Clinical Study On Voice Dysfunction Caused By Laryngopharyngeal Reflux Through Abnormal Vocal Fold Movement And Voice Onset

Purpose and SignificanceLaryngopharyngeal reflux(LPR)has a very close relationship with voice dysfunction.LPR not only causes voice dysfunction,but also causes vocal fold hyperplasia disease.More than 50%of voice outpatients have LPR.Previous studies have believed that LPR can cause vocal fold edema and vocal fold proliferative lesions,leading to voice dysfunction by causing damage to the throat mucosa.However,recent studies have shown that LPR patients without proliferative lesions and edema of vocal folds still suffer from vocal fatigue and voice dysfunction,but the pathological process is not very clear.Some disorders of vocal fold movement(such as paradoxial vocal fold movement and laryngeal spasm)were mostly caused by LPR.In addition,we often observed that some patients with vocal fatigue have unilateral vocal fold movement hypomobility in clinical practice,which suggested that laryngopharyngeal reflux would have a relationship with vocal fold movement.However,clinically,LPR was suspected to be diagnosed by the static Reflux Finding Score(RFS)under laryngoscope,Lack of research on vocal fold movement characteristics of LPR patients.LPR would cause secondary laryngeal muscle tension dysphonia,but it is not clear whether it will affect the vocal fold voice onset process.This paper will qualitatively and quantitatively measure the vocal fold movement and voice onset process of LPR patients without vocal fold proliferative lesions through stroboscopic laryngoscope video and laryngeal high-speed photography video,study the characteristics of vocal fold movement and voice onset in LPR patients and their impact on voice function,and provide theoretical basis and new research direction for further understanding and treating the voice problems of LPR patients.MethodsIn this study,LPR patients without proliferative lesions of vocal fold,patients with unilateral vocal fold movement hypomobility and normal healthy volunteers who met the inclusion and exclusion criteria were enrolled.Subjects filled in the questionnaire(Reflux Symptom Index(RSI)and Voice Handicap Index-10(VHI-10))and completed the corresponding clinical examinations,which mainly included:voice function assessment(CAPE-V assessment,acoustic assessment and laryngeal aerodynamic assessment),oral and pharyngeal Dx pH 24-hour monitoring,stroboscopic laryngoscopy,laryngeal high-speed videoendoscopy and laryngeal CT examination.The following assessments were performed:①LPR diagnosis:RSI and RFS were positive to diagnose suspected LPR,the RYAN index of Dx pH monitoring was abnormal to objectively diagnose LPR,and PPI empirical treatment was effective to diagnose LPR;②Evaluation of vocal fold movement:A.Quantitative evaluation:use Phantom camera control software to quantitatively measure vocal fold movement process(vocal fold movement distance,vocal fold movement frame number,vocal fold movement speed)in stroboscopic laryngoscope video,and quantitatively measure vocal fold movement process(vocal fold adduction and abduction time)in laryngeal highspeed videoendoscopy,and calculate the difference of bilateral vocal fold movement parameters of each subject;B.Qualitative evaluation:two doctors subjectively evaluated the characteristics of unilateral vocal fold movement hypomobility(bilateral vocal fold movement asymmetry,unilateral vocal fold movement hypomobility or bilateral vocal folds not at the same level)on the stroboscopic laryngoscope video;③Evaluation of voice onset process:evaluate voice onset process(voice onset mode and voice onset time(VOT))in laryngeal high-speed videoendoscopy;④Evaluation of vocal fold vibration:in the laryngeal oscillogram of laryngeal high speed videoendoscopy,measure the vocal fold vibration parameters(Open Quotient(OQ)),use KIP software to analyze the video of laryngeal high speed videoendoscopy,measure the frequency and amplitude of the front,middle and back positions of the vocal fold,and compare the symmetry of bilateral vocal fold vibration;⑤Three-dimensional structure evaluation of the larynx:import the original Dicom data of the dynamic CT of the larynx into the Mimic software to perform three-dimensional reconstruction of the larynx,measure the distance between the vertical planes of the bilateral vocal folds and the three-dimensional structure parameters of the vocal folds(glottic space,the distance between the vertical planes of the bilateral vocal folds,the length,width and thickness of the vocal folds,and the convergence angle below the glottis);⑥Objective voice function evaluation:The laryngeal aerodynamic parameters(Subglottic Pressure(SGP),Glottic Resistance(GR),Phonation Threshold Pressure(PTP)and Mean phonation Airflow Rate(MFR))were collected by the Phonological aerodynamic system,and the voice acoustic parameters(Fundamental frequency(F0),fundamental frequency perturbation(Jitter),amplitude perturbation(Shimmer)and Noise Harmonic Ratio(NHR))were analyzed by MDVP software.SPSS 25.0 statistical software was used to analyze the experimental data.Results1.The objective voice function of LPR patients was worse than that of normal subjects:the parameters related to the subglottic pressure(SGP,GR and PTP)in the laryngeal aerodynamic parameters of LPR patients were higher than those of the normal group,while the airflow parameters of LPR patients were lower than those of the normal group;The voice acoustic parameters of LPR patients(Jitter,Shimmer and NHR)were lower than those of the normal group.2.Abnormal vocal fold movement in LPR patients:The stroboscopic laryngoscope showed that the unilateral vocal fold movement in LPR patients was weakened,and the abnormal rate of unilateral vocal fold movement hypomobility was as high as 60%,significantly higher than that in the normal group(P<0.05);The difference in the number of frames of bilateral vocal fold movement in LPR group was greater than that in the normal group(P<0.05),and the difference in vocal fold movement speed and bilateral vocal fold movement speed in LPR group was also greater than that in the normal group(P<0.05);Similar results were also found under high speed laryngography.The adduction time of vocal folds in LPR group was shorter than that in normal group(P<0.05),and the difference of bilateral vocal fold abduction time in LPR group was greater than that in normal group(P<0.05).However,the difference of vocal fold vibration parameter OQ between LPR group and normal group was not statistically significant(P>0.05).3.LPR patients caused voice dysfunction through unilateral vocal fold movement hypomobility and vertical glottis insufficiency.The patients with unilateral vocal fold movement hypomobility would have glottis vertical insufficiency.77.78%of patients with unilateral vocal fold movement hypomobility had glottis vertical insufficiency(range:0.3-1.9mm),which was significantly more than that of the normal group(P<0.05).The distance and thickness of bilateral vocal fold vertical plane of patients with unilateral vocal fold movement hypomobility were greater than that of the normal group(P<0.05).Vertical glottis insufficiency had worse voice function.In LPR patients,the laryngeal aerodynamic and acoustic parameters of patients with vertical glottis insufficiency were worse than those of patients with glottis insufficiency,and the vocal fold vibration of patients with vertical glottis insufficiency was asymmetric.4.LPR patients caused abnormal voice function through hard voice onset.42.5%LPR can cause the phonation mode of hard voice onset.The number of hard voice onset in LPR group was more than that in normal group(P<0.05),and the VOT in LPR group was greater than that in normal group(P<0.05).The phonation mode of hard voice onset can cause the abnormality of objective voice function.In LPR patients,the PTP in hard voice onset group was greater than that in non-hard voice onset group(P<0.05),and the Shimmer in hard voice onset group was greater than that in non-hard voice onset group(P<0.05).In addition,the hard voice onset mode required longer VOT(194.61ms),which was significantly higher than that in the non-hard voice onset group(89.4ms)(P<0.05).Conclusions1.The vocal fold movement behavior of LPR patients had changed:under stroboscopic laryngoscope,unilateral vocal fold movement hypomobility,bilateral vocal fold movement asymmetry or vertical glottic insufficiency may occur;High speed laryngography showed that the adduction time of both vocal folds and the abduction time of one vocal fold were shortened,while the abduction time of the other vocal fold was prolonged,indicating that the vocal fold movement of LPR patients was irritable,and it would cause the hypomobility of vocal fold abduction.These would provide a reference for the objective evaluation of vocal fold movement function in LPR patients,and also provide a theoretical basis for the paradoxical vocal fold movement and laryngeal spasm disease caused by LPR,which can not effectively abduct the vocal fold.2.Patients with unilateral vocal fold movement hypomobility often had glottis vertical plane insufficiency.LPR patients with glottis vertical plane insufficiency had poorer voice acoustic parameters,need greater SGP to drive vocal fold vibration,and vocal fold vibration was asymmetric.These results indicated that unilateral vocal fold movement hypomobility and vertical glottis insufficiency can cause voice dysfunction in LPR patients.In clinical evaluation of LPR patients without vocal fold hyperplasia and vocal fatigue,it was necessary to evaluate whether there was unilateral vocal fold movement hypomobility and vertical glottic insufficiency.3.LPR patients caused voice dysfunction and vocal fatigue through hard voice onset:LPR patients’ voice onset changed,requiring longer VOT,and prone to hard voice onset,indicating that LPR patients’ voice onset was slow and prone to vocalization fatigue;Patients with hard voice onset need more PTP to start phonation and caused changes in acoustic parameters,suggesting that the way of hard voice onset would lead to voice dysfunction in LPR patients.These would provide a theoretical basis for the treatment of vocal fatigue and hoarseness in LPR patients by voice training with modifying hard voice onset.