CHRM4 and Cognitive impairment: When analyzing the association between circulating level of autoantibodies with cognitive impairment, SBI patients who reported cognitive impairment had significantly lower median titers of anti-α1AR (12 vs. 15, p = 0.013), anti-β1AR (9 vs. 11, p = 0.05), and anti-M4R (5 vs. 8, p = 0.005) in comparison to SBI patients who did not report cognitive impairment (Figure 3 and Table 3).