PERINEURIAL DISORDERS

• Proliferation: Perineuriosis (Proliferation of perineurial cells in endoneurium)
• Disintegration: Trauma; Leprosy
• Inflammation: Perineuritis; Wallerian degeneration; CIDP; Spanish toxic oil
• Inclusions: Fabry's; Xanthomatous neuropathy

PERINEURITIS

H&E stain	H&E stain
Perineuritis Perineurium (arrow): Rarified & thickened Mononuclear inflammation: Mainly in epineurium Number of axons in endoneurium: Reduced	Another fascicle from same nerve: Perineurium (arrow): Normal staining & thickness There is no inflammation.
Acid phosphatase stain
Confluent red stained cells, probably macrophages, mainly in perineurium.

Toluidine blue stain	Toluidine blue stain
Toluidine blue stained plastic sections Differential fascicular loss (Left): More axons are lost from fascicle on left than on right Perineurium Thickened (Left) Infiltrated by foamy phagocytic cells (Right) Epineurium: Perivascular inflammation