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Biomedical subjects

F H McDowell

Publications and source records attributed to F H McDowell.

At least 19 recordsLinked to original sources
PubMed1991

"Early" initiation of levodopa treatment does not promote the development of motor response fluctuations, dyskinesias, or dementia in Parkinson's disease.

We reviewed the histories of patients seen in a large Parkinson's disease clinic from 1983 to 1989 to determine if there is a relationship between the timing of initiation of levodopa therapy and the development of motor response fluctuations, dyskinesias, and dementia. There were no factors predisposing to the development of response fluctuations or dementia. Younger age at disease onset predisposed to the development of dyskinesia. Dyskinesias occurred in a greater proportion of patients in whom the initiation of levodopa therapy was delayed by more than 2 years from disease diagnosis than among those in whom treatment was started earlier. We thus failed to identify any adverse consequences of early levodopa treatment in our patient population.

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PubMed1991

Activation of rehabilitation.

Following the demonstration that catecholamine levels in the cerebral hemispheres were considerably reduced with stroke, efforts were made to change this situation in experimental animals. It was found that the use of amphetamine (CAS 300-62-9) greatly enhanced the recovery time of animals following experimental stroke, and that agents which block the release or function of catecholamines in the central nervous system seem to delay recovery. These observations have been used to determine whether or not the same conditions exist for humans with stroke. To date in one study there is evidence that use of amphetamine early after a stroke may enhance the rehabilitation process. The rehabilitation process can be impaired by a number of situations, the most common of which is depression. It has been shown that treatment of depression for patients with stroke in rehabilitation may improve the outcome as well as the speed of outcome. Prognosis for patients with stroke who enter rehabilitation programs is related to the degree of central nervous system damage. Those patients with only motor dysfunction tend to do much better in programs than those who have in addition sensory or visual disturbances. Usually maximum improvement of function following stroke and rehabilitation care occurs in the first three months. Carefully planned rehabilitation programs for patients following stroke with realistic goals can greatly improve the patients' function and enable them to remain as independent as possible.

Animals↗
PubMed1979

Administration of human somatotropin in levodopa-treated patients with Parkinsonism.

To investigate further the role of growth hormone (GH) on the cerebral effects of levodopa, human somatotropin (human growth hormone) was administered to four patients with parkinsonism with varying response to chronic levodopa therapy. The doses of somatotropin (5 IU) were administered on alternate days for four days, and the effects of this hormone on the patient's symptomatic control, dyskinesia, plasma GH, and dopa levels were evaluated and compared with those of patients receiving saline injections. We have demonstrated that administration of exogenous human somatotropin, even during marked and sustained elevations of plasma GH levels, does not alter the therapeutic or side effects of levodopa therapy. With one exception, plasma dopa levels after human somatotropin administration remained unchanged. We conclude that neither the endogenous increases of GH in response to levodopa nor those attained following human somatotropin administration modify in any consistent way the therapeutic and side effects of chronic levodopa therapy, and that the episodic releases of GH in response to levodopa occur independently of its cerebral effects.

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PubMed1979

Plasma DOPA and growth hormone in parkinsonism: oscillations in symptoms.

In 19 patients with Parkinson disease, we studied the relationship of the therapeutic effect of levodopa, or dyskinesia, to the plasma content of DOPA and growth hormone (GH). Those with stable responses to levodopa, individually or as a group, showed stable and lower plasma DOPA levels than those with unstable symptomatic responses. These results show that stable and oscillating clinical responses in Parkinson disease parallel plasma DOPA levels, suggesting that there are different mechanisms in peripheral levodopa metabolism and that extracerebral mechanisms are important in regulating the availability of levodopa to the brain. Plasma GH did not differ in the two groups, suggesting that the secretion of GH is independent of the effects of levodopa in parkinsonism.

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PubMed1978

Cyproheptadine in levodopa-induced dyskinesia in parkinsonism.

The neuroendocrine properties and the beneficial effects of cyproheptadine in tardive dyskinesia led to the testing of this drug in levodopa-induced dyskinesia. Cyproheptadine administered to 6 parkinsonian patients in doses of up to 42 mg/day was of no significant benefit in either dyskinesia or symptom control. Improvement in appetite was reported by 3 patients. These observations suggested that different mechanisms may be responsible in the pathogenesis of phenothiazine and amine-induced dyskinesia. The failure to control levodopa-induced dyskinesia selectively with serotonin agonists and antagonists and the accentuation of the dyskinesia in the presence of anticholinergic agents further suggest that substances that increase directly central cholinergic activity may be effective in the control of levodopa-induced dyskinesia.

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PubMed1976

Atherosclerotic cerebral infarction: pathophysiologic aspects.

When the supply of substrate to the brain is threatened, homeostatic mechanisms induce cerebral vasodilatation to compensate for the insufficiency. When a region of the brain is rendered completely ischemic, local infarction occurs. The size of the infarct depends partly on the availability of collateral circulation and the adequacy of the homeostatic mechanisms controlling blood flow in stillpatent vessels. Several approaches to acute-phase treatment of stroke derive from clinical and experimental studies of cerebral blood flow and metabolism. We must conclude that both surgical and nonsurgical therapeutic measures have been of limited value in the treatment of cerebral infarction and that the basic therapy for completed stroke remains good medical management of complications and attentive nursing care.

Blood Flow Velocity↗
PubMed1976

Rehabilitating patients with stroke.

Experience at the Burke Rehabilitation Center indicates that a rehabilitation program established early and giving proper attention to both personal and medical aspects can make it possible for 80% of stroke victims to return home and to function with reasonable adequacy. Rehabilitation efforts should begin as soon as possible after a stroke and can be effectively carried out in community hospitals.

Activities of Daily Living↗
PubMed1976

Mental symptoms in Parkinson's disease during chronic treatment with levodopa.

Mental symptoms increased in frequency among 100 patients with parkinsonism treated with levodopa. Dementia was found in about one-third of patients throughout the 6-year treatment period. Thirteen patients became demented during the study, and dementia worsened severely in seven others. Agitated confusion became increasingly frequent and was observed in 60 percent of patients taking levodopa for 6 years. Withdrawal from levodopa decreased agitation, but not dementia. Ten patients received L-tryptophan along with levodopa, but no change in mentation was observed. In view of previous studies of mentation in Parkinson's disease and reports of widespread neuronal changes in the brain of autopsied patients with parkinsonism, our results suggest that the high incidence of dementia in patients with Parkinson's disease who take levodopa reflects prolongation of the course of the illness rather than a direct effect of the medication.

Adult↗
PubMed1976

Piribedil: its synergistic effect in multidrug regimens for parkinsonism.

Piribedil, a dopamine agonist, was administered to 13 patients with long-standing Parkinson's disease whose major symptoms were not well controlled on levodopa, anticholinergics, alpha-methyldopa, amantadine, or a combination of these agents. Twelve of the 13 clearly benefited from the addition of Piribedil although side effects precluded long term use in two cases. Beneficial results were obtained by using a combination of Piribedil, levodopa, and anticholinergic drugs. Side effects (hallucinations, confusion, dyskinesias) were frequent, but were usually reversible by lowering the dosage of levodopa or the accompanying anticholinergic medication. The synergistic effect of Piribedil and other antiparkinsonian drugs emphasizes the need for careful titration of all available medications in difficult cases and demonstrates the usefulness of dopamine receptor stimulators when drugs acting presynaptically have failed.

Aged↗
PubMed1975

Treatment of "on-off effect" with a dopa decarboxylase inhibitor.

Irregularities in motor response after continuing levodopa therapy of Parkinson disease (the "on-off effect") were assessed with the addition of L-alpha-methyldopa hydrazine (carbidopa) in a double-blind study. Thirteen of 20 patients improved while receiving carbidopa and levodopa while only four of 17 patients improved while receiving placebo and levodopa. Twenty-three of 37 patients improved in a subsequent non-blind trial of carbidopa plus levodopa. Improvement was not dependent on an increase in dose or frequency of levodopa administration. Adverse effects included dyskinesia, imbalance, and confusion; nausea was eliminated. On patient died of glomerulonephritis that predated the drug trial, but worsened progressively during and after it. Carbidopa's suppression of the "on-off effect" suggests that extracerbral factors may be important in this phenomenon.

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PubMed1975

Five years' treatment of Parkinson's disease with levodopa. Therapeutic results and survival of 100 patients.

One hundred patients with Parkinson's disease, who started taking levodopa before the end of 1968, have been assessed after 5 years. Forty-seven patients are still being followed on levodopa, and half of them are at least 25% better than at their pretreatment evaluation. However, the average functional rating is returning toward baseline from its remarkable improvement at 1/2 to 2 years. Abnormal involuntary movements, rapid oscillations in motor performance, postural instability, and dementia have become the major adverse effects. Thirty-two of the 100 patients have died. Life-table analysis shows an excess mortality of 1.9 compared with the U.S. population, a figure that is lower than the 2.9 reported before levodopa's use. Despite its inability to cure Parkinson's disease, levodopa provides symptomatic relief for a prolonged time and it remains the single most effective medication for the illness.

Adult↗
PubMedDate not supplied

Factors influencing outcome and length of stay in a stroke rehabilitation unit. Part 1. Analysis of 248 unscreened patients--medical and functional prognostic indicators.

A retrospective analysis of 248 patients with stroke (average age 67, range 17-98) admitted to a stroke rehabilitation unit over a sixteen month period showed that 80% of these patients were able to return home after an average length of stay (LOS) of 43 days. At discharge 85% of the group were ambulatory and 56% required no help in daily living activities. Severity of weakness on admission, long onset-admission intervals, the presence of severe perceptual or cognitive dysfunction or a homonymous hemianopsia in addition to a motor deficit were related to unfavorable outcome and increased LOS. The age of the patient, dysphasia or a hemisensory deficit in addition to weakness, or diabetes, hypertension, or ASHD were unrelated to the patients' functional status on discharge, discharge disposition, or LOS. Many patients with "unfavorable prognostic signs" made significant improvement after admission and were subsequently discharges. Thus, while the above findings may predict which patients can make maximal gains in a short term treatment facility, they also show that most patients, even those with "poor prognostic signs," can make enough functional improvement to be managed at home after a relatively short hospitalization.

Activities of Daily Living↗