The effect of presymptomatic hypertension in posterior reversible encephalopathy syndrome

The effect of blood pressure (BP) on the lesion distribution of posterior reversible encephalopathy syndrome (PRES) is controversial. The aim of this study was to identify the relationship between brain lesion distribution patterns and BP.

Sixty-five patients with PRES were selected from the database. Data regarding brain MRI findings, clinical symptoms, medical conditions, and BP at the presymptomatic period (24 hr before the symptom onset) and at the symptom onset were collected. The brain lesion distribution degree was numerically calculated (lesion scoring point [LSP]) and compared with BP and medical conditions.

Mean onset-MAP was higher than mean pre-MAP. Pre-MAP correlated with onset-MAP. The LSP was significantly correlated with pre-MAP (p = 0.009, correlation coefficient [cc] = 0.323), whereas no significant correlation was found between LSP and onset-MAP (p = 0.159, cc = 0.177). Similarly, when patients were grouped by mean MAP values, LSP was significantly higher in the patients with high MAP at the presymptomatic period (p = 0.004), whereas no difference was found in the LSP value between patients with low MAP and high MAP at the symptom onset (p = 0.272).

The patient with PRES who has relatively higher BP in the presymptomatic period would be more likely to have wider lesion distribution than the patient with lower BP. BP elevation during presymptomatic period may be a heralding sign of impending PRES and a factor affecting the severity of PRES although BP was not investigated at earlier time points.