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International Journal of Surgery... Jul 2023Thyroid disease is a common endocrine disorder, and thyroid surgeries and postoperative complications have increased recently. This study aimed to explore the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Thyroid disease is a common endocrine disorder, and thyroid surgeries and postoperative complications have increased recently. This study aimed to explore the effectiveness of intraoperative nerve monitoring (IONM) in endoscopic thyroid surgery using subgroup analysis and determine confounding factors.
MATERIALS AND METHODS
Two researchers individually searched for relevant studies published till November 2022 in the PubMed, Embase, Web of Science and Cochrane Library databases. Eventually, eight studies met the inclusion criteria. Heterogeneity was assessed using the Cochran's Q test, and a funnel plot was implemented to evaluate publication bias. The odds ratio or risk difference were calculated using fixed-effects models. The weighted mean difference of continuous variables was calculated. Subgroup analysis was performed according to the disease type.
RESULTS
Eight eligible papers included 915 patients and 1242 exposed nerves. The frequencies of transient, permanent and total recurrent laryngeal nerve (RLN) palsy were 2.64, 0.19 and 2.83%, respectively, in the IONM group and 6.15, 0.75 and 6.90%, respectively, in the conventional exposure group. In addition, analysis of the secondary outcome indicators for the average total length of surgery, localisation time of the RLN, recognition rate of the superior laryngeal nerve and length of incision revealed that IONM reduced the localisation time of the RLN and increased the identification rate of the superior laryngeal nerve. Subgroup analysis showed that IONM significantly reduced the incidence of RLN palsy in patients with malignancies.
CONCLUSIONS
The use of IONM significantly reduced the incidence of transient RLN palsy during endoscopic thyroid surgery, but it did not significantly reduce the incidence of permanent RLN palsy. However, the reduction in the total RLN palsy was statistically significant. In addition, IONM can effectively reduce the location time of the RLN and increase the recognition rate of the superior laryngeal nerve. Therefore, the application of IONM for malignant tumours is recommended.
Topics: Humans; Thyroid Gland; Thyroidectomy; Recurrent Laryngeal Nerve; Monitoring, Intraoperative; Recurrent Laryngeal Nerve Injuries; Vocal Cord Paralysis
PubMed: 37318897
DOI: 10.1097/JS9.0000000000000393 -
Acta Otorrinolaringologica Espanola 2012The neuroanatomy of voice and speech is complex. An intricate neural network is responsible for ensuring the main functions of the larynx: airway protection, cough and... (Review)
Review
The neuroanatomy of voice and speech is complex. An intricate neural network is responsible for ensuring the main functions of the larynx: airway protection, cough and Valsalva production, and providing voice. Coordination of these roles is very susceptible to disruption by neurological disorders. Neurological disorders that affect laryngeal function include Parkinson's disease, stroke, amyotrophic lateral sclerosis, multiple sclerosis, dystonia and essential tremor. A thorough neurological evaluation should be routine for any patient presenting with voice complaints suggestive of neurogenic cause. Endoscopic visualisation of the larynx using a dynamic voice assessment with a flexible laryngoscope is a crucial part of the evaluation and ancillary tests are sometimes performed. Otolaryngologic evaluation is important in the diagnosis and treatment of neurological disorders that affect laryngeal function.
Topics: Algorithms; Botulinum Toxins, Type A; Diagnostic Techniques, Neurological; Electric Stimulation Therapy; Electromyography; Genetic Therapy; Humans; Laryngeal Diseases; Laryngeal Muscles; Laryngeal Nerves; Laryngoscopy; Motor Neurons; Nerve Net; Nerve Transfer; Nervous System Diseases; Neurologic Examination; Neurophysiology; Physical Examination; Sound Spectrography; Voice Disorders
PubMed: 21349470
DOI: 10.1016/j.otorri.2010.12.003 -
Acta Medica Academica Nov 2018The purpose of this paper is to review the current data on the coexistence of non-recurrent laryngeal nerve (RLN) and vascular variations. (Review)
Review
OBJECTIVE
The purpose of this paper is to review the current data on the coexistence of non-recurrent laryngeal nerve (RLN) and vascular variations.
METHODS
A systematic literature search was conducted on MEDLINE for case reports, original articles and reviews regarding the presence of non-RLN and coexisting vascular variants.
RESULTS
From the literature search, 104 cases of non-RLN with confirmed vascular variants were reported. More specifically, 97.7% (n=101) of cases involved a right and 2.3% (n=3) a left non-RLN. The most common concurrent vascular variant reported with a right non-RLN was an aberrant right subclavian artery (97%; n=98). One case report (0.9%) of an intrathyroidal right common carotid artery was noted and 2 cases (1.9%) were associated with normal vascular anatomy. Furthermore, all 3 cases of a left non-RLN were associated with a right aortic arch, while 2 of them were also accompanied with situs inversus.
CONCLUSIONS
The presence of vascular variations of the great vessels must prompt the surgeon to search for a non-RLN. Intraoperative neuromonitoring increases the detection rate of non-RLN. Further research is required to determine anatomic landmarks for the perioperative identification of a non-RLN, allowing its protection from potential injury.
Topics: Aorta, Thoracic; Arteries; Cardiovascular Abnormalities; Carotid Artery, Common; Humans; Laryngeal Nerve Injuries; Laryngeal Nerves; Recurrent Laryngeal Nerve; Situs Inversus; Subclavian Artery; Thyroidectomy
PubMed: 30585070
DOI: 10.5644/ama2006-124.230 -
Ear, Nose, & Throat Journal Sep 2019Superior laryngeal nerve neuralgia (SLNN) is an anterior neck pain syndrome that is underrecognized and, as a result, is often misdiagnosed. We present a series of... (Review)
Review
Superior laryngeal nerve neuralgia (SLNN) is an anterior neck pain syndrome that is underrecognized and, as a result, is often misdiagnosed. We present a series of patients who were diagnosed with and subsequently treated for SLNN. Nineteen patients were treated with oral nonsteroidal anti-inflammatory drugs (NSAIDs) and/or a therapeutic neck injection with 2% lidocaine and 40% triamcinolone acetonide. All patients completed a visual analog scale (VAS) to rate the level of pain before and after treatment. Four patients rated their pain as mild, 14 as moderate, and 1 as severe according to the VAS. Of the 19 patients, 8 chose to proceed with a 2-week course of NSAIDs and only 1 of them had complete resolution of their symptoms. A total of 18 patients underwent therapeutic neck injections, with a complete response to injection therapy in 10 patients. Five patients described a minimal residual foreign body sensation and 3 patients complained of mild residual pain. In this study, we found that therapeutic neck injections are effective not only in confirming the diagnosis but also in treating pain.
Topics: Adult; Aged; Anesthetics, Local; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Drug Combinations; Female; Humans; Ibuprofen; Injections; Laryngeal Nerves; Lidocaine; Male; Middle Aged; Neck Pain; Neuralgia; Pain Measurement; Retreatment; Syndrome; Triamcinolone Acetonide; Young Adult
PubMed: 30995862
DOI: 10.1177/0145561318823373 -
Current Opinion in Otolaryngology &... Dec 2014The superior laryngeal nerve (SLN) provides motor innervation to the cricothyroid muscle. However, the functions of this muscle and the anatomic variations of the nerve... (Review)
Review
PURPOSE OF REVIEW
The superior laryngeal nerve (SLN) provides motor innervation to the cricothyroid muscle. However, the functions of this muscle and the anatomic variations of the nerve that supplies it are not fully understood. SLN paresis and paralysis (SLNp) is difficult to diagnose because of a lack of consistent laryngeal findings, and its effects on the voice likely go beyond simple pitch elevation control.
RECENT FINDINGS
Although SLNp has traditionally been thought to lead to voice pitch limitation, recent research findings reveal multiple roles for this nerve in voice and speech. Cricothyroid muscles are the primary controls of fundamental frequency of voice. SLNp can lead to significant contraction of pitch range, vocal fold vibratory phase asymmetry, and acoustic aperiodicity, thus leading to an overall poor vocal quality. In addition, cricothyroid muscles may also play a role in pitch lowering and shifting from voiced to unvoiced sounds during speech.
SUMMARY
Subtle signs, symptoms, and diagnostic findings associated with SLNp make this disorder difficult to characterize clinically. Lack of treatment methodologies to restore the dynamic action of the cricothyroid muscles poses difficulties in treating patients with this condition. A more thorough understanding of the effects of SLNp will improve diagnosis and treatment.
Topics: Humans; Laryngeal Nerve Injuries; Laryngeal Nerves; Prognosis
PubMed: 25136863
DOI: 10.1097/MOO.0000000000000097 -
The Annals of Otology, Rhinology, and... Feb 2024Superior laryngeal nerve (SLN) block consists of injection of steroid and anesthetic at the internal branch of the SLN entry site. Prior case series have demonstrated...
OBJECTIVE
Superior laryngeal nerve (SLN) block consists of injection of steroid and anesthetic at the internal branch of the SLN entry site. Prior case series have demonstrated beneficial effects on neurogenic cough. SLN blocks have also recently shown benefit for paralaryngeal pain. We describe short-term outcomes for multiple symptoms of irritable larynx syndrome (ILS) including neurogenic cough, dysphonia related to laryngeal hypersensitivity, inducible laryngeal obstruction (ILO), paralaryngeal pain, and isolated globus.
METHODS
Retrospective review from 2 institutions of patients undergoing a single SLN block for the indications listed. Variables include age, sex, indication(s), known vagus neuropathy, and patient-reported outcomes at short-term follow-up.
RESULTS
A total of 209 patients were included (59 males, 150 females; age: 58 ± 13 years). Twenty-six patients (12%) had a history of a vagus nerve injury. Indications included neurogenic cough (n = 149), dysphonia related to laryngeal hypersensitivity (n = 66), paralaryngeal pain (n = 50), ILO (n = 23), and isolated globus (n = 3). Some patients had multiple indications. Significant improvements in patient-reported measures occurred after a single SLN block within 2 to 4 weeks for neurogenic cough (cough severity index; 25.2 ± 11.2 to 19.0 ± 12.8; < .001), dysphonia (voice handicap index-10; 22.1 ± 12.2-18.0 ± 13.3; = .005), and ILO (dyspnea index; 21.0 ± 14.9-14.7 ± 15.7; = .017). Subjective pain improved in 23 of 39 patients with paralaryngeal pain. There was no observed improvement for isolated globus. Presence of known vagal neuropathy or therapy around the time of SLN block did not affect outcome.
CONCLUSION
SLN block can be an effective component of treatment for a variety of ILS symptoms. Patients may experience some improvement after 1 injection.
LAY SUMMARY
Symptoms of irritable larynx syndrome, such as neurogenic cough, paralaryngeal pain, inducible laryngeal obstruction, and dysphonia related to laryngeal hypersensitivity can be challenging to manage. In-office Superior Laryngeal Nerve blocks can serve as a quick, well tolerated, adjunctive treatment with positive short-term outcomes.
LEVEL OF EVIDENCE
4.
Topics: Male; Female; Humans; Middle Aged; Aged; Dysphonia; Larynx; Laryngeal Diseases; Airway Obstruction; Laryngeal Nerves; Cough; Pain
PubMed: 37608685
DOI: 10.1177/00034894231194384 -
Lung Feb 2014Cough and swallow are highly coordinated reflex behaviors whose common purpose is to protect the airway. The pharynx is the common tube for air and food/liquid movement... (Review)
Review
Cough and swallow are highly coordinated reflex behaviors whose common purpose is to protect the airway. The pharynx is the common tube for air and food/liquid movement from the mouth into the thorax, has been largely overlooked, and is potentially seen as just a passive space. The thyropharyngeus muscle responds to cough inducing stimuli to prepare a transient holding area for material that has been removed from the subglottic airway. The cricopharyngeus muscle participates with the larynx to ensure regulation of pressure when a bolus/air is moving from the upper airway through to the thorax (i.e., inspiration or swallow) or the reverse (i.e., expiration reflex or vomiting). These vital mechanisms have not been evaluated in clinical conditions but could be impaired in many neurodegenerative diseases, leading to aspiration pneumonia. These newly described airway protective mechanisms need further study, especially in healthy and pathologic human populations.
Topics: Animals; Cough; Deglutition; Humans; Laryngeal Nerves; Larynx; Pharynx; Pneumonia, Aspiration; Reflex; Trachea
PubMed: 24297325
DOI: 10.1007/s00408-013-9540-y -
Journal of Veterinary Internal Medicine Jul 2018Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses,... (Review)
Review
Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis. The associated laryngeal dysfunction and exercise intolerance in athletic horses commonly leads to surgical intervention, retirement or euthanasia with associated financial and welfare implications. Despite speculation, there is a lack of consensus and conflicting evidence supporting the primary classification of RLN, as either a distal ("dying back") axonopathy or as a primary myelinopathy and as either a (bilateral) mononeuropathy or a polyneuropathy; this uncertainty hinders etiological and pathophysiological research. In this review, we discuss the neuropathological changes and electrophysiological deficits reported in the RLn of affected horses, and the evidence for correct classification of the disorder. In so doing, we summarize and reveal the limitations of much historical research on RLN and propose future directions that might best help identify the etiology and pathophysiology of this enigmatic disorder.
Topics: Animals; Cranial Nerve Diseases; Horse Diseases; Horses; Recurrent Laryngeal Nerve
PubMed: 29691904
DOI: 10.1111/jvim.15142 -
Chemical Senses Dec 2020The larynx plays a key role in airway protection via the laryngeal chemoreflex (LCR). This involuntary reflex can be evoked when hazardous substances activate mucosal... (Review)
Review
The larynx plays a key role in airway protection via the laryngeal chemoreflex (LCR). This involuntary reflex can be evoked when hazardous substances activate mucosal receptors, which send signals to be processed within the brainstem. Although the LCR is meant to be protective, the reflex can become hyperstimulated, even to benign stimuli, which can result in pathological disorders, such as chronic cough and inducible laryngeal obstruction. In this review, we will outline the mechanism of the LCR and its associated pathological disorders.
Topics: Airway Obstruction; Animals; Apnea; Brain Stem; Chemoreceptor Cells; Cough; Humans; Laryngeal Nerves; Larynx; Reflex; Respiration Disorders
PubMed: 33247587
DOI: 10.1093/chemse/bjaa069 -
European Annals of Otorhinolaryngology,... Sep 2021Vocal morbidity resulting from damage to the motor branch of the superior laryngeal nerve (SLN) after endocrine surgery is well known, but diagnosis is often delayed....
OBJECTIVES
Vocal morbidity resulting from damage to the motor branch of the superior laryngeal nerve (SLN) after endocrine surgery is well known, but diagnosis is often delayed. The present study aimed to quantify these vocal changes acoustically (main objective), and correlate this with the vocal complaints of patients with suspected SLN motor impairment (secondary objective).
MATERIAL AND METHODS
Thirty females patients with suspected injury of the SLN cricothyroid branch (CT-) were compared to 30 patients without postoperative vocal impairment (CT+) and to 30 control subjects. Mean, minimal and maximal fundamental frequencies (F0mean, F0min and F0max) and vocal range were measured on /e/ at high frequency, sirens (glissandi), a reading text, and minimal intonation pairs. Subjective vocal impairment was evaluated on the Voice Handicap Index (VHI).
RESULTS
A lowering of F0mean associated with vocal range reduction by one fifth (in the reading text) seemed to be specific to CT- patients. Production of questions was affected, with differences in melodic curve and attack. Thyroidectomy within 2 months in itself (without suspected SLN cricothyroid branch injury) also affected these parameters, but to a lesser degree. CT- patients reported greater voice impairment than CT+ patients or controls (P=0.0004).
CONCLUSION
Alterations in speech intonation, quantified on minimal pair test, and self-assessed vocal handicap (VHI) are tools that can easily be used in daily practice to screen for SLN motor branch lesion.
Topics: Female; Humans; Laryngeal Nerves; Self Concept; Thyroidectomy; Voice; Voice Disorders
PubMed: 33309220
DOI: 10.1016/j.anorl.2020.11.007