Biomedical subjects
Publications and source records attributed to K D Sethi.
Voluntary gaze may evoke a number of neurological phenomena such as vertigo, tinnitus, blepharoclonus, eyelid nystagmus, "facial nystagmus," involuntary laughter, and seizures. We report two patients in whom eccentric gaze evoked facial twitching and arm movement. Electroencephalograms remained unchanged during these movements. The pathogenesis of these movements is unclear but may involve ephaptic transmission.
The prevalence of dystonia was studied in 125 veterans on chronic antipsychotic therapy using a detailed and systematic examination. Twenty-seven out of 125 had dystonic manifestations. The most common areas involved were hands and jaw. There was no relation between the presence or absence of dystonia, and duration of neuroleptic therapy. There was a tendency for tardive akathisia to occur more frequently in patients with dystonia than in those without it (Fisher's exact probability test, p = 0.0656). Tardive dystonia in its milder forms may be more common than currently believed.
Clinically phenytoin-induced movement disorders may resemble neuroleptic-induced tardive dyskinesia (TD). Neuroleptic-induced TD is thought to be related to an increase in the number and affinity of dopamine D2 receptors. We investigated the interaction of phenytoin with dopaminergic systems by measuring dopamine behavior and receptor changes in animals treated with phenytoin alone or in combination with chlorpromazine. Phenytoin alone or in combination produced significant behavioral supersensitivity without alteration of dopamine D2 receptor density or affinity. This animal study suggests that phenytoin may aggravate neuroleptic-induced tardive dyskinesia through mechanisms other than the dopamine D2 receptors.
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In clinical practice, distinguishing drug-induced parkinsonism from Parkinson's disease may be difficult. Asymmetry is generally not felt to be common in drug-induced parkinsonism. The authors investigated asymmetry of signs and symptoms in 20 patients with drug-induced parkinsonism. Tremor was identified in seven patients, slowness in five, and mixed symptoms in eight. A notable asymmetry of signs was seen in six patients. As in Parkinson's disease, subgroups seem to exist within the group of patients with drug-induced parkinsonism, and an asymmetry of signs and symptoms is not uncommon.
We report 6 patients with hemichorea/hemiballism of vascular origin who were treated with divalproex sodium (Depakote). Four of 6 responded initially. Marked improvement was seen in 2 patients only and in 1 of these hemiballism recurred despite continuing therapy. Divalproex sodium is not uniformly effective in the treatment of hemichorea/hemiballism.
Epilepsia partialis continua (EPC) in multiple sclerosis is extremely rare. We report a case of a patient with clinically definite multiple sclerosis who developed EPC. Magnetic resonance imaging (MRI) depicted high signal in subcortical white matter and basal ganglia. A combination of lesions may be important in the generation of EPC.
We describe the first case of Miller Fisher syndrome, a Guillain Barré variant, complicating systemic lupus erythematosus. The symptoms and signs mimicked a brainstem syndrome. Despite treatment with high dose gamma globulin, our patient worsened and required mechanical ventilation. After plasma exchange, the patient improved.
The effects of scopolamine (anticholinergic) and methysergide (antiserotonergic) on memory and long-latency auditory cognitive evoked potentials (EPs) were tested in 16 normal adults. Recent memory was impaired by both drugs. In contrast, scopolamine, but not methysergide, significantly delayed P3 latency and decreased P3 amplitude. Immediate memory and the earlier EP components (i.e., N1 and P2) were unaffected. The findings support the hypothesis that cholinergic neurons are important in the neuronal networks generating the P3 potential. Serotonergic neurons do not appear to play a major role in the networks that generate the P3.
Metoclopramide hydrochloride (Reglan) is a widely prescribed drug for treatment of upper gastrointestinal symptoms. Although the drug is relatively safe, a growing body of literature has noted movement disorders after its administration. We have reported six cases of metoclopramide-induced parkinsonism seen in consultation over a two-year period. Five of these six patients had renal failure. Their parkinsonism improved on discontinuation of metoclopramide therapy. Metoclopramide-induced parkinsonism is not rare, and appropriate dose reduction in patients with renal failure will help reduce the incidence of this morbidity.
Propionic acidemia usually presents in the newborn period with severe metabolic acidosis and lethargy. A 31-year-old man with adult onset chorea and dementia had propionic acidemia due to propionyl CoA carboxylase deficiency. Metabolic investigations may prove useful in patients with movement disorder of unknown etiology.
Death rates for Parkinson's Disease (PD) in the U.S.A. and the state of Georgia were investigated for the period 1979-83. Age adjusted death rates for the U.S.A. were greater in whites than blacks and greater in men and women. No differences were found in Georgia between urban and rural counties. Death rates were not higher in countries containing paper mills.
Two women with a presumptive diagnosis of Hallervorden-Spatz syndrome had a combination of dystonia and parkinsonism. One had retinitis pigmentosa. Neuropsychological testing revealed decreased verbal fluency and visuoconstructional and motor deficits. Magnetic resonance imaging performed with a high-field-strength unit (1.5 Tesla) showed striking abnormalities in the globus pallidus bilaterally ("eye-of-the-tiger" sign). Magnetic resonance imaging may prove useful in the diagnosis of Hallervorden-Spatz syndrome.
Although hemichorea is often ascribed to a vascular lesion, generalized chorea of adult onset is often thought to be due to degenerative diseases. We describe a 74-year-old woman with generalized chorea that was diagnosed at autopsy as due to multiple lacunar infarcts in the basal ganglia. Generalized chorea in adults may be caused by vascular disease of the basal ganglia.
A common symptom of myasthenia gravis is eyelid ptosis. Often, the edrophonium test is negative, particularly in ocular myasthenia gravis. Myasthenic weakness is often improved by cold. We applied ice packs to the eye in 10 myasthenic patients and 7 disease controls. Eight of 10 patients with myasthenia gravis improved, whereas none of the controls improved. The ice pack test is useful in the diagnosis of myasthenia gravis.
Despite the propensity of sarcoid granulomas to be clustered around blood vessels, transient ischemic attacks and strokes are rare. A 43-year-old man had recurrent transient dysarthria and right hemiparesis; a biopsy specimen showed neurosarcoidosis. There was complete resolution of both symptomatology and the subdural sarcoid mass lesion with the administration of corticosteroid therapy.
Rhabdomyolysis leading to acute renal failure necessitating hemodialysis is described in three chronic alcoholics. In each case an acute medical or surgical event, but not alcoholic intoxication, was implicated. Renal biopsies demonstrated acute tubular necrosis with intraluminal deposits consisting of Tamm-Horsfall protein and myoglobin. After recovery all three patients were demonstrated to have proximal muscle weakness with similar electromyographic abnormalities but nerve-conduction was impaired in only two. Muscle biopsies showed mixed, but predominantly type II fiber atrophy and reduced muscle phosphorylase levels. In the one patient tested the lactate response to forearm muscle ischemia was abnormal. It is postulated that chronic alcoholics may be predisposed to rhabdomyolysis and acute renal failure following acute medical and surgical stress as well as acute alcohol abuse. The muscle damage in these patients may be due to impaired intra cellular glycogen metabolism.
A standardized neurologic assessment scoring instrument was developed and tested for use in a multicenter trial of hypervolemic hemodilution in acute hemispheric stroke. Components of the neurologic examination pertinent to hemispheric stroke syndromes were emphasized. The scale was evaluated using 16 acute stroke patients for concurrent validity (Pearson coefficient r = 0.89 compared with global assessments by neurologists or neurosurgeons) and interobserver reliability (r = 0.95 interobserver reliability estimate). Such a scale should prove useful in quantifying neurologic deficits in hemispheric stroke and in following changes in neurologic status during multicenter acute treatment protocols.