Magnetic FResonance Imaging Features of Posterior Reversible Encephalopathy Syndrome (PRES)- A Hospital Based Study

Abstract

                                                 ABSTRACT

OBJECTIVE:  To identify MRI imaging features and lesion distribution pattern in patients of posterior reversible encephalopathy syndrome (PRES).

 METHODS: It is a descriptive study which was done in radiology department of a tertiary care hospital in Quetta from 1^st December 2014 to 29^th February 2016. Patients with any clinical neurological presentation reporting to radiology department for MR examination, having imaging findings suggestive of  PRES on MRI brain were included in the study. Clinical and imaging follow up were also done. MRI sequences included axial and sagittal T1W, T2W, FLAIR, DWI and ADC which were analyzed by two radiologists in double blind interpretation. The imaging features and dominant lesion distribution pattern were identified and categorized in respective groups.   

RESULTS:   26 patients were included in the study. Mean age of patients was 35.9years. Male to female ratio was 1:2.7. All patients showing typical features of focal vasogenic edema on MR study. 24 patients showed symmetrical or near symmetrical lesions bilaterally and 02 patients showed lesions in only one hemisphere. Distribution patterns were occcipito-parietal region (58%), temporoparietal region (19%), frontal region (15%) and basal ganglia/ deep white matter  (8%).  Most common clinical presentation was altered mental status (35%) followed by headache (31%), seizures (23%) and visual disturbances (11%). Observed risk factors for PRES were preeclampsia / eclampsia (50%), severe hypertension (23%), renal failure (15%), septicemia (8%) and renal transplant (4%).

CONCLUSION:   PRES is a neuroradiological entity and a reversible neurological syndrome if diagnosed early. There are distinctive MR imaging features and lesion distribution pattern which helps in quick identification of this disease. This makes MRI the modality of choice for evaluation of PRES.

KEYWORDS: Posterior reversible encephalopathy syndrome (PRES), magnetic resonance imaging (MRI), imaging features, vasogenic edema.