Multiple Sclerosis and other Neurological Conditions
Anisa M. Carlson, BA
Medical Student
University of Minnesota Medical School
Minneapolis, Minnesota, United States
Andrew Dang, DO
Physical Medicine & Rehabilitation Physician
Park Nicollet
Maple Grove, Minnesota, United States
Min Jeong P. Graf, MD
Chair, Department of PM&R; Medical Director, TBI Outpatient Program; Assistant Professor, UMN PM&R
Hennepin Healthcare
Minneapolis, Minnesota, United States
Anisa M. Carlson, BA
University of Minnesota Medical School
Minneapolis, Minnesota, United States
Osmotic Demyelination Syndrome (ODS), Traumatic Brain Injury (TBI).
Case Description:
52-year-old male with a history of chronic hyponatremia presented with lethargy, seizures and confusion after a fall. Head CT was negative, and workup revealed severe hyponatremia of 97 and CK of 8971. Acute management included hypertonic saline. During hospitalization he was diagnosed with TBI, and also developed bilateral upper extremity myoclonus, tremor, hyperreflexia, weakness and dysarthria. Brain MRI one month later showed moderate T2 hyperintensity within the central pons, suspicious for ODS. He required moderate-to-maximum assistance with ADLs, his 6-minute-walk-test (6MWT) was 47 meters, and functional gait assessment (FGA) was 23/30. The patient was followed closely by a brain injury outpatient program with rehabilitation therapies. Within five months, there was resolution of myoclonus and tremor, significant improvements in 6MWT to 600 meters, FGA to 29/30, and no significant cognitive impairment with the patient working full-time without restrictions.
Discussions: ODS commonly results from rapid correction of hyponatremia. Individuals with severe hyponatremia are at high risk for ODS even with careful sodium correction. Manifestations of ODS are highly variable: central pontine myelinolysis causes encephalopathy, dysarthria, dysphagia, weakness and ocular/pupillary disorders, while extrapontine myelinolysis depends on the impacted region and may include myoclonus, tremor, and ataxia. In cases of inconclusive imaging, follow-up MRI is recommended within one-to-two weeks. However, MRI alone is often insufficient for prognosis, as neither initial lesion size nor evolution correlates reliably with clinical outcomes.
Conclusions: This case illustrates that meaningful recovery is possible in the setting of severe hyponatremia compounded by factors like TBI. Clinical importance of this case stems from understanding that even with cautious correction of sodium, obtaining follow-up advanced imaging can provide additional insight especially when concerned for ODS. Individuals with ODS may have extensive and varied rehabilitation needs, thus, longitudinal rehab follow-up is essential in supporting patients’ functional improvement.
