Laryngeal sensory dysfunction in laryngeal hypersensitivity syndrome

Area of Science:

• Otolaryngology
• Neurology
• Speech and Hearing Science

Background:

• Laryngeal dysfunction encompasses conditions like chronic refractory cough (CRC), paradoxical vocal fold movement (PVFM), muscle tension dysphonia (MTD), and globus pharyngeus.
• These conditions are often managed as distinct entities, despite potential shared underlying mechanisms.

Purpose of the Study:

• To investigate the hypothesis of a common sensory laryngeal dysfunction, termed 'laryngeal hypersensitivity' syndrome.
• To compare symptoms and sensory function across patients diagnosed with CRC, PVFM, MTD, and globus pharyngeus.

Main Methods:

• 103 participants, including healthy controls and patients with CRC, PVFM, globus, and MTD.
• Utilized self-report questionnaires (Symptom Frequency and Severity Scale, Voice Handicap Index, Laryngeal Paraesthesia Questionnaire) and quantitative sensory testing (capsaicin cough reflex, saline challenge, swallow tests, acoustic voice analysis, cough monitoring, voice stress tests).

Main Results:

• Case groups reported significantly higher symptom burdens than controls.
• All patient groups exhibited similar symptom patterns across cough, respiration, vocal, and upper airway domains.
• Objective testing revealed overlapping sensory impairments among the four patient groups, with cross-sensory stimulation observed.

Conclusions:

• Discrete laryngeal syndromes share significant clinical overlap and a common sensory dysfunction, supporting the 'laryngeal hypersensitivity' hypothesis.
• Reconceptualizing these functional laryngeal disorders as a manifestation of laryngeal hypersensitivity offers a novel management approach.