Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a patient with mitochondrial encephalomyopathy presenting parkinsonism, as well as her brother who had ataxia but not parkinsonism. Both patients had myopathy, deafness, and insulin-dependent diabetes mellitus. The proband was a 55-year-old woman, who has developed progressive difficulty in walking and slowness of movement since 53 years of age, becoming bed-ridden at 55. Neurological examination revealed mental impairment, a masked face, Myerson's sign, vertical supranuclear ophthalmoplegia, and severe sensorineural deafness, hypokinesia, rigidospasticity, and weakness of the extremities. But tremor and cerebellar ataxia were absent. Her 48-year-old brother gradually developed weakness of the lower extremities and drunken gait over a few years. On neurologic examination, vertical supranuclear ophthalmoplegia, moderate sensorineural deafness, and cerebellar ataxia were present, but parkinsonism was absent. Three other siblings were reported to have died in early childhood. Cranial MR imaging showed cerebral atrophy and mild atrophy of the cerebellar vermis as well as mild periventricular hyperintensities in T2-weighted images in both patients. However, no infarcts were seen. Laboratory investigations revealed slightly elevated lactate and pyruvate levels in the proband and elevation of pyruvate in her brother. A biopsy specimen obtained from the quadriceps muscle showed ragged-red fibers with modified Gomori trichrome staining, and a decrease of complex I+III and complex II+III activity in the proband. Mitochondrial DNA (mtDNA) analysis using the polymerase chain reaction and restriction enzyme Apa I showed a point mutation in the tRNA(Leu)(UUR)) gene (an A to G transition at nucleotide 3243) in both patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Mitochondrial encephalomyopathy associated with parkinsonism and a point mutation in the mitochondrial tRNA(Leu)(UUR)) gene]. 802 31

A 60-year-old woman had developed ptosis, progressive external ophthalmoplegia and action tremor over the last ten years. Physical examination also revealed short stature and retinal pigmentation. Anaerobic forearm exercise test showed increase of basal lactate and rise of lactate/piruvate index. Biceps biopsy displayed numerous ragged red fibers. Respiratory chain studies were consistent with complex I deficiency. Point mutations or deletions in mitochondrial DNA were not found. MR identified a diffuse leukoencephalopathy over both cerebral hemispheres, mesencephalon, pons and cerebellum. The late and sporadic onset of a progressive external ophthalmoplegia outlining a Kearns-Sayre syndrome is striking. A leukoencephalopathy associated with mitochondrial encephalomyopathy is an infrequent finding. The action tremor of this patient could be symptomatic of her mitochondrial disfunction.
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PMID:[Mitochondrial encephalomyopathy of late presentation with progressive ophthalmoplegia, tremor and diffuse leukoencephalopathy]. 1061 22

We report three members of a family, who exhibited a phenotype similar to 'myoclonus epilepsy with ragged-red fibers' but had a genotype usually associated with 'mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes'. The patients, a 48-year-old female, and her two sons, aged 21 and 19 respectively, presented with photo-reactive syncopal episodes, disturbances of gait and writing, dysarthria and finger tremor since the 3rd and 2nd decade of life, respectively, that were accompanied also by numbness and weakness of the extremities. Subsequently, cerebellar ataxia and myoclonus were also noted. Electromyography revealed both myogenic and neurogenic muscular changes, and nerve conduction studies demonstrated a sensory-motor neuropathy. Biopsy showed ragged-red fibers with strongly stained SDH-positive vessels in skeletal muscles, and a marked loss of myelinated fibers of the sural nerves. Mitochondrial (mt) DNA analyses of peripheral blood, muscles and nerves revealed that all members had a heteroplasmic np3271 (T-C) point mutation in the mitochondrial tRNA-Leu gene (UUR). This family is unique, in that all patients presented with a myoclonus epilepsy with ragged-red fibers-like phenotype and had a distinctive peripheral neuropathy, while the detected mtDNA 327l (T-C) mutation has been reported to date only in rare cases of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes
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PMID:A mitochondrial encephalo-myo-neuropathy with a nucleotide position 3271 (T-C) point mutation in the mitochondrial DNA. 1140 19

A 53-year-old woman underwent several ischemic stroke-like episodes and later developed incomplete, bilateral ophthalmoplegia, left vision deterioration, and bilateral tremor. The clinical course, laboratory data, and muscle histology led to a diagnosis of mitochondrial encephalomyopathy. No other etiology could be identified in the background of her disabling bilateral postural-kinetic tremor. As this tremor did not respond to pharmacological therapy, left thalamotomy and subsequently right thalamic deep brain stimulator (DBS) implantation were performed, which resulted in an excellent clinical outcome. The Fahn-Tolosa-Marin Tremor Rating Scale improved from 110 to 11 points. This case suggests that the rare tremor caused by mitochondrial encephalopathy may be treated long-term with either thalamotomy or thalamic DBS implantation.
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PMID:Neurosurgical treatment of tremor in mitochondrial encephalopathy. 1702 63

Mitochondrial diseases (MIDs) are a large group of heterogeneous disorders due to mutations in either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) genes, the latter encoding proteins involved in mitochondrial function. A multisystem clinical picture that involves several organs, including both the peripheral and central nervous systems, is a common presentation of MID. Movement disorders, even isolated ones, are not rare. Cerebellar ataxia is common in myoclonic epilepsy with ragged red fibers (MERFF) due to mutations in the mitochondrial transfer RNA (tRNA) lysine gene, in Kearns-Sayre syndrome due to mtDNA deletions, in sensory ataxic neuropathy with dysarthria and ophthalmoplegia (SANDO) due to nuclear POLG1 gene mutations, and also in ARCA2, Friedreich's ataxia, SPG7, SCA28 and autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) due to mutations in nuclear genes involved in mitochondrial morphology or function. Myoclonus is a key feature of MERFF, but may also be encountered in mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), ARCA2, POLG1 mutations and Leigh syndrome. Dystonia is common in Leigh syndrome (which may be caused by 75 different genes) and in Leber hereditary ocular neuropathy (LHON) plus disease, due to mutations in mtDNA genes that encode subunits of NADH dehydrogenase, as well as in ARCA2, pantothenate kinase-associated neurodegeneration (PKAN), mitochondrial membrane protein-associated neurodegeneration (MPAN) and POLG1 mutations. Other movement disorders are rarer (such as parkinsonism, tremor, chorea). Although parkinsonism is more frequent in POLG1 mutations, and myoclonus in MERFF, most movement disorders are found either isolated or combined in numerous MIDs. The presence of associated neurological signs, whether central or peripheral, or of evocative magnetic resonance imaging (MRI) abnormalities (striatal necrosis) should prompt a search for MID. In cases of a particular clinical spectrum (LHON, MERFF, Kearns-Sayre, SANDO, SPG7, ARCA2, ARSACS), a search for the most frequently implicated mutation(s) is recommended. In other cases, muscle biopsies followed by metabolic and genetic studies may be useful for arriving at a diagnosis.
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PMID:Movement disorders in mitochondrial diseases. 2777 46