This 59-year-old right-handed man exhibited unusual behavioral changes. He had been diagnosed with Parkinson disease (PD) four years ago. Since then, he was benefiting motorically from pramipexole, gradually increased to 1 mg three times a day. While he felt there were no problems, his wife reported that over the past year he became more withdrawn. She reported that he no longer played tennis on Saturdays, a lifelong tradition, nor did he ride his motorcycle, which he always loved doing. Previously a very social person, he did not participate in social activities and preferred to stay at home. He was spending most of his time playing games on the computer, most of them for money, something he had never done before. His wife noticed he was now sleeping less as he played until late hours. They could not tell how much money had been spent in these games. He continued to work, but his supervisor noticed a decline in his performance which he attributed to spending a significant amount of time playing on the computer.