(Kiosk 4) Osmotic Demyelination Syndrome

Case Diagnosis: Osmotic Demyelination Syndrome

Case Description: A 46 year old man with a past medical history of alcohol use disorder presented to the hospital with lethargy and a sodium level of 106. During the sodium level correction, the patient became suddenly unresponsive and remained in a coma for weeks. Upon awakening, he experienced severe dysarthria, dysphagia, and spastic quadriplegia. His condition required the placement of a percutaneous endoscopic gastrostomy (PEG) tube and the participation in interdisciplinary rehabilitation.

Discussion: Risk factor for ODS include severe hyponatremia, between 105-120 mEq/L along with repletion at a rate greater than 12 mEq within 24 hours, a history of alcohol use disorder, malnutrition, and liver disease.

The pathophysiology of ODS remains unclear. The current proposed theory suggests that brain cells fail to adapt to rapidly changing serum osmolarity causing major cellular dysfunction. In the case of hyponatremia, water will shift from the brain cells into the extra-cellular space causing demyelination in the pons.

Clinically, pontine demyelination leads to dysarthria, dysphagia, facial weakness, mutism, and in severe cases, locked-in syndrome.
Extrapontine involvement may lead to psychiatric symptoms such as catatonia, athetosis, dystonia, and tremors. Management with dopamine is the current accepted course of action.

Brain MRIs is superior to head CTs. MRIs can become positive weeks after the clinical onset. 50% will have early central pontine demyelination and 40 % will have both central and extrapontine demyelination.

Setting: The patient performed his therapy in an acute inpatient rehabilitation unit.

Assessment/Results: With the help of speech-language therapy, his speech significantly improved. Physical therapy helped him transfer and ambulate better using a walker. Occupational therapy allowed for improved upper extremity motor skills in the setting of severe initial flexor tone.

Conclusion: This case report emphasize the importance of a comprehensive rehabilitation program in order to maximize recovery and improve functional outcome in patients with ODS.