Risk of Stroke After Posterior Reversible Encephalopathy Syndrome

A case study of posterior reversible encephalopathy syndrome: Not always reversible with detrimental consequences

ABSTRACT

Posterior reversible encephalopathy syndrome, or PRES, is often an unrecognized sequela of uncontrolled hypertension that is associated with a significant risk of mortality. It is poorly understood and can lead to endothelial dysfunction with disturbance of the blood-brain barrier and subsequent brain edema. Headache, seizures, encephalopathy, and visual disturbances are among the most common symptoms associated with PRES. Testing and evaluation should be quickly initiated not only to solidify the diagnosis but also to rule out others such as infection or stroke. Prompt identification of the symptoms of PRES can potentially reverse long-term side effects such as life-long seizures or visual deficits.

Experimental Models of Posterior Reversible Encephalopathy Syndrome: A Review From Pathophysiology to Therapeutic Targets

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity characterized by nonspecific symptomatology (eg, headache, visual disturbances, encephalopathy, and seizures) and classically cortical and subcortical vasogenic edema predominantly affecting the parietooccipital region. PRES etiologies are usually dichotomized into toxic PRES (eg, antineoplastic drugs, illicit drugs) and clinical condition-associated PRES (eg, acute hypertension, dysimmune disorders). Although the pathophysiology of PRES remains elusive, 2 main pathogenic hypotheses have been suggested: cerebral hyperperfusion due to acute hypertension and cerebral hypoperfusion related to endothelial dysfunction. Research into the pathogenesis of PRES has emerged through the development of animal models in the last decade. The motivation for developing a suitable PRES model is 2-fold: to fill in knowledge gaps of the pathophysiological mechanisms involved, and to open new perspectives for clinical assessment of pharmacological targets to improve therapeutic management of PRES. All current models of PRES have a hypertensive background, on which other triggers (acute hypertension, inflammatory, drug toxicity) have been added to address specific facets of PRES (eg, seizures). The initial model consisted in inducing a reduced uterine perfusion pressure that mimics preeclampsia, a leading cause of PRES. More recently, a model of stroke-prone spontaneously hypertensive rats on high-salt diet, originally developed for hypertensive small vessel disease and vascular cognitive impairment, has been studied in PRES. This review aims to discuss, depending on the research objective, the benefits and limitations of current experimental approaches and thus to define the desirable characteristics for studying the pathophysiology of PRES and developing new therapies.

[Posterior reversible encephalopathy syndrome in autoimmune disorders]

Posterior reversible encephalopathy syndrome (PRES) is characterized by nonspecific symptoms, including not only pronounced non-focal and various focal neurological signs but also specific neuroimaging features, including vasogenic edema affecting predominantly the posterior area. PRES usually develops in the setting of acute arterial hypertension. However, it is not uncommon for PRES to develop in non-hypertensive patients, including people with autoimmune disorders (multiple sclerosis, neuromyelitis optica spectrum disorder, etc). PRES could also be due to the toxic effects of drugs or other substances. The pathophysiological mechanisms of PRES include impaired autoregulation of cerebral blood flow due to acute arterial hypertension and toxic endotheliotropic effects of endogenous and exogenous factors.

Demographic Disparities in the Incidence, Clinical Characteristics, and Outcome of Posterior Reversible Encephalopathy Syndrome in the United States

OBJECTIVES

To estimate age-specific, sex-specific, and race-specific incidence of posterior reversible encephalopathy syndrome (PRES) in the United States.

METHODS

We conducted a retrospective cohort study using the State Inpatient Database of Florida (2016-2019), Maryland (2016-2019), and New York (2016-2018). All new cases of PRES in adults (18 years or older) were combined with Census data to compute incidence. We evaluated the generalizability of incident estimates to the entire country using the 2016-2019 National Readmissions Database (NRD).

RESULTS

Across the study period, there were 3,716 incident hospitalizations for PRES in the selected states. The age-standardized and sex-standardized incidence of PRES was 2.7 (95% CI 2.5-2.8) cases/100,000/y. Incidence in female patients was >2 times that of male patients (3.7 vs 1.6 cases/100,000/y, p < 0.001). Incidence increased with age in both sexes (p-trend <0.001). Similar demographic distribution of first hospitalization for PRES was also noted in the entire country using the NRD. Age-standardized and sex-standardized PRES incidence in Black patients (4.2/100,000/y) was significantly greater than in Non-Hispanic White (2.7/100,000/y) and Hispanic patients (1.2/100,000/y) (p < 0.001 for pairwise comparisons).

DISCUSSION

The incidence of PRES in the United States is approximately 3/100,000/y, but incidence in female patients is >2 times that of male patients. PRES incidence is higher in Black compared with non-Hispanic White and Hispanic patients.

Misdiagnosis of Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome in the Emergency Department

Background Cerebrovascular dysregulation syndromes, posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS), are challenging to diagnose because they are rare and require advanced neuroimaging for confirmation. We sought to estimate PRES/RCVS misdiagnosis in the emergency department and its associated factors. Methods and Results We conducted a retrospective cohort study of PRES/RCVS patients using administrative claims data from 11 states (2016-2018). We defined patients with a probable PRES/RCVS misdiagnosis as those with an emergency department visit for a neurological symptom resulting in discharge to home that occurred ≤14 days before PRES/RCVS hospitalization. Proportions of patients with probable misdiagnosis were calculated, characteristics of patients with and without probable misdiagnosis were compared, and regression analyses adjusted for demographics and comorbidities were performed to identify factors affecting probable misdiagnosis. We identified 4633 patients with PRES/RCVS. A total of 210 patients (4.53% [95% CI, 3.97-5.17]) had a probable preceding emergency department misdiagnosis; these patients were younger (mean age, 48 versus 54 years; P<0.001) and more often female (80.4% versus 69.3%; P<0.001). Misdiagnosed patients had fewer vascular risk factors except prior stroke (36.3% versus 24.2%; P<0.001) and more often had comorbid headache (84% versus 21.4%; P<0.001) and substance use disorder (48.8% versus 37.9%; P<0.001). Facility-level factors associated with probable misdiagnosis included smaller facility, lacking a residency program (62.2% versus 73.7%; P<0.001), and not having on-site neurological services (75.7% versus 84.3%; P<0.001). Probable misdiagnosis was not associated with higher likelihood of stroke or subarachnoid hemorrhage during PRES/RCVS hospitalization. Conclusions Probable emergency department misdiagnosis occurred in ≈1 of every 20 patients with PRES/RCVS in a large, multistate cohort.

Long-term risk of seizure after posterior reversible encephalopathy syndrome

OBJECTIVE

Patients with posterior reversible encephalopathy syndrome (PRES) can develop seizures during the acute phase. We sought to determine the long-term risk of seizure after PRES.

METHODS

We performed a retrospective cohort study using statewide all-payer claims data from 2016-2018 from nonfederal hospitals in 11 US states. Adults admitted with PRES were compared to adults admitted with stroke, an acute cerebrovascular disorder associated with long-term risk of seizure. The primary outcome was seizure diagnosed during an emergency room visit or hospital admission after the index hospitalization. The secondary outcome was status epilepticus. Diagnoses were determined using previously validated ICD-10-CM codes. Patients with seizure diagnoses before or during the index admission were excluded. We used Cox regression to evaluate the association of PRES with seizure, adjusting for demographics and potential confounders.

RESULTS

We identified 2095 patients hospitalized with PRES and 341,809 with stroke. Median follow-up was 0.9 years (IQR, 0.3-1.7) in the PRES group and 1.0 years (IQR, 0.4-1.8) in the stroke group. Crude seizure incidence per 100 person-years was 9.5 after PRES and 2.5 after stroke. After adjustment for demographics and comorbidities, patients with PRES had a higher risk of seizure than patients with stroke (HR, 2.9; 95% CI, 2.6-3.4). Results were unchanged in a sensitivity analysis that applied a two-week washout period to mitigate detection bias. A similar relationship was observed for the secondary outcome of status epilepticus.

INTERPRETATION

PRES was associated with an increased long-term risk of subsequent acute care utilization for seizure compared to stroke.