DATSCAN

Differentiate essential tremor from tremor due to a Parkinson Syndrome, including:

1. Idiopathic Parkinson’s disease (PD) 
2. Multiple system atrophy (MSA)
3. Progressive supranuclear palsy (PSP)

Dopaminergic neurodegeneration is seen all the above three disease states. 
DaTscan cannot distinguish between these three conditions.

I-123 ioflupane,  binds with high affinity to the presynaptic dopamine transporter (DaT) protein