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

Genetic studies have suggested homogeneity between the Baltic-type and Mediterranean-type progressive myoclonic epilepsy. Magnetoencephalography was applied to elucidate the mechanism underlying the giant evoked responses in cortical reflex myoclonus. A new concept of negative myoclonus mediated by cortical reflex mechanism was proposed. Cortical myoclonus was demonstrated in various neurodegenerative or metabolic disorders, such as presenile or senile dementia, olivopontocerebellar atrophy, and myoclonus epilepsy associated with ragged-red fibres. Myoclonus in corticobasal degeneration is especially noteworthy because it has clinical and electrophysiological features of cortical reflex myoclonus, but its latency is shorter compared with the conventional cortical reflex myoclonus. Clinical features of 'palatal myoclonus' were reported by the name of 'palatal tremor'.
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PMID:Myoclonus. 758 53

Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant neurodegenerative disorder characterized clinically by various combinations of myoclonus, epilepsy, cerebellar ataxia, choreoathetosis, dementia and psychiatric symptoms. Based on the phenomenon of anticipation, the gene for DRPLA was recently identified. DRPLA is caused by unstable expansion of a CAG repeat in the gene located on the short arm of chromosome 12. As have been observed in Huntington's disease and SCA1, there is a strong correlation between the age of onset and the size of CAG repeats. Furthermore, patients with larger repeats tend to show a PME (progressive myoclonus epilepsy) phenotype as well as earlier ages of onset. More prominent anticipation and larger intergenerational increase of CAG repeats in paternal transmission can be accounted for by the meiotic instability of CAG repeats in male gametogenesis. Comparison of size distributions of CAG repeats in Japanese, African-American and white populations revealed that 7.4% of the Japanese alleles had greater than 19 repeats, whereas none of the whites and 1% of the African-American alleles were of this size. The results may account for the ethnic predilection of DRPLA.
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PMID:Dentatorubral-pallidoluysian atrophy (DRPLA). Molecular basis for wide clinical features of DRPLA. 761 90

Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant neurodegenerative disease characterized by various combinations of ataxia, choreoathetosis, myoclonus, epilepsy and dementia as well as various ages of onset. We have identified a specific unstable trinucleotide repeat expansion in a gene on the short arm of chromosome 12 as the pathogenic mutation for DRPLA. We investigated how the degree of the expansion of the CAG repeat affects the clinical manifestations of DRPLA. The sizes of the expanded alleles were well correlated with the ages of onset (r = -0.6955, P < 0.001). Patients with progressive myoclonus epilepsy (PME) phenotype had larger expansions (62-79 repeats) and earlier ages of onset (onset before age 20). Furthermore, most of the patients with PME phenotype inherited their expanded alleles from their affected fathers. On the other hand, patients with non-PME phenotype showed later ages of onset (onset after age 20) and smaller expansions (54-67 repeats). When ages of onset of each clinical symptoms are compared with sizes of the CAG repeat, there is again a remarkably high correlation of the sizes of CAG repeat with each of the clinical symptoms. Thus the wide variation in clinical manifestations of DRPLA can now be clearly explained based on the degree of CAG repeat expansion, which strongly indicates that the expanded alleles are intimately involved in the neuronal degeneration in dentatofugal and pallidofugal systems.
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PMID:Dentatorubral-pallidoluysian atrophy (DRPLA): close correlation of CAG repeat expansions with the wide spectrum of clinical presentations and prominent anticipation. 762 Jan 20

We report on clinical, electrophysiological, neuroradiological, and morphological data from 19 patients with different types (late infantile, juvenile, and adult) of neuronal ceroid-lipofuscinosis (NCL), observed in the last 10 years at the Neurological Institute of Milan. Late Infantile NCL (LINCL) (8 patients, 4m/4f). Age at onset: 2-4 1/2 years. Seizures (6 patients) or decline of mental capacities (2 patients) were the presenting symptoms, followed by myoclonus and ataxia; visual loss and optic atrophy occurred in 6 patients within 3 years. All but 2 children became bedridden within 3 1/2 years. CT and MRI demonstrated different degrees of cerebral and cerebellar atrophy within 3 years from onset of the disease. Ultrastructural studies showed fingerprint profiles (FP) and osmiophilic bodies (OB) in circulating lymphocytes; curvilinear bodies (CB) and FP were detected in eccrine secretory cells. Juvenile NCL (JNCL) (7 patients, 4m/3f). Age at onset: 6-9 years. Visual loss with retinal degeneration was the presenting symptoms, accompanied in all but 2 patients by slight mental impairment. Seizures occurred within 2-4 years. CT and MRI detected cerebral or cerebellar atrophy in those patients (5 patients) with a clinical follow-up longer than 4 years. Electron microscopy showed FP on circulating lymphocytes, and both FP and CB on skin biopsy specimens. Adult NCL (ANCL) (4 patients, 3 m/1f). Age at onset: 12-50 years. Progressive myoclonus epilepsy (1 patient) or dementia with motor disturbances (3 patients) were the clinical phenotypes of the disease. MRI demonstrated cerebral and cerebellar atrophy within 6 years from onset. Electron microscopy disclosed FP in cytoplasmic vacuoles inside eccrine secretory cells.
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PMID:Neuronal ceroid-lipofuscinosis: a clinical and morphological study of 19 patients. 766 17

Based on five case studies, the suggestion is that, if physiological myoclonus can be excluded, antidepressant - or neuroleptic-induced myoclonus must as a rule be presumed to be a most subtle indication of increased cerebral exitability, an epileptic fragment or, in some instances, a myoclonus epilepsy. In each of the reported cases EEG recordings reflected epilepsy-specific potentials. Whether, however, the scope of differences in the EEG recordings and the N1/P1 amplitude increase of the SSEP may be used as an additional diagnostic criterion to determine the risk of epileptic seizures, should depend on the type of myoclonus chiefly induced. This would require more extensive neurophysiological examinations which should mainly include the back-averaging to permit, beside the EEG, a better evaluation of the relatively easily obtainable SSEP findings.
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PMID:[Psychotropic drug-induced myoclonus]. 776 44

Dentatorubral-pallidoluysian atrophy is an autosomal dominant neurodegenerative disease characterized by various combinations of ataxia, choreoathetosis, myoclonus, epilepsy, and dementia as well as a wide range of ages at onset. A specific unstable trinucleotide repeat expansion in a gene on the short arm of chromosome 12 was recently identified as the pathogenic mutation for this disease. We investigated how the degree of expansion of the CAG repeat effects the clinical manifestations of dentatorubral-pallidoluysian atrophy. The size of the expanded alleles was well correlated with the age at onset (r = -0.696, p < 0.001). Patients with the progressive myoclonus epilepsy phenotype had larger expansions (62-79 repeats) and an earlier age at onset (onset before age 21). Furthermore, most of the patients with the progressive myoclonus epilepsy phenotype inherited their expanded alleles from their affected fathers. On the other hand, patients with the non-progressive myoclonus epilepsy phenotype showed smaller expansions (54-67 repeats) and a later age at onset (onset at or after age 21). Detailed analyses of clinical features demonstrated that ataxia, involuntary movement of either myoclonus or choreoathetosis, and intellectual decline are cardinal features of dentatorubral-pallidoluysian atrophy, with myoclonus and epilepsy being observed more frequently in patients with an earlier age at onset. Thus the wide variation in clinical manifestations of dentatorubral-pallidoluysian atrophy can now be clearly explained based on the degree of CAG repeat expansion, which strongly indicates that the expanded alleles are intimately involved in the neuronal degeneration in dentatofugal and pallidofugal systems.
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PMID:Dentatorubral-pallidoluysian atrophy: clinical features are closely related to unstable expansions of trinucleotide (CAG) repeat. 777 50

Anticipation refers to the progressively earlier onset and increase in disease severity in successive generations. We studied four families with hereditary dentatorubral-pallidoluysian atrophy (DRPLA), a neurodegenerative disease, and anticipation was present in the mode of inheritance. In subsequent generations DRPLA shows an earlier onset and more severe as well as additional symptoms. Older onset patients suffer from cerebellar ataxia with or without dementia, whereas younger onset patients present as progressive myoclonus epilepsy syndrome, which consists of mental retardation, dementia, and cerebellar ataxia as well as epilepsy and myoclonus. Anticipation with paternal transmission was significantly greater than with maternal transmission.
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PMID:Anticipation in hereditary dentatorubral-pallidoluysian atrophy. 800 97

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurologic disorder characterized by variable combinations of myoclonus, epilepsy, cerebellar ataxia, choreoathetosis and dementia. By specifically searching published brain cDNA sequences for the presence of CAG repeats we identified unstable expansion of a CAG in a gene on chromosome 12 in all the 22 DRPLA patients examined. A good correlation between the size of the CAG repeat expansion and the ages of disease onset is found in this group. Patients with earlier onset tended to have a phenotype of progressive myoclonus epilepsy and larger expansions. We propose that the wide variety of clinical manifestations of DRPLA can now be explained by the variable unstable expansion of the CAG repeat.
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PMID:Unstable expansion of CAG repeat in hereditary dentatorubral-pallidoluysian atrophy (DRPLA). 813 40

We describe a patient with progressive myoclonus epilepsy (late-onset Lafora's disease). Onset was in early adult life, and death was at age fifty-four. The initial symptoms were epileptic seizures and progressive dementia, with later occurrence of myoclonus. Lafora bodies were ubiquitous and in neuronal perikarya in many areas. Dust-like granular bodies predominated in the neuropil of cerebral cortex, substantia nigra, and striatum. Abnormal deposits were also found in the myocardium.
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PMID:Late-onset Lafora's disease with typical intraneuronal inclusions. 817 May 76

We performed a 5-year clinical and electrophysiologic follow-up study on two sibling cases with myoclonus epilepsy with ragged-red fibers. Both had myoclonus, intention tremor, slight muscle weakness, slight mental disturbance, hearing impairment, and optic atrophy. Neither had epileptic attacks or truncal or gait ataxia. Biochemical activity of cytochrome c oxidase was at the lower limit of the normal range of values, and an adenine to guanine transition mutation at nucleotide 8344 in the transfer RNA specific for lysine of mitochondrial DNA was detected in both cases. The electroencephalograms showed slowing of basic patterns, diffuse spike-and-wave complexes, occipital dominant wave-and-spike phantoms, 6- and 14-Hz positive spikes, and photosensitivity. No definite deterioration of basic patterns was seen, and diffuse spike-and-wave complexes and photosensitivity gradually disappeared during the slowly progressive clinical course. P2 latencies of pattern-reversal visual evoked potentials throughout the clinical course and III through V interpeak latencies of auditory brainstem responses at follow-up were prolonged without giant sensory evoked potentials in both cases.
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PMID:Myoclonus epilepsy with ragged-red fibers: a clinical and electrophysiologic follow-up study on two sibling cases. 822 33


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