The changing face of osmotic demyelination syndrome: A retrospective, observational cohort study

Objective To describe long-term outcomes of osmotic demyelination syndrome (ODS) in an updated cohort. Methods We performed a retrospective medical records review of cases of ODS at the Massachusetts General and Brigham and Women9s Hospitals using International Classification of Diseases-9th edition codes and a text-based search for central pontine myelinolysis, extrapontine myelinolysis, and osmotic demyelination syndrome (1999–2018). Cases were individually selected based upon patients having neuroimaging and symptoms consistent with ODS, and no other potentially explanatory etiology. Modified Rankin scale (mRS) scores were extracted at pre-hospitalization, hospital discharge, 6-months post-discharge, and at the most recently available clinical visit. Results We identified 45 cases of ODS (mean age 48.4 years, range 0.07–75 years; 58% female). Common co-morbidities included liver disease (26%, n = 12), alcoholism (43%, n = 20), and kidney failure (20%, n = 9). Twenty-nine percent of patients had a rapid correction of hyponatremia. Twenty-nine percent had other electrolyte abnormalities. Only 59% (24/41) of patients with complete electrolyte data had abnormalities that could explain their ODS. At 6-month follow-up, 16% of patients were deceased and 60% of patients had minimal to no disability (mRS 0–2). Conclusions ODS has a diverse range of clinical presentations. Not all patients have electrolyte abnormalities. The prognosis is generally favorable, although 1 in 6 patients had died at 6 months, likely due to underlying disease states.