Among the aetiologies of child and adult polyneuropathy, a distinction can be made between acquired and hereditary causes. Guillain–Barré syndrome (GBS) and chronic demyelinating inflammatory polyneuropathy (CIDP) are the most common acquired causes of this group of diseases, whereas Charcot-Marie-Tooth disease is the archetypal genetic cause. The latter is characterised by significant clinical and genetic heterogeneity (almost 100 different genes are responsible for this condition). In clinical practice, especially if it involves sporadic cases without identifiable relatives with the condition, it is sometimes difficult to distinguish between the two aetiologies, which has an impact on therapeutic decision-making (since the inflammatory causes are potentially treatable with a treatment that is generally effective).
In an article published in February 2021, German researchers reported their experience in the use of volumetric muscle imaging of the lower limbs as a discriminating diagnostic method. Thirteen patients with CMT, 27 with the classic form of CIDP and 17 with another form of neuropathy, all underwent an MRI examination using a 1.5 Tesla Magnetic Resonance Imaging Scanner, with image acquisition and interpretation using semi-automatic processing. Muscle volume was shown to correlate well with residual muscle strength in foot dorsiflexion, and with CMT functional score. In CIDP, the muscles were distinctly less atrophied compared to the CMT cases. The authors also showed that muscle volume could vary after a one-year interval, emphasising the usefulness of this method in patient follow-up.