Determinants of recovery from severe posterior reversible encephalopathy syndrome

Abstract

Objective: Few outcome data are available about posterior reversible encephalopathy syndrome (PRES). We studied 90-day functional outcomes and their determinants in patients with severe PRES.

Design: 70 patients with severe PRES admitted to 24 ICUs in 2001-2010 were included in a retrospective cohort study. The main outcome measure was a Glasgow Outcome Scale (GOS) of 5 (good recovery) on day 90.

Main results: Consciousness impairment was the most common clinical sign, occurring in 66 (94%) patients. Clinical seizures occurred in 57 (81%) patients. Median mean arterial pressure was 122 (105-143) mmHg on scene. Cerebral imaging abnormalities were bilateral (93%) and predominated in the parietal (93%) and occipital (86%) white matter. Median number of brain areas involved was 4 (3-5). Imaging abnormalities resolved in 43 (88%) patients. Ischaemic and/or haemorrhagic complications occurred in 7 (14%) patients. The most common causes were drug toxicity (44%) and hypertensive encephalopathy (41%). On day 90, 11 (16%) patients had died, 26 (37%) had marked functional impairments (GOS, 2 to 4), and 33 (56%) had a good recovery (GOS, 5). Factors independently associated with GOS<5 were highest glycaemia on day 1 (OR, 1.22; 95%CI, 1.02-1.45, p = 0.03) and time to causative-factor control (OR, 3.3; 95%CI, 1.04-10.46, p = 0.04), whereas GOS = 5 was associated with toxaemia of pregnancy (preeclampsia/eclampsia) (OR, 0.06; 95%CI, 0.01-0.38, p = 0.003).

Conclusions: By day 90 after admission for severe PRES, 44% of survivors had severe functional impairments. Highest glycaemia on day 1 and time to causative-factor control were strong early predictors of outcomes, suggesting areas for improvement.

Figure 1. Patient flow chart, clinicoradiologic features, management, and 90-day follow-up in 70 patients with severe posterior reversible encephalopathy syndrome.

¥ Hypertension was defined according to the 2007 European guidelines for the management of arterial hypertension(16). Grade 1: mild hypertension (systolic blood pressure [SBP], 140–159 mmHg and/or diastolic blood pressure [DBP], 90–99 mmHg); Grade 2: moderate hypertension (SBP, 160–179 mmHg and/or DBP, 100–109 mmHg); Grade 3: severe hypertension (SBP≥180 mmHg and/or DBP≥110 mmHg) ‡ Mean arterial pressure (2/3 diastolic +1/3 systolic pressure) § Nine patients with haemorrhagic complications at first imaging: 3 with no follow-up imaging studies, 3 with persistent haemorrhagic abnormalities by follow-up imaging, and 3 with resolution of the haemorrhagic abnormalities Ψ According to the Logistic Organ Dysfunction (LOD) score †The primary outcome measure was the score on the Glasgow Outcome Scale (GOS) 90 days after onset of severe posterior reversible encephalopathy syndrome. A score of 1 indicates death; 2, a vegetative state (the patient is unable to interact with the environment); 3, severe disability (the patient is unable to live independently but can follow commands); 4, moderate disability (the patient is capable of living independently but unable to return to work or school); and 5, mild or no disability (the patient is able to return to work or school). A favourable outcome was defined as a score of 5 and an unfavourable outcome as a score lower than 5. The day-90 GOS score was known in all 70 patients.