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Findings in muscle in complex I (NADH coenzyme Q reductase) deficiency
Author(s) -
Koga Yasutoshi,
aka Ikuya,
Kobayashi Masanori,
Tojyo Megumu,
Nihei Kenji
Publication year - 1988
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410240609
Subject(s) - mitochondrial myopathy , lactic acidosis , mitochondrial encephalomyopathies , encephalopathy , atrophy , cytochrome c oxidase , medicine , pathology , endocrinology , myopathy , gastroenterology , biology , mitochondrion , biochemistry , mitochondrial dna , gene
Thirteen of 15 patients with complex I deficiency had the multisystemic form, with strokelike episodes and other symptoms that fulfilled the diagnostic requirements for MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes), and 2 had only muscle fatigability and weakness, having the purely myopathic form. In the multisystemic form, 12 patients had ragged‐red fibers. All multisystemic patients had myopathic histochemical abnormalities that consisted of mild to moderate variation in fiber size (13), disorganized intermyofibrillar networks (12), type 2 fiber atrophy (10), and an increased number of type 2C fibers (9). Five of 13 multisystemic patients had Decemberreased cytochrome c oxidase (CCO) activity in extrafusal fibers, with sparing of intrafusal muscle fibers. In the myopathic form, pathological findings were similar to those in the multisystemic form. In addition to complex I and NADH dehydrogenase activities being Decemberreased, the CCO activity was significantly Decemberreased (less than 50% of control value) in 8 patients, especially when the disease was in its advanced stages, suggesting that CCO enzyme might be secondarily affected as the disease progresses.