The muscular process is the insertion point of the posterior and lateral cricoarytenoid muscles.
13) As has been shown in glycogen depletion studies, diffusion of botulinum toxin from an injected thyroarytenoid muscle into the adjacent lateral cricoarytenoid muscle may also contribute to the arrest of adduction.
6,9,12,13) A typical finding is symmetric high uptake at the muscle origin and insertion of the arytenoid cartilage, posterior cricoarytenoid muscles
, and some less intense uptake along the course of thyroarytenoid and vocalis muscle (11) (Figure 1).
7] This is in contrast to other evidence that suggests that fast-twitch fibers in the thyroarytenoid and lateral cricoarytenoid muscles
are reinnervated more rapidly and to a greater degree than slow-twitch fibers.