Rhomboencephalitis due to cocaine-induced bony erosion of skull base

Sagittal T2 (A), axial T2 fluid-attenuated inversion recovery (B), and sagittal T1 with contrast MRI (C) show a large bony defect in the skull base with erosion of the sphenoid sinus walls and perforated nasal septum. There is abnormal T2 hyperintensity and enhancement in the brainstem with clival erosion (arrow where most severe) and marrow enhancement.

Axial T2 fluid-attenuated inversion recovery MRI of the brain demonstrates decreased T2 fluid-attenuated inversion recovery hyperintensity in the medulla following 6 weeks of IV antibiotics.