Background and Purpose—The aims of this study were to determine the relationships between changes in the latency and amplitude of the P300 event-related potential component and cognitive impairments in patients after a transient ischemic attack (TIA) or a minor stroke and to assess the application of P300 in screening for cognitive impairments. 
Methods—Sixty-five TIA or minor stroke patients diagnosed by the neurology department of Beijing Tiantan Hospital affiliated with Capital Medical University from June 2015 to December 2016 and 30 healthy people evaluated during the same period were included. All patients were examined using neuropsychological scales and event-related potentials within 7±3 days after onset of the disease. The TIA/minor stroke group was divided into a non-cognitive impairment group (normal cognition, NC) and a cognitive impairment group. The cognitive impairment group was further divided into a vascular cognitive impairment with no dementia (VCIND) group and a vascular dementia (VD) group to analyze the relationship between P300 latency or amplitude and neuropsychological scale scores after a TIA/minor stroke. 
Results—The P300 latency at each recording electrode was longer in the NC and VCIND groups than in the healthy control group (P<0.001), and the P300 latency was longer in the VCIND group than in the NC group (P<0.001). When the P300-Fz latency cut-off value was 358.6 ms, the sensitivity for diagnosing cognitive impairments in patients after a TIA/minor stroke was 0.875, and the specificity was 0.765. 
Conclusions—The P300 latency delay can be used to detect cognitive impairments in patients after a TIA/minor stroke, and the P300-Fz latency is more sensitive for diagnosing cognitive impairments in TIA/minor stroke patients.

The Application of P300 in Cognitive Impairment Assessment after a Transient Ischemic Attack or Minor Stroke