A previously healthy 40-year-old woman presented with subacute onset of a left homonymous hemianopia. Contrast-enhanced magnetic resonance imaging of the brain revealed a T2-hyperintense lesion in the right thalamus, with associated subtle gadolinium enhancement (Figure 1), and a small periventricular lesion. Although her visual symptoms were improving, a new left-sided hemiparesis developed 3 weeks later. Additional magnetic resonance imaging of the brain showed extension of the original thalamic lesion into the right internal capsule, with persistent contrast enhancement. Her visual and motor symptoms gradually improved over 3 months.