An Uncommon Cause Of Altered Mental Status In A Patient With Systemic Lupus Erythematosus

Introduction: Altered mental status is one of the most common presentations that leads to an admission to intensive care unit. Posterior reversible encephalopathy syndrome (PRES), which is commonly encountered in association with various medical conditions, is an uncommon but probably under-diagnosed cause of this presentation. Case report: A 51-year-old woman was admitted to our ICU because of alteration of consciousness. She was in her usual state of health the night before although she complained of a mild headache. She became unarousable on the following morning and her husband immediately brought her to our institution. She had a significant history of SLE that was diagnosed five years ago with malar rash, photosensitivity rash, polyarthritis, positive ANA and anti-smith antibody. Her only current medication was hydroxychloroquine. Upon admission, she was found to be hypertensive with BP of 170/90 mmHg. Neurological examination was remarkable for GCS of five without any focal neurological deficit. Laboratory investigations were remarkable for an elevation of creatinine (2.4 mg/dL from baseline of 1.0 mg/dL) and an abnormal urinalysis with numerous dysmorphic RBCs and WBCs. CT brain demonstrated ill-defined hypodensity in the subcortical white matter of both posterior parietal lobes. A subsequent MRI brain revealed T2 hyper-intense signal in cortex and subcortical white matter of the same lobes (Figure). She was diagnosed with PRES and was immediately treated with intravenous labetalol. Her BP gradually came down to normal range and her mental status gradually improved as she became completely alert and oriented on the fourth day of admission. She underwent renal biopsy during this admission which revealed type IV lupus nephritis. Treatment with steroid and cyclophosphamide was initiated. Comment: Patient with PRES usually presents with headache, seizure, nausea, confusion or coma in a more severe case. A broad range of medical conditions, including hypertension, eclampsia, use of immunosuppressive agent, and autoimmune disorders has been implicated as causes of this syndrome. Neuroimaging is crucial to the diagnosis. Typical findings include symmetrical edema of white matter predominantly in the parieto-occipital lobes. These abnormalities are best depicted by MRI (hyper-intense signal on T2 and FLAIR technique). Prognosis is favorable as the neurological deficit is usually reversible in days to weeks after blood pressure control, as seen in this patient. However, delay in initiating the appropriate treatment can lead to a permanent neurological damage. Thus, physician should have a high index of suspicion for this syndrome especially in patients with known associated illnesses.

Duke Scholars

Author Narat Srivali Medicine, Pulmonary, Allergy, and Critical Care Medicine