Case 271.

History An 11-year-old boy taking oral antibiotics for meningitis diagnosed 3 months earlier presented to the emergency department with a 1-week history of intermittent emesis, dizziness, and vertigo and a 1-day history of wobbly gait and bilateral lower extremity paresthesia without confusion. His metabolic profile was normal. Contrast material-enhanced MRI of the brain was performed, and selected images are shown ( Fig 1 - 4 ). Figure 1a: Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. Axial fluid-attenuated inversion recovery (6000/120) MRI and axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1b: Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. Axial fluid-attenuated inversion recovery (6000/120) MRI and axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1c: Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. Axial fluid-attenuated inversion recovery (6000/120) MRI and axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1d: Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. Axial fluid-attenuated inversion recovery (6000/120) MRI and axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 2a: Axial fast spin-echo T1-weighted MRI (496/8) and axial reconstruction of three-dimensional fast field-echo T1-weighted contrast-enhanced (7 mL of gadobutrol, Gadavist; Bayer Healthcare Pharmaceuticals, Berlin, Germany) MRI (7.98/3.72) of regions similar to those in Figure 1 . Figure 2b: Axial fast spin-echo T1-weighted MRI (496/8) and axial reconstruction of three-dimensional fast field-echo T1-weighted contrast-enhanced (7 mL of gadobutrol, Gadavist; Bayer Healthcare Pharmaceuticals, Berlin, Germany) MRI (7.98/3.72) of regions similar to those in Figure 1 . Figure 3a: Axial diffusion-weighted MRI (3090/71) and axial apparent diffusion coefficient map (3090/71) of regions similar to those in Figure 1 . Figure 3b: Axial diffusion-weighted MRI (3090/71) and axial apparent diffusion coefficient map (3090/71) of regions similar to those in Figure 1 . Figure 4: Three-dimensional maximum intensity projection image (25/3.45) of the posterior cerebral circulation obtained with MR angiography of the head.