Axonal swellings

AXONAL SWELLINGS

Giant axonal neuropathy
Polyglucosan bodies

Most commonly found with increasing age and diabetes.
Also occur in toxic neuropathies
- Carbon disulfide; DMAPN; N-hexane; Methyl N-butyl ketone; Disulfiram; Acrylamide
CNS disorders with axonal swellings
- Giant axonal neuropathy; Vitamin E deficiency; Neuroaxonal dystrophy; Polyglucosan body disease
May be composed of neurofilaments or axonal organelles.
Swellings in proximal motor axons are found in ALS & IDPN toxicity.

Giant Axonal Neuropathy

From Pr P Landrieu

Many enlarged thinly myelinated, or unmyelinated, axons.
Reduced number of myelinated axons.

From Pr P Landrieu

Enlarged unmyelinated, or thinly myelinated, axons.

From Pr P Landrieu

Teased axons with focal swellings (Arrows).

From T Mozaffar

Long curly eyelashes; Curled scalp hair

Polyglucosan Bodies

Staining properties
- H&E: Basophilic
- Toluidine blue: Metachromatic
- PAS: Positive
- Other postive stains: Iodine; Silver; Alcian blue
Electron microscopy
- Consist of randomly arranged granules & branched filaments
- No limiting membrane
Location
- PNS: Within myelinated axons
- CNS: Corpora amylacea; Lafora bodies; Bielchowsky bodies
Associations
- Normal aging
- Intramuscular nerves
- Adult polyglucosan disease
- Lafora body disease
- Type IV glycogenosis

VvG stains: Longitudinal section (Left); Cross section (Right)

Swellings (focal) in intramuscular terminal axons

PAS stain

Polyglucosan bodies in intramuscular nerve

H&E stain

VvG stain

PAS stain

Toluidine blue stain

Ultrastructure: From Robert Schmidt

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2/9/2007