Osmotic Demyelination Syndrome Presenting as Extrapontine Myelinolysis with or without Central Pontine Myelinolysis

Abstract

Background and objective: Osmotic demyelination syndrome (ODS) refers to a spectrum of clinicoradiologic syndrome which occurs due to pontine and extrapontine involvement due to myelinolysis. It is well described in association with rapid correction of hyponatremia and in alcoholics. In this case series, we have reviewed clinical presentation, neuroimaging features, and clinical outcomes of five patients diagnosed with ODS. Methods: The hospital medical records of all patients diagnosed with ODS between September 2018 and May 2020 at our hospital were analyzed retrospectively. Patients’ relevant clinical details and laboratory findings were recorded and magnetic resonance imaging (MRI brain) was reviewed. Those cases having imaging or clinical picture not clearly consistent with diagnosis were excluded. Results: Patients included in the study were 49 to 69 years old. All patients were treated as a case of hyponatremic encephalopathy in local hospitals. All patients had initial improvement followed by neurologic deterioration for which they were referred to our hospital. Possible etiologies of hyponatremia were recurrent vomiting and diuretic induced in two patients each and alcohol induced in one patient. Three out of five patients showed isolated extrapontine involvement on MRI. All patients showed improvement on dopaminergic drugs, whereas one patient had residual pseudobulbar symptoms which improved on follow-up. Conclusion: This series represents cases with clinical, etiopathogenic and radiologic spectrum of the ODS. ODS is a potentially treatable condition and rewarding results can be obtained by prompt diagnosis and management of associated secondary complications.