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.
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.
Case reports /series report some success with:
Oral & iv steroids +/- azathioprine, ACTH.
No mention of intragam / PE.