Botulinum toxin treatment for oropharyngeal dysphagia in patients with stroke

Temporal Characteristics of Penetration and Aspiration in Patients with Severe Dysphagia Associated with Lateral Medullary Syndrome

To assess the severity and timing of penetration and aspiration (PA) of severe dysphagia after lateral medullary syndrome (LMS) and its association with temporal characteristics. We performed videofluoroscopic swallowing studies (VFSS) in 48 patients with LMS and severe dysphagia and 26 sex- and age-matched healthy subjects. The following temporal measures were compared between groups: velopharyngeal closure duration (VCD); hyoid bone movement duration (HMD); laryngeal vestibular closure duration (LCD); upper esophageal sphincter (UES) opening duration (UOD); stage transition duration (STD) and the interval between laryngeal vestibular closure and UES opening (LC-UESop). The association between temporal measures and Penetration-Aspiration Scale (PAS) scores was analyzed. Differences in timing measures were compared between subgroups (safe swallows, and swallows with PA events during and after the swallow). PAS scores ≥ 3 were seen in 48% of swallows (4% occuring before, 35% occurred during and 61% after the swallow) from the LMS patients. Significantly longer STD and LC-UESop were found in the patients compared to the healthy subjects (p < 0.05). Significant negative correlations with PA severity were found for HMD, LCD, and UOD. Short UOD was the strongest predictor with an area under the receiver-operating-characteristic curve of 0.66. UOD was also significantly shorter in cases of PA after the swallow (p < 0.01). Patients with LMS involving severe dysphagia exhibit a high frequency of PA (mostly during and after swallowing). PA events were associated with shorter UOD, HMD, and LCD. Notably, shortened UOD appears to be strongly associated with PA.

Guidelines for the Use of Botulinum Toxin in Otolaryngology From the Korean Society of Laryngology, Phoniatrics and Logopedics Guideline Task Force

The Korean Society of Laryngology, Phoniatrics and Logopedics created a task force to establish clinical practice guidelines for the use of botulinum toxin (BT) in otolaryngology. We selected 10 disease categories: spasmodic dysphonia, essential vocal tremor, vocal fold granuloma, bilateral vocal fold paralysis, Frey's syndrome, sialocele, sialorrhea, cricopharyngeal dysfunction, chronic sialadenitis, and first bite syndrome. To retrieve all relevant papers, we searched the CORE databases with predefined search strategies, including Medline (PubMed), Embase, the Cochrane Library, and KoreaMed. The committee reported 13 final recommendations with detailed evidence profiles. The guidelines are primarily aimed at all clinicians applying BT to the head and neck area. In addition, the guidelines aim to promote an improved understanding of the safe and effective use of BT by policymakers and counselors, as well as in patients scheduled to receive BT injections.

Research progress on transcranial magnetic stimulation for post-stroke dysphagia

Dysphagia is one of the most common manifestations of stroke, which can affect as many as 50–81% of acute stroke patients. Despite the development of diverse treatment approaches, the precise mechanisms underlying therapeutic efficacy remain controversial. Earlier studies have revealed that the onset of dysphagia is associated with neurological damage. Neuroplasticity-based transcranial magnetic stimulation (TMS), a recently introduced technique, is widely used in the treatment of post-stroke dysphagia (PSD) by increasing changes in neurological pathways through synaptogenesis, reorganization, network strengthening, and inhibition. The main objective of this review is to discuss the effectiveness, mechanisms, potential limitations, and prospects of TMS for clinical application in PSD rehabilitation, with a view to provide a reference for future research and clinical practice.

Clinical effect of repetitive transcranial magnetic stimulation on dysphagia due to stroke

BACKGROUND

Repetitive transcranial magnetic stimulation (rT) could change the excitability of the cerebral cortex, and control the neurotransmitter release, with the therapeutic effect depending on stimulation intensity and position. In this study, we used 3 Hz rTMS to stimulate the pharyngeal cortical area of the lesioned hemisphere and to explore its clinical significance in the treatment of dysphagia after acute cerebral infarction.

METHODS

A total of 61 in-patients with acute dysphagia caused by cerebral infarction hospitalized in the department of neurology of our hospital were included in this study and were assigned into the control and rTMS group. Patients in the control group only accepted the basic treatment of rehabilitation training, while patients in the rTMS group received additional rTMS (3 Hz) stimulation. The levels of the water swallowing test (WST) 14 days before and after the treatment of rTMS (3 Hz) would be recorded.

RESULTS

After different therapies in two groups, 9 patients of the control group showed excellent curative effect, with a recovery rate of 31.0%. However, in the rTMS group, the swallowing function of 21 patients was significantly improved, with a recovery rate of 65.6%. Comparison results showed that the recovery rate of the rTMS group was much better than the control group (P < 0.05), indicating an effective therapeutic effect of 3 Hz rTMS on patients with dysphagia after acute cerebral infarction.

CONCLUSION

Stimulating the target cortical representation areas of pharyngeal of the lesioned hemisphere with cerebral infarction by the rTMS (3 Hz) could improve the patients' function.

Botulinum Toxin Injection for the Treatment of Upper Esophageal Sphincter Dysfunction

Dysphagia associated with upper esophageal sphincter (UES) dysfunction remarkably affects the quality of life of patients. UES injection of botulinum toxin is an effective treatment for dysphagia. In comparison with skeletal muscles of the limb and trunk, the UES is a special therapeutic target of botulinum toxin injection, owing to its several anatomical, physiological, and pathophysiological features. This review focuses on (1) the anatomy and function of the UES and the pathophysiology of UES dysfunction in dysphagia and why the entire UES rather than the cricopharyngeal muscle before/during botulinum toxin injection should be examined and targeted; (2) the therapeutic mechanisms of botulinum toxin for UES dysfunction, including the choice of injection sites, dose, and volume; (3) the strengths and weaknesses of guiding techniques, including electromyography, ultrasound, computed tomography, and balloon catheter dilation for botulinum toxin injection of the UES.

Efficacy and Safety of Transcranial Direct Current Stimulation on Post-Stroke Dysphagia: A Systematic Review and Meta-Analysis

Dysphagia is one of the most common symptoms in patients after stroke onset, which has multiple unfavorable effects on quality of life and functional recovery. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation that is widely used to improve deglutition function. Recently, some studies have confirmed that tDCS enhances deglutition function after stroke. However, the number of evaluation indexes used in those studies was small, and the number of trials included was limited. Most importantly, the optimal stimulation protocol is still uncertain and the safety of tDCS has not been reviewed. Therefore, we conducted a systematic review and meta-analysis to address these shortcomings.

METHODS

Seven databases were searched entirely, including Pubmed, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Service System (SinoMed), Wan-fang database, and the Chinese Scientific Journals Database (VIP) from inception to 31 December 2021. Two reviewers independently evaluated the eligibility of retrieved data according to the selection criteria and assessed the methodological quality of the studies using the Cochrane risk of bias tool. Outcomes, measures, and indicators used in this study included the dysphagia outcome and severity scale (DOSS), modified Mann assessment of swallowing ability (MMASA), functional oral intake scale (FOIS), functional dysphagia scale (FDS), and Kubota's water-drinking test (KWDT). Sensitivity and subgroup analyses were performed to evaluate the intervention effect more specifically.

RESULTS

Fifteen trials with a total of 787 participants (394 subjects in the tDCS groups were treated with true tDCS, and 393 subjects in the control groups were wait-listed or treated with sham tDCS) involving tDCS for dysphagia after stroke and were included in the meta-analysis. Results of this meta-analysis confirmed that tDCS had a positive effect on post-stroke dysphagia. Subgroup analyses revealed that bilateral and high-intensity stimulation with tDCS had a more significant impact on post-stroke dysphagia. Furthermore, no adverse events occurred during the application of tDCS for post-stroke dysphagia.

CONCLUSION

tDCS can promote the recovery of deglutition function in patients with dysphagia after stroke. In addition, bilateral stimulation and high-intensity stimulation may have better effects. However, the safety evidence for tDCS and post-stroke dysphagia is insufficient.

Upper Gastrointestinal Functional and Motility Disorders in Children

Children with disorders affecting the sensory and motor functions of the esophagus will present primarily with swallowing dysfunction, dysphagia, and chest pain, and those with disorders affecting the normal function of the stomach will present with symptoms like abdominal pain, nausea, and vomiting. Recent advances in the mechanisms of disease and technology have increased our understanding of gastrointestinal physiology and that knowledge has been applied to develop new diagnostic studies and therapeutic interventions. We present an overview of the clinical presentation, diagnosis, and treatment of common primary and secondary functional and motility disorders affecting the upper gastrointestinal tract in children.

Comparative efficacy of non-invasive neurostimulation therapies for poststroke dysphagia: A systematic review and meta-analysis

OBJECTIVE

To explore the effect of non-invasive neurostimulation therapies on dysphagia patients after stroke.

METHODS

We searched MEDLINE (Ovid), PubMed, Embase, Web of Science, ScienceDirect, and Cochrane library databases until April 22, 2020. All published and unpublished randomized controlled trials (RCT) were included. Full texts were independently reviewed. The risk of RCT bias was evaluated by two independent assessors using the Cochrane risk of bias tool. The primary outcome measure was swallowing function before and after neurostimulation therapy. The effect sizes are calculated from the extracted data and combined into a comprehensive summary statistic.

RESULT

A total of 27 randomized controlled trials were included in this study, involving 914 stroke patients (27 intervention groups and 20 control groups). Meta-analysis showed that compared with the control group, noninvasive neurostimulation therapies (repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), surface neuromuscular electrical stimulation (sNMES) or pharyngeal electrical stimulation (PES)) had a better effect (SMD = 0.91; 95% CI: 0.54-1.27; Z = 4.84; P < 0.00001; I² = 86%). In the subgroup analysis based on type of stimulus, rTMS appeared to perform better. In the subgroup analysis based on clinical phase, stimulation applied in the acute phase may be more effective. In the subgroup analysis based on the site of injury, the brainstem injury group seemed to achieve better outcomes. In the subgroup analysis based on stroke type, the cerebral infarction group had better outcomes than the cerebral infarction/hemorrhage mixed group.

CONCLUSIONS

Non-invasive neurostimulation therapies can effectively promote the recovery of dysphagia after stroke.

The Effect of Combined Guidance of Botulinum Toxin Injection with Ultrasound, Catheter Balloon, and Electromyography on Neurogenic Cricopharyngeal Dysfunction: A Prospective Study

BACKGROUND

Cricopharyngeal botulinum toxin (BTX) injection is one of the treatments for neurogenic cricopharyngeal dysfunction (CPD). We conducted this prospective study to investigate the effect and safety of BTX injection for neurogenic CPD with a novel guidance.

METHODS

Twenty-one patients with neurogenic CPD whose symptoms did not reduce after conventional swallowing therapy were included in this study. The impact of BTX injection on the swallowing function of the patients was evaluated.

KEY RESULTS

After the injection, the Functional Oral Intake Scale (FOIS) score increased in 17 of 21 patients (80.9%), which ranged from 1 to 3 (P < 0.001). Moreover, there was a significant reduction in the UES opening impairment (P < 0.01), UES residual pressure (P < 0.05), duration of UES relaxation, penetration-aspiration scale score (P < 0.05), secretion (P < 0.05), vallecular residue (P < 0.01), and left (P < 0.05) and right (P < 0.05) pyriform sinus residue. With at least 6 months of follow-up, we found that FOIS continued to increase in patients who showed improvement after the injection (i.e., FOIS 5-7 points), while it remained unchanged in patients without improvement after the injection. There were no side effects reported in this study.

CONCLUSION & INFERENCES

BTX injection into the cricopharyngeal muscle guided by ultrasound, catheter balloon, and electromyography possibly has a long-lasting effect that can effectively and safely improve the swallowing function of patients with neurogenic CPD.

Design and implementation of botulinum toxin on cricopharyngeal dysfunction guided by a combination of catheter balloon, ultrasound, and electromyography (BECURE) in patients with stroke: study protocol for a randomized, double-blinded, placebo-controlled trial

Background

Cricopharyngeal dysfunction (CPD) occurs in various neurological disorders, especially stroke. The treatment approaches of CPD include swallowing training, cricopharyngeal dilation, botulinum toxin (BTX) injection, and cricopharyngeal myotomy. BTX injection into the cricopharyngeal muscle is effective and safe for some patients with dysphagia, with a success rate between 43 and 100% (mean = 76%). However, well-designed randomized controlled clinical trials are needed to verify its efficacy and safety for the treatment of CPD. The objective of this study is to explore the efficacy and safety of BTX for neurogenic cricopharyngeal achalasia, when administering an injection into the cricopharyngeal muscle guided by a novel precise positioning method, that combines ultrasound, catheter balloon, and electromyography (BECURE).

Methods

BECURE is a single-center randomized, placebo controlled, double-blinded, superiority clinical trial. To detect a significant difference between the 2 groups, a sample size of 44 patients is estimated. The intervention is BTX versus placebo, with 1:1 randomization. The randomization sequence from 1 to 44 was generated using the Statistical Package for Social Sciences. The study is divided into two phases. In the first phase, patients will be injected with BTX or the placebo. In the second phase, patients who received a placebo injection and those who did not respond to the first BTX injection will receive an injection of BTX. The primary outcome is the score of the Functional Oral Intake Scale (FOIS). The secondary outcomes are as follows: upper esophageal sphincter (UES) residual pressure, UES resting pressure, duration of UES relaxation, velopharyngeal and laryngopharyngeal peak pressure, UES opening, pharyngeal construction ratio, residue of bolus in the epiglottis valley or piriform sinus, and penetration and aspiration.

Discussion

Dysphagia is a common complication of stroke. There is lack of high-quality evidence for the efficacy of BTX in treating neurogenic CPD. This study will clarify whether BTX injection into the cricopharyngeal muscle can be effective and safe for patients with stroke and CPD.

Trial registration

Chinese Clinical Trial Register (ChiCTR1900025562). Registered on September 1, 2019.

Use of the Penetration-Aspiration Scale in Dysphagia Research: A Systematic Review

The penetration-aspiration scale (PAS) is an 8-point scale used to characterize the depth and response to airway invasion during videofluoroscopy. Though widely used in the field of deglutition, there is a lack of consensus regarding the statistical properties of the scale. In order to better understand the state of the literature and the statistical use of the PAS, a systematic review was undertaken to descriptively examine trends in statistical and reporting practices of the PAS since its inception. Online databases were searched for studies citing the original PAS article, which yielded 754 unique articles. Of these, 183 studies were included in the review. Results showed inconsistencies in the statistical use of the scale; 79 studies treated the PAS as ordinal, 71 as categorical, and 49 as interval. Ten types of categorizations were identified. Reporting of power analyses (9%), as well as inter- (26%) and intra-rater (17%) reliability, was uncommon. Among studies that administered multiple bolus volumes or consistencies, 55% reported PAS analyses at the participant/group level only. This review confirms the existence of discrepancies in the statistical treatment of the PAS. A lack of consensus among researchers limits comparisons between studies. The approach to handling this scale dictates the statistical tests used, potentially affecting results and interpretations. Consistent application of statistically sound approaches to PAS analyses is vital for the future of deglutition research.

Endoscopic botulinum toxin injection for treatment of pharyngeal dysphagia in patients with cricopharyngeal dysfunction

BACKGROUND

Dysphagia associated with neurologic disorders is a problem worldwide. However, few studies have assessed the efficacy of endoscopic botulinum toxin injections into the cricopharyngeal muscle using a pharyngoscope.

METHODS

Fourteen patients who received an endoscopic botulinum toxin injection due to cricopharyngeal muscle dysfunction and a neurological disorder from 2006 to 2017 were retrospectively reviewed at a single tertiary medical center. The toxin was injected at a 100 international unit (IU) total dose under direct endoscopic vision. The success of the procedure was evaluated comprehensively using the following: clinical resolution of the previous symptoms, functional oral intake scale (FOIS) for the clinical evaluation of swallowing, and videofluoroscopic swallowing study (VFSS) to check decreased retention of barium at the pyriform sinus and the epiglottic vallecula.

RESULTS

The study included 12 males and 2 females (mean age, 58 years old; range, 37-82 years). Three patients (21.4%) were confirmed clinically and eleven were confirmed by VFSS. Eleven patients (78.6%) were managed successfully with the injection. Three patients (21.4%) did not improve despite the injection.

CONCLUSION

An endoscopic botulinum toxin injection may be a good treatment option for patients with dysphagia and cricopharyngeal dysfunction due to a neurological disorder. Large, prospective, long-term follow-up studies are needed in the future.

Botulinum Toxin Is Effective in the Management of Neurogenic Dysphagia. Clinical-Electrophysiological Findings and Tips on Safety in Different Neurological Disorders

Background and Aims: Neurogenic dysphagia linked to failed relaxation of the upper esophageal sphincter (UES) can be treated by injecting botulinum toxin (BTX) into the cricopharyngeal (CP) muscle. We compared the effects of this treatment in different neurological disorders with dysphagia, to evaluate its efficacy over time including the response to a second injection. Materials and Methods: Sixty-seven patients with neurogenic dysphagia associated with incomplete or absent opening of the UES (24 with brainstem or hemispheric stroke, 21 with parkinsonian syndromes, 12 with multiple sclerosis, and 10 with spastic-dystonic syndromes secondary to post-traumatic encephalopathy) were treated with the injection of IncobotulinumtoxinA (dose 15-20 U) into the CP muscle under electromyographic guidance. The patients were assessed at baseline and after the first and second treatment through clinical evaluation and fiberoptic endoscopy of swallowing, while their dysphagia was quantified using the Dysphagia Outcome and Severity Scale (DOSS). An electrokinesiographic/electromyographic study of swallowing was performed at baseline. Results: Most patients responded to the first BTX treatment: 35 patients (52.2%) were classified as high responders (DOSS score increase >2 levels), while other 19 patients (28.4%) were low responders (DOSS score increase of ≤2 levels). The effect of the first treatment usually lasted longer than 4 months (67%), and in some cases up to a year. The treatment efficacy remained high also after the second injection: 31 patients (46.3%) qualified as high responders and other 22 patients (32.8%) showed a low response. Only in the parkinsonian syndromes group we observed a reduction in the percentage of high responders as compared with the first treatment. Side effects were mostly mild and reported in non-responders following the first injection. A severe side effect, consisting of ingestion pneumonia, was observed following the second BTX injection in two patients who had both been non-responders to the first. Non-responders were characterized electromyographically by higher values of the oropharyngeal interval. Conclusion: These findings confirm the effectiveness of IncobotulinumtoxinA injection in the treatment of neurogenic dysphagia due to hyperactivity and relaxation failure of the UES. Caution should be used as regards, the re-injection in non-responders to the first treatment.

Failed Deglutitive Upper Esophageal Sphincter Relaxation Is a Risk Factor for Aspiration in Stroke Patients with Oropharyngeal Dysphagia

Background/Aims

We attempted to examine the relationship between abnormal findings on high-resolution manometry (HRM) and videofluoroscopic swallowing study (VFSS) of the pharynx and upper esophageal sphincter (UES), and to identify the risk factors for aspiration.

Methods

We performed VFSS and HRM on the same day in 36 ischemic stroke patients (mean age, 67.5 years) with dysphagia. Pressure (basal, median intra bolus, and nadir), relaxation time interval of the UES, and mesopharyngeal and hypopharyngeal contractility (as a contractile integral) were examined using HRM. The parameters of VFSS were vallecular residue, pyriform sinus residue, vallecular overflow, penetration, and aspiration. The association between the parameters of VFSS and HRM was analyzed by the Student’s t test.

Results

Three (8.3%) and 4 (11.1%) stroke patients with dysphagia had pyriform sinus residue and vallecular sinus residue, respectively, and 5 (13.8%) patients showed aspiration. Mesopharyngeal and hypopharyngeal contractile integrals in patients with residue in the pyriform sinus were significantly lower than those in patients without residue in the pyriform sinus (P < 0.05). Relaxation time intervals in patients with aspiration were significantly shorter than those in patients without aspiration (P < 0.05), and multivariate regression analysis revealed a shorter relaxation time interval as the main risk factor for aspiration (OR, 0.03; 95% CI, 0.01–0.65; P < 0.05).

Conclusions

Manometric measurements of the pharynx and UES were well correlated with abnormal findings in the VFSS, and a shorter relaxation time interval of the UES during deglutition is an important parameter for the development of aspiration.

Oropharyngeal dysphagia: manifestations and diagnosis

Swallowing disorders (dysphagia) have been recognized by the WHO as a medical disability associated with increased morbidity, mortality and costs of care. With increasing survival rates and ageing of the population, swallowing disorders and their role in causing pulmonary and nutritional pathologies are becoming exceedingly important. Over the past two decades, the study of oropharyngeal dysphagia has been approached from various disciplines with considerable progress in understanding its pathophysiology. This Review describes the most frequent manifestations of oropharyngeal dysphagia and the clinical as well as instrumental techniques that are available to diagnose patients with dysphagia. However, the clinical value of these diagnostic tests and their sensitivity to predict outcomes is limited. Despite considerable clinical research efforts, conventional diagnostic methods for oropharyngeal dysphagia have limited proven accuracy in predicting aspiration and respiratory disease. We contend that incorporation of measurable objective assessments into clinical diagnosis is needed and might be key in developing novel therapeutic strategies.

Effectiveness of Non-invasive Brain Stimulation in Dysphagia Subsequent to Stroke: A Systemic Review and Meta-analysis

The objective of this study is to assess the efficacy and safety of non-invasive brain stimulation (NIBS) in patients with dysphagia subsequent to stroke. A systematic search of the literature published by Medline (January 1, 1976 through June 21, 2013), EMBASE (January 1, 1985 through June 21, 2013), and the Cochrane Library (January 1, 1987 through June 21, 2013) was conducted for all relevant articles related to NIBS, dysphagia, and cerebrovascular disorders (CVD). Two reviewers (S.N.Y and S.B.P) independently evaluated the eligibility of retrieved data according to the selection criteria and assessed methodological quality of the studies using the 'assessing risk of bias' table recommended in the Cochrane Handbook for Systematic Reviews of Interventions (version 5.0.2). Six randomized controlled trials (59 intervention groups and 55 placebo groups) were identified as addressing the use of NIBS for dysphagia after CVD and were included in the meta-analysis. The function scale score improvement of dysphagia in patients treated with NIBS was statistically significant compared with that of patients who underwent sham stimulation (standardized mean difference = 1.08, 95 % confidence intervals = 0.29-1.88, p = 0.008; I (2) = 72 %). A subgroup analysis based on the type of intervention (three repetitive transcranial magnetic stimulation (rTMS) studies and three transcranial direct current stimulation (tDCS) studies) revealed a statistically significant beneficial effect of NIBS compared with sham stimulation in the rTMS group, but not in the tDCS group. When the results were examined based on intervention site (ipsilesional vs. contralesional site stimulation), no statistically significant difference was noted between two groups. No complications of NIBS were reported in this analysis.

Treatment of gastrointestinal sphincters spasms with botulinum toxin A

Botulinum toxin A inhibits neuromuscular transmission. It has become a drug with many indications. The range of clinical applications has grown to encompass several neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum toxin A provides benefit in diseases of the gastrointestinal tract. Although toxin blocks cholinergic nerve endings in the autonomic nervous system, it has also been shown that it does not block non-adrenergic non-cholinergic responses mediated by nitric oxide. This has promoted further interest in using botulinum toxin A as a treatment for overactive smooth muscles and sphincters. The introduction of this therapy has made the treatment of several clinical conditions easier, in the outpatient setting, at a lower cost and without permanent complications. This review presents current data on the use of botulinum toxin A in the treatment of pathological conditions of the gastrointestinal tract.

Botulinum toxin for upper oesophageal sphincter dysfunction in neurological swallowing disorders

BACKGROUND

Adequate upper oesophageal sphincter (UOS) opening is critical to safe and efficient swallowing due to the close proximity of the UOS to the airway entrance. Many people with neurological conditions, progressive and non-progressive, present with UOS dysfunction. The consequences for the person include difficulty swallowing food with subsequent choking and aspiration (passage of material into the trachea beyond the level of the true vocal cords). Clinical complications include aspiration pneumonia, weight loss, dehydration and malnutrition. Tube feeding is often indicated but is associated with increased mortality. Quality of life is also frequently impacted. A range of interventions exist that aim to improve UOS function and swallowing. These include compensatory strategies, rehabilitation techniques, pharmacological interventions and surgery. Over the last two decades, botulinum toxin has been gaining popularity as an intervention for UOS dysfunction, with some evidence to suggest that it is successful in improving swallow function. Despite a number of studies investigating its efficacy, there is a lack of consensus regarding whether this intervention is effective in improving swallowing for individuals with UOS dysfunction associated with neurological disease.

OBJECTIVES

To establish the efficacy and safety of botulinum toxin use aimed at improving UOS dysfunction in people with swallowing difficulties (dysphagia) associated with non-progressive and progressive neurological disease.

SEARCH METHODS

We searched the following electronic databases for published trials: the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (1950 to 2013); EMBASE (1980 to 2013); AMED (Allied and Complementary Medicine) (1941 to 2013); CINAHL (Cumulative Index to Nursing and Allied Health Literature) (1937 to 2013). We also searched major clinical trials registers: CCT (http://www.controlled-trials.com); Clinical Trials (http://www.clinicaltrials.gov); Chinese Clinical Trial Register (www.chictr.org); ACTR (http://www.actr.org.au/. We examined the reference lists of all potentially relevant studies to identify further relevant trials. We handsearched published abstracts of conference proceedings from both the Dysphagia Research Society and the European Society of Swallowing Disorders. Digestive Disease Week (published in Gastroenterology) was also handsearched. Additionally, we searched ProQuest Dissertations & Theses for dissertation abstracts.

SELECTION CRITERIA

Only randomised controlled trials were sought.

DATA COLLECTION AND ANALYSIS

Independent searches were completed by JR, AM, MC and MW. Two review authors (JR and MW) independently inspected titles, abstracts and key words identified from the literature search.

MAIN RESULTS

No randomised controlled studies were retrieved. Twenty-nine studies were excluded, mainly on the basis of trial design.

AUTHORS' CONCLUSIONS

It was not possible to reach a conclusion on the efficacy and safety of botulinum toxin as an intervention for people with UOS dysfunction and neurological disease. There is insufficient evidence to inform clinical practice. Directions for future research are provided.