APOE and Alzheimer disease: Baseline mean motor evoked potentials (MEPs) amplitude did not differ between APOE4, APOE3 AD patients and HS (APOE4: 1.11 ± 0.64 mV; APOE3: 1.06 ± 0.45 mV; HS: 1.09 ± 0.58 mV).