Osmotic Demyelinating Syndrome and COVID-19

ABSTRACT

Introduction: Osmotic demyelination syndrome (ODS) is a dreaded complication of rapid sodium correction in high-risk hyponatremic patients. Predisposing factors include chronic alcoholism, malnourishment, severe hyponatremia. SARS-Cov2 infection may also be a risk factor as it is linked with multiple patterns of brain injury, renal damage and hyponatremia. Case Description Patient is a 48-year-old female with history of alcohol use disorder who presented with malaise, vomiting, diarrhea for 3 days. On admission, the patient was stuporous and confused. She was clinically hypovolemic. Initial labs demonstrated severe hyponatremia (102 mmol/L), hypokalemia (2.2 mmol/L), HCO3 of 35mmol/L, lactic acid of 4 mmol/L, no EtOH, preserved GFR. SARS-CoV2 PCR was positive. She was not hypoxic, her chest X-ray was clear. The patient was resuscitated with 1L of isotonic saline, potassium correction was attempted. Her bloodwork 4 hours later showed Na of 113 mmol/L and K of 2.4 mmol/L. At this point patient had prominent diuresis, UNa was 13mmol/L, Uosm 175mOsm/kg and U spec gravity 1.006. Immediately DDAVP and D5W were started. She had a poor response to this therapy and her sodium continued raising even at maximal doses. At 24h her sodium was 118 mmol/L and at 48h it was 125mmol/L with stabilization at this level. She had clinical improvement and was more responsive on day 3. On the following days, sodium gradually drifted toward 132 mmol/L. On day 5 she developing worsening mental status. She was found poorly responsive with fixed gaze, aphasia, minimally removing extremities from pain, able to blink when asked. Brain MRI revealed signal abnormalities in the central pons, bilateral thalami, caudate, basal ganglia, subinsular regions consistent with ODS. Intensive treatment was restarted with D5W and DDAVP. Na of 124mmol/L was achieved at 24h. Over the course of the following days, she had partial recovery. She was discharged to rehab, able to smile, move her head and partially move her extremities. Discussion(s) SARS-Cov2 causes hyponatremia through several mechanisms. Poor oral intake, gastrointestinal loses, kidney injury and SIADH have been described. All of them may occur at the same time and cause hypovolemic/euvolemic states with high ADH. Volume replacement rapidly shuts off the ADH drive predisposing patients to get sodium overcorrection.