Vocal cord dysfunction/inducible laryngeal obstruction: novel diagnostics and therapeutics

ABSTRACT

Introduction

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is an important medical condition but understanding of the condition is imperfect. It occurs in healthy people but often co-exists with asthma. Models of VCD/ILO pathophysiology highlight predisposing factors rather than specific mechanisms and disease expression varies between people, which is seldom appreciated. Diagnosis is often delayed, and the treatment is not evidence based.

Areas covered

A unified pathophysiological model and disease phenotypes have been proposed. Diagnosis is conventionally made by laryngoscopy during inspiration with vocal cord narrowing >50% Recently, dynamic CT larynx was shown to have high specificity (>80%) with potential as a noninvasive, swift, and quantifiable diagnostic modality. Treatment entails laryngeal retraining with speech pathology intervention and experimental therapies such as botulinum toxin injection. Multidisciplinary team (MDT) clinics are a novel innovation with demonstrated benefits including accurate diagnosis, selection of appropriate treatment, and reductions in oral corticosteroid exposure.

Expert opinion

Delayed diagnosis of VCD/ILO is pervasive, often leading to detrimental treatments. Phenotypes require validation and CT larynx can reduce the necessity for laryngoscopy, thereby fast-tracking diagnosis. MDT clinics can optimize management. Randomized controlled trials are essential to validate speech pathology intervention and other treatment modalities and to establish international standards of care.

KEYWORDS:

• Vocal Cord Dysfunction
• Inducible laryngeal obstruction
• Asthma
• Speech pathology intervention
• Botulinum toxin

Article highlights

• Research is needed to examine VCD/ILO phenotypes, diagnostic, and triage pathways and to conduct controlled trials of speech pathology and other interventions.

• Current understanding of VCD/ILO is limited.

• Disease expression varies between people, but this is seldom appreciated.

• Diagnosis is often delayed, and treatment is not evidence based.

• Recently a unified pathophysiological model and disease phenotypes have been proposed that will require further validation.

• Diagnosis is conventionally made by laryngoscopy but dynamic CT larynx is specific and has potential as a noninvasive, swift, and quantifiable diagnostic modality.

• First-line treatment commonly entails speech pathology intervention but efficacy studies are lacking. Experimental therapies such as botulinum toxin injection also require further study.

• Multidisciplinary team (MDT) clinics for patients with suspected VCD/ILO are a novel innovation.

• Benefits of MDT clinics include accurate and swift diagnosis, allocation for appropriate treatment and reductions in urgent care and oral corticosteroid exposure.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.