Profound Hypomagnesemia Due to Proton Pump Inhibitor Use-Associated Wernicke’s Encephalopathy: A Case Report on Excitotoxicity

Hypomagnesemia is a frequently underdiagnosed condition. Its clinical consequences can be serious, with a wide variety of clinical presentations. Magnesium deficiency is often multifactorial, and this insufficiency can exacerbate or delay the recovery of other conditions. Magnesium is increasingly studied in the central nervous system for its regulation of excitotoxicity and its anti-apoptotic role. We describe the clinical case of a 50-year-old woman who presented to the emergency department with neurological symptoms characterized by dysarthria, headaches, photophobia, paresthesias, vertigo, multidirectional nystagmus, and gait instability. Her hospitalization revealed profound multifactorial hypomagnesemia (< 0.10 mmol/L). This condition results from diarrhea, chronic use of a proton pump inhibitor, alcohol consumption, and malnutrition. These electrolyte imbalances, along with the clinical presentation of Wernicke's encephalopathy, led to her admission to the intensive care unit. Her overall condition and neurological symptoms improved following the correction of her biochemical abnormalities, intravenous hydration, and thiamine supplementation. The patient was discharged from the hospital eight days later. In conclusion, hypomagnesemia is an electrolyte disorder whose neurological presentations remain rare but severe. Hypomagnesemia is a rare and insidious consequence of proton pump inhibitors and should be monitored frequently. The action of magnesium in the central nervous system is neuroprotective; it reduces inflammation and decreases excitotoxicity, a mechanism also involved in the pathophysiology of Wernicke's syndrome. This association is even more pertinent considering magnesium is necessary for the conversion of thiamine into its active form. Hypomagnesemia should be investigated more systematically and actively monitored, as the replenishment of the body's reserves can be time-consuming.