- Extended testing. The first and last gait tests (done before starting iTBS and after the eighth session) require coming off any Parkinson's medication for at least 12 hours before the test. On these test days, subjects also undergo a clinical examination, short neuropsychological test battery, a computer-based reaction time test and depression and quality-of-life rating scales. These procedures are repeated in a follow-up visit 1 month after the last session.