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

Myoclonus is a phenomenon which cuts through a considerable number of neurological conditions. It occurs in a variety of epileptic conditions (Primary generalized epilepsy, hypsarrhythmia, Lennox-Gastaut syndrome, also known as "petit mal variant"), in inborn errors of metabolism (Tay-Sachs disease, forms of ceroid lipofuscinosis), in neurobiochemically still poorly understood forms of degenerative processes such as Essential hereditary myoclonus epilepsy (Lafora-Unverricht-Lundborg), in benign heredo-degenerative disorders (Hartung's syndrome), in CNS infections (SSPE, Jakob-Creutzfeldt disease), in metabolic encephalopathies (renal failure, hypoglycemia), in CNS poisoning, in acute cerebral anoxia and in post-anoxic states. The EEG plays a crucial role in the differential diagnosis of these conditions by the demonstration of a) presence or absence of typical inter-ictal abnormalities, and b) various correlates of the myoclonic ictal event.
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PMID:Myoclonus and the electroencephalogram, a review. 11 May 3

Nerve conduction, EEG, visual evoked potentials, electroretinograms and somatosensory evoked potentials were investigated in 3 children with the Bielschowsky-Jansky-type and in 1 child diagnosed as Spielmeyer-Vogt-type of neuronal ceroid lipofuscinosis. Electroretinographic responses were abolished in all of them. Electroencephalograms showed high amplitude, irregular delta-theta activity and spike- or polyspike-wave discharges without localized preponderance. As a characteristic feature for the Bielschowsky-Jansky type grossly enlarged evoked responses to single light flashes were recorded. Somatosensory evoked potentials were increased in amplitude in 2 patients. Myoclonic jerks of the pyramidal type could be elicited by electrical stimuli to the median nerve. The possibility to differentiate certain neurometabolic disorders of childhood by simple electrophysiological parameters is discussed.
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PMID:Evoked potentials in neuronal ceroid lipofuscinosis. 48 41

Genetic storage diseases with prominent myoclonus include classic infantile Tay-Sachs disease and juvenile neuropathic Gaucher's disease among the sphingolipidoses, most of the variants of the sialidoses and ceroid-lipofuscinoses, and Lafora disease. The character of the myoclonus differs from disease to disease and often changes as the disease runs its course. For example, massive myoclonic jerks to sound with rapid habituation and a prolonged refractory period are characteristic of the early stages of Tay-Sachs disease; children with late infantile ceroid-lipofuscinosis are most sensitive to light flashes below 3 Hz, those with juvenile Gaucher's disease at 6 to 10 Hz, and those with Lafora disease at 15 to 20 Hz, whereas young adults with sialidosis are not sensitive to either light or sound but are highly sensitive to somatosensory stimulation and movement. Some patients with sialidosis were found to have two distinct types of myoclonus: (a) a stimulus-insensitive facial myoclonus without EEG correlate that persisted in slow-wave sleep and (b) stimulus-sensitive massive jerks associated with vertex positive EEG spikes on which sleep had the paradoxic effect of suppressing jerks while stimulating spikes. Systematic EEG and event-related potential studies, including backward averaging from jerks and detailed anatomic studies of postmortem specimens with modern histochemical techniques, may help illuminate these intriguing differences. New modalities are needed to treat the myoclonus of these diseases since it generally responds poorly to currently available pharmacologic agents.
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PMID:Myoclonus in neuronal storage and Lafora diseases. 308 Aug 54

Fifty-seven consecutive patients with myoclonus from various causes were studied by electrophysiological techniques. Giant somatosensory evoked potentials (SEPs) were observed almost exclusively in patients with progressive myoclonic epilepsy (PME) and diseases with similar clinical features that included lipidosis, neuronal ceroid lipofuscinosis and posthypoxic myoclonus. On the basis of combinations of the giant SEP and the myoclonus-related cortical spike demonstrated by jerk-locked averaging, myoclonus in these patients was classified into four types. In patients with 'cortical reflex' myoclonus (type I) who showed both the giant SEP and the myoclonus-related cortical spike, these two cortical activities were similar in terms of wave form, scalp topography, time relationship to either the long latency (C) reflex or myoclonus, the following cortical excitability, the effect of antimyoclonus drugs and alterations during slow wave sleep. It is therefore postulated that the giant SEP is generated, at least in part, by common physiological mechanisms to the myoclonus-related cortical spike, or that the latter may comprise a constituent of the former. In most patients with PME or allied diseases, both afferent and efferent components of the SEP are enhanced, but in some patients, only one of the two components seems to be predominantly enhanced.
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PMID:Pathogenesis of giant somatosensory evoked potentials in progressive myoclonic epilepsy. 391 84

We reported a case of late infantile neuronal ceroid-lipofuscinosis. The patient was an 8-year-old boy presenting with marked psychomotor deterioration, progressive visual failure due to retinal degeneration and optic atrophy, startle reaction to auditory stimuli, frequent myoclonus and generalized convulsions. The routine laboratory examinations were all normal. EEG was markedly abnormal because of poorly organized background activity and frequent paroxysmal spike-and-wave complexes. CT scan showed evidence of severe atrophy of the cerebrum, cerebellum and brainstem. Electron microscopic examination of the biopsied rectum revealed fingerprint profiles in the neurons and pericytes beneath the muscularis mucosa. Cultured skin fibroblasts also contained electron dense inclusions, some of which showed fingerprint profiles. Urinary glycopeptides were normal. Lyscsomal enzyme activities in leukocytes and cultured fibroblasts were normal. Neurophysiological studies revealed giant cortical potentials evoked by the auditory as well as somatosensory stimulation. Simultaneous recording of the somatosensory evoked EEG and EMG potentials disclosed that the myoclonus in this patient was stimulus-sensitive and compatible with the cortical reflex myoclonus. With regard to hypothetical pathogenesis of this disease, we studied lipoperoxide in the blood before and after anti-oxidant therapy. We also measured vitamin A and carotene, since these substrates are related to retinoic acid. Although vitamin A and carotene were normal, lipoperoxide was slightly elevated. However, it was not influenced by the treatment with anti-oxidant. Significance of elevated lipoperoxide to the pathogenesis of this diseases has not solved.
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PMID:[A case of neuronal ceroid-lipofuscinosis (Jansky-Bielshowsky type): morphological, biochemical and electrophysiological studies (author's transl)]. 627 66

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

A subset of lipophilic neurons in the brain tissue of late infantile neuronal ceroid lipofuscinosis (LINCL) cases shows in addition to finely granular storage lipopigment, larger spheroidal lysosomal inclusions, so called protein-type myoclonus bodies. Their incidence, significance, and biochemical composition have not been determined. To further characterize this type of lysosomal storage material, immunocytochemistry to subunit c of mitochondrial ATP synthase at the light and electron microscopy level, electron microscopy, and lectin histochemistry were applied. The majority of spheroidal inclusions were nonreactive to subunit c, the main protein component of the storage material in LINCL. These inclusions also showed no binding sites for the eight lectins examined, although six of the lectins used labeled finely granular storage material. According to electron and immunoelectron microscopy, spheroidal inclusions were composed of more homogeneous and more densely arranged material than typical curvilinear profiles, with shorter membranous profiles and sometime filamentous structures. The dissimilarities disclosed between finely granular lipopigment with curvilinear profiles and spheroidal inclusions in LINCL brain tissue suggest that either protein(s) other than subunit c are present in spheroidal inclusions, or subunit c in these sites undergoes conformational or proteolytic changes. These changes require further biochemical evaluations.
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PMID:Topographic variabilities of immunoreactivity to subunit c of mitochondrial ATP synthase and lectin binding in late infantile neuronal ceroid-lipofuscinosis. 766 27

A 9-month-old domestic shorthair cat was humanely killed because of uncoordinated gait, myoclonus, seizures and reduced vision. Histological, immunohistochemical and ultrastructural examination revealed a neuronal storage disease consistent with neuronal ceroid-lipofuscinosis (NCL). Neurons contained Sudan black- and luxol fast blue-positive material which was autofluorescent. Immunohistochemically, the storage material was found to contain subunit c of mitochondrial ATP synthase, a protein recently recognized as the main component of the storage material in NCL. Ultrastructurally, the material consisted of curvilinear and fingerprint bodies, which are indicative of NCL.
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PMID:Neuronal ceroid-lipofuscinosis in a domestic cat: clinical, morphological and immunohistochemical findings. 926 41

Based on small numbers of patients, it is possible to make the following suggestions rather than categorical statements. For myoclonic seizures and epilepsies which are not otherwise specified, valproate seems of proven efficacy. Ethosuximide may be a useful adjunct. The exact place of lamotrigine, which controls some myoclonia and makes them worse in other patients, requires further study. The findings are clearer when specific syndromes are considered. Valproate is the treatment of first choice for benign myoclonic epilepsy in infants, myoclonic astatic epilepsy, epilepsy with myoclonic absences, eyelid myoclonia with absences, juvenile myoclonic epilepsy and progressive myoclonus epilepsy. The addition of ethosuximide to valproate can be helpful to those with myoclonic absences, where this combination appears more beneficial than either valproate or ethosuximide alone and in eyelid myoclonia with absences. Lamotrigine can be effective therapy for juvenile myoclonic epilepsy and eyelid myoclonia with absences when used alone and, in conjunction with other antiepileptic drugs (AED) (usually valproate) for early myoclonic encephalopathy, myoclonic-astatic epilepsy and particularly, epilepsy with myoclonic absences. The myoclonia of infantile neuronal ceroid lipofuscinosis respond to lamotrigine. Severe myoclonic epilepsy of infants usually worsens with lamotrigine, but occasionally, children improve. Zonisamide added to clonazepam and valproate or a barbiturate, can reduce the cascade of myoclonia in progressive myoclonus epilepsies for at least 2 years, but relapse may occur thereafter.
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PMID:Myoclonus and epilepsy in childhood: a review of treatment with valproate, ethosuximide, lamotrigine and zonisamide. 947 47

We report autopsy cases of two brothers with the late infantile form of neuronal ceroid lipofuscinosis (LINCL) and examine apoptotic cell death in autopsied brains. Both patients showed psychomotor developmental delay, cerebellar ataxia, convulsions, visual disturbance and myoclonus, and they became bedridden around the age of 6-7 years. Macular changes, mimicking cherry-red spots, were observed on funduscopy, but conjunctival biopsy failed to disclose storage materials. In these cases, the autopsies demonstrated severe atrophy with neuronal loss and gliosis throughout the brain and spinal cord, except the hypothalamic neurons and motor neurons in the brain-stem and spinal cord, and autofluorescent lipofuscin-like materials of two types, fine granular deposits and coarse round bodies, were stored in the remaining neurons and glial cells, and in the epithelial cells of various visceral organs. Immunostaining for mitochondrial subunit C visualized the fine granular deposits but not the coarse round bodies. The nuclei of neurons and glia cells were stained by in situ nick end labeling, which was more pronounced in the younger case, although the expression of both bcl-2 and bcl-x was not significantly altered in these cases. It is suggested that immunohistochemistry for subunit C may be useful for diagnosis of NCL, and further investigations are necessary to clarify the relationship between LINCL and apoptosis, especially in severely affected cases.
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PMID:Pathological study on sibling autopsy cases of the late infantile form of neuronal ceroid lipofuscinosis. 1008 55


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