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Superior Laryngeal Nerve (superior + laryngeal_nerve)
Selected AbstractsExploring the phonatory effects of external superior laryngeal nerve paralysis: An In vivo model,THE LARYNGOSCOPE, Issue 4 2009Nelson Roy PhD Abstract Objectives/Hypothesis: Little is known regarding the phonatory consequences of unilateral external superior laryngeal nerve (ESLN) paralysis. By selectively blocking the ESLN with lidocaine HCl (with laryngeal electromyography verification), we modeled acute, unilateral cricothyroid (CT) muscle dysfunction to explore possible acoustic, aerodynamic, auditory-perceptual and auto-perceptive effects. Study Design: Prospective, repeated measures, experimental design. Methods: Ten, vocally-normal adult males underwent lidocaine block of the right ESLN. Multiple measures of phonatory function across a variety of vocal tasks/conditions were acquired before and during the block using standard data acquisition and analysis protocols. Results: During ESLN block, phonatory frequency range was significantly reduced with compression of both upper and lowermost regions of the pitch range. Mean speaking fundamental frequency increased significantly during oral reading. Acoustic analysis, aerodynamic assessment, and auditory- perceptual evaluation by blinded listeners revealed modest increases in phonatory instability (jitter), increased laryngeal airway resistance with no objective evidence of glottic insufficiency, and mild deterioration in voice quality most evident during high pitched voice productions, respectively. Participants uniformly rated their speaking and singing voices as worse during the block with significant weakness, effort, and tightness that they perceived as a mild level of impairment. Conclusions: These data support generally mild changes to the speaking voice, which extend beyond reductions in pitch range only, and shed light on the potential untoward phonatory effects of acute, unilateral CT dysfunction. Laryngoscope, 2009 [source] Management of hyperfunctioning single thyroid nodules in the era of minimally invasive thyroid surgeryANZ JOURNAL OF SURGERY, Issue 5 2009Charles Tan Both surgical excision and radioiodine ablation are effective modalities in the management of hyperfunctioning thyroid nodules. Minimally invasive thyroid surgery (MITS) using the lateral mini-incision approach has previously been demonstrated to be a safe and effective technique for thyroid lobectomy. As such MITS may offer advantages as a surgical approach to hyperfunctioning thyroid nodules without the need for a long cervical incision or extensive dissection associated with formal open hemithyroidectomy. The aim of the present study was to assess the safety and efficacy of MITS for the treatment of hyperfunctioning thyroid nodules. This is a retrospective case study. Data were obtained from the University of Sydney Endocrine Surgical Unit Database from 2002 to 2007. There were 86 cases of hyperfunctioning thyroid nodules surgically removed during the study period, of which 10 (12%) were managed using the MITS approach. The ipsilateral recurrent laryngeal nerve was identified and preserved in all cases with no incidence of temporary or permanent nerve palsy. The external branch of the superior laryngeal nerve was visualized and preserved in eight cases (80%). There were no cases of postoperative bleeding. There was one clinically significant follicular thyroid carcinoma in the series (10%). In nine of 10 cases (90%) normalization of thyroid function followed surgery. MITS is a safe and effective procedure, achieving the benefits of a minimally invasive procedure with minimal morbidity. As such it now presents an attractive alternative to radioiodine ablation for the management of small hyperfunctioning thyroid nodules. [source] NERVE STIMULATION IN THYROID SURGERY: IS IT REALLY USEFUL?ANZ JOURNAL OF SURGERY, Issue 5 2007Thorbjorn J Loch-Wilkinson Background: Monitoring of the recurrent laryngeal nerve (RLN) has been claimed in some studies to reduce rates of nerve injury during thyroid surgery compared with anatomical dissection and visual identification of the RLN alone, whereas other studies have found no benefit. Continuous monitoring with endotracheal electrodes is expensive whereas discontinuous monitoring by laryngeal palpation with nerve stimulation is a simple and inexpensive technique. This study aimed to assess the value of nerve stimulation with laryngeal palpation as a means of identifying and assessing the function of the RLN and external branch of the superior laryngeal nerve (EBSLN) during thyroid surgery. Methods: This was a prospective case series comprising 50 consecutive patients undergoing total thyroidectomy providing 100 RLN and 100 EBSLN for examination. All patients underwent preoperative and postoperative vocal cord and voice assessment by an independent ear, nose and throat surgeon, laryngeal examination at extubation and all were asked to complete a postoperative dysphagia score sheet. Dysphagia scores in the study group were compared with a control group (n = 20) undergoing total thyroidectomy without nerve stimulation. Results: One hundred of 100 (100%) RLN were located without the use of the nerve stimulator. A negative twitch response occurred in seven (7%) RLN stimulated (two bilateral, three unilateral). Postoperative testing, however, only showed one true unilateral RLN palsy postoperatively (1%), which recovered in 7 weeks giving six false-positive and one true-positive results. Eighty-six of 100 (86%) EBSLN were located without the nerve stimulator. Thirteen of 100 (13%) EBSLN could not be identified and 1 of 100 (1%) was located with the use of the nerve stimulator. Fourteen per cent of EBSLN showed no cricothyroid twitch on EBSLN stimulation. Postoperative vocal function in these patients was normal. There were no instances of equipment malfunction. Dysphagia scores did not differ significantly between the study and control groups. Conclusion: Use of a nerve stimulator did not aid in anatomical dissection of the RLN and was useful in identifying only one EBSLN. Discontinuous nerve monitoring by stimulation during total thyroidectomy confers no obvious benefit for the experienced surgeon in nerve identification, functional testing or injury prevention. [source] Surgical anatomy of the external branch of the superior laryngeal nerve and its clinical significance in head and neck surgeryCLINICAL ANATOMY, Issue 2 2008Xenophon Kochilas Abstract Injury of the external branch of the superior laryngeal nerve (EBSLN) increases the morbidity following a variety of neck procedures and can have catastrophic consequences in people who use their voice professionally. Identification and preservation of the EBSLN are thus important in thyroidectomy, parathyroidectomy, carotid endarterectomy, and anterior cervical spine procedures, where the nerve is at risk. There are large variations in the anatomical course of the EBSLN, which makes the intraoperative identification of the nerve challenging. The topographic relationship of the EBSLN to the superior thyroid artery and the upper pole of the thyroid gland are considered by many authors to be the key point for identifying the nerve during surgery of the neck. The classifications by Cernea et al. ([1992a] Head Neck 14:380,383; [1992b] Am. J. Surg. 164:634,639) and by Kierner et al. ([1998] Arch. Otolaryngol. Head Neck Surg. 124:301,303), as well as clinically important connections are discussed in detail. Along with sound anatomical knowledge, neuromonitoring is helpful in identifying the EBSLN during neck procedures. The clinical signs of EBSLN injury include hoarseness, decreased voice projection, decreased pitch range, and fatigue after extensive voice use. Videostroboscopy, electromyography, voice analysis, and electroglottography can provide crucial information on the function of the EBSLN following neck surgery. Clin. Anat. 21:99,105, 2008. © 2008 Wiley-Liss, Inc. [source] Effects of Insulin-Like Growth Factor-1 Gene Transfer on Myosin Heavy Chains in Denervated Rat Laryngeal Muscle,THE LARYNGOSCOPE, Issue 2 2004Paul W. Flint MD Abstract Objectives/Hypothesis: To determine whether the myotrophic activity of human insulin-like growth factor (hIGF)-1 promotes restoration of normal myosin heavy chain (MHC) composition after nerve injury, MHC composition was analyzed after hIGF-1 gene transfer in denervated rat laryngeal muscle. Study Design: Animal model to study effects of gene transfer on laryngeal paralysis. Methods: In anesthetized rats, the left recurrent and superior laryngeal nerves are cut and suture ligated. A midline thyrotomy is performed, and the thyroarytenoid muscle is injected with a polyvinyl-based formulation containing a muscle specific expression system and hIGF-1 DNA (treatment group) or saline (control group). After 30 days, animals were killed, and the thyroarytenoid muscle was removed and processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDSPAGE). Densitometric measurements were obtained to determine composition of MHCs. Results: As previously described, MHC composition in denervated laryngeal muscle was characterized by a decrease in type IIB and IIL and up-regulation of IIA/IIX. Compared with controls, hIGF-1 treated animals demonstrated a significant increase in expression of type IIB and IIL and a significant decrease in expression of type IIA/X. Conclusions: These findings suggest that the myotrophic effect of hIGF-1 gene transfer results in normalization of MHC composition in denervated muscle, with suppression of type IIA/X MHC and promotion of type IIL expression. [source] | ||||||||||