Central Pontine and Extrapontine Myelinolysis: A Case Report and Neurotological Findings

We report a patient with central and extrapontine myelinolysis (CPM/EPM) who did not demonstrate any electrolyte disturbance during the course of the disease. A 53-year-old male with a history of alcoholism and diabetes mellitus, complained of progressive gait disturbance, dysarthria and dysphagia. He developed gaze nystagmus on upward gaze and rebound nystagmus to the primary position from upward gaze. The electronystagmogram showed saccadic pursuit, impairment of visual suppression and markedly impaired optokinetic nystagmus, although saccadic ocular movement appeared normal. Auditory brainstem response demonstrated prolonged I-V and III-V inter peak bilaterally. T2-weighted MR imaging demonstrated high-intensity areas at the bottom of the pons and middle cerebellar peduncle bilaterally. A diagnosis of central and extrapontine myelinolysis was based on the clinical course and MRI findings. An alcoholic history and hyperglycemia might have contributed to the development of CPM/EPM in this patient.