A medical device with closed-loop responsive stimulation may include techniques to mitigate the impact on the therapy output of noise coupled into the medical device. A medical device according to this disclosure may determine the presence of noise and alter the closed loop policy to provide the necessary therapy to the patient and avoid prolonged under stimulation caused by the noise. The medical device may continue therapy, while testing for noise. When the device determines the noise level no longer affects the output therapy, the device may return the closed loop policy to a no-noise mode of operation. The medical device may also include techniques to mitigate the impact of manual adjustment while the medical device is subject to noise or is responding to changes in the patient's physiological signals.