The application of event-related potential N270 in detecting mild cognitive impairment in Parkinson disease / 中华神经科杂志

ABSTRACT

Objective To find a sensitive index which can reveal the mild cognitive impairment in non-demented patients with Parkinson’s disease (PD).Methods Thirty PD patients without clinical dementia and 34 age-matched normal controls performed a matching-to-sample task while event-related potential (ERP) was recorded from their scalp. There were two kinds of stimulus pairs in this study condition 1, the second stimulus (S2) in a pair was identical to the first one (S1) (match condition); condition 2, S2 conflicted with S1 in their color attribute (conflict condition). Subjects were required to press a button in the match condition and another button in the conflict condition.Results In the match condition, P100, N150, P180, N200, and P300 were elicited by S2. In the conflict condition, potentials following N200 went continuously to negativity and formed another component,N270,before P300. The N270 component was evoked by S2 of conflict condition in both controls and patients. The patient group showed a delayed and smaller N270 than the control group[peak latency P3,patients(317?37) ms,controls(298?31) ms;P4, patients (313?35) ms,controls (293?34) ms;amplitude P3,patients (-3.06?2.51) ?V,controls (-4.55?2.86) ?V]. The peak amplitude of P300 was decreased in the patient group [P4,patients (6.94?3.95) ?V,controls (9.58?3.80) ?V], but the peak latency of P300 did not differ significantly between the two subject groups. There was no difference between the two groups in peak latency and amplitude of N150.Conclusion PD patients have cognitive impairment even in the absence of a clinical dementia. N270 is subtler than P300 in revealing the mild cognitive impairment.