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

The response of myoclonus to oral and intravenous L-5-hydroxytryptophan (5-H.T.P.) in combination with a peripheral decarboxylase inhibitor (carbidopa) and to clonazepam has been examined in 9 patients. Moderate improvement or complete cessation of myoclonus followed treatment with one or both of these regimens in 5 patients, 1 of whom also responded to the concurrent administration of L-tryptophan and a monoamineoxidase inhibitor. The remaining 4 patients were at best only slightly improved by either 5-H.T.P. or clonazepam. The responsive group consisted of 3 patients with a history of anoxia, 1 patient with non-history of severe head injury, and 1 patient with non-progressive focal myoclonus and epilepsy. This group had low levels of 5-hydroxyindole acetic acid in the lumbar cerebrospinal fluid. It is suggested that 5-H.T.P. plus carbidopa, L-tryptophan plus a monoamine-oxidase inhibitor, and clonazepam may all act by elevating brain levels of serotonin (5-H.T.) and that some human myoclonic syndromes may be specifically related to a cerebral deficiency of 5-H.T.
Lancet 1975 Sep 06
PMID:Manipulation of brain serotonin in the treatment of myoclonus. 5 Dec 40

A case of adult type mucolipidosis with beta-galactosidase and sialidase deficiency is described. This patient, a woman aged 20, had mental retardation, macular cherry-red spots, corneal clouding, gargoyle-like face, cerebellar ataxia, myoclonus and convulsions beginning at the age of 14. Bony deformities, vacuoles in the peripheral lymphocyte and foamy cells in the bone marrow were also noted. Biopsy study of the sural nerve and vermiform appendix disclosed many vacuoles in almost every kind of cells, although the accumulated substance in these vacuoles could not be characterized histochemically or ultrastructurally. Deficient leukocyte beta-galactosidase and sialidase were confirmed. There was increased urinary sialoglycopeptide and increased siliac acid and hexosamine in the glycoprotein of lymphocytes. Leukocytes sialidase activites of the parents were 30 to 50% of the control values. These results suggest a genetic defect of sialidase.
J Neurol 1979 Sep
PMID:Adult type mucolipidosis with beta-galactosidase and sialidase deficiency. Histological and biochemical studies. 9 67

A familial disorder was characterized by chorea, ataxia, myoclonus, convulsions, dementia, and mental retardation. In five cases, the main lesion affected cerebellar dentate nuclei, with nerve cell loss, gliosis, chromatolysis, and grumose degeneration. Fibrous glial cell proliferation was detected in the globus pallidus.
Neurology 1978 Sep
PMID:Familial chorea and myoclonus epilepsy. 9 88

The anticonvulsant potency and neurological toxicity of two new catalytic inhibitors of GABA-transaminase have been assessed in acute experiments in baboons with a natural syndrome of photic epilepsy. gamma-Acetylenic GABA, 160--200 mg/kg, or gamma-vinyl GABA, 450--950 mg/kg, intravenously, gave complete protection against generalised myoclonus or seizure responses induced by photic stimulation (in baboons without or with priming with subconvulsant doses of allylglycine). The protection became maximal 1--3 h after injection, and continued for 7--24 h. Signs characteristic of the acute toxicity of anticonvulsant drugs (nystagmus and ataxia) were not seen. The potential use of these compounds in human epilepsy deserves investigation.
Psychopharmacology (Berl) 1978 Sep 15
PMID:Blockade of epileptic responses in the photosensitive baboon, Papio papio, by two irreversible inhibitors of GABA-transaminase, gamma-acetylenic GABA (4-amino-hex-5-ynoic acid) and gamma-vinyl GABA (4-amino-hex-5-enoic acid). 10 Aug 12

Electroencephalographic studies were carried out in 30 patients with various kinds of myoclonus. It was confirmed that the technique of jerk-locked averaging with a backward averaging program was useful for detecting cortical spikes in association with the spontaneously occurring myoclonus, which are not recognized on the convential polygraph, and for evaluating the temporal and topographical relationship between the spike and the myoclonus. By this technique, cortical spikes were shown to precede the myoclonus of a contralateral upper extremity muscle by 7 to 15 ms ith progressive myoclonic epilepsy showed a high amplitude somatosensory evoked potential (SEP) in response to electrical stimulation of the median nerve. The N33 component of this high amplitude SEP was found to be similar to the myoclonus-related cortical spike in their wave form, time relationship and topographical distribution, suggesting an involvement of similar physiological mechanisms in the genesis of both phenomena. Myoclonus in these patients is compatible with "pyramidal" or "cortical loop reflex" type.
Brain 1978 Sep
PMID:Electroencephalographic studies myoclonus. 10 Dec 79

The effects of four neural excitants (damphetamine, cocaine, nicotine, and strychnine) on myoclonic and clonic seizure susceptibility were investigated in two age groups (30 and 120 days) of short-sleep mice. Amphetamine and cocaine decreased susceptibility to myoclonus in young mice and increased susceptibility in mature mice. These effects were attenuated by pretreatment with haloperidol, indicating mediation by a dopaminergic system. Amphetamine did not alter clonic susceptibility in either age group of mice, whereas cocaine affected clonic susceptibility and myoclonus. These effects were not attenuated by haloperidol, indicating mediation by systems other than dopamine. Nicotine decreased susceptibility to myoclonus and increased susceptibility to clonus, whereas strychnine increased susceptibility to both types of seizure. Haloperidol, however, failed to alter any of these effects. These results are consistent with our previous work which suggests that a dopaminergic mechanism in these mice undergoes marked developmental changes between 30 and 120 days of age.
Psychopharmacology (Berl) 1979 Sep
PMID:Maturational changes related to dopamine in the effects of d-amphetamine, cocaine, nicotine, and strychnine on seizure susceptibility. 11 67

The periodic nocturnal myoclonus of a patient with hyperexplexia has been studied. Evidence has been given that the jerks are spontaneous arousal reactions. The temporal characteristics of the jerks have been analysed. The jerks appear to be correlated with the respiratory rhythm and the data suggest a correlation of the jerks with circulatory and respiratory higher order waves. The results are discussed with relation to the literature concerning spontaneous sleep jerks.
J Neurol Sci 1978 Sep
PMID:Periodic nocturnal myoclonus in a patient with hyperexplexia (startle disease). 21 39

Fifteen patients with a variety of myoclonic syndromes were studied clinically, pharmacologically, and physiologically. CSF tryptophan, 5HIAA, and HVA were also measured. Of these patients, 8 were improved to varying degrees by therapy with 5HTP, tryptophan in combination with MAOI (but not tryptophan alone), and clonazepam. This group included 6 cases of post-anoxic myoclonus, one case of post-traumatic myoclonus and one undiagnosed case of non-progressive focal myoclonus and epilepsy. In this group low levels of CSF 5HIAA were found compared to non-responsive cases and controls. Two cases of dysynergia cerebellaris myoclonica, 2 cases of undiagnosed aetiology, 2 cases of essential myoclonus, and one case of palatal myoclonus failed to respond to drug therapy. However, even amongst the responsive group the improvement varied. The most dramatic responses were seen in those patients in whom physiological study suggested that myoclonus was mediated by brain-stem structures. Less dramatic responses were seen in patients in whom the myoclonus appeared to originate from cortical structures. The neurochemical basis of myoclonus responding to 5HT precursors and clonazepam is discussed. It is suggested that such myoclonus arises from a relative hypoactivity of the 5HT neuronal system which results in a release of abnormal responses to sensory stimuli which characterize this type of myoclonus.
Brain 1977 Sep
PMID:Clinical, biochemical, and physiological features distinguishing myoclonus responsive to 5-hydroxytryptophan, tryptophan with a monoamine oxidase inhibitor, and clonazepam. 41 60

The clinical and pathological features of a fourth patient with progressive encephalomyelitis with rigidity are reported and compared with those previously described. It is suggested that the muscular rigidity, abnormal postures, painful muscular spasms, and myoclonus are a product of excessive and abnormal discharges of alpha motor neurones caused by their release from control by spinal internuncial neurones. A count of neuronal perikarya in the ventral horns confirmed that the disease selectively destroyed small and medium sized neurones, most of which were spinal internuncial neurones. Experimental, clinical, and pathological evidence concerning spinal internuncial neurones is reviewed and found to conform to this theory. The pathogenesis of opsoclonus may be similar.
J Neurol Neurosurg Psychiatry 1979 Sep
PMID:Spinal internuncial neurones in progressive encephalomyelitis with rigidity. 50 76

Myoclonus occurs in a variety of pathological conditions, some inherited. We recently evaluated 3 members of a Louisiana-Texas family with an autosomal dominant disorder manifested by adult-onset, generalized, stimulus-sensitive myoclonus and slowly progressive distal muscle weakness and wasting. The analyses of cerebrospinal fluid homovanillic acid and 5-hydroxyindoleacetic acid before and after probenecid provided some evidence of impaired turnover of central dopamine and serotonin. Treatment with clonazepam resulted in complete and lasting improvement of the myoclonus. A postmortem examination in 1 member of the family revealed chiefly neuronal degeneration of the anterior horn cells, Clark's nucleus, and the lower cranial nerve nuclei. A similar syndrome has not previously been reported.
Ann Neurol 1979 Sep
PMID:Hereditary myoclonus and progressive distal muscular atrophy. 53 21


1 2 3 4 5 6 7 8 9 10 Next >>