Methods and systems are directed to evaluating a pathological condition and involve acquiring muscle movement signals, such as electromyogram (EMG) or accelerometer signals, and detecting the presence of the pathological condition. Methods and systems also provide for detecting sleep-related involuntary muscle disorders and non sleep-related involuntary muscle disorders using muscle movement signals. Drug therapy, transcutaneous electric nerve stimulation therapy, or other therapy may be delivered to treat a detected or diagnosed involuntary muscle disorder.