A case of mitochondrial myopathy with peripheral neuropathy *
The patient was a 41-year-old man with mitochondrial myopathy with peripheral neuropathy. He had experienced weakness at 8 years old and at 28 years old experienced transient bilateral ptosis, external ophthalmoplegia and recurrent weakness in his bilateral upper and lower limbs. The weakness was progressive and dysarthria and dysphagia appeared. A muscle biopsy from the quadriceps femoris muscle showed myopathic changes with ragged-red fibers. On electron microscopy these fibers contained abnormal mitochondria with swelling. Biceps brachii muscle at 41 years old showed the myopathic changes had worsened. An electromyogram disclosed a neurogenic pattern. A nerve conduction study revealed a delay in sensory conduction lime. A sural nerve biopsy at 30 years old had shown a mild loss of both large and small myelinated fibers and axonal degeneration. In our case, we found neither abnormal mitochondria nor inflammation in the sural nerve. This may support the hypothesis that peripheral neuropathy results from metabolic derangement due to mitochondrial dysfunction. It cannot be denied that the existance of abnormal mitochondria and inflammation because sural nerve was little block. (Accepted on August 12. 1998) Kawasaki Igakkaishi 24 (2 ) : 107-111. 1998
