P26-F A role for tremor analysis in the differential diagnosis of PD and MSA

Background/Objectives The identification between Parkinson’s disease (PD) and multiple system atrophy (MSA) is challenging due to the presentation of similar motor symptoWe thus aim to develop a reliable marker derived from the tremor characteristics to identify the two conditions. Methods Ninety-one PD patients and 49 MSA-P patients were included. Each of them completed a 30-s test in each of the following conditions: resting and posture state. The tremor was measured using electromyography (EMG) surface electrodes and accelerators. The dominant frequency, resting tremor occurrence rate (RTOR) and harmonic occurrence rate (HOR) of the tremor were analyzed. Results We observed that compared to the PD group, the dominant frequency of both resting and posture tremor in the MSA-P group was significantly higher in upper limbs (p  Conclusion The harmonic is a reliable measure to separate PD from MSA with high sensitivity and specificity. Other parameters including dominant tremor frequency and tremor types could also provide meaningful information for diagnosis. The convenient and non-invasive tremor analysis would promote the diagnostic accuracy of PD and MSA.