Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four children who at ages from five months to three years developed an acute (one case), subacute (two cases) and chronic form (one case) clinical picture of ataxia, myoclonus, ocular dyskinesia and behaviour disorder are reported. In one of them there was, in addition mental retardation. Response to treatment with ACTH was successful. Clinical and evolutive characteristics of this process as well as the variety of ocular manifestations are emphasized.
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PMID:[Kinsbourne's disease. Study of four cases (author's transl)]. 69 15

Physiologic studies were performed on a patient who demonstrated lightning eye movements, palatal myoclonus and myoclonic jerks of the left platysma and sternocleidomastoid muscles. The myoclonus and lightning eye movements were separate phenomena with no defined relationship to each other. Analysis of this ocular dyskinesia identified strictly horizontal saccadic oscillations, 2 to 5 Hz in frequency, with amplitudes varying greatly but often reaching 25 degrees. A brief stationary period between each saccadic oscillation was frequently observed. They were particularly induced by vertical or horizontal ocular pursuit as well as sustained upward or downward ocular deviation. Caloric nystagmus abolished the oscillations but they persisted, irregularly, during optokinetic nystagmus. Thus a faulty visual fixation mechanism is postulated to precipitate lightning eye movements. Constrast studies revealed a mass lesion arising from the right dorsolateral portion of the medulla. These results indicate that lightning eye movements occur with caudal as well as rostral brain-stem lesions. From the clinical findings cerebellar pathway involvement is likely.
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PMID:Lightning eye movements. 124 81

The authors review the literature describing the neural symptoms induced by tricyclic antidepressants, especially tremor, seizures, akathisia, myoclonus, dyskinesia and delirium. Sedation, modifications of sleep, memory and appetite are also described. Tremor and myoclonus are the most frequent drug-induced neural symptoms. Delirium is most often caused by high-dosage treatments. The pathophysiology of akathisia and dyskinesia raises important questions concerning the mode of action of antidepressants.
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PMID:Neural symptoms induced by tricyclic antidepressants: phenomenology and pathophysiology. 131 56

Levodopa-induced dyskinesias (LID) in Parkinson's disease (PD) may be classified into three main categories: "On" dyskinesias, diphasic dyskinesias (DD), and "off" periods. The study of 168 parkinsonian patients showed that about half (n = 84) showed one pattern of LID only. A combination of two was present in 68, and 16 had the three presentation patterns. A fairly good correlation between type of dyskinesia and presentation pattern was established. Chorea, myoclonus, and dystonic movements occurred during the "on" period. Dystonic postures, particularly affecting the feet, were mainly present in the "off" period, but a few patients had a diphasic presentation. Repetitive stereotyped movements of the lower limbs always corresponded to DD. Acute pharmacological tests using dopamine agonists (subcutaneous apomorphine 3-8 mg; intravenous lisuride 0.1-0.15 mg) and dopamine antagonists (intravenous sulpiride 200-400 mg and intravenous chlorpromazine 25 mg) were performed in 40 patients. Dopamine agonists enhanced "on" dyskinesias and markedly reduced or abolished "off" period dystonia and DD. Dopamine antagonists reduced all types of LID but usually aggravated parkinsonism. These clinical and pharmacological results indicate that LID in PD are a heterogeneous phenomenon difficult to explain on the basis of a single pathophysiological mechanism.
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PMID:Levodopa-induced dyskinesias in Parkinson's disease: clinical and pharmacological classification. 135 58

The effect of 3-week daily injection of 5 or 15 mg enkephalin-like tetrapeptides (TP) into the rostral neostriatum was studied in chronic experiments on rats with implanted microcannulas. According to the type of TP, hyperkinesia or a pathological cataleptic status was registered in disorder of conditioned reflex behavior of rats. Myoclonus of the muscles of the face and the muscles of the front limbs was encountered from the 10th till the 120th minute after the injection and was characterized by dynamic changes during chronic administration of the agent and clearly defined stage of generalization. A pathologic cataleptic status (rigidity) in an animal kept in a suspended position occurred 120-140 minutes after the microinjection and lasted for up to 100 sec. The effect of the agent depended on the dose and stage of its chronic injection. The results of the study allow the conclusion on the principal possibility of the striatal enkephalinergic system being involved in the genesis of neuromotor dyskinesia and dysfunction of the basal ganglia, which is manifested by disorders of conditioned reflex behavior and motor extrapyramidal deviations.
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PMID:[Neuromotor dyskinesia occurring during repeated injections of enkephalins into the rat striatum]. 181 78

A 41-year-old female of mitochondrial myopathy characterized by recurrent paralytic ileus and atonic bladder with the evidence of peripheral nerve involvement was described. This patient was admitted to our hospital because of the episode of paralytic ileus and atonic bladder at the age of 40 and 41 (1987). She had noticed sporadic headache from 1967, constipation from 1977, tinnitus and hearing disturbance from 1984. One month after her second admission in 1987, her symptoms of paralytic ileus and atonic bladder gradually disappeared. She was then transferred to the department of neurology for the evaluation of underlining neurological disorders. Neurological examination revealed dementia, oro-lingual dyskinesia, and proximal muscular weakness. However, none of the following signs or symptoms were observed; Ophthalmoplegia, blepharoptosis, retinitis pigmentosa, myoclonus, cerebellar ataxia, sensory disturbance, and orthostatic hypotension. Deep tendon reflexes were normal. Planter responses were flexor. Pyruvate and lactate were elevated in both serum and cerebrospinal fluid. Brain CT scan displayed moderate cerebral atrophy and basal ganglia calcifications. EMG was normal except for the external anal sphincter muscles which showed a denervation pattern. Motor nerve conduction velocity was normal in the right median and the right peroneal nerves. Sensory nerve conduction velocity was also normal in the right median and the right sural nerves. However, the amplitude of sensory potential was low in both these nerves. Atonic type of neurogenic bladder was noted on cystometry. There was a lack of voiding desire. The number of active sweat glands iontophoretically stimulated by pilocarpine was reduced. The most prominent feature of the muscle biopsy (the left biceps brachii) was myopathic changes with ragged-red fibers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Paralytic ileus and atonic bladder in a case of mitochondrial encephalomyopathy--electrophysiological, chemical and pathological study with evidence of the peripheral nerve involvement]. 255 55

Experiments are described in which the gamma-aminobutyric acid (GABA) antagonist bicuculline was injected into the lentiform complex of conscious monkeys. Injections into either the lateral segment of the globus pallidus, or the medial part of the putamen, gave rise to chorea of the contralateral limbs and/or orofacial region. Control injections of vehicle alone were without effect. Injections of bicuculline into the lateral part of the putamen gave rise to contralateral myoclonus. The chorea produced by lateral pallidal or medial putaminal injections was virtually indistinguishable from the dyskinesia (chorea/ballism) which has been shown, in previous studies, to be induced by injection of GABA antagonists into the subthalamic nucleus. It is proposed that the primary site of action of the GABA antagonist in producing chorea, in the present studies, was the lateral segment of the globus pallidus. The mode of action is suggested to be interruption of GABAergic transmission from the striatum to the lateral pallidal segment. Since this also occurs in Huntington's disease, it is proposed that experimental chorea induced by this method in the monkey may be a useful model of the dyskinesia seen in Huntington's disease in man. Loss of influence of inhibitory striatopallidal fibres would lead to abnormally increased activity of lateral pallidal neurons. These in turn project to the subthalamic nucleus, upon which they have an inhibitory action. Dyskinesia is thus produced by physiological inhibition of the subthalamic nucleus, whose destruction, both in man and the monkey, is known to produce ballism. It is proposed that ballism and chorea share common neural mechanisms, both involving the loss of influence of the subthalamic nucleus on the medial segment of the globus pallidus.
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PMID:Chorea and myoclonus in the monkey induced by gamma-aminobutyric acid antagonism in the lentiform complex. The site of drug action and a hypothesis for the neural mechanisms of chorea. 317 91

Dementia and extrapyramidal signs combine in both Alzheimer's disease (AD) and Parkinson's disease (PD) to produce various degrees of clinical overlap between the two diseases. Rest tremor, positive motor response to dopaminergic drugs, bradyphrenia and disproportionate deficits in visuospatial function, dating capacity, recency discrimination, sequencing and set-shifting are specific features of PD; myoclonus, orofacial dyskinesia, aphasia and rapidly progressive global dementia favours AD. A clearer analysis of the underlying brain-behaviour relationships is necessary to advance our understanding of the origin of cognitive and motor impairment and its treatment.
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PMID:Clinical similarities and differences between Alzheimer's disease and Parkinson's disease. 331 3

Chronic treatment of parkinsonism with levodopa or levodopa/carbidopa is associated with problems that include dyskinesia, on-off phenomena, hallucinosis, and possible loss of therapeutic efficacy. We studied the effects of a period of transient drug withdrawal (drug holiday) in 16 patients who manifested these complications of chronic levodopa therapy. Patients were evaluated daily before, during, and after the period of drug withdrawal. Eleven of the 16 patients exhibited enhanced motor responsiveness after the holiday and required only half of the initial daily dose for improved motor performance. Most levodopa-induced side effects decreased after the holiday. Hallucinosis was ameliorated in all cases. The frequency of on-off phenomena and myoclonus also diminished. Sensitivity to levodopa-induced dyskinesia was not affected by the drug holiday. Because most patients required lower dosage after the holiday, dyskinesias were no longer present. These observations suggest that parkinsonian patients who suffer complications of chronic levodopa therapy may benefit from a period of drug withdrawal.
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PMID:Drug holiday and management of Parkinson disease. 719 5

Dyskinetic syndromes are conditions with involuntary movements. They can have different causes, but are often due to dysfunction of the basal ganglias. The clinical picture varies but all show spontaneous alterations in intensity as well as deterioration with stress. This often leads to misjudgment of cases of dyskinesia. It is however important to be aware of these syndromes as medical treatment is effective in many cases. The treatment of tremor, tics, chorea, myoclonus, dystonia and medically induced dyskinesia is reviewed and the clinical pictures are briefly described.
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PMID:[Treatment of dyskinetic syndromes]. 799 12


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