Posterior reversible encephalopathy syndrome in an HIV-infected patient on antiretroviral treatment: what is the risk factor?

Posterior reversible encephalopathy syndrome (PRES) is a rare but well-described syndrome associated with a high morbidity and a substantial mortality. We present an illustrative case of an HIV-infected but virologically suppressed patient who complained of visual impairment accompanied by severe headache and epileptic seizures. The cerebral CT scan and the follow-up cranial MRI confirmed the diagnosis of PRES. Unlike the cases of HIV-infected patients with PRES published so far, our patient suffered neither from advanced immunodeficiency nor from opportunistic infection or from any other evident predisposing factor. This case highlights that the absence of classical risk factors does not exclude the diagnosis of PRES. We discuss the hypothesis that in accordance with the new pathophysiological theory, persistent HIV-associated cerebrovascular reactivity in combination with endothelial dysfunction may represent an undetected risk factor for the development of PRES in virologically and immunologically stable patients.