Individual time course of pre- and postsynaptic PET imaging may improve differential diagnosis of Parkinson’s disease and multiple system atrophy: a case report

BACKGROUND: Many in vivo studies have shown a difference in pre- and/or postsynaptic imaging between Parkinson’s disease and multiple system atrophy; however, time course differences in pre- and postsynaptic imaging between Parkinson’s disease and multiple system atrophy have not been rigorously investigated. CASE PRESENTATION: We report serial positron emission tomography images of both dopamine transporters and dopamine D(2) receptors, obtained from a Japanese patient with Parkinson’s disease who underwent positron emission tomography scanning at ages 71, 72, 74, and 75 years, and another Japanese patient with multiple system atrophy who underwent positron emission tomography scanning at ages 65, 66, and 67 years. Volumes-of-interest were placed on the striatal subregions. The percentage decreases between the first and last images showed that dopamine transporter availability decreased with disease progression in both patients, but that dopamine D(2) receptor availability decreased only in the patient with multiple system atrophy. A partial correlation analysis between dopamine transporter and dopamine D(2) receptor availability, controlling for the effects of striatal subregional differences, revealed a positive correlation in the patient with multiple system atrophy (r = 0.893, P = 0.0002), but no significant correlation in the patient with Parkinson’s disease (r = −0.036, P = 0.89). CONCLUSIONS: The time course of pre- and postsynaptic imaging can be considerably different between Parkinson’s disease and multiple system atrophy, and may be useful in improving the accuracy of discrimination between Parkinson’s disease and multiple system atrophy.