Bioelectrical brain signals may be monitored at one more regions of the brain of a patient by a medical device. The monitored bioelectrical signals may be used to select one or more therapy cycle parameters, e.g., on cycle duration and/or off cycle duration, for therapy delivered to treat a patient disorder. In one example, the off cycle duration of a therapy may be selected based on the washout period determined from sensed brain signals of the patient following delivery of therapy during an on cycle. In another example, the on cycle duration and/or off cycle duration of a therapy may be selected to maintain the value of one or more characteristics of a brain signal (e.g., cortical activity) of patient within a threshold range of a target value defined for the characteristic that is associated with effective treatment of the patient disorder.
