Rationale: Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic condition often linked to hypertension, eclampsia, or renal failure. PRES typically presenting with seizures, headaches, visual disturbances, and altered mental status. A rarer form, the central variant of PRES, involves atypical radiologic findings such as edema in central brain structures. PRES has not been previously associated with adrenal insufficiency, making this case novel and significant.

Patient concerns: A 59-year-old woman with a history of hypertension, chronic obstructive pulmonary disease, and previous COVID-19 infection presented to the emergency department with seizures and altered mental status. She exhibited a fluctuating systolic blood pressure (79-195 mm Hg) and had a Glasgow Coma Scale (GCS) score of 7.

Diagnoses: Initial imaging and laboratory tests were inconclusive. Continuous electroencephalogram indicated focal cortical irritability, raising concerns about seizures. Brain magnetic resonance imaging revealed increased T2-weighted signals in the bilateral cerebellar hemispheres, consistent with central variant PRES. Endocrine evaluation showed primary adrenal insufficiency, confirmed by low AM cortisol levels and a positive cosyntropin stimulation test.

Interventions: The patient was started on levetiracetam for seizure management and hydrocortisone for adrenal insufficiency. She was intubated for airway protection but later extubated as her condition stabilized.

Outcomes: Follow-up magnetic resonance imaging showed progressive resolution of the cerebellar T2 hyperintensities. The patient was discharged on day 15 with no residual neurological deficits. At a 3-month follow-up, she remained seizure-free and continued oral hydrocortisone and levetiracetam.

Lessons: This case highlights adrenal insufficiency as a possible novel precipitant of the central variant of PRES, emphasizing the need for prompt diagnosis and treatment to prevent serious neurological outcomes. The underlying pathophysiological mechanism of PRES from adrenal insufficiency is most likely labile blood pressure causing rapid alterations in cerebral perfusion pressure (CPP) precipitating PRES.