<qa>  What is the effect of botulinum toxin usually outlasts the weakness itDystonic spasms are intriguing in that they may be suppressed or triggered by sensory input such as postural change, tactile stimuli, alternative movements or even thought processes 9. Studies are revealing that the involuntary muscle spasms may be due, at least in part, to abnormal sensory processing of spindle afferent information 10-12. This may help explain the nature of these sensory tricks as well as why the effect of treatment using botulinum toxin usually outlasts the weakness it creates. 