[A case of mitochondrial encephalomyopathy with peripheral neuropathy and autonomic symptoms].

We report a 28-year-old man with mitochondrial encephalomyopathy with peripheral neuropathy and autonomic symptoms. Muscle biopsy from the quadriceps femoris muscle showed myopathic changes with ragged-red fibers and abnormal mitochondria. He experienced recurrent and acute weakness in his bilateral lower limbs. Needle electromyogram revealed neurogenic changes, and the amplitude of muscle action potential was low in the right posterior tibial nerve. Sural nerve biopsy showed a marked loss of both large and small myelinated fibers, and moderate to severe axonal degeneration was diagnosed. He experienced autonomic symptoms (nausea, constipation, hypoidosis and urinary retention) along with the weakness in his lower limbs which is considered to be a very rare situation. We hypothesized that autonomic symptoms in this case were due to the axonal degeneration that included unmyelinated fibers.