Chronic Pain Syndromes and Their Laryngeal Manifestations

Laryngeal and Global Somatosensation in Primary Muscle Tension Dysphonia

INTRODUCTION

Primary muscle tension dysphonia (pMTD) is a functional voice disorder that reduces communicative abilities and adversely impacts occupational productivity and quality of life. Patients with pMTD report increased vocal effort, fatigue, discomfort, and odynophonia. Although laryngeal and paralaryngeal muscle tension and hyperfunction are the most commonly proposed mechanisms underlying these symptoms, recent studies suggest pMTD may have more to do with the somatosensory system. However, relationships between voice symptoms and somatosensory mechanisms are poorly understood, creating challenges for mechanistic-based pMTD management. The first objective was to compare laryngeal, paralaryngeal, and global somatosensation between subjects with and without pMTD. The second was to determine relationships between pMTD symptoms and somatosensation.

METHODS

Fifty-two (20 pMTD and 32 control) subjects underwent laryngeal sensory testing with aesthesiometers, as well as peripheral mechanosensory and dynamic temporal summation testing to paralaryngeal and limb regions. Voice symptom severities (vocal effort, fatigue, discomfort, and odynophonia) were collected on 100-mm visual analog scales before and after laryngeal sensory testing. Participants also completed the Central Sensitization Inventory.

RESULTS

Patients with pMTD reported significantly higher laryngeal sensations (P = 0.0072) and voice symptom severities (P < 0.001) compared with the control group, and had significantly more vocal tract discomfort postlaryngeal sensory testing compared with the prelaryngeal sensory testing timepoint (P = 0.0023). However, there were no significant group differences in laryngeal airway protection responses suggestive of peripheral laryngeal hypersensitivities (P = 0.444). There were also no significant group differences on paralaryngeal or global sensitivities (P > 0.05), and no correlations between severity of voice symptoms and perceptual laryngeal sensations or hypersensitivities (P > 0.05).

CONCLUSION

Patients with pMTD perceive more sensitivities in the larynx and feel more sensations related to the voice (vocal effort, fatigue, discomfort, and pain). However, in general, patients with pMTD do not have abnormal peripheral laryngeal hypersensitivities, increased global somatosensation, or heightened central sensitivity. The lack of significant correlations between peripheral laryngeal hypersensitivities and voice symptom severity ratings suggests these outcome variables target distinct mechanistic constructs.

Voice Disorders in Patients with Fibromyalgia: Case Series and Review of the Literature

OBJECTIVE

To investigate the prevalence of phonatory disorders and their impact on quality of life in a cohort of patients with fibromyalgia (FMS), and to review the literature.

STUDY DESIGN

Prospective cohort study.

METHODS

All adult patients presenting to the rheumatology clinic at a tertiary referral center between January 2024 and April 2024 and diagnosed with FMS were prospectively recruited. The primary outcome measure used to screen for dysphonia was the Voice Handicap Index-10 (VHI-10). All patients were also asked to fill the Fibromyalgia Rapid Screening Tool (FiRST) and the short form of the McGill pain questionnaire (SF-MPQ).

RESULTS

A total of 70 female patients were included, divided equally into a study and control group (n = 35). The mean FiRST score and the mean SF-MPQ score were significantly higher in the study group compared to the control group (6.20 ± 1.05 vs 1.26 ± 1.65) and (26.14 ± 13.16 vs 2.6 ± 4.23), respectively. There was a statistically significant difference in the mean VHI-10 score between the study group and the control group (8.51 ± 7.66 vs 0.74 ± 0.98; P < 0.001). More than one third of patients in the study group had a VHI-10 score above 11 (37.1%) compared to none in the control group (P < 0.001). There was a strong positive correlation between the VHI-10 score and the FiRST and SF-MPQ scores (r = 0.612; P < 0.001 and r = 0.794; P < 0.001, respectively).

CONCLUSION

The findings suggest that two out five patients with FMS have vocal complaints that impact their quality of life. Healthcare providers need to recognize these phonatory disorders, that are often masked by other systemic manifestations of the disease.

Respiratory dysfunction in persistent somatic symptoms: A systematic review of observational studies

OBJECTIVE

This systematic review aims to analyze the existing literature investigating respiratory functioning in people with Persistent Somatic Symptoms (PSS) compared to healthy controls, to identify patterns of respiratory disturbances by symptom or syndrome, and describe any respiratory outcomes consistent across diagnoses.

METHODS

A systematic review following PRISMA guidelines was conducted. A comprehensive search was carried out across five databases (PubMed (NCBI), PsycArticles (Ovid), Web of Science (Core Collection), Embase, and Scopus) using two customised search strings for persistent somatic symptoms and objective respiratory parameters. Title/abstract screening and data extraction were carried out independently by two reviewers. The modified Newcastle-Ottawa Scale was used for quality assessment of the studies. Studies investigating baseline respiratory functioning in adult patients with PSS compared to healthy controls, using at least one objective respiratory were included.

RESULTS

18 studies met the inclusion criteria for the review, with a pooled sample size of n = 3245. Chronic pain conditions were found to be the most prevalent subset of diagnoses of interest, comprising six of the studies. 10 studies included measures of lung capacity, flow and/or volume, nine studies reported measures of ventilation, and four studies investigated respiratory muscle functioning. 13 of the included studies reported significant differences in at least one objective respiratory measure between groups (at rest). Scores on self-reported measures of dysnpea and breathlessness were higher in patients compared to healthy controls, while objective respiratory outcomes were varied.

CONCLUSION

The current systematic review is consistent with previous literature suggesting more pronounced experiences of breathlessness in patients with PSS, and significant disparities between reported dyspnea and objective respiratory outcomes. Research investigating the uncoupling between subjective and objective respiratory outcomes is needed to understand the mechanisms behind breathing disturbances in PSS.

The Prevalence and Nature of Eating and Swallowing Problems in Adults with Fibromyalgia: A Systematic Review

Fibromyalgia is a complex chronic pain condition characterized by widespread pain, fatigue, cognitive dysfunction, and sleep disturbances. People with fibromyalgia can experience both autonomic and somatic disturbances, cognitive and mental health symptoms, and hypersensitivity to external stimuli. Fibromyalgia often co-occurs with a range of well-researched comorbidities (e.g., temporomandibular disorders, migraine, and irritable bowel syndrome). However, emerging research suggests that individuals with fibromyalgia also often experience eating, drinking, and swallowing problems (e.g., odynophagia, glossodynia, etc.). However, there is very little known about these issues, their psychosocial impact, or the best means of managing them clinically. As such, the aim of this research was to examine the epidemiology, prevalence and nature of eating and swallowing problems in adults with fibromyalgia as reported within previous research. A systematic search of electronic databases, selected conference proceedings, and reference lists was completed in March 2021, with no date or language restrictions. Studies reporting the presence and nature of eating and drinking problems in this cohort were included. Eligibility was assessed by two independent reviewers who also critically appraised the included studies using the Joanna Briggs Tool. This literature search yielded a total of 38 potentially eligible studies, with 6 studies included in analysis. Studies were highly heterogeneous in methodology and design, with meta-analysis showing that dysphagia and GERD are prevalent in fibromyalgia patients (51.9% and 25.9%, respectively), among other issues. From review of existing literature, eating and swallowing problems appear to be common among adults with fibromyalgia, with potential additional repercussions for activity, participation, and quality of life. Further research is required to prospectively investigate these issues, with patient and public involvement necessary to guide impactful research planning.

Interoception, Voice Symptom Reporting, and Voice Disorders

OBJECTIVES

Interoception may play a role in how individuals perceive their voice disorder. The first objective of this study was to investigate relationships between interoception and voice disorder class (functional, structural, neurological). The second objective was to determine relationships between interoception and voice-related outcome measures between patients with functional voice and upper airway disorders and typical voice users. The third objective was to determine whether patients with primary muscle tension dysphonia (a type of functional voice disorder) had different levels of interoceptive awareness than typical voice users.

STUDY DESIGN

Prospective cohort study.

METHODS

One hundred subjects with voice disorders completed the multidimensional assessment of interoceptive awareness-2 (MAIA-2). Voice diagnosis and singing experience were also acquired from each patient's medical chart. Voice handicap (VHI-10) and Part 1 of the vocal fatigue index (VFI-Part1) scores were obtained from patients diagnosed with functional voice and upper airway disorders. MAIA-2, VHI-10, VFI-Part1, and singing experience were also obtained from 25 typical voice users. Multivariable linear regression models were used to assess the association between response variables and voice disorder class, adjusting for singing experience, gender, and age.

RESULTS

There were no significant group differences between voice disorder class (functional, structural, neurological) after adjusting for multiple comparisons. Participants with functional voice and upper airway disorders who scored significantly higher on the VHI-10 and VFI-Part1 had lower Attention Regulation sub-scores on the MAIA-2 (P's<0.05). Patients with primary muscle tension dysphonia scored significantly lower on the Emotional Awareness MAIA-2 subscale than typical voice users (P=0.005).

CONCLUSION

Patients with functional voice disorders with lower capabilities to attend to body sensations may score higher on voice-related patient-reported outcome measures, like the VHI-10 and VFI-Part1. Patients with primary muscle tension dysphonia may also have lower capabilities in processing their body sensations than typical voice users.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

Scoping review and interpretation of myofascial pain/fibromyalgia syndrome: An attempt to assemble a medical puzzle

BACKGROUND

Myofascial Pain Syndrome (MPS) is a common, overlooked, and underdiagnosed condition and has significant burden. MPS is often dismissed by clinicians while patients remain in pain for years. MPS can evolve into fibromyalgia, however, effective treatments for both are lacking due to absence of a clear mechanism. Many studies focus on central sensitization. Therefore, the purpose of this scoping review is to systematically search cross-disciplinary empirical studies of MPS, focusing on mechanical aspects, and suggest an organic mechanism explaining how it might evolve into fibromyalgia. Hopefully, it will advance our understanding of this disease.

METHODS

Systematically searched multiple phrases in MEDLINE, EMBASE, COCHRANE, PEDro, and medRxiv, majority with no time limit. Inclusion/exclusion based on title and abstract, then full text inspection. Additional literature added on relevant side topics. Review follows PRISMA-ScR guidelines. PROSPERO yet to adapt registration for scoping reviews.

FINDINGS

799 records included. Fascia can adapt to various states by reversibly changing biomechanical and physical properties. Trigger points, tension, and pain are a hallmark of MPS. Myofibroblasts play a role in sustained myofascial tension. Tension can propagate in fascia, possibly supporting a tensegrity framework. Movement and mechanical interventions treat and prevent MPS, while living sedentarily predisposes to MPS and recurrence.

CONCLUSIONS

MPS can be seen as a pathological state of imbalance in a natural process; manifesting from the inherent properties of the fascia, triggered by a disrupted biomechanical interplay. MPS might evolve into fibromyalgia through deranged myofibroblasts in connective tissue ("fascial armoring"). Movement is an underemployed requisite in modern lifestyle. Lifestyle is linked to pain and suffering. The mechanism of needling is suggested to be more mechanical than currently thought. A "global percutaneous needle fasciotomy" that respects tensegrity principles may treat MPS/fibromyalgia more effectively. "Functional-somatic syndromes" can be seen as one entity (myofibroblast-generated-tensegrity-tension), sharing a common rheuma-psycho-neurological mechanism.