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)

Bismuth subsalicylate preparations are over-the-counter products for gastrointestinal complaints. Bismuth toxicity causes delirium, psychosis, ataxia, myoclonus, and seizures and is reversible over several weeks or months, when bismuth intake is stopped. We report a 54-year-old man with a 6-week history of progressive confusion and memory difficulty and a 2-3-week history of involuntary movements and gait impairment. His encephalopathy was further characterized by marked multifocal myoclonic jerks, coarse postural tremors, postural instability, and gait ataxia. He gradually improved. Extensive toxic, metabolic, and infectious workup demonstrated bismuth toxicity. Spinal tap and brain magnetic resonance scan were normal. Electroencephalography showed bihemispheric slowing. As his encephalopathy cleared, he reported using bismuth subsalicylate long term (daily intake of 8 oz). Bismuth levels 5 weeks after cessation of bismuth were elevated and normalized after 12 weeks. He followed a typical course for bismuth toxicity with subacute progressive encephalopathy and gradual recovery. Creutzfeldt-Jakob was strongly considered due to his rapidly progressive encephalopathy, multifocal myoclonus, and ataxia. Due to its rarity, bismuth toxicity is often overlooked. We hope this presentation will increase recognition of bismuth toxicity. We believe more detailed labeling of bismuth products is needed to avoid similar toxicity from this readily available product.
 ...
PMID:Bismuth subsalicylate toxicity as a cause of prolonged encephalopathy with myoclonus. 775 66

Mild myoclonus is reasonably common with various cyclic antidepressants. However, antidepressants rarely cause severe myoclonus, and no risk or predisposing factors have been reported in the literature. We report a case of exceptionally severe myoclonus developing at therapeutic doses and modest serum levels of imipramine. The patient went on to experience dystonia and catatonia. Both of these were in typical settings (after haloperidol and with psychotic bipolar depression, respectively) and responded to typical treatment. On further investigation, the patient was found to have left-sided schizencephaly and a corresponding history of very mild developmental delay. We suggest that the onset of one movement disorder after drug therapy (eg, myoclonus) may predict the development of other movement disorders (e.g., catatonia). We further propose that severe tricyclic-induced myoclonus should prompt the physician to rule out a coexisting structural lesion of the central nervous system.
 ...
PMID:Severe imipramine-induced myoclonus in a patient with psychotic bipolar depression, catatonia, and schizencephaly. 795 45

Two cases of basal ganglia calcification involving the globus pallidus are presented. Both patients had cognitive dysfunction, temporal lobe-like symptoms (including amnestic state, perceptual distortions, or complex visual hallucinations), and myoclonus. Patient 1 manifested depression, auditory hallucinations, anxiety, paranoia, and postural tremor; patient 2 manifested multifocal dystonia with dystonic tremor. These cases supplement other reports of psychotic features and dementia associated with pallidal pathology. Additionally, the phenomena encountered in these cases are considered in light of recent advances in our understanding of basal ganglia functional pathways. These cases afford a potential pathophysiological window to the possible role of the globus pallidus in these neuropsychiatric conditions. In concert with other recent findings, these cases suggest specific pathway involvement in hallucinations, paranoia, depression, myoclonus, and dystonia. Further research will indicate if these pathways play a role in schizophrenia, mood disorders, and anxiety disorders.
 ...
PMID:Neuropsychiatric disorders, myoclonus, and dystonia in calcification of basal ganglia pathways. 801 2

The "Predictors Study" is a prospective cohort study of the natural history of Alzheimer disease (AD), the aim of which is to identify milestones in disease progression and to develop a model to predict disease course in individual patients. The empirical background to this study is based on previous reports that the presence of extrapyramidal signs (EPS), myoclonus, and psychosis in AD may signify greater disease severity at any given stage and a more rapid course of the disease over time. The present analyses were conducted to determine whether these independent "predictor" variables were associated with greater disease severity at baseline within a new cohort of 224 mild AD patients recruited from three different medical centers (in New York, Baltimore, and Boston). Measures of disease severity were provided by the modified Mini-Mental State Examination (mMMSE) and the Blessed Dementia Rating Scale (BDRS), which measures functional capacity. Independent variables were EPS, delusions, and slowing of the posterior dominant EEG rhythm. The frequency of myoclonus and hallucinations was too low to permit adequate statistical assessment of their effects at this time. EPS and EEG slowing were associated with low mMMSE scores, whereas delusions were primarily associated with impaired functional capacity. These effects were independent of the influence of age and disease duration. These results indicate that the effects of these independent variables can be detected at mild stages of AD and that these effects can be generalized across different geographical regions.
 ...
PMID:Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). II. Neurological, psychiatric, and demographic influences on baseline measures of disease severity. 848 Dec 23

In a population-based study of 198 patients with probable early-onset Alzheimer's disease (AD), we studied the occurrence of extrapyramidal signs (tremors and rigidity), myoclonus, psychosis and seizures, as well as their predictive value for mortality. The presence of tremors was significantly associated with the presence of rigidity. The occurrence of myoclonus was significantly associated with the occurrence of seizures. Psychosis and seizures in AD patients were not associated with mortality. The occurrence of extrapyramidal signs and myoclonus at any point in time during the course of AD increased the risk of mortality significantly. When evaluating their relative importance, extrapyramidal signs appeared to be the most important predictor of mortality.
 ...
PMID:Clinical features and mortality in patients with early-onset Alzheimer's disease. 865 78

Dementia of the Alzheimer-type (DAT) is characterized by progressive cognitive decline, variably combined with frontal lobe release signs, parkinsonian symptoms and myoclonus. The features of diffuse Lewy body disease (DLBD), the second most common cause of degenerative dementia, include progressive cognitive deterioration, often associated with levodopa-responsive parkinsonism, fluctuations of cognitive and motor functions, psychotic symptoms (visual and auditory hallucinations, depression), hypersensitivity to neuroleptics and orthostatic hypotension. A recent report suggests that positron emission tomography studies in patients with degenerative dementia may be useful in the differential diagnosis of DAT and DLBD. However, the diagnostic role of single-photon emission tomography (SPET) studies remains to be established. The aim of this study was therefore to evaluate regional cerebral perfusion [with either technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) or 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPET] and striatal dopamine transporter density [using iodine-123 2 beta-carboxymethoxy-3 beta-[4-iodophenyl]tropane (123I-beta-CIT) SPET] in patients with DAT and DLBD. Six patients with probable DAT and seven patients with probable DLBD were studied. Blinded qualitative assessment by four independent raters of 99mTc-HMPAO or 99mTc-ECD SPET studies revealed bilateral temporal and/or parietal hypoperfusion in all DAT patients. There was additional frontal hypoperfusion in two patients and occipital hypoperfusion in one patient. In the DLBD group, regional cerebral perfusion had a different pattern. In addition to temporoparietal hypoperfusion there was occipital hypoperfusion resembling a horseshoe defect in six of seven patients. In the DAT group, the mean 3-h striatal/cerebellar ratio of 123I-beta-CIT binding was 2.5 +/- 0.4, with an increase to 5.5 +/- 1.1 18 h after tracer injection. In comparison, in the DLBD patients the mean 3-h striatal/cerebellar ratio of 123I-beta-CIT binding was significantly reduced to 1.7 +/- 0.3, with a modest increase to 2.1 +/- 0.4 18 h after tracer injection (P < 0.05, Scheffe test, ANOVA). These results suggest that 99mTc-HMPAO or 99mTc-ECD and 123I-beta-CIT SPET may contribute to the differential diagnosis between DAT and DLBD, showing different perfusion patterns and more severe impairment of dopamine transporter function in DLBD than in DAT.
 ...
PMID:Brain perfusion scintigraphy with 99mTc-HMPAO or 99mTc-ECD and 123I-beta-CIT single-photon emission tomography in dementia of the Alzheimer-type and diffuse Lewy body disease. 914 72

Two patients with presumed encephalitis lethargica are presented with clinical features suggestive of two forms of the disease described by Von Economo: One patient had a psychosis and a mute-akinetic syndrome associated with myoclonus. The second patient presented with a psychosis and fever, developing severe dyskinesias involving the mouth, trunk and limbs, together with respiratory irregularities and presumed hypothalamic disturbance and disturbance of consciousness. In both cases, initial cerebrospinal fluid (CSF) examination revealed an elevated white cell count (predominantly lymphocytes), elevated protein in case 2, and oligoclonal bands in both cases. Computed tomography (CT) brain scan was normal but in both cases EEG revealed diffuse slow wave activity. A 18F-Dopa positron emission tomography (PET) scan in case 2 was normal. The medical management of both patients is discussed. In case 1, L-Dopa improved the akinesia, while the myoclonus responded to clonazepam. In case 2, the severe dyskinesias failed to respond to a number of drugs, and she ultimately required paralysis to relieve her almost continuous movements. Both patients responded rapidly and dramatically to intravenous methylprednisolone. We suggest that steroid treatment should be considered in the acute phase of patients with features suggestive of encephalitis lethargica.
 ...
PMID:Clinical features and management of two cases of encephalitis lethargica. 915 30

Clozapine elicits dose-dependent myoclonic jerks in partially restrained rats and induces paroxysmal electroencephalographic changes, myoclonus, and convulsive seizures in a small but significant percentage of patients. With the hypothesis that the central excitatory effects of clozapine may relate to the unique therapeutic activity of this agent, rats were administered repeated alternate day or weekly very low dose (1 mg/kg) injections of clozapine in an attempt to induce the central excitatory effect through sensitization or kindling. Although initial administrations of this dose elicited no motor response or other behavioral change, repeated administration of the same low dose on either the alternate-day or weekly schedule caused increasing numbers of myoclonic seizure-like jerks (MJs) reaching 75-110 MJs/hour by the sixth clozapine injection. Clozapine-sensitized animals exhibited a significantly different pattern of early gene expression in two subcortical sites compared with vehicle-treated controls. These findings may have importance for the treatment of psychosis.
 ...
PMID:Sensitization with clozapine: beyond the dopamine hypothesis. 934 26

Ramsay Hunt syndrome (RHS) is a rare condition within the progressive myoclonic epilepsies syndrome (PME), with a triad of action myoclonus, grand mal seizure and severe cerebellar ataxia. There are few reports about the psychiatric disturbances associated with PME or RHS. The present study examines the evidence that RHS may accompany an organic mental syndrome, ethanol's effective suppression of myoclonus, and the possible resultant problem of alcohol dependence in RHS patients. Two brothers with the previous long-standing diagnosis of RHS and their mental symptoms of persecutory delusion and depression are reported, as well as the additional problem of alcohol dependence in one of them. The cerebellar dysfunction found in RHS may be associated with an underlying organic condition. Determination of the relationship between cerebellar dysfunction and psychosis in RHS will require further study. Although the mechanism of the suppression of myoclonus by alcohol remains unclear, patients should be allowed to drink socially, and alcohol consumption should not be totally prohibited. However, effective treatment of the problems of alcohol tolerance, abuse, or dependence requires the cooperation of both neurologists and psychiatrists.
 ...
PMID:Progressive myoclonic epilepsies syndrome (Ramsay Hunt syndrome) with mental disorder: report of two cases. 1059 82

The frequency of sleep complaints in patients with Parkinson's disease (PD) is estimated to be between 60-90% and a variety of either disease-related or secondary mechanisms and the dopaminergic treatment itself contributes to the development of different sleep disturbances. These comprise slight, fragmented sleep with increased number of arousals and awakenings, and PD-specific motor phenomena such as nocturnal immobility, rest tremor, eye-blinking, dyskinesias, and other phenomena such as periodic and nonperiodic limb movements in sleep, restless legs syndrome, fragmentary myoclonus, and respiratory dysfunction in sleep. Depression and hallucinations/psychosis further complicate the picture. The incidence of REM sleep behavior disorder (RBD) with nightmares and violent behavior is increased in PD and may occur as a preclinical disease-related symptom. A careful sleep history of patients and their partners, polysomnograms when necessary, motor and psychiatric assessments should precede individual treatment strategies, which include adjusting dopaminergic daytime treatment, benzodiazepines for RBD, reduction of anticholinergic drugs, and, if necessary, clozapine for nocturnal psychosis.
 ...
PMID:Sleep dysfunction in Parkinson's disease. 1078 36


<< Previous 1 2 3 4 5 6 Next >>