LGI1 and Cognitive impairment: Internalized LGI1-IgGs consistently co-localized with ADAM22 (Fig. 4D, inset) and internalization was observed from the sera of patients with (n = 3) and without (n = 6) cognitive impairment, and from LGI1-IgGs with both dominant IgG1 (n = 3) and IgG4 (n = 6) subclasses, but not with healthy control sera (n = 5) or at 4°C, a condition known to inhibit internalization.