Pontine and bilateral cerebellar lesion in osmotic demyelination syndrome associated with uncontrolled type II diabetes mellitus: a case report

Osmotic demyelination syndrome (ODS) as a result of the hyperosmolar hyperglycemic state is rare and can present with variable neurological manifestation due to lysis of myelin sheath. CASE PRESENTATION: A 44-year diabetic male presented with complaints of sudden onset, progressive bilateral weakness in lower limbs, and slurring of speech for the past 1.5 months. Cerebellar examination showed a bilaterally impaired finger nose test, dysdiadochokinesia, impaired heel shin test, and an impaired tandem gait. MRI brain (T2 and fluid-attenuated inversion recovery sequences) showed high signal intensity in the central pons and bilateral cerebellum. With a diagnosis of ODS with poorly controlled diabetes, he was treated with insulin, metformin, and supportive measures following which his symptoms subsided gradually. CLINICAL DISCUSSION: A rapid correction of hyponatremia is considered the most common cause of ODS. Variations in plasma glucose levels, a rare cause of ODS, can cause an abrupt osmolality change causing pontine and extrapontine myelinolysis. Prevention of rapid correction of hyponatremia and rapid changes in plasma osmolality in vulnerable patients is the mainstay of treatment. CONCLUSIONS: Clinical features, imaging studies, and monitoring of serum osmolality, serum glucose, and electrolytes aid in diagnosis and favorable outcomes for the patient.