Clinicoradiological factors influencing the reversibility of posterior reversible encephalopathy syndrome: a multicenter study.
OBJECTIVE
The aim of this retrospective study was to clarify the relation between the reversibility of posterior reversible encephalopathy syndrome (PRES) with three factors: the anatomical region of the brain involved, the background clinical cause, and the diffusion weighted image (DWI) intensity of PRES lesions.


METHODS
This multicenter study, conducted by the PRES Study Group of the Neuroradiology Workshop, involved 52 cases from 28 institutions. Initial and follow-up magnetic resonance imaging were compared regarding the reversibility of PRES lesions according to anatomical location and clinical background. Initial DWI and apparent diffusion coefficient (ADC) maps were reviewed in 20 cases.


RESULTS
Reversibility was significantly lower (P < 0.01) in the brain stem (44%) and deep white matter (47%) compared to the other cortical and subcortical areas (76%-91%). The reversibility was greater in the eclampsia subgroup followed by the hypertension and chemotherapy subgroups. DWI, even with ADC maps, had limitations in predicting the outcome of PRES lesions.


CONCLUSIONS
The typical cortical and subcortical PRES lesions showed reversibility, whereas the brain stem and deep white matter lesions showed less reversibility. PRES due to eclampsia showed maximum reversibility compared to hypertension- and drug-related PRES. DWI, even with ADC maps, had limitations in predicting the course of PRES.
Pande
Ajaya R
AR
Department of Radiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan.
Ando
Kumiko
K
Ishikura
Reiichi
R
Nagami
Yuki
Y
Takada
Yoshihiro
Y
Wada
Akihiko
A
Watanabe
Yoshiyuki
Y
Miki
Yukio
Y
Uchino
Akira
A
Nakao
Norio
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D001927:Brain Diseases / Q000209:etiology / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004461:Eclampsia / Q000473:pathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011379:Prognosis; D012189:Retrospective Studies