

Antiparkinson Agents↗
PubMed1989

[Cerebral imaging and dementia].

Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease.

Dementia↗
PubMed1989

Abnormal ocular movements in Parkinson's disease. Evidence for involvement of dopaminergic systems.

Quantitated automated electro-oculographic data from 45 parkinsonian patients were compared with those from 30 normal control subjects. Patients were selected with idiopathic Parkinson's disease without other associated neurological disease or dementia; 20 had never received antiparkinsonian drugs and in 25 such treatment had been stopped for at least 2 days. Saccade latency, amplitude and peak velocity, smooth pursuit peak velocity, optokinetic nystagmus (OKN) maximal and mean velocities and vestibulo-ocular reflex (VOR) suppression by vision or imagination were significantly altered in patients, whereas VOR gain in darkness was normal. Alterations of saccade latency and smooth pursuit peak velocity were more severe in the more advanced stages of the disease and saccade latency directed towards the symptomatic side was slightly delayed in hemiparkinsonian patients. Saccade amplitude improved 90 min after a single oral dose of L-DOPA. These results suggest a possible dopaminergic control of some ocular movements.

Adult↗
PubMed1989

A randomised controlled study of bromocriptine versus levodopa in previously untreated Parkinsonian patients: a 3 year follow-up.

The long term effects of a de novo treatment with levodopa versus bromocriptine were compared in respectively 13 and 15 previously untreated patients with Parkinson's disease in a prospective randomised trial. Thirteen patients were treated with levodopa alone (mean dose 444, SEM 63 mg daily) whereas 15 others received bromocriptine alone (mean dose 50, SEM 6 mg daily) during 37, SEM 4 and 32, SEM 4 months respectively. For a similar decrease in the Columbia rating scale, the nature of long term side effects was different in the two groups: three patients on levodopa developed peak-dose dyskinesias and one other dystonia. With bromocriptine, one patient developed a severe psychosis whereas 3 others suffered from primary lack of efficacy (1 case) or late decrease in efficacy (2 cases). These results demonstrate the potential of D2 dopamine agonists (like bromocriptine) in the de novo treatment of Parkinson's disease; however, their use is limited by their lack of efficacy and/or the occurrence of neuropsychiatric side effects.

Bromocriptine↗
PubMed1989

SPECT study of cerebral blood flow reactivity after acetazolamide in patients with transient ischemic attacks.

We investigated 15 patients with one or more transient ischemic attacks (TIAs) in the internal carotid artery territory within the month following the most recent TIA. Cerebral blood flow (CBF) was measured by single-photon emission computed tomography, using intravenous xenon-133 before and after injection of 1 g acetazolamide. Six patients had severe carotid stenosis or occlusion; the other nine patients had no significant carotid lesions. Twenty age-matched volunteers free of neurologic symptoms or history were used as controls. Mean CBF in the sylvian region was not significantly different between patients and controls. Seven patients exhibited a focal hypoperfusion at rest in the symptomatic hemisphere, and their hypoperfused areas were hyporeactive after administration of acetazolamide. Seven other patients exhibited hyporeactive areas after acetazolamide administration while their CBF tomograms at rest were normal. Thus, CBF abnormalities were detected in 14 of the 15 patients. Our findings suggest that CBF measured early after acetazolamide administration could be useful to confirm the clinical diagnosis of TIA. In the nine patients with no significant lesion of the internal carotid artery, the areas of hypoperfusion were small and were probably related to the focal ischemic event. In the six patients with severe lesions of the internal carotid artery, abnormalities were of variable size and intensity but were often large and pronounced. The discrepancy between these two subgroups of patients could be ascribed to the hemodynamic influence of the internal carotid artery lesions. Moreover, our findings may provide some insight into the pathophysiology of TIAs.

Acetazolamide↗
PubMed1988

Two weeks of treatment with deprenyl (selegiline) does not prolong L-dopa effect in parkinsonian patients: a double-blind cross-over placebo-controlled trial.

We investigated the influence of 2 weeks of treatment with deprenyl on the acute effect of a single dose of 200 mg of L-dopa in a double-blind cross-over placebo-controlled trial in 16 parkinsonian patients with wearing-off phenomena. Deprenyl induced no significant benefit in the duration or the maximal improvement of L-dopa's effect. Moreover, deprenyl treatment did not improve the patient's motor status.

Aged↗