Neuromuscular

CMT 1A

Muscle
Nerve
  Schwann cells

Nerve


Toluidine blue
Onion Bulbs
  Some contain myelinated axons; Others are empty
  Myelin sheaths: Thick; Normal or Thin
  Contain abundant non-myelinating Schwann cells

Toluidine blue

Axons
  Reduced numbers: Large & Small
  Some onion bulbs have no axons
  Some small axons are present in layers within & around onion bulbs

SMI31: Neurofilament

SMI31: Neurofilament

SMI31: Neurofilament

Schwann cells in Onion bulbs

Contain: NCAM & P0 protein


NCAM
Non-myelinating Schwann cells: In layers within onion bulbs

NCAM

Schwann cells in Onion bulbs also contain P0 protein

Neurofilament (Green) & P0 (Red) stains

CMT 1A: Muscle

Fiber size
  Large fibers: Hypertrophied
  Small fibers: Very small; Grouped; Some pyknotic nuclear clumps

H&E

H&E
Grouped atrophy
Perimysium: Replaced by fat

Congo red

Small muscle fibers: Dark on NADH stain

NADH

Fiber types
  Large fibers: Type grouping
  Small fibers: Grouped; Type 2

ATPase pH 4.3

Chronic changes: Perimysium is replaced by fat

Sudan black

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1/18/2017