Vocal cord paralysis: clinical and electrophysiologic features.

Vocal cord paralysis may occur in isolation or as part of a constellation of findings in neurological disease. We investigated the pathophysiology of these disorders with laryngeal electromyography (LEMG). We studied 44 patients with idiopathic vocal cord paralysis, confirmed by laryngoscopy. The major LEMG finding, present in 29 vocal cords, was evidence of active or chronic denervation in the thyroarytenoid (TA), indicating recurrent laryngeal neuropathy. Denervation of the cricothyroid (CT) in 5 patients indicated superior laryngeal neuropathy. TA and CT involvement in 1 patient indicated proximal laryngeal or vagus nerve damage. LEMG was performed in 48 patients with other laryngeal disorders. LEMG proved to be a safe and effective procedure in the diagnosis of laryngeal neuropathy as distinguished from supranuclear and mechanical disorders of the larynx.