Acute Effects of Preladenant (SCH 420814) on Dyskinesia and Parkinsonism in Levodopa Treated Participants (P05550)

Dyskinesia was scored on a scale of 0 (absent), 1 (mild) , 2 (moderate), 3 (severe) and 4 (incapacitating) for seven body parts (face, neck, trunk, each arm and each leg) based on the worse dyskinesia noted during the entire measurement time. Scores were assessed at Hours 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0 and 8.0. The dyskinesia score was the sum of the scores for the seven body parts. The peak dyskinesia score was recorded for each participant regardless of what timepoint the score was achieved. The total possible score for an individual at each timepoint could range from 0 to 28 with higher scores indicating greater effects of the dyskinesia. The mean peak dyskinesia score was calculated using the individual peak values.

Tapping was measured with two manual counters with keys that were depressed to register a count. The participant alternately tapped each counter using the index finger of the more affected hand for 60 seconds and was not allowed to use more than one finger to tap. The participant was instructed to tap as rapidly as possible while being timed for 60 seconds. The counts were recorded for the two counters at Hours 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0 and 8.0. The peak tapping score was recorded for each participant regardless of what timepoint the score was achieved. The mean peak finger tapping score was calculated using the individual peak values.

Tremor was scored on a scale of 0 (absent), 1 (mild, 2 (moderate), 3 (severe) and 4 (incapacitating) for seven body parts (face, neck, trunk, each arm and each leg) based on the worse tremor observed during the time spent with participant while taking other study measurements(vital signs, drawing samples, performing the tapping and walking tasks). Scores were assessed at Hours 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0 and 8.0. The tremor score was the sum of scores for seven body parts. The peak tremor score was recorded for each participant regardless of what timepoint the score was achieved. The total possible score for an individual at each timepoint could range from 0 to 28 with higher scores indicating more effects of the tremors. The mean peak tremor score was calculated using the individual peak values.

Walking speed assessment began with the participant being seated in an armless chair. Then while being timed, the participant stood up with their arms crossed on their chest and walked 6 meters, turned around, returned to the chair and sat. Timing was stopped when the participant's buttocks hit the chair and the total time was recorded. If the participant could not arise in 60 seconds, 60 seconds was entered in this line of the report form and the participant was tested again but allowed to push off to get out of the chair. Sixty seconds was the maximum time allowed to complete the walking assessment, thus 60 seconds was recorded as the time if they could not complete the task within this time limit. Walking speed was assessed at Hours 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7.0 and 8. The peak walking speed was recorded for each participant regardless of what timepoint the score was achieved. The mean peak walking speed was calculated using the individual peak values.