Posterior Reversible Encephalopathy Syndrome in a Uremic Woman Without Hypertension: A Case Report
1 Department of Medical Education, National Taiwan University Hospital , Taipei, Taiwan
2 Department of Neurology, Yuanlin Christian Hospital, Changhua, Taiwan
A 72-year-old woman with end-stage renal disease presented to our ward due to right hemiparesis and aphasia had developed for days. In addition, status epilepticus was noted in emergency room and was alleviated after receiving depakine. She was afebrile with a regular heart rate and rhythm. Systolic blood pressures ranged from 120-142mmHg, with diastolic blood pressure ranging from 54-72mmHg. During hospitalization, T2-weighted magnetic resonance imaging (MRI) revealed extensive asymmetrical confluent abnormal patchy high signal intensity lesions over bilateral basal ganglia, bilateral thalami and bilateral fronto-temporo-parietal and occipital lobes subcortical and periventricular white matters. These findings were consistent with posterior reversible encephalopathy syndrome (PRES). CSF study was non-contributory, and electrolyte levels were within normal limits. We prescribed dexamethasone 5 mg Q8H for vasogenic edema. The patient received hemodialysis twice every week previously, but the Hickman cath occluded recently. We implanted a new one smoothly on the 5th day of admission. She became well-oriented after these procedures. 9 days later, follow-up brain MRI revealed residual asymmetrical confluent abnormal patchy lesions over bilateral frontoparietal and Rt posterior temporal lobes. The basal ganglia and bilateral thalami lesions showed almost complete regression. She had no further seizure episodes during 2 months follow-up.
PRES is a clinical syndrome consists of headache, visual changes, generalized seizure and altered mental status. It is frequently associated with hypertension, sepsis, autoimmune disorders, or renal failure. Corticosteroids may improve vasogenic edema, but there is no solid evidence for usage in PRES. Despite PRES being associated with hypertensive crisis, approximately 15 to 20 percent of patients can be normotensive or hypotensive during initial evaluation, as our patient presented. This finding suggests that the mechanism is not completely explained by defects in auto-regulation of the cerebral vasculature. Further investigations will be necessary to bring clarity and confirm the mechanism.