Posterior Reversible Encephalopathy Syndrome Following Recreational Nitrous Oxide Use: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic diagnosis characterized by acute neuropsychiatric symptoms, including headache, visual disturbances, seizures, hallucinations, and encephalopathy, in conjunction with neuroimaging findings of posterior-predominant vasogenic edema in the cerebral hemispheres. Several risk factors, including uncontrolled hypertension, eclampsia, renal failure, autoimmune diseases, and exposure to cytotoxic and immunosuppressive drugs, have been implicated in the development of PRES. We present a rare case of PRES in a patient with a history of polysubstance abuse who presented with acute mental status changes and obtundation. The diagnosis of PRES was established based on the clinical presentation of encephalopathy and brain imaging findings demonstrating transient vasogenic edema predominantly affecting the posterior cerebral hemispheres on magnetic resonance imaging (MRI). The etiology in this case was attributed to recreational nitrous oxide misuse and intoxication, which likely resulted in vasogenic edema in the posterior lobes, leading to acute, transient neurologic dysfunction followed by recovery. To our knowledge, the association between recreational nitrous oxide abuse and PRES has not been previously reported. This case highlights a potentially underrecognized neurological complication of nitrous oxide misuse and underscores the need for clinical vigilance and further investigation into the pathophysiologic consequences of its recreational use.