Neurogenic Laryngeal Disorders

The larynx is critical to performing complex tasks of airway protection, phonation, respiration, and deglutition. Various focal and systemic neurologic disorders impact the larynx, causing deficits that lead to dysfunction in voice, speech, breathing, and swallowing function. The most common hyperfunctional neurolaryngeal disorders include spasmodic dysphonia (laryngeal dystonia), essential vocal tremor, and muscle tension dysphonia. Some hypofunctional neurolaryngeal disorders include parkinsonian disorders, neuromuscular junction diseases, and myopathies. A multidisciplinary approach involving evaluation by neurologists, voice-trained otolaryngologists and speech-language pathologists is often key to diagnosis and treatment of these challenging and sometimes lifelong disorders. Botulinum toxin injection into the laryngeal musculature is currently the gold-standard treatment for both spasmodic dysphonia and vocal tremor. However, much research is being conducted to advance less invasive and more definitive medical and surgical treatment interventions. This review contains 3 figures, 11 videos, 6 tables and 29 references Keywords: laryngeal neurophysiology, laryngeal dystonia, adductor spasmodic dysphonia, abductor spasmodic dysphonia, essential vocal tremor, hyperfunctional voice disorders, hypofunctional voice disorders, botulinum toxin injection