A 45-year-old chronic alcoholic admitted with confusion is found to have serum sodium of 108 mEq/L. He receives hypertonic saline and the sodium is corrected to 130 mEq/L within 36 hours. Three days later he develops quadriparesis, dysarthria, dysphagia, and pseudobulbar palsy with preserved consciousness. MRI shows a central pontine lesion. What is the most likely diagnosis?

• A Wernicke encephalopathy
• B Marchiafava-Bignami disease
• C Central pontine myelinolysis (osmotic demyelination syndrome) ✓
• D Alcoholic cerebellar degeneration

Explanation

Rapid correction of hyponatremia in a chronically malnourished alcoholic causes osmotic demyelination of the central basis pontis, presenting as spastic quadriparesis, pseudobulbar palsy, and dysarthria with consciousness typically preserved. Wernicke encephalopathy features confusion, ophthalmoplegia, and ataxia and improves with thiamine, so the temporal link to sodium correction identifies the key diagnosis here.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.