The clinical and radiological spectrum of posterior reversible encephalopathy syndrome: a retrospective series of 24 patients.

BACKGROUND AND PURPOSE: Some patients with posterior reversible encephalopathy syndrome (PRES) present with atypical clinical and neuroimaging findings. The purpose of this study is to review the clinical and neuroimaging findings in patients diagnosed with PRES.

METHODS: We retrospectively included all patients diagnosed with PRES between January 2005 and March 2009. We reviewed demographic, clinical and laboratory data, neuroimaging findings, and prognosis.

RESULTS: Twenty-four patients were included with a median age of 19 years. The clinical presentations included seizures (91.7%), headache (83.3%), visual disturbance (62.5%), encephalophathy (29.2%), and paralysis (8.3%). Co-morbidities included systemic lupus erythematous (29.2%), kidney disease (20.8%), eclampsia (20.8%), renal artery stenosis (12.5%), Takayasu arteritis (4.2%), Sheehan's syndrome (4.2%), allergic purpura (4.2%), and acute intermittent porphyria (4.2%). Acute elevation of blood pressure was found in 22 patients (91.7%). Ten patients (41.7%) used steroids or immunosuppressants, three (12.5%) had acute renal failure before the symptoms. Atypical neuroimaging features included involvement of the frontal lobe (54.2%), basal ganglia (4.2%) or cortex (8.3%), and irreversible lesions (3/18, 16.7%).

CONCLUSIONS: A large proportion of patients with PRES may present with atypical neuroimaging findings. Apart from the known risk factors, such as hypertension, immunosuppressants, and renal failure of various etiologies may be the precipitants of PRES.