quency was significantly lower in AD (7.80 6 1.44 Hz) than in FTLD patients (8.576 1.34 Hz) (p1⁄40.006) (Figure 1). This difference was visible for all dominant frequency peaks, independent of channel. When analyzing only the definite patient subgroups, this difference was even more pronounced (AD: 7.22 6 1.11 Hz; FTD: 8.90 6 1.26 Hz; p<0.001). Based on ROC analysis (Figure 2), classification could be made based on a cut-off frequency of 7.32 Hz (accuracy: 61.3%) in the total group or 8.79 Hz in the definite subgroup (accuracy: 78.4%). Interestingly, a reverse correlation was found for maxpeak frequency and age at disease onset in the FTLD group (Pearson’s r1⁄4-0.365, p1⁄40.009, in definite subgroup: r1⁄4-0.708 p1⁄40.001).Conclusions:Quantitative analysis of the EEG maxpeak frequency is an easy and useful measure for the differentiation between AD and FTLD.