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Biomedical subjects

W C Koller

Publications and source records attributed to W C Koller.

14 recordsLinked to original sources

Hemiballism and tremor due to ependymal cyst.

A 21-year-old woman was admitted with right hemiballism and tremor. She had tremor since the age of 6 years. At age 12, an intracerebral, left paraventricular space-occupying lesion was found and treated with 4,500 rads. Increasing tremor was associated with mass enlargement. By age 20, there was insidious presentation of right hemiballism. At age 21, she had craniotomy and a large septate cyst was opened and drained. Biopsy of the cyst wall revealed that it was consistent with ependymal cyst. Postoperatively the hemiballism resolved and the tremor improved. This case is unusual due to the presentation of hemiballism caused by ependymal cyst.

Adult

Initiating treatment of Parkinson's disease.

Treatment of Parkinson's disease (PD) can be divided into two categories: symptomatic therapy (restoring dopamine levels toward normal and reversing functional disability) and preventive therapy (interfering with the pathophysiologic mechanism of PD to prevent or decrease the rate of progression of the disease). Regarding symptomatic treatment, although anticholinergic preparations generally are considered effective for the symptoms of tremor and rigidity without altering bradykinesia, their effectiveness is limited and adverse reactions are common; their role should be restricted to use as adjuvants to levodopa therapy. Amantadine has been shown to be as effective as anticholinergics, but it lacks long-term efficacy. Dopamine agonists--bromocriptine, pergolide mesylate and lisuride in Europe--are not as effective as levodopa and therefore rarely are used as initial therapy; their proposed role, too, is as adjuvants to levodopa therapy. Levodopa is the most effective drug presently available for the treatment of PD; its introduction is accompanied by rapid and dramatic reduction of symptoms and signs. Initial adverse reactions are not usually a major problem; and although there is speculation that initiation of therapy should be delayed because of possible long-term complications, clinically distinguishing these from problems related to disease progression itself is difficult. The possibility that nigral cell death is mediated by oxidative mechanisms provides the basis for considering antioxidant therapy as protective treatment; selegiline, an antioxidant, has been found to delay the need for symptomatic therapy. It is suggested that initial treatment of Parkinson's disease begin with both preventive therapy with selegiline and symptomatic treatment with the sustained-release preparation of levodopa, which may be associated with fewer long-term complications.

Amantadine

When does Parkinson's disease begin?

A long preclinical or asymptomatic period may occur in Parkinson's disease (PD). Many long-latency parkinsonian syndromes exist. The presence of early-life risk factors is consistent with a long prodromal period. Marked degeneration of the substantia nigra and loss of striatal dopamine are necessary before clinical symptoms develop. Lewy bodies, the histological hallmark of PD, occur in 10% of normal individuals over age 50. Clinical symptoms develop slowly and are often intermittent in early PD. Nonmotor signs, eg, depression or sensory changes, often precede motor signs by many years. Reduction of striatal dopamine can be detected with PET in "at-risk" asymptomatic individuals. Individual sensitivity to drug-induced parkinsonism also suggests a preclinical state. Biologic markers may eventually be able to detect preclinical PD.

Aging

Clinical and experimental studies of phenytoin-induced hyperkinesias.

Phenytoin administration occasionally leads to the induction of hyperkinetic movement disorders. The pathophysiologic basis of this phenomena is unknown, but thought to be a toxic effect of phenytoin. Study of two cases of this disorder and a review of the literature suggest that antecedant pathologic changes in the basal ganglia are prerequisites for the development of phenytoin-induced hyperkinesias. In an animal model of tardive dyskinesia, phenytoin was found to enhance neuroleptic-induced behavioral supersensitivity but have no effect in control animals. We conclude that phenytoin induced hyperkinesias reflect a specific effect of phenytoin on an abnormal neural substrate and suggest the presence of an otherwise silent pathological alteration of the corpus striatum. The diagnostic value of an episode of phenytoin-induced hyperkinesia is discussed.

Aged

Chorea induced by oral contraceptives.

A rare complication of oral contraceptive therapy is the induction of chorea. We here describe five cases of chorea in patients receiving low- or high-dose estrogen-containing contraceptives. All patients were nulliparous, young (average age 19 years), and became symptomatic shortly (average of 5 weeks) after initiation of contraceptive therapy. Two patients previously suffered an episode of Syndenham chorea; one experienced chorea in the course of Henoch-Schönlein purpura; and two had a history of congenital cyanotic heart disease without chorea. Dyskinesia resolved in all patients upon discontinuing the medication. Patients with preexisting striatal abnormalities appear more susceptible to oral contraceptive-induced chorea which is reversible on drug discontinuation. The mechanism of oral contraceptive-induced chorea is unknown, but clinical and experimental data suggest that it involves altered central dopaminergic activity.

Adolescent

Calcification of the basal ganglia: computerized tomography and clinical correlation.

During a 1-year period, 4219 consecutive computerized tomograms (CT) were reviewed for basal ganglia calcification; 14 patients with such calcification were identified. Calcifications on CT scan were bilateral in 12 of these cases and unilateral in 2. All bilateral calcifications were symmetric. The globus pallidus was the site of calcification in 13 of the 14 patients. Bilateral dentate nucleus calcification was seen in one patient. Skull radiograms were normal in all but one. Patients had diverse symptoms that were often explained by other findings, suggesting that calcifications may be coincidental and that basal ganglia calcification may not be a nosologic entity. Disturbances of calcium metabolism were not found in these patients, minimizing the pathophysiologic significance of altered calcium metabolism and the need for extensive endocrinologic evaluation. The finding of basal ganglia calcification alone does not justify invasive diagnostic procedures. Extrapyramidal signs may be associated with basal ganglia calcification; parkinsonism associated with basal ganglia calcification differs from idiopathic parkinsonism in being resistant to levodopa therapy.

Adult

Dapsone-induced peripheral neuropathy.

Peripheral neuropathy is a rare complication of dapsone therapy. This neuropathy appears primarily to be of the motor type, and recovery occurs on discontinuation of the drug therapy. The patient in this report developed a marked motor deficit as well as a selective marked loss of vibration sense shortly after the initiation of a relatively low dose of dapsone. Recovery was rapid on cessation of the therapy. This patient was found to be a slow acetylator of isoniazid, and therefore is probably a slow acetylator of dapsone. The possible mechanisms of the neurotoxicity of dapsone and the role of altered metabolism are discussed.

Acne Vulgaris

Alteration of basal ganglia evoked responses by reserpine and L-dopa.

The effects of reserpine and L-Dopa on basal ganglia evoked potentials were investigated in cats. The caudate response resulting from substantia nigra stimulation and the substantia nigra response elicited by globus pallidus stimulation were increased at several hours after the systemic administration of reserpine. L-Dopa in the presence of dopa decarboxylase inhibition (MK-486) depressed these responses and reversed the effect of reserpine at 0.5 h after administration. Reserpine did not reverse the L-Dopa effect. Reserpine and L-Dopa caused no significant change in responses between other basal ganglia structures. These data give evidence that the basal ganglia are major sites for reserpine and L-Dopa action.

Animals