Neuromuscular

CHRONIC INACTIVE DENERVATION WITH REINNERVATION

Muscle Fiber Type Grouping


ATPase pH 9.4 stain

 Normal: "Checkerboard"
pattern of type I (Light)
and II (Dark) fibers.

ATPase pH 9.4 stain

ATPase pH 9.4 stain
Chronic denervation: Type I and type II muscle fibers are clustered in groups.
Type II fibers in this biopsy are mostly type IIB (pH 4.6, below right).

ATPase pH 4.3 stain
ATPase pH 4.6 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

8/4/2011