Immune-mediated neuropathies: role of single-fiber conduction velocity

Immune-mediated neuropathies are acquired diseases that considerably vary in their pattern of nerve involvement. Peripheral nerves may have segmental or diffuse involvement, creating great variability in the exact clinical presentation (Magy et al., 2011; Padua et al., 2013). The diagnosis is based upon clinical examination, which may demonstrate weakness and/or sensory impairment, depending on affected nerves, degree of suffering and type of involvement (Van den Bergh et al., 2010). Neurophysiology supports the diagnostic process, providing information about nerve function. In particular, reduction of nerve conduction velocity (NCV) and conduction blocks may be found (Van den Bergh et al., 2010). In recent years, nerve ultrasound (US) has been used to demonstrate morphological alterations in nerves affected by immune-mediate neuropathies, including increased cross sectional area (CSA), hypoechoic or hyperechoic pattern (especially depending on the disease duration) and abnormalities in fascicles (Lucchetta et al., 2015).