Understanding Risk and Recovery in Vocal Fold Paralysis

To summarize and critically review recent literature on spontaneous recovery from unilateral vocal fold paralysis (UVFP), with emphasis on the time to vocal recovery and its implications for the physiology of recurrent laryngeal nerve (RLN) injury and repair. Analyses of the time to spontaneous vocal recovery in UVFP have generated probabilities of recovery that can be used to counsel patients within the first 12 months of the onset of UVFP, replacing the traditional recommendation of waiting 12 months prior to pursuing permanent intervention. In addition, mathematical modeling of the recovery times has yielded insights into the physiology of RLN reinnervation following injury. Most patients with UVFP who experience vocal recovery do so within 6–9 months. The recovery pattern differs between idiopathic UVFP and iatrogenic UVFP. For iatrogenic UVFP, the severity of RLN injury dictates the time to recovery and the eventual probability of recovery, not the distance between the injury site and the larynx.