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

The CNS diseases that are associated with mitochondrial myopathy have been reviewed in this chapter. The disorders causing myoclonus have been compared to those in which myoclonus has been reported. Both groups have been associated with lactate and pyruvate accumulation, and both have a wide spectrum of clinical and pathologic findings. Deficiency of components of the respiratory chain has been offered as an explanation for the mitochondrial accumulation in the muscles of these patients. Skeletal muscle respiratory-chain components may be deficient, and there is experimental evidence that indicates that mitochondria will proliferate in muscle and other tissues when vital nutrients are withheld. There are two features of these patients that separate them from other patients with myoclonus. The first is the elevation of serum lactate and pyruvate due to deficient oxidative phosphorylation. The second is a pedigree that indicates maternal inheritance.
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PMID:Myoclonus and mitochondrial myopathy. 308 Aug 47

We report four patients with a progressive myoclonic ataxic syndrome and associated coeliac disease. The onset of the neurological syndrome followed the gastrointestinal and other manifestations of coeliac disease while on a gluten-free diet, in the absence of overt features of malabsorption or nutritional deficiency. The condition progressed despite strict adherence to diet. The neurological syndrome was dominated by action and stimulus sensitive myoclonus of cortical origin with mild ataxia and infrequent seizures. Plasmapharesis and immunosuppressive treatment were tried in two patients but were not beneficial. Post-mortem examination of the brain in one case showed selective symmetrical atrophy of the cerebellar hemispheres with Purkinje cell loss and Bergmann astrocytosis, and with preservation of the cerebral hemispheres and brainstem. Coeliac disease should be considered in the differential diagnosis of all patients presenting with a progressive myoclonic ataxic syndrome.
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PMID:Progressive myoclonic ataxia associated with coeliac disease. The myoclonus is of cortical origin, but the pathology is in the cerebellum. 749 72

Pellagra is caused by nicotinic acid deficiency; it is rarely encountered in developed countries, and it is mainly related to poverty and malnutrition, as well as with chronic alcoholism. We report the case of an alcoholic patient who was diagnosed with pellagra and administered B-complex vitamin tablets that did not contain niacin. A few weeks later, the patient developed nervousness, irritability, insomnia and, consequently, delusional ideas and hallucinations, for which he had to be hospitalized. After his admission, the patient manifested loss of consciousness and myoclonus. All of his symptoms (cutaneous, neurological, and psychiatric) resolved fully with treatment with niacin in combination with other B-complex vitamins. All undiagnosed encephalopathies in alcoholic patients should be treated with multiple vitamin therapy, including nicotinic acid.
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PMID:Pellagra encephalopathy following B-complex vitamin treatment without niacin. 1524 45

We report a 47-year-old alcoholic man with alcoholic pellagra encephalopathy (APE) showing myoclonus and ataxia as chief complaints. He had been a heavy drinker for 30 years. He had noticed appetite loss and subsequently showed a subacutely progressive gait disturbance. He had no history of diarrhea, dementia, or dermatitis. On admission, he showed severe alcoholic liver cirrhosis with a large amount of ascites, limbs and truncal ataxia, myoclonus of the limbs and areflexia, although his consciousness was alert and there were no sign of dermatitis. Though the plasma level of ammonia was normal, we started administration of amino acids suspecting hepatic encephalopathy. Symptoms showed no improvement, and subsequent administration of thiamine was also ineffective. A decreased serum level of niacin was demonstrated. After administration of nicotinamide, the symptoms improved gradually. This patient received a diagnosis of APE. Endemic pellagra, characterized by the classical triad of dermatitis, diarrhea and dementia, is known to be caused by a dietary deficiency of the niacin, and has now become very rare in developed countries. At present, pellagra is encountered most often in patients with chronic alcoholism, which is called APE. APE patients often show only disturbance of consciousness. Although several reports has described ataxia and myoclonus in patients with APE, APE patients with myoclonus and ataxia as chief complaints have not previously been reported. On autopsy cases, central chromatolysis of neurons in the dentate nucleus of the cerebellum, gracile and cuneate nuclei, and the Clarke's column has been demonstrated. The APE patients would show myoclonus and ataxia as their first symptoms. In conclusion, we would like to emphasize that administration of niacin should be started for the treatment of chronic alcoholic patients showing myoclonus and ataxia even without the classical triads found in endemic pellagra patients.
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PMID:[A suspected case of alcoholic pellagra encephalopathy with marked response to niacin showing myoclonus and ataxia as chief complaints]. 1651 10

The spinocerebellar ataxias (SCA) are a large group of inherited disorders affecting the cerebellum and its afferent and efferent pathways. Their hallmark symptom is slowly progressive, symmetrical, midline, and appendicular ataxia. Some may also have associated hyperkinetic movements (chorea, dystonia, myoclonus, postural/action tremor, restless legs, rubral tremor, tics), which may aid in differential diagnosis and provide treatable targets to improve performance and quality of life in these progressive, incurable conditions. The typical dominant ataxias with associated hyperkinetic movements are SCA1-3, 6-8, 12, 14, 15, 17, 19-21, and 27. The common recessive ataxias with associated hyperkinetic movements are ataxia telangiectasia and Friedreich's ataxia. Fragile X tremor-ataxia syndrome (FXTAS) and multiple-system atrophy (a sporadic ataxia which is felt to have a genetic substrate) also have hyperkinetic features. A careful work-up should be done in all apparently sporadic cases, to rule out acquired causes of ataxia, some of which can cause hyperkinetic movements in addition to ataxia. Some testing should be done even in individuals with a confirmed genetic cause, as the presence of a secondary factor (nutritional deficiency, thyroid dysfunction) can contribute to the phenotype.
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PMID:Spinocerebellar degenerations. 2149 73

Lysosomal integral membrane protein-2 (LIMP2) mediates trafficking of glucocerebrosidase (GBA) to lysosomes. Deficiency of LIMP2 causes action myoclonus-renal failure syndrome (AMRF). LIMP2-deficient fibroblasts virtually lack GBA like the cells of patients with Gaucher disease (GD), a lysosomal storage disorder caused by mutations in the GBA gene. While GD is characterized by the presence of glucosylceramide-laden macrophages, AMRF patients do not show these. We studied the fate of GBA in relation to LIMP2 deficiency by employing recently designed activity-based probes labeling active GBA molecules. We demonstrate that GBA is almost absent in lysosomes of AMRF fibroblasts. However, white blood cells contain considerable amounts of residual enzyme. Consequently, AMRF patients do not acquire lipid-laden macrophages and do not show increased plasma levels of macrophage markers, such as chitotriosidase, in contrast to GD patients. We next investigated the consequences of LIMP2 deficiency with respect to plasma glycosphingolipid levels. Plasma glucosylceramide concentration was normal in the AMRF patients investigated as well as in LIMP2-deficient mice. However, a marked increase in the sphingoid base, glucosylsphingosine, was observed in AMRF patients and LIMP2-deficient mice. Our results suggest that combined measurements of chitotriosidase and glucosylsphingosine can be used for convenient differential laboratory diagnosis of GD and AMRF.
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PMID:Action myoclonus-renal failure syndrome: diagnostic applications of activity-based probes and lipid analysis. 2421 38

Dopamine transporter (DaT) single-photon emission computed tomography (SPECT) and [18F]fluoro-L-DOPA ([18F]DOPA) positron emission tomography (PET) facilitate the investigation of dopaminergic hypofunction in neurodegenerative diseases. DaT SPECT and [18F]DOPA PET have been adopted as survey tools in clinical trials. In a large study on Parkinson's disease, 4-15% of subjects clinically diagnosed with early-stage Parkinson's disease had normal dopaminergic functional imaging scans. These are called Scans without Evidence of Dopamine Deficit (SWEDDs), and are considered to represent a state different from Parkinson's disease. Neurological diseases that exhibit parkinsonism and have normal dopaminergic cells in the nigrostriatal system (e.g., essential tremor, psychogenic parkinsonism, DOPA-responsive dystonia, vascular parkinsonism, drug-induced parkinsonism, manganism, brain tumor, myoclonus-dystonia (DYT11), and fragile X syndrome) might be diagnosed with SWEDDs. True bradykinesia with fatigue or decrement may be useful for distinguishing between Parkinson's disease and SWEDDs. However, because SWEDDs encompass many diseases, their properties may not be uniform. In this review, we discuss DaT SPECT, the concept of SWEDDs, and differential diagnosis.
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PMID:[Scans without Evidence of Dopamine Deficit (SWEDDs)]. 2676 1