Most changes involved therapy, mainly the initiation of new therapy. Additionally, following investigation with DaTSCAN a change in diagnosis was observed in just over half of all patients. Other relevant impacts were the shortening or lengthening visit intervals during follow-up and the withholding of a challenge test with either levadopa or apomorphine,[2] both of which have economic implications in addition to potential patient benefits.

In another study of 150 patients with a normal DaTSCAN image, of which 36 were on anti-Parkinson's medication, a normal DaTSCAN result permitted cessation of medication in 27 patients, 92% of which experienced no subsequent deterioration.[3]

Both these studies give added emphasis to the recommendation made by the UK's Parkinson's Disease Consensus Working Group that states "treatment should, if possible, be deferred until the putative diagnosis has been confirmed".[4]