[Case of Leber's hereditary optic neuropathy with mitochondrial DNA 11778 mutation exhibiting cerebellar ataxia, dilated cardiomyopathy and peripheral neuropathy].

We report the case of a 28-year-old woman with Leber's hereditary optic neuropathy (LHON) associated with cerebellar ataxia, dilated cardiomyopathy and peripheral neuropathy. She had a mitochondrial DNA point mutation from guanine to adenine at nucleotide position 11778 and developed ataxic gait within 2 years after the onset of bilateral visual loss. A neurological examination detected horizontal nystagmus, bradylalia, and truncal and bilateral limb ataxia of the cerebellar type. She could walk, albeit unsteadily. There was no weakness in her arms and legs. Tendon jerks were diminished in both the upper arms. Bilateral knee and ankle jerks were absent, and the plantar responses were neutral. Paresthesia of the stocking type was present but no reduction of pinprick, position or vibration senses was detected in the paresthetic regions. Romberg's sign was negative. Brain MRI showed atrophic changes in both the cerebellar vermis and the hemispheres. Nerve conduction studies detected mildly decreased motor nerve conduction velocities in the median, ulnar and posterior tibial nerves. Ultrasound cardiography showed a dilated left ventricle. It was not possible to clarify the relationship between LHON and cerebellar atrophy, cardiomyopathy, and peripheral neuropathy. However, physicians, need to be aware that the patients may develop various neurological complications after the onset of optic neuropathy in LHON.