Twenty-four-hour tremor recordings in the evaluation of the treatment of Parkinson's disease.

A new method of prolonged recording of EMG provides a good estimate of spontaneous and induced diurnal variations in resting tremor in Parkinson's disease. It provides a record and a measure of the effects of treatment. Tremor intensity shows considerable variations even over short periods of time. Therefore short-term measurements of tremor are unhelpful. Long-term recordings agree better with the patient's assessment than with the clinical rating score. Repeated recordings over a similar 10-h period on 3 consecutive days in one patients showed fairly constant measures of occurrence and intensity of tremor. In contrast to accelerometer measurements of tremor, artefacts caused by movements and general activity of the patient do not materially interfere with tremor evaluation using surface EMG.