2016 年 33 巻 2 号 p. 158-161
Peripheral neuropathies are common disorders in the daily medical practice, and often cause weakness, numbness, pain, and autonomic symptoms. The several specific clinical laboratory tests are useful for the diagnosis of peripheral neuropathies. Nerve conduction studies are not useful for evaluating small fibre neuropathy, such as early stage of transthyretin–related familial amyloid polyneuropathy (TTR–FAP) characterized by involvement of small fibres such as Aδ and C fibres. To evaluate small fiber neuropathies, various autonomic function tests, such as laser–Doppler flowmetry, sweating tests using capsule type sweating ratemeter, electrogastrography, R–R interval study, 123I–MIBG myocardial scintigraphy, head–up tilt test, and intraepidermal nerve fiber density, are useful. TTR–FAP is an autosomal–dominant inherited disorder characterized by systemic accumulation of amyloid fibrils in various organs and peripheral nerves. To date, more than 130 mutations in the TTR gene have been reported. In TTR–FAP, several therapies have been developed in the recent decade. In addition to liver transplantation, tetramer structure stabilizers were developed. Also, gene silencing drugs are under clinical trials.
