In 2009 a supposedly definitive list for qualifying for CIDP was produced (by statisticians and leading Neurologists in the US). The simplified version is:
Patients with symptoms for over 8 weeks would be classed as CIDP if:
- No genetic abnormality
- No other substances introduced for other issues
AND EITHER
- 75% of nerve tests had a response with over 50% of these showing an issue
OR
- Symmetric weakness in all four limbs and weakness in at least one of the hips and shoulders
However these are not seen as relevant by the majority of NEUROLOGISTS!
Treatments
The only treatments that are proven (clinically in a randomised control trial - RCT) to work on CIDP are:- Prednisone (Steroids) - 40 to 95% of patients respond positively, after 2 months of usage is the peak benefit. There is a 30% chance of remission.
- Plasma Exchange - similar responses to Steroids - the main issue is access (thus not the first line therapy)
- IVIG - much later process, though the initial trials were much shorter - 6 weeks. Around 40-50% respond. Later trials showed similar numbers made an improvement (on arms and legs) at 47.5%, though in the same trials 22.5% who had placebo improved which means you get better anyway. But they still don't know how it works!
Dr Barohn states his recommended 1st line treatments are Prednisone or IVIG and if they do not respond then switch to the other (say after a couple of months). Roughly 50% respond to the first and 50% respond to the second, so 75% overall. If they are already in the hospital then Plasma is a much easier option as this makes it much easier to administer.
Other potential treatments mentioned (copyright names in brackets):
- Mycophenolate (Cellcept) - Not proven
- Interferon (Avonex) - trials negative
- Etanercept (Enbrel) - not proven
- Rituximab (Rituxan) - not impressed in neuropahy, not seen much response
- Alemtuzumab (Campath) - too toxic!
SubCutaneous IVIG (SCIG) - new development of IVIG trials being run now.
Improvements are seen first in the muscles nearer to the core (hips, shoulders) before the ones further away (feet, fingers).
CIDP Prognosis
In 1975 (P J Dyck) created a set of stats and this was reviewed in 2007:1975 2007
Mortality: 11% 3.1%
Working with Disability: 60% 63%
Not Working: 8%
Wheelchair bound: 28% 7%
Recovered: 4% 31.1% (however with treatment)
Aids to Walk: 28%
CIDP Caveats
- Don't undertreat (IVIG especially - min 2 to 3 months)
- Don't overtreat (Steroids really nasty side effects)
- Don't expect too much from the treatments
- Change treatments if it doesn't work
The likelyhood of patients ever fully recovering is very low, less than 10%. Most people will never recover fully and to tell them so is completely misleading. Strength will be much better - hopefully, but there will be weakness remaining.
