Posterior Reversible Encephalopathy Syndrome (PRES) as the Initial Presentation of Systemic Lupus Erythematosus With Lupus Nephritis: A Case Report.

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological entity most often associated with acute hypertension, renal failure, or autoimmune diseases. PRES as an initial manifestation of systemic lupus erythematosus (SLE) has been described but remains rare. Early recognition and treatment of the underlying condition are essential to ensure a favorable outcome. We report the case of an 18-year-old North African female residing in Belgium, admitted for gastrointestinal symptoms associated with severe arterial hypertension, acute renal failure, and neurological manifestations, including seizures and visual disturbances. Brain magnetic resonance imaging (MRI) showed bilateral posterior and basal nuclei hyperintensities consistent with PRES. Laboratory investigations revealed impaired renal function and immunological abnormalities, including positive antinuclear and anti-double-stranded DNA antibodies. Further evaluation confirmed lupus nephritis, establishing the diagnosis of SLE. Treatment included prompt blood pressure control, antiepileptic therapy, high-dose corticosteroids, and immunosuppressive therapy targeting lupus nephritis. The patient experienced complete neurological recovery with resolution of seizures and visual symptoms. Follow-up imaging demonstrated radiological improvement, and renal function gradually recovered under immunosuppressive treatment. This case illustrates PRES as a rare inaugural manifestation of SLE in the context of hypertensive emergency and lupus nephritis. Early diagnosis and management of both neurological and systemic involvement are crucial to achieve complete neurological recovery and improve long-term outcomes. Strict blood pressure control and timely evaluation for SLE are critical in suspected PRES, and clinicians should be aware that atypical involvement of the basal ganglia may occur.