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

Baltic myoclonus epilepsy (BME) is a neurodegenerative disease characterized by tonic-clonic seizures, myoclonus and a progressive course. The aim of the present study was to assess the clinical symptoms and signs of possible involvement of the autonomic nervous system (ANS) and objectively evaluate autonomically mediated cardiovascular reflexes in this syndrome. Fifteen patients with BME and 14 healthy control subjects were studied. Thirteen (87%) of the patients had symptoms suggesting ANS dysfunction. The most common symptoms were postural dizziness and sweating disturbances. The heart rate variation during deep breathing was lower in patients than in controls. The heart rate response and systolic blood pressure response during tilting were similar in both groups. Our results suggest a mild parasympathetic hypofunction and an intact sympathetic function in ambulatory patients with BME.
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PMID:Autonomic nervous system function in Baltic myoclonus epilepsy. 211 65

It has been suggested from studies of patients with progressive myoclonus epilepsy that the term Ramsay Hunt syndrome should be abandoned, as its use has led to nosologic confusion, and because, in the light of modern diagnostic techniques, the majority of cases can be allocated to specific disease categories, chiefly, Unverricht-Lundborg disease (Baltic myoclonus) and mitochondrial encephalomyopathy. Review of 30 cases of this syndrome, defined as progressive ataxia and myoclonus and infrequent seizures in the absence of dementia, showed that a clinical or biochemically supported diagnosis could not be made in 43%. This low diagnostic yield probably reflects differences in ascertainment of patients; those described here were referred with a syndrome of progressive myoclonic ataxia (the Ramsay Hunt syndrome) rather than progressive myoclonus epilepsy. These two syndromes share common causes, but a smaller proportion of patients with progressive myoclonic ataxia can currently be diagnosed precisely during life.
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PMID:Progressive myoclonic ataxia (the Ramsay Hunt syndrome). 212 Nov 21

It has been found that PME without Lafora bodies is more common in Finland than elsewhere. The incidence is 1:20,000. The mode of inheritance is autosomal recessive. At first the children are healthy. Stimulus-sensitive myoclonic jerks and grand mal seizures appear at the age of 6 to 15 years. The EEG shows a generalized disturbance with spike-wave or polyspike-wave paroxysms which increase during photic stimulation. Myoclonic jerks incapacitate the patient. Within 5 years after the onset of the first symptoms, many patients have a disorder of gait and may become confined to bed. Sodium valproate alone or combined with clonazepam is the most effective therapy. However, the course of the disease is progressive. The mean age at death has been 24 years but appears to be increasing. The etiology and pathogenesis of PME without Lafora bodies are unknown. Increased excretion of indican has been noted, suggesting deficient intestinal absorption of L-tryptophan. A loss of Purkinje cells is the most prominent neuropathological feature. No inclusion bodies are present. Finnish PME patients are similar to the patients described by Unverricht from Estonia and by Lundborg from Sweden. Neuropathological data from these patients are not available. Clinically, these patients could form an entity with Finnish patients defined as a Baltic or Nordic type of PME. The gene is enriched in Finland, but elsewhere it is rare.
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PMID:Baltic myoclonus. 241 50

Action myoclonus, reviewed in this chapter, is the term applied to arrhythmic muscular jerking induced by voluntary movement. It is made worse by attempts at precise or coordinated movement (intention myoclonus) and may also be provoked by certain sensory stimuli. The effective stimuli for action myoclonus is probably feedback from muscle afferents, although it may be initiated by corollary discharge from motor cortex to reticular formation before or at the onset of voluntary movement. The condition is usually associated with diffuse neuronal disease such as post-hypoxic encephalopathy, uremia, and the various forms of PME, although action myoclonus may be limited to one limb in some cases of focal cerebral damage. It is caused by hyperexcitability of the sensorimotor cortex (cortical reflex myoclonus) or reticular formation (reticular reflex myoclonus), or both. No consistent pathological change has been reported in autopsied cases of action myoclonus. The underlying disorder appears to be a loss of inhibitory mechanisms involving serotonin and possibly GABA as transmitter agents. The term PME is used for the association of myoclonus with degenerative changes in the nervous system which are commonly diffuse but may predominate in certain systems. There may or may not be associated tonic-clonic seizures, other manifestations of epilepsy, or dementia. Those cases of PME associated with Lafora inclusion bodies and cerebral storage diseases can be distinguished from the system degenerations. Systems which may be involved in the latter group include cerebellodentatorubral, pyramidal, extrapyramidal, optic, auditory, posterior columns and gracile and cuneate nuclei, spinocerebellar pathways, motor neurons of cranial nerves and anterior horns, and muscle fibers. Confronted with this diversity of pathological change, it seems unnecessary to make any clinical distinction between Ramsay Hunt syndrome and Unverricht-Lundborg syndrome (Baltic myoclonus) because cerebellar signs are found in patients described under both headings. Additional systems may be involved in individuals or families who are otherwise typical. All three names could well be joined in an eponymous title (Unverricht-Lundborg-Hunt disease) or the condition simply known as the systems degeneration type of PME, as Halliday (43) suggested. The cause of the condition (or spectrum of conditions) is at present unknown. Action myoclonus usually responds to sodium valproate or clonazepam, and some individuals, particularly those with posthypoxic myoclonus, improve with the administration of serotonin precursors.
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PMID:Action myoclonus, Ramsay Hunt syndrome, and other cerebellar myoclonic syndromes. 308 Aug 51

Fifty-five consecutive cases of myoclonus owing to various etiologies were studied by conventional EEG-EMG polygraphic recordings and/or jerk-locked or back averaging. The technique of back-averaging was shown to be useful not only for detecting EEG correlates of myoclonus that are not recognizable on the routine polygraph but also for investigating the temporal and topographic relationship between the EEG activities and myoclonus. Thirteen of 17 cases of PME and related disorders, in whom back-averaging and SEP were studied, were shown to have both a myoclonus-related cortical spike over the contralateral central area, preceding the myoclonus of an upper extremity by 6 to 22 msec, and a giant SEP accompanied by an enhanced C reflex. In these cases of "cortical reflex myoclonus," the myoclonus-related spike was similar to the P25-N33 components of the giant SEP in its wave form, scalp topography, temporal relationship to myoclonus or to C reflex, succeeding cortical excitability, and drug effect. All of this suggests participation of common physiological mechanisms in those two activities. In two cases of PME, in which myoclonus involved bilateral proximal muscles synchronously, the myoclonus-related spike was maximal near the vertex, and there was no giant SEP. The significance of this subgroup remains undetermined. In six cases of the PME group, back-averaging was inapplicable because of rare occurrence of myoclonus, but they showed a typical giant SEP accompanied by an enhanced C reflex. In CJD, back-averaging demonstrated a sharp wave or PSD over the contralateral hemisphere, preceding the myoclonus by 50 to 85 msec. This form of myoclonus seems to be subcortical in origin. In essential myoclonus and oculopalatal-somatic myoclonus, there was neither myoclonus-related cortical spike nor giant SEP. Electrical stimulation of the peripheral nerve at variable intervals after the myoclonus onset (jerk-locked-SEP paradigm) was shown to be useful for investigating the influence of myoclonus on cortical excitability.
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PMID:Electroencephalographic correlates of myoclonus. 308 Aug 53

Progressive myoclonus epilepsy (PME) without Lafora bodies, or Baltic myoclonus epilepsy, is characterized by stimulus-sensitive myoclonus, generalized tonic-clonic seizures, and an irregularly progressive course beginning between 6 and 15 years of age. The EEG displays spike-and-wave paroxysms with irregular dominant activity. Baltic myoclonus epilepsy is a single-gene disorder inherited in an autosomal recessive pattern. Early cases were reported from Estonia, and many are now found in Finland, suggesting that the gene frequency is increased in those sharing the Finno-Ugric linguistic base. The use of phenytoin should be avoided in this disorder since its continued administration alone or with other antiepileptic drugs is associated with intellectual and motor deterioration, aggressive behavior, increasing ataxia, and even death. Treatment with valproate and the concomitant elimination of phenytoin have been associated with marked improvement in most cases. Baltic myoclonus epilepsy must be distinguished from Lafora body PME, which is relentlessly progressive and invariably fatal, but can usually be differentiated on clinical grounds.
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PMID:Effect of phenytoin on the mental and physical function of patients with Baltic myoclonus epilepsy. 311 15

A survey of 15 families in the USA with Baltic myoclonus epilepsy showed that the 27 individuals who were affected had the following clinical picture from about the age of 10: photosensitive, occasionally violent, myoclonus, usually worse upon waking; generalised tonic-clonic seizures, sometimes associated with absence attacks; and light-sensitive, generally synchronous, spike-and-wave discharges on EEG that preceded clinical manifestations. Necropsy revealed marked loss of Purkinje cells of the cerebellum, but no inclusion bodies. Since the disease was confined to sibs and consanguinity was present in two families, autosomal recessive inheritance is probable. The disease progressed more rapidly in these families than it did in the early cases, seen in the Baltic region. This difference could be due to a toxic effect of phenytoin because phenytoin given alone or with other antiepileptic drugs was associated with progressive motor and intellectual deterioration, marked ataxia, and even death. Treatment with valproic acid, and the concomitant reduction or elimination of phenytoin, has been associated with marked improvement in at least 8 patients. Baltic myoclonus epilepsy must be distinguished from Lafora body disease, which is invariably fatal and discernible on clinical grounds.
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PMID:"Baltic" myoclonus epilepsy: hereditary disorder of childhood made worse by phenytoin. 613 60

Eleven patients with long-standing progressive myoclonus epilepsy, PME, and age- and sex-matched epileptic controls received L-tryptophan (L-Trp) 100 mg/kg body weight combined with carbidopa in addition to their usual anticonvulsant regimen. During six weeks of the trial an improvement in activities of daily living and a decrease of action myoclonus was noted in the PME patients. The frequency of seizures compared with the past year decreased significantly in the PME patients, but not in the epileptic controls. Changes in the EEGs of the PME patients were scant, but a slight decrease was noted in myoclonic spikes. Both plasma Trp and platelet 5-HT increased significantly and at least as much as in epileptic controls. 5-HIAA and HVA concentrations in the CSF of the PME patients increased significantly during the trial. The results support previous findings concerning Trp treatment in PME, and longer trials with Trp + carbidopa could be of value in this disease.
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PMID:L-tryptophan-carbidopa trial in patients with long-standing progressive myoclonus epilepsy. 617 51

A boy of Finnish descent developed nerve deafness at six years of age, action myoclonus two years later, generalized myoclonic seizures when 16 years old and muscular atrophy at the age of 17 years. Bulbar palsy caused his death from inhalational pneumonia when he was 19 years old. Autopsy disclosed no significant changes in the cerebral cortex, thalamus, striatum, Purkinje cells or dentate nucleus. The most striking histological finding was degeneration of motor neurones in cranial nerves and anterior horns of the spinal cord, with neuroaxonal dystrophy of nucleus gracilis and cuneatus. While nerve deafness and spinal muscular atrophy have been recorded (each in different families) in association with progressive myoclonic epilepsy, the combination of these features has not previously been reported. Reasons are put forward for regarding all the system degenerations found in PME, including Unverricht-Lundborg disease (Baltic myoclonus) and the Ramsay Hunt syndrome, as variations of the same disorder.
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PMID:Progressive myoclonic epilepsy, nerve deafness and spinal muscular atrophy. 643 45

In 3 patients with the syndrome of Unverricht-Lundborg's myoclonus-epilepsy electropolygraphic examinations were carried out during night sleep. A substantial disorganization of the sleep was revealed, the degree of which correlated with the gravity of the clinical picture. This disorganization manifested itself in pronounced changes of the electroencephalographic phenomenology of the sleep and disturbance of its structure with a prolongation of the 1st stage and the delta-sleep and a shortening of the 2nd stage and the quick sleep phase. An insufficient EEG desynchronization was noted in the periods of awakeness, drowsiness, and quick sleep: this pointed to defective functioning of the brain desynchronizing systems. In distinction from other forms of epilepsy the pathological paroxysmal activity was prevalent also in the period of the awakeness, and diminished in parallel with the depth of the sleep. The myoclonic hyperkinesis got also weaker at the stage of slow sleep, but became more intense at the quick sleep stage. The data obtained point to a pronounced dysfunction of the non-specific activating and deactivating systems of the brain in myoclonus-epilepsy. This dysfunction is associated with an organic affection of the trunco-diencephalic structures and the influence of the active epileptic process.
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PMID:[Sleep disorders in the Unverricht-Lundborg myoclonic epilepsy syndrome]. 681 Jun


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