This chapter discusses case of a 61-year-old woman who came to improve her quality of life. Her speech was understandable, although she had developed dysarthria and dysphagia. Previous medical history included arthritis and bilateral sensorineural hearing loss since childhood. On examination, she was cognitively intact. There are dysmetric saccades, occasional facial myokymia, mild dysarthria, and an impaired vestibulo-ocular reflex. In regard to her diagnosis, she had been tested for treatable causes of ataxia and for genetic etiologies given her positive family history. Treatable causes of ataxia include paraneoplastic syndromes, toxins, Wilson’s disease, and numerous immune-mediated syndromes, including anti-GAD and antigliadin antibodies. Her myoclonus, sensorineural hearing loss, and family history of hearing loss all directed us toward testing for mitochondrial disorders, specifically mitochondrial epilepsy with ragged red fibers (MERRF). Patients with MERRF typically present with myoclonus and subsequently develop ataxia, myopathy, and generalized seizures.