Volume matters: the influence of different botulinum toxin-A dilutions for sialorrhea in amyotrophic lateral sclerosis.

INTRODUCTION: We aimed to determine the effect of different botulinum toxin-A (BTX-A) dilutions on the treatment efficacy and side effects for amyotrophic lateral sclerosis (ALS) related sialorrhea.

METHODS: Ten patients were enrolled in the study. BTX-A dilution for Group A was 100 U in 1 ml of saline, whereas the dilution for Group B was 100 U in 2 ml of saline. Both groups received 20 U of BTX-A in each parotid gland, and assessments were made by means of the Drooling Impact Scale, items 1 and 3 of the ALS functional rating scale, and visual analog scales for drooling and swallowing function.

RESULTS: Although both groups exhibited a similar improvement in drooling, Group B had a mild but significant deterioration in bulbar function that was not evident in Group A.

CONCLUSIONS: These results suggest that BTX-A has a safer profile when reconstituted with 1 ml instead of 2 ml of saline.