Rinsho Shinkeigaku (Clinical Neurology)

Case Report

Chronic progressive external ophthalmoplegia that could not be diagnosed by biceps muscle biopsy, but was genetically diagnosed by extraocular muscle biopsy

Wataru Shiraishi, M.D., Ph.D.1)2)3), Takahisa Tateishi, M.D., Ph.D.1)4), Yu Hashimoto, M.D.1), Ryo Yamasaki, M.D., Ph.D.1), Jun-ichi Kira, M.D., Ph.D.1)5)6) and Noriko Isobe, M.D., Ph.D.1)

1) Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University
2) Department of Neurology, Kokura Memorial Hospital
3) Shiraishi Internal Medicine Clinic
4) Department of Medicine, Kurume University School of Medicine
5) Translational Neuroscience Center, Graduate School of Medicine, and School of Pharmacy at Fukuoka, International University of Health and Welfare
6) Department of Neurology, Brain and Nerve Center, Fukuoka Central Hospital

A 48-year-old Japanese male experienced slowly progressive diplopia. He had no family history and was negative for the edrophonium chloride test. Blood analysis showed elevated lactic acid and pyruvic acid levels, suggesting mitochondrial disease. A muscle biopsy from the biceps brachii was performed, but no pathological or genetical mitochondrial abnormalities were detected. Subsequently, he underwent muscle plication for diplopia in which the right inferior rectus muscle was biopsied. Genetic examination of genomic DNA extracted from the extraocular muscle tissue revealed multiple mitochondrial gene deletions, with a heteroplasmy rate of approximately 35%, resulting in the diagnosis of chronic progressive external ophthalmoplegia. In mitochondrial diseases, the tissue distribution of mitochondria with disease-associated variants in mtDNA should be noted, and it is important to select the affected muscle when performing a biopsy for an accurate diagnosis.
Full Text of this Article in Japanese PDF (2139K)

(CLINICA NEUROL, 62: 946|951, 2022)
key words: CPEO, mitochondrial disease, multiple deletions, extraocular muscle biopsy, mitochondrial DNA

(Received: 27-Jul-22)