Effective and efficient diagnosis of parkinsonism: the role of dopamine transporter SPECT imaging with ioflupane I-123 injection (DaTscan™).

Parkinson's disease (PD), the second-most common neurodegenerative disease, is characterized by motor and nonmotor symptoms. PD is often misdiagnosed; inappropriate treatment due to misdiagnosis has undesired consequences, as does delayed diagnosis. Unfortunately, most people with PD receive a diagnosis only after motor symptoms have emerged, by which time 40% to 60% of dopamine neurons have already been lost.