Association of degree and type of edema in posterior reversible encephalopathy syndrome with serum lactate dehydrogenase level: initial experience.

Purpose: Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity characterized by headache, blurred vision and seizures with typical parieto-occipital predominantly vasogenic edema, occasionally with cytotoxic edema. The association between the degree and type of edema in PRES with biochemical parameter, especially serum lactate dehydrogenase, has not been determined.

Material And Methods: Thirty-five patients with typical clinical symptoms and characteristic MR imaging findings of PRES were included in this study. The extent of brain edema was graded on the anatomical distribution by 2 observers blinded to patients' clinical record, as well as the type of brain edema determined on DWI and ADC map. The levels of biochemical parameters were correlated with the degree of edema and compared between different types of edema.

Results: Serum LDH concentrations between patients with cytotoxic edema and with vasogenic components were not statistically different (NWU test, U=93.0, Z=1.818, P=0.069). Only serum lactate dehydrogenase (LDH) concentration was significantly correlated with the score of brain edema distribution (Spearman's rho correlation, r=0.721, P=0.00). No relationship was found between other biochemical parameters and the degree and type of brain edema.

Conclusion: Increased serum LDH level, which plays an essential role in endothelial injury, may be a potential risk factor for the development of edema in PRES.