Progressive brachial plexus enlargement in hereditary transthyretin amyloidosis
Alessandro Salvalaggio, Daniele Coraci, Laura Obici, Mario Cacciavillani, Marco Luigetti, Anna Mazzeo, Francesca Pastorelli, Marina Grandis, Tiziana Cavallaro, Giulia Bisogni, Alessandro Lozza, Chiara Gemelli, Luca Gentile, Massimo Russo, Mario Ermani, Gian Maria Fabrizi, R. Plasmati, Federica De Napoli, Marta Campagnolo, Francesca Castellani, Fabrizio Salvi, Silvia Fenu, Grazia Devigili, Davide Pareyson, Roberto Gasparotti, Claudio Rapezzi, Carlo Martinoli, Luca Padua, Chiara Briani
Abstract
Axonal polyneuropathy is the main feature of hereditary transthyretin amyloidosis (ATTRv). Nerve morphological abnormalities have been reported, but longitudinal changes have never been assessed. We performed a prospective widespread nerve ultrasound evaluation and nerve cross-sectional area (CSA) was compared with baseline data in both ATTRv patients and pre-symptomatic carriers. Thirty-eight subjects were evaluated (mean follow-up 17.1 months), among them 21 had polyneuropathy while 17 were pre-symptomatic carriers. CSA significantly increased at brachial plexus in both groups (p = 0.008 and p = 0.012) pointing to progressive brachial plexus enlargement as a longitudinal biomarker of both disease progression and disease occurrence in pre-symptomatic carriers.