A question about small fiber neuropathy associated with Vasculitis?
 

I'm terribly confused just now. After a bout of influenza A and a chest infection my small fiber neuropathy symptoms have progressed as far as the top of my thighs - giving a prickly wet sensation from my ankles up to just beneath my groin. I have awful throb in feet, inner ankles and up through my shins into my knees and similar in hands, wrists and around my elbows into my upper arms and shoulders.

Alongside this I'm having a worsening of vestibular issues (dizziness), an unpleasant ache in my jaw and ears and on the bridge of my nose. I haven't had a nose bleed or sores for a few weeks but I have spells of these and I have completely lost my sense of taste and smell.

Someone who really knows their stuff has suggested that I might have Wegener's Granulamatosis - a type of Vasculitis. I don't see much on this site about Vasculitis induced peripheral neuropathy? Is it different in the way it manifests itself to other forms? Is it progressive usually or is it typically milder can anyone tell me?

I don't have skin involvement or kidney problems and my rheumatologist seems content to accept the SFN as part of my RA. But I'm not so sure because of the systemic problems but lack of joint swelling. I'm due to start Imuran next week as long as my chest X-ray is clear and my white blood cells are normal. I'm really hoping it helps the small fiber neuropathy and the ENT issues too - regardless of whether they are part of my RA or of a vascular disease process. It would be good to learn more from anyone who suffers from SFN as part of a Vasculitis disease. Mat

There is considerable overlap--
 

--in possible symptomatolgy in the vascultic/connective tissue anti-nuclear antibody variant autoimmune conditions (just one of the reasons they are hard to diagnose, and why sometimes people are put in that catchall "unspecified connective tissue disease" category). And, of course, within a given condition, different organ systems/tissues may be targeted to greater/lesser extent.

All of them, however, can have neuropathy as a secondaryeffect, and these are usually through ischemic mechanisms or compressive effects from swelling/inflammation (rather than through autoimmune cross-reactivity, though that is a possibility).

See:

http://www.hopkinsmedicine.org/neuro...europathy.html

http://neuromuscular.wustl.edu/antib...tml#vasculitis

Thanks - I'm so glad I asked this question here now because these links are invaluable. However - in non scientist layman's terms can you tell me whether this means that the types of secondary neuropathies which often go with vascular and connective tissue diseases are less likely to progress over time? Presumably when the neuropathy is triggered by the inflammatory process then dampening down the immune system might work? - although my rheumatologist warned that in the context of medicine sense/ logic doesn't always prevail.

I feel mine is progressing in that it seems the length dependency is growing but the severity or level of numbness/ intensity of pain has not really altered much in two years that I've suffered it. Some days are worse than others but my main observation is that it seems to be spreading rather than intensifying. Presumably if it was a primary immune mediated neuropathy such as Guillaine Barrre or CIDP then it would be likely to cause demynalation whereas vasculitic neuropathy shouldn't - in theory anyway?

Vasculitic associated neuropathy--
 

--does tend to be more axonal than demyelinating due to the mechanisms involved, though one can get secondary demyelination if the axon frays.

In general, it's much easier to repair myelin on nerves than the underlying axon, provided whatever is causing damage abates. So axonal repair takes a long time. It's been estimated that under optimal conditions axons can grow at a rate of about a millimeter each day, but that means for long axon branches repair can take months to years, and there will probably be some odd sensations along the way as the fibers have to fight their ways through and around other tissue. Very often such repair is patchy and incomplete, and the nerves regrow in rather different pathways than they originally were.

I would think that with vasculitis if the damage to the blood vessels can be controlled, and the swelling and inflammation reduced, that would give the nerves chances to regenerate. But given the "flare", "relapse-remit" nature of a lot of these conditions, nascent repair might be setback during the next flare, and the process might need to start over again. I'm not surprised that you're reporting a slow spread of symptoms even if their severity over time does not differ that much; that would be expected with a slowly spreading/progressing vasculitic condition. The key would be to get the autoimmune process and attack on tissue as controlled as possible.

I have a friend with Bechet's (one of these conditions) that reports his neuropathy seems to get a little better from time to time, then relapses when he flares, particularly in those areas of the body in which he gets swelling. It's very much a pattern and seems to be related to his fluctuating steroid dosing (that is used to help keep the Bechet's in check).