Subjects treated with botulinum toxin A had greater improvement in the principal target of treatment at weeks 4 , 6 , 8 , and 12 ( P < 0.001 , P < 0.001 , P = 0.03 , and P = 0.02 , respectively ) ; at week 6 , 40 of the 64 subjects in the botulinum-toxin group ( 62 percent ) , as compared with 17 of the 62 in the placebo group ( 27 percent ) , reported improvement of at least one point on the Disability Assessment Scale in the principal target of treatment ( P < 0.001 ) .
