A 47-year-old man with major depressive disorder, treated with bupropion XL 450 mg daily, and mild bilateral hand action tremors since his youth, presented with new onset left hand and leg rest tremor. A diagnosis of tremor-dominant young-onset Parkinson's disease was initially made based on his neurological examination, lack of prior exposure to dopamine receptor blockers, and a DaTscan showing dopamine deficiency in the right putamen. Although the unilateral rest tremor responded to a dopamine agonist, the action tremors worsened and he developed problematic impulse control disorders. The first DaTscan was performed after holding bupropion XL for 8 days, as recommended by the manufacturer. After holding bupropion XL for 8 weeks, a second DaTscan performed at the same nuclear medicine center revealed normal striatal dopaminergic activity. A subsequent Syn-One skin biopsy was negative for phosphorylated alpha-synuclein depositions. It was concluded that the initial diagnosis of Parkinson's disease was incorrect, partially based on a false positive DaTscan. 

A medication hold duration of five elimination half-lives (8 days) may be insufficient for avoiding bupropion interference in the accuracy of Ioflupane ¹²³I SPECT scans. A longer hold duration should be considered to ensure an accurate finding of dopamine deficiency.