Navigating the complexity of osmotic demyelination syndrome in the elderly: insight from three cases

Abstract

Osmotic demyelination syndrome (ODS) results from rapid shifts in serum osmolality and can be triggered by various factors such as hyponatremia, hyperglycaemia, malnutrition, alcohol abuse, and liver disease. Although hyponatremia prevalence increases with age, ODS typically manifests between ages 30 to 50, indicating a complex age-susceptibility relationship. Its pathophysiology involves brain volume restoration adaptation, with rapid correction of osmolality leading to dehydration and subsequent demyelination. Hyperglycaemia-induced ODS results from rapid correction of hyperosmolar states, overwhelming neuronal compensatory mechanisms. Neuroimaging, usually MRI, is crucial for diagnosis, revealing hyperintense lesions. Clinical manifestations vary widely, from dysarthria and dysphagia to spastic quadriparesis, with poor outcomes, especially in older patients. Below, three cases of ODS in elderly patients are presented, each with distinct clinical presentations and outcomes. Case1 highlights the association between rapid correction of hyperglycaemia and ODS while Case 2 and 3 illustrates the consequences of overly rapid correction of hyponatremia. Diagnosing Osmotic Demyelination Syndrome (ODS) in the elderly poses challenges due to overlapping clinical features with conditions like encephalopathy, delirium, and postictal confusional states, which closely mimic ODS. Further research is needed to better understand the pathophysiology and optimize management approaches, especially in vulnerable populations like the elderly.