Neuropathy & CNS Demyelination

05 November 2004

 Clinically rare occurrence

Many case report & small case series

Attributed to avitaminosis, compression,  malnutrition, cytotoxic drugs.

Hasson et al, 1958: 12/20  autopsied MS cases showed demyelination in peripheral nerves.

Pollock et al, 1977: 8/10 MS patients with no clinical evidence of peripheral neuropathy. Sural nerve bx showed 50% reduction in myelin thickness.

Lassman et al, 1981: acute MS with no clinical evidence of PN except slight decrease in NCV & prolonged distal latency in peroneal n. Autopsy confirmed central demyelination as well as widespread demyelination & inflammatory cells in nerve roots.

Thomas, 1987: 6 cases of chronic demyelinating polyneuropathy (bx confirmed) with CDMS.

Sarova-Pinhas, 1995:  Electrophysiologic abnormalities of >2 nerves in 45.5% MS patients with sensory complaints (n=22). No correlation with age, disease duration, disease course, neurologic disability.

Peripheral nerve abnormalities

Demyelination/ remyelination with onion bulb formation

Occasionally inflammatory infiltrates

Drulovic et al, 1998: 2 MS patients with tomaculous neuropathy (histopath) but PMP22 deletion not tested.

Animal model

Bovine P2 inoculation lead to EAN in rat, EAE in guinea pig, both EAN & EAE in rat & guinea pig but not rabbit.

Chronic & recurrent antigenic stimuli leads to onion bulb formation.

Onion bulb formation is PNS analog of CNS plaque.

Difficulties with interpreting case reports / series:

Leukodystrophies not excluded: MLD, Krabbe’s disease or adrenoleucodystrophy except Thomas’ paper.

GM1 antibodies in 25% of MS patients, but low titres.

Treatment:

Case reports /series report some success with:

Oral & iv steroids +/- azathioprine, ACTH.

No mention of intragam / PE.