Table 2.

Results of trapezius thickness from ultrasonography before and after treatment with onabotulinum toxin A

Time of evaluation of onabotulinum toxin A				Mean difference (95% CI)	P value
Time	Mean ± SD	Time	Mean ± SD
Baseline	9.66 ± 2.07
		60 days	7.35 ± 1.11	2.31 (1.56 to 3.06)	<0.001
		12 months	9.62 ± 1.97	0.04 (−0.10 to 0.1)	0.585
60 days	7.35 ± 1.11
		Baseline	9.66 ± 2.07
		12 months	9.62 ± 1.97	−2.27 (−2.99 to −1.56)	<0.001