Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective...Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated wheth- er adipose-derived stem celt transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells （ADSCs; 8 ×105） or differentiated Schwann-like adipose-derived mesenchymal stem cells （dADSCs; 8×105） or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellu- lar matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.展开更多
The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how vo...The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how voice disorders can be treated using therapy and rehabilitation. Here, we present a continuum-based numerical model of phonation that considers complex fluid-structure interactions occurring in the airway. This model considers a three-dimensional geometry of vocal folds, muscle contractions, and viscoelastic properties to provide a realistic framework of phonation. The vocal fold motion is coupled to an unsteady compressible respiratory flow, allowing numerical simulations of normal and diseased phonations to derive clear relationships between actual laryngeal structures and model parameters such as muscle activity. As a pilot analysis of diseased phonation, we model vocal nodules, the mass lesions that can appear bilaterally on both sides of the vocal folds. Comparison of simulations with and without the nodules demonstrates how the lesions affect vocal fold motion, consequently restricting voice quality. Furthermore, we found that the minimum lung pressure required for voice production increases as nodules move closer to the center of the vocal fold. Thus, simulations using the developed model may provide essential insight into complex phonation phenomena and further elucidate the etiologic mechanisms of voice disorders.展开更多
BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor i...BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor inappropriate airway intervention and increased morbidity.CASE SUMMARY A 61-year-old woman underwent cervical laminectomy,followed by laparoscopic cholecystectomy 10 mo later.Despite adequate reversal of neuromuscular blockade,the patient experienced repetitive respiratory difficulty with inspiratory stridor after extubation.After the second operation,the patient was diagnosed with paradoxical vocal fold motion(PVFM)by an otolaryngologist based on the clinical features and fiberoptic bronchoscopy results,and the patient was successfully treated.CONCLUSION PVFM should be considered a differential diagnosis if a patient presents with stridor after general anesthesia.展开更多
Backgrounds: Injury to the vagus nerve or one of its branches during carotid endarterectomy can result in vocal fold paralysis but the exact mechanism of injury responsible for vocal fold paralysis after carotid endar...Backgrounds: Injury to the vagus nerve or one of its branches during carotid endarterectomy can result in vocal fold paralysis but the exact mechanism of injury responsible for vocal fold paralysis after carotid endarterectomy is unclear. Aims: This study was performed to identify potential predictors of vagus nerve injury and obtain feedback by application of intraoperative continuous vagus nerve monitoring. Materials and Methods: Seventy-four patients undergoing carotid endarterectomy were enrolled. A new vagus nerve electrode was designed for less invasive continuous vagus nerve stimulation and monitoring of the vocal fold electromyogram without disturbing the surgical procedure. The device was rectangular (13 mm × 9 mm), with two small round electrodes set on a flexible silicon plate and tube. The electrode was fully implantable during carotid endarterectomy and was positioned at the most distal site of the vagus nerve by suturing to the connective tissue without nerve dissection. All patients underwent laryngoscopy to assess postoperative vocal fold and pharyngeal wall palsy at one week after carotid endarterectomy. Results: Sudden loss of the vocal fold electromyogram was noted in two patients (during plaque removal and during arterial wall suture in one each). In these two patients, incomplete vocal fold and pharyngeal palsy was confirmed by laryngoscopy. The cause of vagus nerve injury may have been traction at the time of distal internal carotid artery manipulation. The vocal fold electromyogram remained normal during the operation in the other 72 patients. However laryngoscopy revealed postoperative vocal fold and pharyngeal palsy in six patients. These findings suggested that delayed vagus nerve injury can occur after carotid endarterectomy. Conclusion: The continuous vagus nerve monitoring may be worthwhile for elucidating the mechanism of vagus nerve injury related to carotid endarterectomy.展开更多
The change of vocal flinction after vocal fold dehydration due to dryness was discussed along with the treatment eHect of different atomizing agents.Forty-eight staffs from The Central Hospital of Wuhan were recniited...The change of vocal flinction after vocal fold dehydration due to dryness was discussed along with the treatment eHect of different atomizing agents.Forty-eight staffs from The Central Hospital of Wuhan were recniited.All volunteers breathed dry air for vocal fold dehydration.After dry air inhalation,the subjects were randomly divided into four groups,with 12 cases each.Three groups were treatment groups,receiving 0.9%nonnal saline(IS),5%hypertonic saline(HS)and double-distilled water(SW)atomizing inhalation therapy,respectively,and the last group was the control group without treatment.Voice data were collected for all subjects before and immediately after dry air inhalation using the Multi-Dimensional Voice Program(MDVP)system.Atomizing inhalation therapy was given 10 min after dry air inhalation,and voice data were collected using MDVP system at the following time points after atomizing inhalation treatment:5 min,20 min,35 min,50 min,65 min,80 min,95 min,110 min.In the control group,voice data were collected at the same time points and compared with those of treatment groups.The vocal function parameters collected before and after dry air inhalation as well as after treatment were subjected to test using SPSS 16.0 software.In the four groups,jitter(fundamental frequency perturbation),shimmer(amplitude perturbation),and amplitude perturbation quotient(APQ)were significantly increased after dry air inhalation(P<0.05).In IS,HS and SW groups,after atomizing inhalation treatment,there was an obvious reduction in jitter,shimmer and APQ,showing significant differences as compared with those after dry air inhalation(P<0.05).Moreover,these parameters were significantly lower than those in the control group(P<0.05).The jitter,shimmer and APQ in the IS group were significantly lower than those in the HS and SW groups(P<0.05).We are led to a con elusion:Vocal fold dehydration induced by dryness can reduce the stability of voice;such decreased voice stability can be improved by atomizing inhalation therapy;without proper t展开更多
The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to t...The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to the upper mass of the vocal folds, and a parameter Q is introduced to represent the change of glottal configurations and tension imbalance between the left and right sides of vocal folds. Numerical simulations demonstrate that the pathological vocal-fold decreases the threshold of Q to generate nonlinear vocal oscillation, indicating the improvement of the sensitivity of vocal folds to asymmetries and enhancing the coupling between two sides. Furthermore, the pathological vocal-fold can lower the fundamental frequency and eliminate high-order harmonics, For example, the fundamental frequency decreases from 119.94 Hz to 84.95 Hz when Q=0.58 and the sub-glottal pressure 1450 Pa. However, there are no prominent effects on the amplitudes of sub-harmonic and low-order harmonics.展开更多
基金supported by the National Natural Science Foundation of China,No.81470680,81170901the Natural Science Foundation of Beijing of China,No.7132053the Beijing Health Foundation of High-level Technical Personnel in China,No.2014-2-004
文摘Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated wheth- er adipose-derived stem celt transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells （ADSCs; 8 ×105） or differentiated Schwann-like adipose-derived mesenchymal stem cells （dADSCs; 8×105） or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellu- lar matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.
文摘The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how voice disorders can be treated using therapy and rehabilitation. Here, we present a continuum-based numerical model of phonation that considers complex fluid-structure interactions occurring in the airway. This model considers a three-dimensional geometry of vocal folds, muscle contractions, and viscoelastic properties to provide a realistic framework of phonation. The vocal fold motion is coupled to an unsteady compressible respiratory flow, allowing numerical simulations of normal and diseased phonations to derive clear relationships between actual laryngeal structures and model parameters such as muscle activity. As a pilot analysis of diseased phonation, we model vocal nodules, the mass lesions that can appear bilaterally on both sides of the vocal folds. Comparison of simulations with and without the nodules demonstrates how the lesions affect vocal fold motion, consequently restricting voice quality. Furthermore, we found that the minimum lung pressure required for voice production increases as nodules move closer to the center of the vocal fold. Thus, simulations using the developed model may provide essential insight into complex phonation phenomena and further elucidate the etiologic mechanisms of voice disorders.
文摘BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor inappropriate airway intervention and increased morbidity.CASE SUMMARY A 61-year-old woman underwent cervical laminectomy,followed by laparoscopic cholecystectomy 10 mo later.Despite adequate reversal of neuromuscular blockade,the patient experienced repetitive respiratory difficulty with inspiratory stridor after extubation.After the second operation,the patient was diagnosed with paradoxical vocal fold motion(PVFM)by an otolaryngologist based on the clinical features and fiberoptic bronchoscopy results,and the patient was successfully treated.CONCLUSION PVFM should be considered a differential diagnosis if a patient presents with stridor after general anesthesia.
文摘Backgrounds: Injury to the vagus nerve or one of its branches during carotid endarterectomy can result in vocal fold paralysis but the exact mechanism of injury responsible for vocal fold paralysis after carotid endarterectomy is unclear. Aims: This study was performed to identify potential predictors of vagus nerve injury and obtain feedback by application of intraoperative continuous vagus nerve monitoring. Materials and Methods: Seventy-four patients undergoing carotid endarterectomy were enrolled. A new vagus nerve electrode was designed for less invasive continuous vagus nerve stimulation and monitoring of the vocal fold electromyogram without disturbing the surgical procedure. The device was rectangular (13 mm × 9 mm), with two small round electrodes set on a flexible silicon plate and tube. The electrode was fully implantable during carotid endarterectomy and was positioned at the most distal site of the vagus nerve by suturing to the connective tissue without nerve dissection. All patients underwent laryngoscopy to assess postoperative vocal fold and pharyngeal wall palsy at one week after carotid endarterectomy. Results: Sudden loss of the vocal fold electromyogram was noted in two patients (during plaque removal and during arterial wall suture in one each). In these two patients, incomplete vocal fold and pharyngeal palsy was confirmed by laryngoscopy. The cause of vagus nerve injury may have been traction at the time of distal internal carotid artery manipulation. The vocal fold electromyogram remained normal during the operation in the other 72 patients. However laryngoscopy revealed postoperative vocal fold and pharyngeal palsy in six patients. These findings suggested that delayed vagus nerve injury can occur after carotid endarterectomy. Conclusion: The continuous vagus nerve monitoring may be worthwhile for elucidating the mechanism of vagus nerve injury related to carotid endarterectomy.
文摘The change of vocal flinction after vocal fold dehydration due to dryness was discussed along with the treatment eHect of different atomizing agents.Forty-eight staffs from The Central Hospital of Wuhan were recniited.All volunteers breathed dry air for vocal fold dehydration.After dry air inhalation,the subjects were randomly divided into four groups,with 12 cases each.Three groups were treatment groups,receiving 0.9%nonnal saline(IS),5%hypertonic saline(HS)and double-distilled water(SW)atomizing inhalation therapy,respectively,and the last group was the control group without treatment.Voice data were collected for all subjects before and immediately after dry air inhalation using the Multi-Dimensional Voice Program(MDVP)system.Atomizing inhalation therapy was given 10 min after dry air inhalation,and voice data were collected using MDVP system at the following time points after atomizing inhalation treatment:5 min,20 min,35 min,50 min,65 min,80 min,95 min,110 min.In the control group,voice data were collected at the same time points and compared with those of treatment groups.The vocal function parameters collected before and after dry air inhalation as well as after treatment were subjected to test using SPSS 16.0 software.In the four groups,jitter(fundamental frequency perturbation),shimmer(amplitude perturbation),and amplitude perturbation quotient(APQ)were significantly increased after dry air inhalation(P<0.05).In IS,HS and SW groups,after atomizing inhalation treatment,there was an obvious reduction in jitter,shimmer and APQ,showing significant differences as compared with those after dry air inhalation(P<0.05).Moreover,these parameters were significantly lower than those in the control group(P<0.05).The jitter,shimmer and APQ in the IS group were significantly lower than those in the HS and SW groups(P<0.05).We are led to a con elusion:Vocal fold dehydration induced by dryness can reduce the stability of voice;such decreased voice stability can be improved by atomizing inhalation therapy;without proper t
基金supported by the National Basic Research Program of China(Grant No. 2011CB707900)the National Natural Science Foundation of China(Grant Nos. 81127901, 11174141 and 11161120324)the State Key Laboratory of Acoustics, Chinese Academy of Sciences
文摘The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to the upper mass of the vocal folds, and a parameter Q is introduced to represent the change of glottal configurations and tension imbalance between the left and right sides of vocal folds. Numerical simulations demonstrate that the pathological vocal-fold decreases the threshold of Q to generate nonlinear vocal oscillation, indicating the improvement of the sensitivity of vocal folds to asymmetries and enhancing the coupling between two sides. Furthermore, the pathological vocal-fold can lower the fundamental frequency and eliminate high-order harmonics, For example, the fundamental frequency decreases from 119.94 Hz to 84.95 Hz when Q=0.58 and the sub-glottal pressure 1450 Pa. However, there are no prominent effects on the amplitudes of sub-harmonic and low-order harmonics.
