Vasogenic edema in a patient with sickle cell disease.

A 5-8% of patients with sickle cell disease (SCD) develop symptoms of cerebral disease.1 Stroke and cerebral thrombo-embolism are commonly seen while sinus thrombosis occurs rarely.1 These complications have been attributed to the increase in blood flow and viscosity. Vasogenic edema, an increase in the blood brain barrier (BBB) vascular permeability, which contributes to brain tissue damage is rarely reported among patients with SCD.2 A 26-year-old Saudi gentleman with SCD was admitted with generalized bone pain, fever, chills, vomiting, shortness of breath, and impaired level of consciousness. Medical history was significant for recurrent episodes of acute chest syndrome and right hip replacement for avascular necrosis. On examination, he was conscious but drowsy. Blood pressure was 120/72 mm Hg, heart rate 92 bpm, respiratory rate 24 breaths per minute, and temperature 370C. He had severe scleral icterus, bilateral inspiratory crackles on lung examination, heart and the rest of neurological examination were normal. Initial pulse oximeter reading was 60% on room air, and 92% on 100% oxygen. Significant laboratory results were as follows: white blood cell 32.7 x 106/μL, hemoglobin 6.7 g/dL, hematocrit 17.7%, reticulocyte count 5.3% (normal: 0.2-2%), serum urea was 7.4 μmol/L (normal: 62-115 μmol/L), and creatinine was 178 mmol/L (normal: 2.5-6.5 mmol/L), total bilirubin 107 mmol/L (normal: 2-17 mmol/L), direct bilirubin 51 mmol/L (normal: 0-4.5 mmol/L), aspartate amino transferase 183 U/L (normal: 12-37 U/L), and lactate dehydrogenase 1002 U/L (normal: 100-190 U/L). Chest x-ray showed bilateral extensive alveolar infiltrates. While in the emergency room, his level of consciousness deteriorated (Glasgow coma scale of 7), and he became hypoxemic and hypotensive, subsequently he was intubated. Vasopressors were given, and he was transferred to the Medical Intensive Care Unit (MICU). Simple transfusions followed by exchange transfusions were instituted. Hemoglobin fractionation prior to exchange transfusion revealed an HbS of 73%, which was reduced to 38% after therapy. Cardiac vegetations and intramural thrombus were ruled out by transesophageal echocardiography, and fat embolism was ruled out by bronchoalveolar lavage, urine, and retinal examination. The CSF analysis was unremarkable with normal opening pressure. On day 2, his renal functions deteriorated and continuous renal replacement therapy was started. Brain CT scan showed multifocal patchy hypodense areas in subcortical aspects of both hemispheres and the left basal ganglia. Brain MRI showed large patchy confluent lesions of high signal intensity on T2WI and FLAIR sequences predominantly scattered at the subcortical white matter of both cerebral hemispheres with no enhancement suggestive of vasogenic edema. Multiple foci of hemorrhages were noted within the lesion in the left fronto-parietal region (Figure 1). The magnetic resonance angiography as well as magnetic resonance venogram were normal. An EEG revealed a marked diffuse slow wave abnormality without epileptiform discharges. He was treated with broad-spectrum antibiotics, systemic steroids, and was started on prophylactic unfractionated heparin. His hemodynamics and renal functions returned to normal. He underwent tracheostomy and was successfully weaned-off from the ventilator 2 weeks later and was transferred from the MICU. Repeat MRI 4 weeks later upon discharge showed marked resolution of his brain edema. Symptoms and signs that were seen in our patient were not specific. At his initial presentation, our patient showed evidence of increased intra-cranial pressure, headache, visual disturbance, altered alertness, and behavioral changes. His hospital course was complicated by sepsis and multiple organ dysfunction syndrome. The distribution of his MRI abnormalities was suggestive of vasogenic edema involving the white matter, which was reversible in subsequent MRI. Vasogenic edema in general involves white matter more than the grey matter probably due to lower resistance to flow.2 Foci of hemorrhages were seen in our patient only at the posteroparietal region, which Clinical Notes