Occupational vocal cord dysfunction due to exposure to wood dust and xerographic toner

Examining the Influence of Chemosensation on Laryngeal Health and Disorders

Inhaled airborne stimuli are associated with laryngeal disorders affecting respiration. Clinically, several themes emerged from the literature that point to specific gaps in the understanding and management of these disorders. There is wide variation in the types of airborne stimuli that trigger symptoms, lack of standardization in provocation challenge testing using airborne stimuli, and vague reporting of laryngeal symptoms. Scientifically, evidence exists outside the field of voice science that could prove useful to implement among patients with impaired laryngeal-respiration. To expand this area of expertise, here we provide a thematic overview of relevant evidence and methodological tools from the discipline of chemosensory sciences. This review provides distinctions across the three chemosensory systems of olfaction, trigeminal chemesthesis, and gustation, guidance on selecting and delivering common chemosensory stimuli for clinical testing, and methods of quantifying sensory experiences using principles of human psychophysics. Investigating the science of chemosensation reveals that laryngeal responses to inhaled airborne stimuli have explanations involving physiological mechanisms as well as higher cognitive processing. Fortunately, these findings are consistent with current pharmacological and nonpharmacological interventions for impaired laryngeal-respiration. Based on the close relationships among inhaled airborne stimuli, respiration, and laryngeal function, we propose that new perspectives from chemosensory sciences offer opportunities to improve patient care and target areas of future research.

Underlying Mechanisms in Episodic Laryngeal Breathing Disorders

The study and management of episodic laryngeal breathing disorders (ELBD)—characterized by paradoxical laryngeal movement patterns and dyspnea—has traditionally focused on clinical presentation of these conditions. However, the underlying mechanisms driving these entities are largely unknown. This article provides a review of potential underlying mechanisms driving clinical expression in ELBD and suggests approaches to the future study of ELBD etiology.

Irritant-Induced Paradoxical Vocal Fold Motion Disorder

Objectives

To review our experience with the diagnosis and treatment of irritant-induced paradoxical vocal fold motion disorder (IPVFMD).

Study Design

Retrospective chart review.

Setting

Tertiary academic referral center.

Subjects and Methods

Thirty-four cases that met IPVFMD criteria and 76 cases of non-IPVFMD were selected from a database of patients with paradoxical vocal fold motion disorder—the diagnosis of which was made on the basis of flexible fiberoptic laryngoscopy and augmented by an odor challenge. Clinical charts were reviewed to document history of environmental allergies, pulmonary disease, gastroesophageal reflux, psychiatric disorder, fibromyalgia, tobacco use, alcohol use, dysphonia, cough, dysphagia, and treatment outcomes.

Results

There were no statistical differences between the IPVFMD and non-IPVFMD groups. Of the patients who were assigned and attended laryngeal control therapy, 13 (65%) reported improvement of symptoms. Symptom improvement increased to 100% in those patients who attended at least 2 laryngeal control therapy sessions.

Conclusions

IPVFMD should be considered in patients presenting with respiratory symptoms after irritant exposure. Sensitivity of diagnosis can be improved via a standardized approach consisting of a careful history and physical examination, including laryngoscopy in the presence of triggers. Laryngeal control therapy is a well-tolerated and effective method of managing IPVFMD.

Associations between voice ergonomic risk factors and acoustic features of the voice

The associations between voice ergonomic risk factors in 40 classrooms and the acoustic parameters of 40 schoolteachers' voices were investigated. The risk factors assessed were connected to participants' working practices, working postures, and the indoor air quality in their workplaces. The teachers recorded spontaneous speech and sustained /a/ before and after a working day. Fundamental frequency, sound pressure level, the slope of the spectrum, perturbation, and harmonic-to-noise ratio were analysed. The results showed that the more the voice ergonomic risk factors were involved, the louder the teachers' voices became. Working practices correlated most often with the acoustic parameters; associations were found especially before a working day. The results suggest that a risky voice ergonomic environment affects voice production.

Small things make a big difference: particulate matter and exercise

The increased risk of morbidity and mortality among adults and children with pre-existing cardiovascular or respiratory illness from emission-derived particulate matter (PM) is well documented. However, the detrimental effects of PM inhalation on the exercising, healthy population is still in question. This review will focus on the acute and chronic responses to PM inhalation during exercise and how PM exposure influences exercise performance. The smaller ultrafine PM (<0.01 μm aerodynamic diameter) appears to have the most severe health consequences compared with the larger coarse PM (2.5 < PM <10 μm aerodynamic diameter). While the response to PM inhalation may affect those with a pre-existing condition, the healthy population is not immune to the effects of PM inhalation, especially during exercise. This population, including the competitive athlete, is susceptible to pulmonary inflammation, decreased lung function (both acute and chronic in nature), the increased risk of asthma, vascular endothelial dysfunction, mild elevations in pulmonary artery pressure and diminished exercise performance. PM exposure is usually associated with vehicular traffic, but other sources of PM, including small engines from lawn and garden equipment, cigarette smoke, wood smoke and cooking, may also impair health and performance. The physiological effects of PM are dependent on the source of PM, various environmental factors, physical attributes and nature of exercise. There are a number of measures an athlete can take to reduce exposure to PM, as well as the deleterious effects that result from the inevitable exposure to PM. Considering the acute and chronic physiological responses to PM inhalation, individuals living and exercising in urban areas in close proximity to major roadways should consider ambient air pollution levels (in particular, PM and ozone) prior to engaging in vigorous exercise, and those exposed to PM through other sources may need to make lifestyle alterations to avoid the deleterious effects of PM inhalation. Although it is clear that PM exposure is detrimental to healthy individuals engaging in exercise, further research is necessary to better understand the role of PM on athlete health and performance, as well as measures that can attenuate the harmful effects of PM.

Evidence for primary laryngeal inhalant allergy: a randomized, double-blinded crossover study

BACKGROUND

Despite anecdotal reports, no controlled studies to date link allergen exposure with a change in vocal function or dysphonia. The aim of this study was to determine whether allergen exposure in susceptible individuals impairs vocal function.

METHODS

The study was a prospective, double-blind, placebo-controlled study in which subjects serve as their own controls. The participants were 5 inhalant allergic adults with suspected dysphonia from allergies, without evidence of reactive lower airways based on methacholine challenge. All subjects were exposed to 2 experimental conditions in which they were challenged with (1) orally inhaled diluent placebo on 1 day, and (2) orally inhaled allergen on another day. Conditions were randomly ordered across subjects and separated by at least 48 hours. Phonatory threshold pressure (PTP) at the 80th percentile pitch was measured prior to diluent and allergen challenge, and 15 and 60 minutes postchallenge to assess potential change in vocal function after challenge testing.

RESULTS

A repeated measures ANOVA revealed a significant main effect for treatment (allergen vs placebo, p = 0.013) with greater PTP required post-allergen challenge compared to placebo and an effect size of 0.821.

CONCLUSION

A primary causal relationship between allergen exposure and impaired vocal function, as assessed by PTP, was observed in adults with documented allergy independent of asthma or nasal exposure. The current design establishes a safe model for laryngeal inhalant allergen challenge.

Fine and ultrafine particles emitted from laser printers as indoor air contaminants in German offices

PURPOSE

Various publications indicate that the operation of laser printers and photocopiers may be associated with health effects due to the release of gaseous components and fine and ultrafine particles (UFP). However, only sparse studies are available that evaluate the possible exposure of office workers to printer emissions under real conditions. Therefore, the aim of our study was to assess the exposure of office workers to particulate matter released from laser printers and photocopiers.

METHODS

Concentrations of fine particles and UFP were measured before, during, and after the operation of laser printing devices in 63 office rooms throughout Germany. Additionally, the particles were characterized by electron microscopy and energy-dispersive X-ray spectroscopy.

RESULTS

A significant increase of fine particles and UFP was identified in ambient workplace air during and after the printing processes. Particle fractions between 0.23 and 20 μm emitted by the office machines significantly affect particle mass concentrations while printing 500 pages, i.e., during the printing process, PM(0.23-20), PM(2.5), and PM(10) concentrations increased in 43 out of the evaluated 62 office rooms investigated. Additionally, a significant increase was observed in submicrometer particles, with median particle number concentrations of 6,503 particles/cm(3) before and 18,060 particles/cm(3) during the printing process.

CONCLUSIONS

Our data indicate that laser printers and photocopiers could be a relevant source of fine particles and particularly UFP in office rooms.

Paradoxical vocal cord motion: classification and treatment

Paradoxical vocal cord motion (PVCM), or vocal cord dysfunction, is a descriptive term for inappropriate adduction of the vocal folds during respiration. The laryngeal mistiming leads to breathing difficulty and is often misdiagnosed as refractory asthma. The etiology of PVCM has been unclear but has long been hypothesized to be psychological. The present thesis is a prospective study of 170 patients older than 18 years being evaluated for PVCM, with 117 of the 170 (68.8%) identified as having PVCM by video laryngoscopy. Laryngeal edema (P = .021) and reflux (P = .026) were increased in patients with PVCM. A flat inspiratory arm of the flow volume loop during spirometry testing was a predictor of PVCM (P = .034). A subgroup of 47 newly diagnosed patients with PVCM underwent psychological analysis. The psychological profiles were elucidated using the Minnesota Multiphasic Personality Inventory and the Life Experiences Survey to evaluate stress. Compared to established normative data, PVCM demonstrated a conversion disorder pattern (P < .01) but not an anxiety disorder or a correlation with stress. A subgroup, 11 of the 47 (23.4%), had normal psychological outcomes, and two of the 47 (4.3%) were identified as malingering. Previous studies have suggested that PVCM is strictly a psychological disorder. It is proposed that PVCM is a descriptive term that is multifactorial and the etiology should direct treatment. A classification scheme divides PVCM into primary, or psychological, and secondary. The secondary form consists of medical disorders divided into irritable larynx syndrome and neurologic disorders.

Vocal cord dysfunction and asthma

PURPOSE OF REVIEW

Vocal cord dysfunction can occur independently or can co-exist with asthma. It often mimics asthma in presentation and can be challenging to diagnose, particularly in those with known asthma. Vocal cord dysfunction remains under-recognized, which may result in unnecessary adjustments to asthma medicines and increased patient morbidity. There is a need to review current literature to explore current theories regarding disease presentation, diagnosis, and treatment.

RECENT FINDINGS

The underlying cause of vocal cord dysfunction is likely multifactorial but there has been increased interest in hyper-responsiveness of the larynx. Many intrinsic and extrinsic triggers have been identified which in part may explain asthma-like symptomatology. A variety of techniques have been reported to provoke vocal cord dysfunction during testing which may improve diagnosis. There is a significant gap in the literature regarding specific laryngeal control techniques, duration of therapy, and the effectiveness of laryngeal control as a treatment modality.

SUMMARY

Those with vocal cord dysfunction and asthma report more symptoms on standardized asthma control questionnaires, which can result in increasing amounts of medication if vocal cord dysfunction is not identified and managed appropriately. Clinicians need to maintain a high index of suspicion to identify these patients. Videolaryngostroboscopy remains the diagnostic method of choice. Evidence-based guidelines are needed for the most effective diagnostic techniques. Laryngeal control taught by speech pathologists is the most common treatment. Effectiveness is supported in case reports and clinical experience, but not in larger randomized trials which are needed.

What role do mucins have in the development of laryngeal squamous cell carcinoma? A systematic review

Mucins are the dominant component in the protective mucus layer on mucosal surfaces including the larynx. Hence, they are part of the first line of defence against external stimuli including effect of smoking in the larynx. We asked whether existing published evidence supported the hypothesis that alteration in mucins expression/production is related to the laryngeal neoplastic process. The objective of this study is to review published evidence for mucins having an important role in normal laryngeal physiology and the development of laryngeal squamous cell carcinoma (SCC). We aimed to review all available literature on mucins in the larynx in order to develop hypotheses to be tested by future research. Thereby, new potential means of prevention and treatment of laryngeal cancer may be developed. A systematic search of all published literature was conducted. Systematic searches were done in the following databases: AMED, BNI, EMBASE, HMIC, MEDLINE, PsycINFO, CINAHL and HEALTH BUSINESS ELITE from their respective inception up to 11 February 2011. The following keywords were used in combination: mucin, larynx and squamous cell carcinoma. Altogether, 53 studies were identified; 43 studies were excluded following screening of the titles and abstracts. Full text manuscripts for ten studies were obtained for detailed evaluation and five studies were included in this review. No single study fulfilled all relevant criteria. Based on the included studies, we now know that MUC1 is definitely expressed in SCC larynx. However, there is no definitive evidence to suggest that MUC1 and MUC2 are aberrantly expressed in SCC larynx as compared to normal larynx. Further studies using the best available detection technique to detect MUC1, MUC2 and other possible relevant mucins i.e., MUC4 on adequate numbers of normal and SCC specimens are needed to confirm the findings of this review.

Pilot study on acute voice and throat symptoms related to exposure to organic dust: preliminary findings from a provocation test

The aim of this pilot research was to investigate acute voice and throat symptoms related to organic dust exposure among nine subjects with suspected occupational rhinitis or asthma. Subjective voice and throat symptoms were recorded before and after an occupational exposure test. In addition, the study included perceptual assessment of subjects' voice samples recorded before and after the exposure tests. The results showed a number of (statistically) significant voice and throat changes in symptoms based on subjects' own assessments. These symptoms included a hoarse, husky, or tense voice, requiring an extra effort when speaking and difficulty in starting phonation (P < 0.05). Other significant symptoms included feeling of shortness of breath or the need to gasp for air and feeling that the voice is weak or that it does not resonate (P < 0.01). Such changes were not, however, detected by voice clinicians in the listening test of subjects' voice samples recorded before and after the exposure. These results suggest that the larynx reacts to organic dust with symptoms that are felt by the patient rather than heard by the voice clinician. The voice disorder in such cases is a diagnosis based on symptoms expressed by subjects.