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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review covers recent advances in a variety of dyskinesias. Introduction of new drugs for the treatment of myoclonus and sensory biofeedback therapy for focal dystonia are expanding our concepts of these types of movement disorders. Progress in the treatment of action myoclonus is especially noteworthy and has led to the implication of serotonin deficit in the pathophysiology of this syndrome. Knowledge of the biochemical pathology of Huntington's chorea has outpaced therapy for this disorder, but new forms of therapy have been proposed based on the chemical findings. Basic pharmacologic studies suggest pathophysiologic mechanisms for the syndrome known as tardive dyskinesia, but treatment is still far from ideal for this disorder. Other movement disorders with recent therapeutic advances include essential tremor and hemiballism. This review will cover only those dyskinesias in which new therapies have been advanced in the last few years. Aside from parkinsonism, which will not be discussed here, progress in the treatment of movement disorders has been slow, but steady. New drugs are being tested constantly, and the purpose of this review is to call attention to the ongoing evaluation in this field. Descriptions and etiologies for these dyskinesias are covered elsewhere (Fahn, 1976a) and therefore are not repeated here.
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PMID:New approaches in the management of hyperkinetic movement disorders. 30 60

Animal data indicate that serotonin (5-HT) is a major neurotransmitter involved in the control of numerous central nervous system functions including mood, aggression, pain, anxiety, sleep, memory, eating behavior, addictive behavior, temperature control, endocrine regulation, and motor behavior. Moreover, there is evidence that abnormalities of 5-HT functions are related to the pathophysiology of diverse neurological conditions including Parkinson's disease, tardive dyskinesia, akathisia, dystonia, Huntington's disease, familial tremor, restless legs syndrome, myoclonus, Gilles de la Tourette's syndrome, multiple sclerosis, sleep disorders, and dementia. The psychiatric disorders of schizophrenia, mania, depression, aggressive and self-injurious behavior, obsessive compulsive disorder, seasonal affective disorder, substance abuse, hypersexuality, anxiety disorders, bulimia, childhood hyperactivity, and behavioral disorders in geriatric patients have been linked to impaired central 5-HT functions. Tryptophan, the natural amino acid precursor in 5-HT biosynthesis, increases 5-HT synthesis in the brain and, therefore, may stimulate 5-HT release and function. Since it is a natural constituent of the diet, tryptophan should have low toxicity and produce few side effects. Based on these advantages, dietary tryptophan supplementation has been used in the management of neuropsychiatric disorders with variable success. This review summarizes current clinical use of tryptophan supplementation in neuropsychiatric disorders.
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PMID:L-tryptophan in neuropsychiatric disorders: a review. 130 30

Postural myoclonus associated with long-term administration of neuroleptics was demonstrated in schizophrenic patients. Sixty patients who had been taking neuroleptics for more than 3 months were investigated for myoclonus and the relationships between postural myoclonus and age, duration of illness, duration of medication, current daily dose, cumulative dose, occurrence of abnormal finger movement, parkinsonism, and tardive dyskinesia were evaluated. Twenty-three patients (38%) showed postural myoclonus when holding the hands forward with the elbow joints flexed at about 90%. Male patients showed a higher incidence of myoclonus than female patients. Patients with myoclonus had been given significantly higher doses of neuroleptics than those without myoclonus. There was a significant correlation between the occurrence of myoclonus and abnormal finger movement. Electromyographic recordings in 7 patients with prominent myoclonus revealed that arrhythmic jerks occurred in the extensor carpi radialis and posterior deltoid muscles and that the jerks on the left and right side were not synchronized. Clonazepam reduced the frequency of the myoclonic activity.
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PMID:Postural myoclonus associated with long-term administration of neuroleptics in schizophrenic patients. 197 Nov 87

Movement disorders are subdivided based on a variety of criteria. One useful and popular approach to movement disorders, based on clinical phenomenology, categorizes these disorders into two groups, those displaying a poverty of movement (akinesia) and those displaying excessive movement (hyperkinesia). This article discusses diagnosis and treatment of the latter. By necessity, certain hyperkinesias such as hyperexplexia, akathisia, and restless leg syndrome are omitted or only briefly discussed. The major hyperkinesias, dystonia, tremor, tics, chorea (including tardive dyskinesia and ballism), and myoclonus are reviewed and a guide to practical management emphasizing symptomatic treatment is presented.
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PMID:Treatment of hyperkinetic movement disorders. 218 Dec 68

The ability of the selective GABA-receptor agonist, progabide, to suppress abnormal involuntary movements was evaluated in a preliminary open pilot study. 17 patients, 10 males and 7 females, aged 10-78 years, with hyperkinetic movement disorders were included in the study. Daily doses of progabide ranged from 900 to 3600 mg (median 2400 mg) corresponding to 14-45 mg/kg (median 45 mg/kg), while the duration of treatment varied from 2 to 52 weeks. Improvement, with a reduction of involuntary movements exceeding 25%, occurred in two of four patients with Gilles de la Tourette's syndrome, and in two of three patients with postanoxic intention myoclonus, while no consistent beneficial effects were registered in ten patients with Huntington's chorea, postanoxic choreoathetosis, torsion dystonia, tardive dyskinesia, action tremor, essential myoclonus, or oro-branchio-respiratory myoclonus.
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PMID:Progabide in the treatment of hyperkinetic extrapyramidal movement disorders. 386 33

The descriptive aspects of all types of movement disorders and their related syndromes and terminologies used in the literature are reviewed and described. This comprises the features of (a) movement disorders secondary to neurological diseases affecting the extrapyramidal motor system, such as: athetosis, chorea, dystonia, hemiballismus, myoclonus, tremor, tics and spasm, (b) drug induced movement disorders, such as: akathisia, akinesia, hyperkinesia, dyskinesias, extrapyramidal syndrome, and tardive dyskinesia, and (c) abnormal movements in psychiatric disorders, such as: mannerism, stereotyped behaviour and psychomotor retardation. It is intended to bring about a more comprehensive overview of these movement disorders from a phenomenological perspective, so that clinicians can familiarize with these features for diagnosis. Some general statements are made in regard to some of the characteristics of movement disorders.
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PMID:Clinical features of movement disorders. 662 43

Encephalitis lethargica (von Economo's encephalitis), pandemic from 1917 to 1926, opened a window on the study of behavioral consequences of infection-induced subcortical disorder. Widely varying acute manifestations included extrapyramidal disorders, myoclonus, eye movement disorders, paralyses, delirium, mood changes, inverted diurnal rhythms, and catatonia. Major pathological changes involved the substantia nigra, globus pallidus, and hypothalamus. A symptom-free recovery period was often followed by postencephalitic disturbances, typically parkinsonism in adults and conduct disorder in children. Occurrence of depression, mania, obsessive-compulsive disorder, and hyperactivity in post-encephalitic patients anticipated current concepts of the role of the basal ganglia in mood, personality, and obsessional syndromes. Observations of deferred onset and "tardy" hyperkinesias presaged current theories of the pathophysiology of tardive dyskinesia.
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PMID:Encephalitis lethargica: lessons for contemporary neuropsychiatry. 758 Feb 5

We reviewed the medical records and videotapes of 100 patients with tardive dyskinesia (TD) referred to our movement disorders clinic to characterize the spectrum of hyperkinetic movement disorders caused by dopamine receptor blocking drugs (DRBD). Tardive stereotypy, present in 78 patients, was the most common type of TD, followed by tardive dystonia, akathisia, tremor, chorea, and myoclonus. Sixty-four had a combination of these hyperkinesias. In a second study, a "blind" review of videotapes of patients with a variety of movement disorders found that DRBD were the cause of stereotypic movements in 89.3% of patients, and 96.1% of patients with TD had stereotypy. We conclude that stereotypy can be readily differentiated from other hyperkinetic movement disorders and that its presence in an adult is highly suggestive of prior exposure to DRBD.
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PMID:Tardive stereotypy and other movement disorders in tardive dyskinesias. 849 49

It is well established that clozapine is less likely than typical antipsychotic drugs to cause clinically discernible extrapyramidal side-effects. There is a paucity of data, however, on clozapine's motor effects. In this report we compare normal controls to groups of chronic schizophrenic patients treated with either typical antipsychotic drugs or with clozapine. Motor function was measured with a target-matching task, a test relying on submaximal sustained force control. Results indicated that patients on clozapine performed with significantly lower accuracy (greater variability) of force control. Even though the clozapine patients were treatment resistant to typical antipsychotic drugs, and many had a history of tardive dyskinesia, we postulate that the observed deficit is likely due to clozapine treatment rather than to earlier treatments or other factors. The observed force control deficit may be the result of an increase in myoclonus and a generally lower level of overall motor activity.
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PMID:Effect of clozapine on motor function in schizophrenic patients. 879 9

Clozapine is an 'atypical' neuroleptic that improves symptoms of many patients with schizophrenia whose illness is resistant to treatment with other neuroleptics. Unlike the 'typical neuroleptics (chlorpromazine, haloperidol), clozapine does not induce extrapyramidal symptoms such as Parkinsonism and tardive dyskinesia in humans or catalepsy in the rat. However, clozapine frequently causes epileptiform EEG changes and causes seizures in 3-5% of patients treated with this drug in therapeutic doses. Clozapine also induces dose dependent myoclonus in the partially restrained rat. In the experiments reported here, partially restrained rats were administered repeated alternate day or weekly low, fixed doses of clozapine (1 mg/kg). This dose initially caused no behavioral change. Following the third and subsequent administrations, the same dose elicited an increasing number of myoclonic seizure-like jerks reaching 140/h following the 15th injection in rats receiving the same low dose of clozapine on alternate days and 160/h following the 9th injection in animals that received the same dose once weekly. These effects are consistent with kindling, i.e. a progressive increase of brain excitability following repeated administration of a fixed subconvulsive dose of an excitatory agent. Clozapine kindled animals exhibited a significantly different pattern of early gene expression in ventral tegmental area, origin of the mesolimbic-mesocortical dopamine system and in the anterior thalamic nuclei, compared with saline treated controls subjected to exactly the same recording conditions. The evidence of central nervous system excitation with clozapine may be important to the unique therapeutic effect of this atypical antipsychotic in the treatment of symptoms, especially the deficit symptoms, of schizophrenia.
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PMID:Kindling with clozapine: behavioral and molecular consequences. 898 8


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