CNTN1 and sensory ataxia: All patients with anti‐CNTN1 IgG4 antibodies showed sensory ataxia (Doppler, Appeltshauser, Kramer et al., 2015; Doppler, Appeltshauser, Villmann et al., 2015; Miura et al., 2015) and were poorly responsive to IVIg treatment but sensitive to steroid treatments (Miura et al., 2015; Querol et al., 2013).