Meta-analysis of the endogenous N200 latency event-related potential subcomponent in patients with Alzheimer’s disease and mild cognitive impairment

The N200 latency subcomponent has the potential to be an accurate neurophysiological marker of the cognitive deterioration seen in Alzheimer’s disease (AD) and mild cognitive impairment (MCI). Standard mean difference (SMD) estimates of the N200 latency subcomponent were compared in three treatment groups: patients with AD, patients with MCI, and an unrelated elderly control group. Patients with AD had significantly prolonged N200 latencies compared to the control group, pooled SMD: 0.866 (95% CI: 0.517 to 1.214, z = 4.87, p < 0.001). Patients with MCI had significantly prolonged N200 latencies compared to the control group, pooled SMD: 0.578 (95% CI: 0.213 to 0.943, z = 3.31, p = 0.002). When comparing patients with AD and MCI the N200 latencies were similar, pooled SMD: 0.096 (95% CI: −0.261 to 0.453, z = 0.53, p = 0.598). The abnormalities present in the N200 latency subcomponent validate previous research that N200 latency is an informative indicator of information-processing deterioration in patients with cognitive impairment. Clinically, measurements of N200 latency can be used as a risk assessment of elderly patients that may be progressing to mild cognitive impairment and/or Alzheimer’s disease.