A 17-year-old previously healthy girl had progressively worsening episodic pulsative headaches with vomiting over 1 week. Magnetic resonance imaging examination revealed the presence of an expansive left thalamic lesion (Figure 1A and B), while magnetic resonance spectroscopy detected decreased choline to creatine ratio (0.47) within the lesion, suggesting noninflammatory and non-neoplastic nature accompanied by increased lactate peak, consistent with the presence of anaerobic glycolisis (Figure 1C). T1-weighted images showed the presence of thrombus within the straight sinus and internal cerebral vein (Figure 1D). Results from additional tests revealed the presence of coagulopathy, consistent with antiphospholipid syndrome. The patient was not taking oral contraceptives. Administered anticoagulant treatment was associated with marked regression of the left thalamic venous infarct volume 12 days after initial magnetic resonance study (Figure 2). The patient was discharged with complete regression of symptoms and no abnormalities on neurologic examination.