IGLON5 and Classical progressive supranuclear palsy: Gait disturbances are frequent in CASPR2- and IgLON5-antibody syndromes.30–32 IgLON5-antibody disease is associated with a polymorphic sleep disturbance plus progressive supranuclear palsy-like picture with axial rigidity and gait freezing, whereas CASPR2-antibody disease typically has a gait disturbance secondary to episodic or persistent ataxia.