Central pontine and extrapontine myelinolysis: a systematic review.

The purpose was to perform a systematic review of studies on central pontine and extrapontine myelinolysis [forms of osmotic demyelination syndrome (ODS)] and define the spectrum of causes, risk factors, clinical and radiological presentations, and functional outcomes of this disorder. A thorough search of the literature was conducted using multiple databases (PubMed, Ovid Medline and Google) and bibliographies of key articles to identify all case series of adult patients with ODS published from 1959 to January 2013. Only series with five or more cases published in English were considered. Of the 2602 articles identified, 38 case series were included comprising a total of 541 patients who fulfilled our inclusion criteria. The most common predisposing factor was hyponatremia (78%) and the most common presentation was encephalopathy (39%). Favorable recovery occurred in 51.9% of patients and death in 24.8%. Liver transplant patients with ODS had a combined rate of death and disability of 77.4%, compared with 44.7% in those without liver transplantation (P < 0.001). ODS is found to have a good recovery in more than half of cases and its mortality has decreased with each passing decade. Favorable prognosis is possible in patients of ODS, even with severe neurological presentation. Further research is required to confirm the differences found in liver transplant recipients.