An Unusual Presentation of Posterior Reversible Encephalopathy Syndrome

Introduction

Epilepsy is one of the most common reasons for patients presenting to the emergency department (ED). However, epilepsy events have a variety of causes, which we tend to ignore. The leading cause is renal artery dissection with renal infarction. The case reported herein is of a patient without a medical history of epilepsy who presented to the ED with sudden epileptic seizures caused by malignant hypertension.

Case Report

A 58-year-old man with underlying atrial fibrillation and diabetes mellitus presented to our ED with new-onset convulsions. The patient¡¦s blood pressure upon ED arrival was 188/128 mmHg, and he had no medical history of the seizure or hypertension. To determine the cause of the seizure, we performed brain computed tomography (CT), which revealed a subarachnoid hemorrhage in the frontal lobe (Fig. 1). Subsequent brain CT angiography revealed no vascular anomalies. After the patient had recovered from postictal confusion, his medical history was again reviewed. The patient reported intense abdominal pain for the preceding 2 weeks. Subsequently, abdominal CT was performed, which revealed left renal artery dissection complicated with renal infarction (Fig. 2). T2-weighted magnetic resonance imaging (MRI) of the brain parieto-occipital region revealed bilateral subcortical white matter hyperintensities that confirmed the diagnosis of posterior reversible encephalopathy syndrome (PRES) (Fig. 3). The culprit of PRES in this case was nephrogenic hypertension. In addition to controlling hypertension, renal artery stenting was performed. After treatment, regression of vasogenic edema was observed during repeated MRI, and the patient was discharged.

Fig. 1. Brain computed tomography revealing a subarachnoid hemorrhage in the frontal lobe (arrow: subarachnoid hemorrhage).

Fig. 2. Abdominal computed tomography revealing left renal artery dissection complicated with left renal infarction (arrow: renal artery dissection).

Fig. 3. Brain T2-weighted image revealing bilateral parieto-occipital subcortical white matter hyperintensities (arrow: symmetrical areas of hyperintensity).

Discussion

PRES, also known as reversible posterior leukoencephalopathy syndrome, is characterized by various clinical symptoms, such as generalized tonic-clonic seizures, partial seizures, status epilepticus, headache, encephalopathy, altered mental status, and visual loss.1-4 PRES is usually associated with acute hypertension and impaired renal function and is characterized by seizures, altered mental status, and loss of vision. This syndrome is often associated with acute hypertension, which is commonly caused by acute kidney injury or eclampsia.5,6 Although the exact pathophysiological mechanism of PRES remains unclear in most patients, this condition is accompanied by impaired renal function in the form of either chronic or acute kidney injury. Fugate et al.6 reported that 38% of patients with PRES exhibit chronic kidney disease and that more than half exhibit chronic hypertension. Studies have demonstrated that acute pancreatitis may cause PRES.7,8 PRES should be considered a potential differential patient diagnosis. CT imaging could be used for the assessment of arterial ischemia, thrombosis or venous sinus thrombosis in acute settings, but normal CT imaging cannot provide conclusive evidence.9 MRI is considered the gold standard in PRES diagnosis because T2-weighted imaging can clearly reveal hyperintensity.9 According to a systematic review, prompt recognition and treatment can usually resolve the clinical syndrome within a week.

The patient in our study presented to the ED several times because of abdominal pain; however, a new symptom of epilepsy was evident in the present case. Our analysis indicates that abdominal pain and hypertension in the patient were related to renal dissection, which induced PRES. With earlier detection of the correlation between abdominal pain and hypertension and prompt treatment, the new epilepsy incident could have been avoided.