Serial brain magnetic resonance imaging (MRI) scans obtained during the course of the patient's illness. (A) Day 2: T2-weighted MRI scan demonstrates markedly enlarged caudate nuclei (arrows) and increased intensity in the thalami (arrowheads). (B) Eleven days after his initial presentation the abnormalities were resolving (arrows and arrowheads). Of note, the lenticular nucleus was involved (asterisk). (C) Three weeks and (D) two months after his initial presentation the abnormalities continued to improve, but had not resolved completely (arrows, arrowheads). Incidental hypertensive hemorrhage was present (black arrowhead in Figure 1C).