Motor excitability measurements in early stage familial amyloid polyneuropathy: The influence of tafamidis treatment

To test motor fiber excitability in early affected patients with transthyretin (TTR)-type familial amyloid polyneuropathy (TTR-FAP) before and during tafamidis treatment. We examined the left median nerve of 21 healthy-matched controls and 10 early affected TTR-FAP patients using the automated threshold-tracking program, QTRAC. TTR-FAP patients were tested one day before the initiation of tafamidis treatment, 3 and 6 months later. The drug was well-tolerated in all patients; there was no drop-out. No statistical difference was found between healthy controls and TTR-FAP patients at study entry. On treatment, both stimulus intensity for 50% of the maximal motor response and rheobase increased significantly from entry to the last evaluation at 6 months (P