Abstract: Objective To observe the surface electromyography (sEMG) characteristics of pharyngeal swallowing muscles in different swallowing modes in asymptomatic lacunar infarction (LI) patients. Methods From January, 2015 to January, 2017, a total of 32 asymptomatic LI patients (LI group) aged over 60 years were consecutively collected, and 30 normal old subjects matched with age and gender (normal group) were also enrolled. The amplitudes of sEMG activity of infrahyoid muscles and submental muscles in different swallowing modes were recorded, and the root mean square (RMS) was analyzed. Results Significant difference was found in both muscle groups in different swallowing modes in both groups (F>110.67, P<0.001). There was no significance in the RMS in both two muscle groups in rest and dry swallowing modes between two groups (t<1.484, P>0.05). In the 20 ml water swallowing mode, the RMS was lower in the submental muscles in the LI group than in the normal group (t=3.334, P<0.01), and no significant difference was found in the infrahyoid muscles (t=1.871, P>0.05). In the 100 ml continuous drinking mode, the RMSs were significantly lower in both two muscle groups in LI group than in the normal group (t>3.118, P<0.01). Conclusion Swallow abilities decrease in asymptomatic LI. sEMG could be used to evaluate their swallowing function.

Key words: lacunar infarction, swallowing function, surface electromyography, time-domain measures, root mean square