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)

The mutant mice tottering, leaner and the compound heterozygous tottering/leaner exhibit varying degrees of several abnormal neurological phenotypes including petit mal-like epilepsy, ataxia and an intermittent myoclonus-like movement disorder. Aberrant expression of tyrosine hydroxylase in cerebellar Purkinje cells of tottering, leaner and tottering/leaner mice has been observed previously [Austin M. C. et al. (1992) Molec. Brain Res. 15, 227-240; Hess E. J. and Wilson M. C. (1991) Neuron 6, 123-132]. In the present study, the distribution of tyrosine hydroxylase expression was compared with that of Zebrin II in Purkinje cells of adult homozygous tottering and compound heterozygous tottering/leaner mutant mice using single and double immunocytochemistry and double immunofluorescence. The pattern of Zebrin II expression in the cerebella of the mutant mice was identical to that described for normal mice [Hawkes R. et al. (1985) Brain Res. 333, 359-365; Hawkes R. and Leclerc N. (1987) J. comp. Neurol. 256, 29-41]. In addition, sections through tottering and tottering/leaner cerebella demonstrated an exact correspondence between the bands of tyrosine hydroxylase immunoreactivity and bands of Zebrin II immunoreactivity. Similarly, the compartments of the Purkinje cell layer which were negative for Zebrin II staining were also negative for tyrosine hydroxylase immunoreactivity. This study provides evidence that the cerebellar Purkinje cells of tottering and tottering/leaner mice were able to express a normal gene product, Zebrin II, in a normal spatial pattern and the same Purkinje cells can also express an aberrant gene product, tyrosine hydroxylase. This abnormal gene expression may indicate that at least some Purkinje cells in these mutant mice are not functioning normally. This possibility, taken together with the morphological changes observed in many mutant Purkinje cell axons, suggests that Purkinje cell function could be altered in tottering and tottering/leaner mice, thereby contributing to the neurological abnormalities exhibited by these mice. It is also possible that alteration in function of mutant Purkinje cells could correlate with the rostrocaudal zonation pattern described in this study.
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PMID:Co-localization of tyrosine hydroxylase and zebrin II immunoreactivities in Purkinje cells of the mutant mice, tottering and tottering/leaner. 905

Parkinsonism, tremor, chorea-ballismus, dystonia, tardive dyskinesia, myoclonus, tics and akathisia can be induced by many drugs. The drugs that are most frequently implicated in movement disorders are antipsychotics, calcium antagonists, orthopramides and substituted benzamides (e.g. metoclopramide, sulpiride, clebopride, domperidone), CNS stimulants, antidepressants, anticonvulsants, antiparkinsonian drugs and lithium. It is possible for a single drug to induce 2 or more types of movement disorders in the same patient. Movement disorders are not always reversible after drug withdrawal.
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PMID:Drug-induced movement disorders. 909 56

The disease is named after George H. Whipple who, in 1907, was the first to describe an intestinal "lipodystrophy". Although Whipple's disease is generally recognized as a multisystem chronic granulomatous disease, primarily involving the digestive system, it can also appear as a primary neurological disorder in rare cases. Most often it is manifested with loss of weight, diarrhea, malabsorption, abdominal pain, lymphadenopathy, cardiopathy, hyperpigmentation and hypotension. The presence of periodic acid-Schiff (PAS)-positive macrophages in biopsy specimens (not only jejunal) and demonstration of "Whipple's bacilli" visible by electron microscopy, are diagnostic signs of active Whipple's disease. Whipple's disease confined to the CNS is rare. It is rarely found in the differential diagnosis of patients with progressive neurological deterioration. The most common neurological picture includes progressive dementia, external ophalmoplegia, myoclonus, seizures, ataxia, hypothalamic dysfunction (sleep disorders, hyperphagia, polydipsia) and meningitis. Oculofacial-skeletal myorhythmia as a movement disorder, associated with Whipple's disease, is reported. Fulminant course of cerebral Whipple's disease is unusual and unfavourable. The confusing and nonspecific clinical appearance is typical for primary CNS involvement. It has recently been suggested that CNS involvement occurs in all cases, although only 10-20% of patients may show it. The CNS is the most common site of disease relapse. The CT scans and MRI of the brain are often normal, but may show cortical/subcortical atrophy, hydrocephalus, focal or intracerebral mass lesions. The cerebrospinal fluid can sometimes contain PAS-positive macrophages. Brain biopsy is suggested as a diagnostic method in cases of high suspicion of CNS Whipple's disease. However, the lesions are frequently inaccessible and false negative. Without extended antibiotic therapy, the course of Whipple's disease is lethal. Now, the prognosis is good, although the optimal antimicrobial regimen is not clearly established. Initial parenteral therapy (tetracycline, penicilline, streptomycine, chloramphenicol, ampicilline) and peroral long-term treatment with trimetoprime-sulphametoxasole, are recommended. As CNS relapse of Whipple's disease may occur after several years, long-term treatment should include antibiotics that are able to cross the blood-brain barrier. The CNS relapse, in contrast to the systemic ones, is resistant to the treatment. Appropriate therapy instituted earlier in the course of the disease is associated with a better neurological outcome. Early recognition can be critical in Whipple's disease because of irreversible neurological sequelae seen later in the course of this potentially treatable condition. In cases with high clinical suspicion in which Whipple's disease cannot be diagnosed with procedures such as jejunal biopsy, antibiotic therapy is recommended. Recovery of an established neurological deficit may rarely occur. Longterm follow-up studies would help to identify the optimal antibiotic regimen and duration of treatment.
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PMID:[Neurologic disorders in Whipple's disease]. 910 28

Primary defects of mitochondrial DNA leading to respiratory chain dysfunction have been described in association with dystonia, chorea and parkinsonism. Myoclonus remains the commonest movement disorder associated with such defects. The genetic basis of Leigh's syndrome, which is frequently associated with movement disorders, may be mitochondrial or nuclear. Respiratory chain dysfunction has been identified in Huntington's disease in addition to Parkinson's disease, but the cause and relationship of this dysfunction to the pathogenesis of these common disorders is not yet determined.
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PMID:Movement disorders and mitochondrial dysfunction. 926 61

We report three members of a single family with an apparently autosomal dominant, nonparoxysmal, hyperkinetic movement disorder with onset in adolescence. The proband, a 56-year-old woman, manifested dystonia, tremor and myoclonus; one of her daughters exhibited myoclonus with tremor, and the other demonstrated myoclonus with chorea later accompanied by tremor and dystonia. The slowly progressive but not debilitating symptoms were restricted to the head, arms and hands and were only moderately affected by alcohol. Laboratory investigations failed to identify any abnormality, and linkage analysis excluded the region containing the DYT1 locus, indicating that the gene responsible for idiopathic torsion dystonia was not implicated in this family. While this disorder shares manifestations with myoclonic dystonia, essential myoclonus and benign chorea, the marked intrafamilial heterogeneity and the sex-limited phenotype expressed only in females of two generations appear to be unique.
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PMID:Intrafamilial heterogeneity of movement disorders: report of three cases in one family. 926 60

Symptomatic myoclonus syndromes can be caused by a broad range of etiological factors. We report the case of a 40-year-old woman who showed spontaneous and continuous myoclonus with predominance distally and in the arms as the only neurological symptom. CSF evaluation revealed acute neurosyphilis. Six months after antibiotic treatment, the movement disorder had disappeared.
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PMID:[Generalized myoclonus as the only symptom of neurosyphilis]. 944 Dec 59

Fluctuating stiffness and paroxysmal spasms of the trunk and legs are the primary features of stiff-man syndrome and it's variants, progressive encephalomyelopathy with rigidity and myoclonus (PERM) and stiff-leg syndrome. The spasms characterized by hyperextension of the back and legs are both spontaneous as well as stimulus-sensitive. They can be excruciatingly painful and are frequently accompanied by symptoms of autonomic dysregulation. Hyperreflexia may be the only pathological finding on the neurological examination. Most patients show psychiatric disturbances suggestive of psychogenic movement disorder and this may cause delays in adequate pharmacotherapy. The disease progresses over the span of months to years rendering many patients wheelchair-bound or bedridden. GABA-mimetics are most effective in treating symptoms, but tolerance and life-threatening withdrawal symptoms are common drawbacks. For therapy-refractory patients, intrathecal baclofen represents a good alternative. The diagnosis is based on clinical, biochemical and electrophysiological findings. Spasmodic reflex myoclonus is observed in nearly all SMS patients. It consists of well-reproduced reflex EMG-activity commencing 50-80 ms after medial or tibial nerve stimulation and lasting several seconds thereafter. The activity is first myoclonic then spasmodic in nature, and commonly begins in the muscles most severely affected before spreading bidirectionally along the neuraxis. Spasmodic reflex myoclonus and the high incidence of antibodies against GAD are suggestive of an autoimmune disorder affecting GABAergic neurons in the spinal cord, but the precise locus of dysfunction remains to be elucidated.
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PMID:Stiff-man syndrome: an overview. 957 75

Homozygous leaner mice carry an autosomal recessive mutation in the Ca2+ channel subunit gene, alpha1A, causing them to exhibit severe ataxia, petit-mal-like epilepsy and a myoclonus-like movement disorder. Expression of alpha1A mRNA in cerebella from 20-day-old homozygous leaner mice was compared to control mice, using in situ hybridization histochemistry. Expression of alpha1A protein was examined in cerebella from 20-day-old homozygous leaner and control mice using immunocytochemistry. No differences in either mRNA or protein expression of the alpha1A subunit were observed when homozygous leaner mice were compared to age-matched controls. Therefore, functional alterations in P/Q-Type Ca2+ channels containing the alpha1A subunit need to be explored to further understand the relationship of mutations in the alpha1A gene to the pathogenesis of the neurologic disorders occurring in leaner mice.
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PMID:Expression of calcium channel alpha1A mRNA and protein in the leaner mouse (tgla/tgla) cerebellum. 972 1

This is a proposal of the Movement Disorder Society for a clinical classification of tremors. The classification is based on the distinction between rest, postural, simple kinetic, and intention tremor (tremor during target-directed movements). Additional data from a medical history and the results of a neurologic examination can be combined into one of the following clinical syndromes defined in this statement: enhanced physiologic tremor, classical essential tremor (ET), primary orthostatic tremor, task- and position-specific tremors, dystonic tremor, tremor in Parkinson's disease (PD), cerebellar tremor, Holmes' tremor, palatal tremor, drug-induced and toxic tremor, tremor in peripheral neuropathies, or psychogenic tremor. Conditions such as asterixis, epilepsia partialis continua, clonus, and rhythmic myoclonus can be misinterpreted as tremor. The features distinguishing these conditions from tremor are described. Controversial issues are outlined in a comment section for each item and thus reflect the open questions that at present cannot be answered on a scientific basis. We hope that this statement provides a basis for better communication among clinicians working in the field and stimulates tremor research.
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PMID:Consensus statement of the Movement Disorder Society on Tremor. Ad Hoc Scientific Committee. 982 89

Homozygous tottering (tg/tg) and compound heterozygous tottering/leaner (tg/tg(la)) mutant mice exhibit juvenile onset of three abnormal neurological phenotypes: (i) petit mal-like epilepsy; (ii) ataxia; and (iii) an intermittent myoclonus-like movement disorder. Homozygous leaner mice (tg(la)/tg(la)) exhibit early onset of ataxia (postnatal days 10-12), and also exhibit the myoclonus-like movement disorder and evidence of absence seizure activity; the myoclonus-like disorder is most evident in the first month of life, then diminishes in severity and frequency. The ultrastructure of the cerebellar molecular layer was examined in adult (six to eight months) and juvenile (20-25 days) mice of all three mutant genotypes. In mice of all three genotypes and both ages, Purkinje cell dendritic spines were observed to make multiple contacts with individual parallel fiber varicosities in all sections analysed. These multiple synaptic units were observed in both anterior and posterior vermis and hemispheres of the cerebellum, and ranged from two to nine spines/parallel fiber varicosity. Occasionally, one of the postsynaptic spines belonged to an ectopic spine emerging from the proximal region of a Purkinje cell dendrite. This increase in the multiple synaptic index of some parallel fiber varicosities was observed in juvenile tottering mice before the onset of the symptoms of the neurological disorders. This is highly suggestive that the onset of the neurological phenotype is not a primary cause of multiple Purkinje cell dendritic spines synapsing with single parallel fiber varicosities in these mice, but on the contrary, that it could be the cause of the ataxic symptoms.
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PMID:An ultrastructural study of granule cell/Purkinje cell synapses in tottering (tg/tg), leaner (tg(la)/tg(la)) and compound heterozygous tottering/leaner (tg/tg(la)) mice. 1021 73


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