Objective:

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Background:

Posterior reversible encephalopathy syndrome (PRES) results from blood-brain barrier disruption due to impaired cerebral blood flow autoregulation, leading to vasogenic edema, primarily in the parieto-occipital regions. Anterior edema is less typical but possible. Causes include severe hypertension and endothelial disruption, with symptoms such as encephalopathy, headache, or focal neurological deficits. Pheochromocytomas, neuroendocrine tumors that secrete excessive catecholamines, can cause severe hypertension. Approximately 50% of pheochromocytomas are hereditary, such as with MEN2A syndrome—a triad of pheochromocytoma, medullary thyroid cancer, and parathyroid abnormalities. Few reports exist on PRES related to pheochromocytomas, and none specifically concerning MEN2A syndrome.

Design/Methods:

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Results:

A 30-year-old man with a 10-year history of episodic tachycardia, sweating, tremors, and refractory hypertension presented to the emergency department with severe encephalopathy and non-specific speech difficulties. His systolic blood pressure fluctuated between 100-240 mmHg. A prior CT identified bilateral pheochromocytomas, raising suspicion of a pheochromocytoma crisis. He was treated with terazosin and antihypertensives, resulting in rapid symptom improvement. Laboratory tests showed elevated metanephrines. MRI head with and without contrast revealed extensive bilateral T2 FLAIR hyperintensities in the cerebral white matter and right frontal lobe, consistent with PRES versus acute disseminated encephalomyelitis (ADEM). Neurology diagnosed likely PRES. Notably, lesions were non-contrast enhancing and lacked diffusion restriction, aligning more with PRES than ADEM, which typically exhibits abnormal contrast enhancement. ADEM and PRES both manifest with encephalopathy, but ADEM typically has polyfocal neurologic deficits that our patient did not exhibit. Furthermore, he rapidly improved with blood pressure control, unlike ADEM or other inflammatory or infectious processes, especially with such extensive imaging abnormalities. Follow-up imaging showed complete resolution. Genetic testing confirmed MEN2A syndrome.

Conclusions:

This case highlights that PRES can occur secondary to a pheochromocytoma crisis, as with MEN2A syndrome. Clinicians should consider pheochromocytoma and related genetic conditions in young patients with PRES from severe, undifferentiated hypertension.