A personal wearable EEG monitor comprising an implantable electrode part with at least two electrodes (2,3) for measuring an EEG signal of a person. The electrode part comprises an electronic circuit arranged in a housing (1) with each electrode arranged external to the housing. The electrode part comprises a testing circuit for testing functionality of the electrode part. The testing circuit comprises a capacitor (9) coupled in serial connection to at least one of the electrodes, and a test signal generator for providing a test signal. The EEG monitor is adapted for analyzing the signal resulting from the signal generator for identification of faults in the electrode part. The invention further provides a method for detecting a leak current in an implanted EEG monitor part.
