This chapter provides criteria for evaluating permanent impairment of the visual system as it affects an individual’s ability to perform activities of daily living. The visual system consists of the eyes and supporting structures, the neural pathways, and the visual cortex of the brain. The visual system is unique in that it combines the input from two separate eyes into a single visual perception.

Guides to the Evaluation of Permanent Impairment

Objective This guideline provides evidence-based recommendations on treating patients who present with dysphonia, which is characterized by altered vocal quality, pitch, loudness, or vocal effort that impairs communication and/or quality of life. Dysphonia affects nearly one-third of the population at some point in its life. This guideline applies to all age groups evaluated in a setting where dysphonia would be identified or managed. It is intended for all clinicians who are likely to diagnose and treat patients with dysphonia. Purpose The primary purpose of this guideline is to improve the quality of care for patients with dysphonia, based on current best evidence. Expert consensus to fill evidence gaps, when used, is explicitly stated and supported with a detailed evidence profile for transparency. Specific objectives of the guideline are to reduce inappropriate variations in care, produce optimal health outcomes, and minimize harm. For this guideline update, the American Academy of Otolaryngology-Head and Neck Surgery Foundation selected a panel representing the fields of advanced practice nursing, bronchoesophagology, consumer advocacy, family medicine, geriatric medicine, internal medicine, laryngology, neurology, otolaryngology-head and neck surgery, pediatrics, professional voice, pulmonology, and speech-language pathology. Action Statements The guideline update group made strong recommendations for the following key action statements (KASs): (1) Clinicians should assess the patient with dysphonia by history and physical examination to identify factors where expedited laryngeal evaluation is indicated. These include, but are not limited to, recent surgical procedures involving the head, neck, or chest; recent endotracheal intubation; presence of concomitant neck mass; respiratory distress or stridor; history of tobacco abuse; and whether the patient is a professional voice user. (2) Clinicians should advocate voice therapy for patients with dysphonia from a cause amenable to voice therapy. The guideline update group made recommendations for the following KASs: (1) Clinicians should identify dysphonia in a patient with altered voice quality, pitch, loudness, or vocal effort that impairs communication or reduces quality of life (QOL). (2) Clinicians should assess the patient with dysphonia by history and physical examination for underlying causes of dysphonia and factors that modify management. (3) Clinicians should perform laryngoscopy, or refer to a clinician who can perform laryngoscopy, when dysphonia fails to resolve or improve within 4 weeks or irrespective of duration if a serious underlying cause is suspected. (4) Clinicians should perform diagnostic laryngoscopy, or refer to a clinician who can perform diagnostic laryngoscopy, before prescribing voice therapy and document/communicate the results to the speech-language pathologist (SLP). (5) Clinicians should advocate for surgery as a therapeutic option for patients with dysphonia with conditions amenable to surgical intervention, such as suspected malignancy, symptomatic benign vocal fold lesions that do not respond to conservative management, or glottic insufficiency. (6) Clinicians should offer, or refer to a clinician who can offer, botulinum toxin injections for the treatment of dysphonia caused by spasmodic dysphonia and other types of laryngeal dystonia. (7) Clinicians should inform patients with dysphonia about control/preventive measures. (8) Clinicians should document resolution, improvement or worsened symptoms of dysphonia, or change in QOL of patients with dysphonia after treatment or observation. The guideline update group made a strong recommendation against 1 action: (1) Clinicians should not routinely prescribe antibiotics to treat dysphonia. The guideline update group made recommendations against other actions: (1) Clinicians should not obtain computed tomography (CT) or magnetic resonance imaging (MRI) for patients with a primary voice complaint prior to visualization of the larynx. (2) Clinicians should not prescribe antireflux medications to treat isolated dysphonia, based on symptoms alone attributed to suspected gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR), without visualization of the larynx. (3) Clinicians should not routinely prescribe corticosteroids for patients with dysphonia prior to visualization of the larynx. The policy level for the following recommendation about laryngoscopy at any time was an option: (1) Clinicians may perform diagnostic laryngoscopy at any time in a patient with dysphonia. Disclaimer This clinical practice guideline is not intended as an exhaustive source of guidance for managing dysphonia (hoarseness). Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgment or establish a protocol for all individuals with this condition, and it may not provide the only appropriate approach to diagnosing and managing this problem. Differences from Prior Guideline (1) Incorporation of new evidence profiles to include the role of patient preferences, confidence in the evidence, differences of opinion, quality improvement opportunities, and any exclusion to which the action statement does not apply (2) Inclusion of 3 new guidelines, 16 new systematic reviews, and 4 new randomized controlled trials (3) Inclusion of a consumer advocate on the guideline update group (4) Changes to 9 KASs from the original guideline (5) New KAS 3 (escalation of care) and KAS 13 (outcomes) (6) Addition of an algorithm outlining KASs for patients with dysphonia.

https://journals.sagepub.com/doi/pdf/10.1177/0194599817751030

Clinical Practice Guideline: Hoarseness (Dysphonia) (Update).

Evidence-Based Practice: Evaluation and Management of Unilateral Vocal Fold Paralysis

Relapsing polychondritis is a rare multisystem disease involving the cartilaginous and proteoglycan rich structures. The spectrum of clinical presentations may vary from intermittent episodes of painful and often disfiguring auricular and nasal chondritis, to occasional organ or even life-threatening manifestations like airway collapse. There is lack of awareness about this disease due to its rarity. Relapsing polychondritis disease activity index has recently been validated and may help in clinical decision making and research. This article reviews the literature on this disease entity.

https://link.springer.com/content/pdf/10.1007%2Fs10067-013-2328-x.pdf

Relapsing polychondritis: a review

Although recognized as a valuable diagnostic tool for more than 60 years, many laryngologists do not routinely use laryngeal electromyography (LEMG). This may be due to a persisting lack of agreement on methodology, interpretation, validity, and clinical application of LEMG. To achieve consensus in these fields, a laryngeal electromyography working group of European neurolaryngologic experts was formed in order to (1) evaluate guidelines for LEMG performance and (2) identify issues requiring further clarification. To obtain an overview of existing knowledge and research, English-language literature about LEMG was identified using Medline. Additionally, cited works not detected in the initial search were screened. Evidence-based recommendations for the performance and interpretation of LEMG and also for electrostimulation for functional evaluation were considered, as well as published reports based on expert opinion and single-institution retrospective case series. To assess the data obtained by this literature evaluation, the working group met five times and performed LEMG together on more than 20 patients. Subsequently, the results were presented and discussed at the 8th Congress of the European Laryngological Society in Vienna, Austria, September 1–4, 2010, and consensus was achieved in the following areas: (1) minimum requirements for the technical equipment required to perform and record LEMG; (2) best practical implementation of LEMG; (3) criteria for interpreting LEMG. Based on this consensus, prospective trials are planned to improve the quality of evidence guiding the proceedings of practitioners.

Laryngeal electromyography: a proposal for guidelines of the European Laryngological Society

Objectives/Hypothesis:

To analyze existing evidence regarding utility of laryngeal electromyography (LEMG) for prognosis in cases of vocal fold palsy (VFP).



Study Design:

Meta-analysis of studies reporting LEMG results and clinical outcomes in 503 patients with of VFP identified by literature search.



Methods:

Studies were identified by literature search. Method of diagnosis, interval to LEMG, criteria for prognostication, and outcome were assessed. Criteria for prognosis were standardized to the extent possible across all studies, and studies were checked for consistency in outcome measures and assessments. Pooled data were subjected to statistical analysis.



Results:

A total of 296/503 patients (58.8%) had findings predictive with poor prognosis, whereas 207/503 (41.2%) had findings of recovery. According to laryngoscopic examination, 269/296 patients with predicted poor recovery had poor recovery (positive predictive value = 90.9%), whereas 27/296 (9.1%) had good recovery. In patients with findings consistent with recovery, 115/207 (negative predictive value = 55.6%) noted return of motion, whereas 88/207 (44.4%) did not. The odds ratio was 11.56 with 95% confidence interval of 7.10-18.81.



Conclusions:

LEMG is a good predictor of poor recovery in patients with VFP and is clinically useful in identifying candidates for early definitive intervention.

Laryngeal electromyography for prognosis of vocal fold palsy: a meta-analysis.

To analyze existing evidence regarding utility of laryngeal electromyography (LEMG) for prognosis in cases of vocal fold palsy (VFP).

Laryngeal Electromyography for Prognosis of Vocal Fold Palsy

Objectives
To investigate the effect of stretch-and-flow voice therapy on vocal function and handicap.

Study Design
Randomized controlled trial.

Methods
Participants with primary muscle tension dysphonia were randomly assigned to experimental or control groups. Experimental participants received vocal hygiene education followed by 6 weeks of stretch-and-flow voice therapy. Control participants received vocal hygiene education only. Outcome variables consisted of a measure of vocal handicap (Voice Handicap Index [VHI]), maximum phonation time, s/z ratio, and acoustic measures. All measures were obtained at baseline prior to treatment and within 2 weeks posttreatment or at the end of the control period. The pre- to posttreatment measurement change (delta Δ) was applied to statistical analyses.

Results
A multivariate analysis of variance revealed significant group differences in pre-to-post changes on measures of VHI, maximum phonation time, and cepstral peak prominence (CPP) in connected speech and vowels (P = 0.003, 0.013, 0.025, and 0.017 respectively), with a significant reduction of VHI (Cohen's d = 1.6), increase in maximum phonation time (Cohen's d = 1.2), increase of CPP in connected speech (Cohen's d = 1.2), and increase of CPP in vowels (Cohen's d = 1.1) in the experimental group compared to the control group.

Conclusions
This preliminary small sample randomized controlled trial found significantly greater improvement in vocal handicap, maximum phonation time, and acoustic measures of vocal function after participants received stretch-and-flow voice therapy compared to participants receiving vocal hygiene education alone. Additional research incorporating larger samples will be needed to confirm and further investigate these findings.

Level of Evidence
1b. Laryngoscope, 125:1420–1425, 2015

A randomized controlled trial of stretch-and-flow voice therapy for muscle tension Dysphonia

The Effect of Stretch-and-Flow Voice Therapy on Measures of Vocal Function and Handicap

Objectives/Hypothesis
Patients with unilateral vocal fold paralysis (UVFP) are commonly told to wait 12 months for spontaneous recovery. This study aims to 1) determine the time to vocal recovery in UVFP, 2) use that data to develop a neurophysiologically plausible model for recovery, and 3) use the model to generate meaningful predictions for patient counseling.

Study Design
Case series with de novo mathematical modeling.

Methods
Patients with UVFP who could pinpoint a discrete onset of vocal improvement were identified. The time-to-recovery data were modeled by assuming an “early” recovery group with neuropraxia and a “late” recovery group with more severe nerve injury. For the late group, a two-stage model was developed to explain the time to recovery: regenerating axons must cross the site of injury in stage 1 (probabilistic), followed by unimpeded regrowth to the larynx in stage 2 (deterministic).

Results
Of 727 cases of UVFP over a 7-year period, 44 reported spontaneous recovery with a discrete onset of vocal improvement. A hybrid distribution incorporating the two stages (exponentially modified Gaussian) accurately modeled the time-to-recovery data (R2 = 0.918). The model predicts 86% of patients with recoverable UVFP will recover within 6 months, with 96% recovering within 9 months. Earlier vocal recovery is associated with recovery of vocal fold motion and younger age.

Conclusions
Waiting 12 months for spontaneous recovery is probably too conservative. Repair across the site of injury, and not regrowth to larynx, is likely the rate-determining step in reinnervation, consistent with other works on peripheral nerve regeneration.

Level of Evidence
4. Laryngoscope, 2017

Lesley F. Childs

Papers

Laryngeal electromyography for prognosis of vocal fold palsy: a meta-analysis.

Laryngeal Electromyography for Prognosis of Vocal Fold Palsy

A randomized controlled trial of stretch-and-flow voice therapy for muscle tension Dysphonia

The Effect of Stretch-and-Flow Voice Therapy on Measures of Vocal Function and Handicap

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation