The Validity of Auditory Event-Related Potentials in Diagnosis of Dementia: Prospective Study

Abstract

When predicting the probability of a patient's being demented, we found age and N200 and P300 latency to be the most important contributing factors. The probability equation is 1/1 + e(-z); Z = -93.22 + 0.42 x age + 0.03 x N200 latency + 0.14 x P300 latency. The overall rate of correct classification was 93.6% with 90.3% sensitivity and 95.4% specificity. We further collected information about 103 patients (57 nondementia versus 46 dementia) to evaluate the validity of this equation prospectively and to explore the relationship between mental deterioration and auditory event-related potentials (ERPs). The Mini-Mental State Examination (MMSE) and auditory ERPs (elicited by oddball paradigm, linked-ear reference) were performed on each patient. According to this equation, the results showed 87.0% sensitivity and 82.5% specificity. Mood disorder caused most of the false-positive rate. There was a negative correlation between P300 or N200 latency and the sum of MMSE, orientation, attention, recall, and language. This result shows that the greater the deterioration in mental function, the greater the values for N200 and P300 latency. We concluded that the sensitivity and specificity of our equation are satisfactory. Mental deterioration had negative correlation with variables in this equation, but further studies are needed to elucidate the relationship between mood disorder and dementia.