Evaluation of chewing muscles in patients with Parkinson using electromyography-interference pattern analysis

Abstract

Electrical activity of muscles is defined in a spectrum varying from poor to maximal effort with EMG-Interference Pattern Analysis (IPA) methods. This method provides information about changes in motor units in all levels of strength. IPA is a beneficial method in the evaluation of muscle activity, muscle fatigue, works performed by muscles, chronic muscle pain, neuro-urologic and proctologic functions, the treatment of dystonia and spasticity with botulinum toxins, and the diagnosis of neuromuscular disorders. Studies which employed certain parameters of this method revealed that there were some changes associated with muscle fatigue in patients with Parkinson disease. We evaluated 26 patients with Parkinson disease and 26 healthy individuals in our study. We compared parameters of Interference Pattern Analysis between both groups and before and after the combined treatment with levodopa + benserazide + entakapon in Parkinson group. We found that parameters of amplitude measurements, Power Spectrum Analysis and Turn/Amplitude Analysis were lower than healthy individuals in chewing muscles of patients with Parkinson disease. This result may help us determine the prognosis in patients with Parkinson disease. We also showed partial improvement in some parameters of Interference Pattern Analysis after the treatment. This finding may indicate that this method might be used in evaluating the effectiveness of treatment. Fast or excessive fatigue and nutritional problems observed in patients with Parkinson disease might be explained with our study. However we could not exclude the effects of dental condition on maximal contraction. Our findings are consistent with those of other electromyography studies on muscle fatigue in patients with Parkinson disease.