Neuromuscular

CHRONIC INACTIVE DENERVATION WITH REINNERVATION

Muscle Fiber Type Grouping

Associated with: Axon regeneration


 

ATPase pH 9.4 stain

ATPase pH 9.4 stain

ATPase pH 9.4 stain

Normal: "Checkerboard"
pattern of type I (Light)
and II (Dark) fibers.
Chronic denervation:
  Type I and type II muscle fibers are clustered in groups.
  Type II fibers in this biopsy are mostly type IIB (ATPase pH 4.6 stain, below right).

ATPase pH 4.3 stain

ATPase pH 4.6 stain

Fiber type grouping: Incomplete fiber type switching (Varied fiber types in a single group)

ATPase pH 4.3 stain

Axon Loss


Toluidine blue stained plastic section

Nerve: Chronic Inactive Axon Loss (Denervation)
  • Nerve has reduced number of large and small axons.
  • Most large and small axons have nearly normal myelin thickness.
  • There are few thinly myelinated, regenerating axons.

Also see: Ongoing or Active Denervation

Return to Neuromuscular Syndromes

7/21/2014