%0 Journal Article
%T Quantitative sudomotor test helps differentiate transthyretin familial amyloid polyneuropathy from chronic inflammatory demyelinating polyneuropathy.
%A Fortanier E
%A Delmont E
%A Verschueren A
%A Attarian S
%J Clin Neurophysiol
%V 131
%N 5
%D 05 2020
%M 32217467
%F 4.861
%R 10.1016/j.clinph.2020.01.022
%X Transthyretin familial amyloid polyneuropathy (TTR-FAP) is an aggressive hereditary neuropathy characterized by sensory and autonomic dysfunction. There are numerous reports of TTR-FAP misdiagnosed and treated as chronic inflammatory demyelinating polyneuropathy (CIDP), leading to delayed diagnosis, risk of iatrogenic adverse events and increased socio-economic costs. Quantitative sudomotor function measured by electrochemical skin conductance (ESC) appears to be a sensitive test in TTR-FAP. We aimed to evaluate the performance of ESC in differentiating TTR-FAP from CIDP.<BR>Thirty-eight patients with genetically confirmed hereditary TTR amyloidosis and 26 with definite CIDP according to the EFNS/PNS guidelines and negative TTR-FAP genetic testing were involved in this study. We compared the ESC for feet and hands measured by Sudoscan for each patient.<BR>ESC (µS) was significantly lower in TTR-FAP for both hands (72 vs 45, p < 0.0001) and feet (77 vs 35, p < 0.0001). Feet ESC < 64 µS had a 89% sensitivity and a 96% specificity to differentiate between CIDP and TTR-FAP.<BR>Sudoscan is a fast, non-invasive and easy to perform test, able to distinguish CIDP and TTR-FAP patients with good sensitivity and specificity.<BR>Sudoscan can be helpful in distinguishing between CIDP and TTR-FAP.