Neuropathic disorders Each of these biopsies is from a patient with a neuropathy. Amyotrophic lateral sclerosis often produces multiple small regions of grouped atrophy without fiber type grouping.
Targets occur with subacute denervation, probably with some reinnervation.
They are especially coimmon in the gastrocnemius muscle. Large grouped atrophy with large fibers predominantly type 1 and small fibers of mixed type or predominantly type 2 is characteristic of Spinal muscular atrophy .