Natural history of vocal fold paralysis in Arnold-Chiari malformation

Objective: Neurologic disease is the most common cause of bilateral vocal fold paralysis in children. Arnold-Chiari malformations (ACM) account for the majority. Early decompression results in the resolution of preoperative symptoms in the majority of patients. The purpose of present study is to describe the time to vocal fold function recovery following neurosurgical management of children with vocal fold paralysis secondary to ACM. Methods: Prospective case series. Inclusion criteria included diagnoses of both ACM and vocal fold paralysis. All children were followed with office flexible laryngoscopy at two-month intervals following diagnosis until complete return of vocal fold motion was noted. Return of recurrent laryngeal nerve function was confirmed with intraoperative laryngeal electromyography (EMG); one child additionally underwent EMG during partial return of vocal fold function. Results: Four patients met inclusion criteria. Mean age at neurosurgical decompression was 3.1 months (range 1-7.5). Three subjects demonstrated bilateral paralysis; one had a left-sided paralysis. Three subjects, including the child with unilateral paralysis, required tracheotomy. Initial return of vocal fold motion was seen at a mean of 5.75 months after decompression (range 4-8). Complete return of function was seen at a mean of 9.5 months (range 7-12). One child underwent EMG when vocal fold function was initially seen to return, with low-amplitude activity seen. The patient demonstrated full amplitude when EMG was repeated following return of full abduction. EMG likewise confirmed return of motion in the three other subjects. All tracheotomized patients were decannulated without further surgical procedures. Conclusion: Methods of airway management that do not result in permanent alteration of laryngeal anatomy are preferred. Families may be counseled that return of vocal fold function is expected within one year of neurosurgical decompression. The presence of electrical activity on laryngeal EMG may have a role in predicting return of vocal fold motion before complete function is visible on flexible laryngoscopy.