Application Of Surface Electromyography In Examination Of Swallowing Function

BackgroundSwallowing is a whole process that bolus of food from the mouth is chewed and bringed from mouth to esophagus and stomach, which is is one of humanity’s complex and required behavior. Swallowing is divided into oral, pharyngeal and esophageal stages three stages,controlled by the cerebral cortex, medulla oblongata beam cortex, brainstem nucleus, swallowing center and the fifth, seventh, ninth, tenth, eleventh and twelfth pair cranial nerve, slight dysfunction of each stage can lead to swallowing problems or dysphagia. As China entered the aging time, life style change leads to stroke and head and neck trauma increased significantly. There are various reasons increasing the incidence rate of dysphagia significantly,such as traumatic brain injury, intracranial and basicranial operations carrying out widely, head and neck cancer resection radiotherapy and so on. Dysphagia involves multiple disciplines, mainly in otolaryngology head and neck surgery, department of neurology, department of neurosurgery, department of gastroenterology, Department of radiotherapy, the Department of rehabilitation medicine, but has not been payed significant attention by these disciplines. Currently, many methods can examine swallowing function, each has advantages and disadvantages, generally including clinical assessment and instrument examination. Clinical evaluation can be divided into:subjective assessment refer to the doctor inquiry about medical history according to the patient’s chief complaint, subjectively estimate Whether patients have swallowing disorder;objective evaluation are repeated saliva swallowing test, water swallow test and oral feeding function scale. Their advantages are rapid, simple and noninvasive, but the disadvantages are that they need patients’ earnest cooperation, according to clinical symptoms and subjective feelings of patients to assess swallowing function, the sensitivity and specificity of reported vary greatly. Videofluoroscopic swallowing examination and fiberoptic endoscopic evaluation of swallowing are used widely in instrument examination. Videofluoroscopic swallowing examination is also called dynamic swallow examination, under X ray, direct at swallowing of mouth, pharynx, larynx, and esophagus for special imaging, through analysising video by frame,understanding swallowing.This method is clinically used extensively currently,but there is a disadvantage of radiation. Endoscopic examination of swallowing can examine pharyngeal and laryngeal anatomical structure and saliva retention by fiber laryngoscope. The operation method is simple and flexible. Different degrees of patients can accept this check because it can be used in bedside, even in ICU. In addition,the inspection can also found whether there are laryngeal mucosa edema, ulcer granulation, vocal cord paralysis,laryngeal and tracheal stenosis and other abnormal changes, but the drawback is that it focuses on the local observation, getting not much information about the whole process of swallowing, relationship of anatomical structure and bolus and the function of the cricopharyngeal muscle and esophagus. Because endoscopic vision disappeared while swallow, we can only observe vision before and after swallow without the basic motion of bolus when swallow. The detection of pharyngeal phase is still not comprehensive enough, can’t evaluate the change between oral stage and esophageal stage, and the coordination between tongue and throat. Surface electromyography, also called dynamic EMG, is a safe, simple and noninvasive about muscle function examination, in the past20years, foreign scholars have used surface EMG as the preferred method for screening and diagnosing dysphagia. it can quantify work condition and work efficiency of muscle, guiding patients conduct nerve, muscle training, but there is no research reports in China. Objective1.To study the characteristics of surface electromyography in normal adults ahd establish the normal database of duration and amplitude from muscle activity during swallow.2. To study the SEMG change of patients with pharyngeal paraesthesia and explore the cause of pharyngeal paraesthesia.3. To study the possibility of evaluating the degree of pain in patients after tonsillectomy with swallowing surface EMG..MethodsParticipants1. Chapter one126healthy adult volunteers were recruited during May2012to December2012. After signed informed consent, all volunteers were done surface EMG in the electromyogram room in Department of ENT of Navy General. Hospital The study was approved by the Medical Center Ethics Committee of Navy General Hospital. Inclusion criteria:age≥18years, under65years old; with sanity; without ENT or gastrointestinal diseases, dysphagia or odynophagia, willing to accept the assessment. Finally126adults were recruited, including60cases of female,66male; age range18to65years old, and were divided into4groups by age:<30years old group,<40years old group,<50years old group and≥50years old group.2.Chapter two Pharyngeal paraesthesia groups are patients to our clinic complaints of swallowing discomfortable, inclusion criteria:without ENT or gastrointestinal diseases, dysphagia, odynophagia or history of drugs may affect swallowing; with normal oral anatomy structure, without organic diseases or aspiration by endoscopy and swallow esophagography in ENT. Any tonsil lesions, pharyngeal keratosis, hypopharyngeal malignant tumor, epiglottic cyst, styloid process syndromes are excluded. Finally,34patients with pharyngeal paraesthesia were enrolled, aged between20-66years old, including17women,17men.3.Chapter three32patients to receive adenotonsillectomy from May2013to December2013in our hospital were enrolled, including15male,17female,aged between20-60years old. Selection criteria:patients aged>20years old,<60years old; all patients received tonsillectomy based on low-temperatrue plasma radiofrequency under general anesthesia, bleeding5-20ml during operation. Postoperation hemorrhage were not seen in all cases, no postoperative analgesic; without ENT or gastrointestinal diseases, dysphagia or odynophagia; if patients have nerve, mental disease, lung disease, serious hobby of smoke and wine, should be excluded.EMG recording technique1. Equipment:equipment for recording the surface EMG is KEYPOINT full function electromyography from Denmark’s Alpine Biomed,. The software is Keypoint.Classic.The duration and amplitude of muscle activities during every deglutition were recorded.2. Surface electrodes placement:the following4muscle groups are associated with swallowing:orbicularis oris; masseter; the submental muscles group, including anterior belly of digastrics, mylohyoid, genioglossus; the infrahyoid muscle group. These muscles were selected because they are superficial and their muscle movement can be recorded by electromyography during swallowing. Because normal swallowing activity is results of above-mentioned muscle coordinate together, and electrical activity has conductivity, we choose the middle of the neck and1cm above thyroid cartilage for electrode placement. The interelectrode distance was lcm., in other words, two surface electrodes were in an interval of0.5cm from the midline. Primaryly record pharyngeal swallowing activity. The grounding electrode was placed on one side of the wrist. Gently wiping electrode contact positions with alcohol gauze, and coating electrode gel were of help to reduce the resistance.3. Test procedures and recordsElectrode placement after the completion of each test,Each subject was recorded in3styles of swallowing after completion of electrode placement.3.1Dry swallow:subjects were instructed to "Swallow your saliva one time.".3.220ml water swallow:subjects were instructed to "put20ml water all in your mouth, and swallow it a mouth". 3.340ml water swallow:subjects were instructed to "put40ml water in your mouth, try to swallow it one mouth, if not,divide into two",(omit this step in chapter two and chapter three)The above tests are measured2times, and get the mean value. Choose the room temperature cool boiled water in order to prevent burns. The maximum amplitude and duration of EMG activity were recorded during swallowing.4. Visual analogue scale (VAS) shows the degree of pain by0to10a total of11numbers.0means painless,10represents the most painful. Patients selected a number represent the degree of pain according to their degree of pain in the11figures.0point: no pain; less than3points:mild pain, patients can tolerate;4-6points:the pain of the patients influence sleep and patients still can bear, should be given the clinical treatment;7-10points:patients with gradually strong pain, severe pain or pain can’t bear. Record the points on1day after operation and2day after operation,(this step is only for the chapter three)Results1. The durations of sEMG at dry swallow,20ml water swallow and40ml water swallow were (1.133±0.209)s (x±s),(1.097±0.208)s,(1.510±0.432)s, while the amplitudes were (0.332±0.115)mV,(0.308±0.095)mV,(0.399±0.139)mV in normal male group. The durations of sEMG at dry swallow,20ml water swallow and40ml water swallow were (1.118±0.170) s、(1.085±0.209) s和(1.765±0.463) s, while the amplitudes were (0.292±0.100) mV、(0.261±0.113) mV和(0.342±0.129) in normal female group. The amplitudes of sEMG in male were higher than those in female (P<0.05) and the durations had no statistically significant difference between male and female (P>0.05) in all swallow styles except that the duration of40ml water swallow in female was longer than that in male (P<0.05). In all volunteers, the durations of sEMG at40ml water swallow were longer than those at dry swallow and20ml water swallow, and there was no statistically significant difference between dry swallow and20ml water swallow. The amplitude of sEMG at40ml water swallow was higher than that at dry swallow. The amplitude of sEMG at of dry swallow was higher than that at20ml water swallow. There was no statistically significant difference in durations and amplitudes of sEMG among four different age groups of male. In the female groups, there was no statistically significant difference in durations and amplitudes of sEMG among four different age groups except that the duration at40ml water swallow was longer in younger group (<30years old) than in older groups.2. The durations of sEMG at dry swallow and20ml water swallow were (1.128±0.191)s and (1.091±0.208)s, while the amplitudes were (0.313±0.11)mV and (0.286±0.106)mV in Control group. The durations of sEMG at dry swallow and20ml water swallow were (1.178±0.252)s and (1.127±0.178)s, while the amplitudes were (0.341±0.116)mV and (0.316±0.094)mV in Pharyngeal paraesthesia group. There were no statistically significant difference between pharyngeal paraesthesia patients and normal volunteers in the durations and amplitudes of dry swallow and20ml water swallow.Further, comparing by different gender, there were no statistically significant difference between pharyngeal paraesthesia patients and normal volunteers in the durations and amplitudes of all swallow in male, the same result was obtained in female.3. In all swallow styles, the duration and amplitudes of sEMG of dry swallow at first and second day after operation were shorter and less than those before operation. The durations of sEMG of20ml water swallow after operation were longer than those before operation, while the amplitudes were less. There were no significant differences in VAS, duration and amplitudes of sEMG of dry swallow,20ml water swallow between the two days after operation. The change of duration and amplitudes of sEMG after operation had no correlation with the VAS score (p>0.05).Conclusion1. Surface EMG of swallowing is a simple and noninvasive method for evaluating the swallowing function. The sEMG data of swallowing in normal adults got in this study may be used to provide reference for screening swallowing function in adults in the future.2. There were no statistically significant difference between pharyngeal paraesthesia patients and normal volunteers in swallowing electromyography activity, indirectly concluding that pharyngeal paraesthesia patients were not damaged in swallowing function. Psychological intervention should be paid more attention in the treatment.3. sEMG can observe the changes of the muscle activity during swallow after tonsillectomy because of pain. The changes of sEMG may be used as an indicator for using analgesics or stopping use the analgesics, but it cannot be used to evaluate the degree of the pain after tonsillectomy.