Electromyographic measures of asymmetric muscle control of swallowing in Parkinson’s disease

Abstract

Introduction During the early stages, Parkinson’s disease (PD) is well recognized as an asymmetric disease with unilateral onset of resting tremor with varying degrees of rigidity, and bradykinesia. However, it remains unknown if other impairments, such as swallowing impairment (i.e., dysphagia), also present asymmetrically. Purpose The primary aim of this study was to examine muscle activity associated with swallow on the most affected side (MAS) and least affected side (LAS) in persons with PD. A secondary aim was to explore the relationship between differences in muscle activity associated with swallow and subjective reports of swallowing impairment and disease severity. Methods Function of muscles associated with swallowing was assessed using surface electromyography placed over the right and left submental and laryngeal regions during three swallows for a THIN and THICK condition. The Swallowing Quality of Life (SWAL-QOL) questionnaire and the Unified Parkinson’s Disease Rating Scale (UPDRS) were collected as measures of subjective swallow impairment and disease severity, respectively. Results Thirty-five participants diagnosed with idiopathic PD and on a stable antiparkinsonian medication regimen completed this study. Results revealed no significant mean difference in muscle activity during swallow between the more and less affected side. For the laryngeal muscle region, a significant difference in coefficient of variation between the MAS and LAS was revealed for peak amplitude for the THIN swallow condition. For the laryngeal muscle region, a significant association was revealed between muscle activity and disease severity but not subjective reports of swallowing impairment. Conclusion Superficially it appears that swallowing impairment present symmetrical during the early stages of PD, however, our variability data indicates otherwise. These results will be used to inform future studies in specific types of swallowing impairment (i.e., oral dysphagia, pharyngeal dysphagia, and esophageal dysphagia), disease progression, and overall asymmetry.

Using Sequence Analyses to Quantitatively Measure Oropharyngeal Swallowing Temporality in Point-of-Care Ultrasound Examinations: A Pilot Study

“…In response to the issue of invasiveness, recent studies have also begun to explore the use of (surface) electromyography (sEMG) as a non-invasive alternative, and various protocols have been proposed to examine and understand the oral, pharyngeal, and laryngeal muscle activities during swallowing, particularly for neurological dysphagia [5]. For example, sEMG has been used to examine the symmetry of muscle activities among people with Parkinson's disease [6]. However, as discussed in [5], electromyographic examinations of swallowing muscle activities are prone to impedance noise from the skin surface, and the relationship between muscle force and sEMG signal amplitude requires further investigations.…”