Compared with placebo , the Trail Making Test Part B score was improved between baseline and 26 weeks in the PBT2 250 mg group ( 1765 s , 065-3465 ; p = 0042 ) but not in the 100 mg group ( 079 s improvement , -1575 to 1732 ; p = 0925 ) ; neither dose significantly improved cognition on the other tests .