Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) diagnosis is mainly based on the clinical examination and the electromyogram. CIDP is sometimes confused with another demyelinating neuropathy, type 1 Charcot-Marie-Tooth disease. In an article from June 2021, French, Belgian and Swiss neurologists thus identified 35 CMT patients in a cohort of 1,104 CIDP patients, or 3.2%.
Their genetic analysis showed abnormalities in the PMP22 genes (34% of CMT patients), MPZ (31%) and 10 other genes known to be responsible for CMT.
By comparing the 35 patients with CMT to 35 other patients in the cohort, with CIDP:
- CMT starts earlier (39 years on average versus 56 years for IPDC),
- motor weakness is present in 80% of patients with CMT at the time of diagnosis (compared to 29% of patients with CIDP)
- MRI imaging of the brachial plexus is normal in 70% of patients with CMT (versus 40% of patients with CIDP)
- patients with CMT respond less well to treatment with immunosuppressants.
The authors recommend performing genetic analyzes for CMT in anyone suspected of having CIDP, a strategy that is less expensive than mistakenly treating patients with CMT with immunosuppressive therapies (4.6M € vs 2.7M €).
On the same topic: Although rare, border forms between CIDP and CMT also exist in children.
