Acute Tumefactive Inflammatory Demyelination in a Child

Abstract

During the course of an afternoon, a previously healthy 6-year-old boy became irritable and complained of rightsided headache. The next day, he developed left facial droop, and 3 days later, left arm and leg weakness. An examination revealed a left lower facial droop, grade 4/5 left arm and leg power, and a left extensor plantar response. Basic laboratory investigations, including cerebrospinal fluid studies, were unremarkable. Initial head computed tomography revealed a right frontoparietal hypodense lesion, surrounded by vasogenic edema with subfalcine herniation. Cranial magnetic resonance imaging the next day (Fig 1A,B) demonstrated a large right, frontal hyperintense lesion and a small hyperintensity in the right occipital lobe, both enhancing on postgadolinium T1 imaging. Spinal cord magnetic resonance imaging produced normal results. High dose dexamethasone was initiated. Given the diagnostic uncertainty and the importance of an accurate diagnosis to guide treatment, a brain biopsy was performed. The biopsy (Fig 1C-F) revealed inflammatory demyelination. No pathologic evidence of malignancy was observed, and the evaluations for viral, fungal, and bacterial infection produced negative results. The diagnosis was consistent with acute tumefactive inflammatory demyelination. The dexamethasonewas gradually withdrawn. A further neurologic examination produced normal results after 1 month. Magnetic resonance imaging demonstrated gradual improvement over time (Fig 1G,H).