title: The vagal nerve stimulation outcome, and laryngeal effect: Otolaryngologists roles and perspective.
abstract: BACKGROUND
  Epilepsy is one of the most common neurologic disorders. Vagus nerve stimulation (VNS), first investigated in 1938 and subsequently studied as a potential therapy for epilepsy. The FDA approved the use of VNS in 1997 as an adjunctive non-pharmacologic symptomatic treatment option for refractory epilepsy for adults and adolescents over 12years. VNS can cause laryngeal and voice side effects that can be managed by otolaryngologists safely and effectively.
  
  
  OBJECTIVE
  This study is to review the outcomes of vagal nerve stimulator (VNS) implantation in terms of the surgical procedures, complications, seizure frequency, and the clinical effect on larynx and vocal folds motion.
  
  
  METHODS
  Series of thirty consecutive patients who had VNS implantation between 2007 and 2014 were recruited. Seizure-frequency outcome, surgical complications and device adverse effects of VNS were retrospectively reviewed. Additional evaluation included use of the Voice Handicap Index and Maximum Phonation Time (MPT) were conducted before and after the implantation. Videolaryngoscopy was used to evaluate the vocal fold mobility before and after the VNS implantation.
  
  
  RESULTS
  Seizure frequency reduction over a minimum of 2years of follow up demonstrated: 100% in seizure frequency reduction in 1 patient, drastic reduction in seizure frequency (70-90%) in 9 patients, a good reduction in terms of seizure frequency (50%) in 8 patients, a 30% reduction in 5 patients, no response in 6 patients, and 1 patient had increased frequency. The most commonly reported adverse effects after VNS activation were coughing and voice changes with pitch breaks, as well as mild intermittent shortness of breath in 33% of patients. For those patients secondary supraglottic muscle tension and hyper function with reduced left vocal fold mobility were noticed on videolaryngoscopy, though none had aspiration problems. Surgical complications included a wound dehiscence in one patient (3%) which was surgically managed, minor intra-operative bleeding 3%; a superficial wound infection in one patient (3%) which was treated conservatively, none of the complications necessitated VNS removal.
  
  
  CONCLUSIONS
  VNS appears to be an effective non-pharmacologic adjuvant therapy in patients with medically refractory seizures. With the favorable adverse-effect profile previously described, VNS is generally well tolerated and of a great benefit to such patients. Laryngeal side effects, of which hoarseness being of the greatest repetition, are the most common after the VNS implantation. VNS can affect the voice and reduced vocal cord motion on the implantation side with secondary supraglottic muscle tension. Otolaryngologists are not only capable of performing VNS implantation, but can also manage surgical complications, assess laryngeal side effects and treat them as needed.
authors.affiliation: Otolaryngology Department, Faculty of Medicine, Jordan University of Science and Technology, P O Box 3030, Irbid 22110, Jordan. Electronic address: aialomari@just.edu.jo.
authors.forename: Ahmad I
authors.initials: AI
authors.lastname: Al Omari
authors.affiliation: Otolaryngology Department, Faculty of Medicine, Jordan University of Science and Technology, P O Box 3030, Irbid 22110, Jordan.
authors.forename: Firas Q
authors.initials: FQ
authors.lastname: Alzoubi
authors.affiliation: Otolaryngology Department, Faculty of Medicine, Jordan University of Science and Technology, P O Box 3030, Irbid 22110, Jordan.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Alsalem
authors.affiliation: Department of Otolaryngology, UAB Voice and AeroDigestive Center, 563 Boshell Building 1808 7th Avenue South Birmingham, AL 35233, USA.
authors.forename: Samah K
authors.initials: SK
authors.lastname: Aburahma
authors.affiliation: Otolaryngology Department, Faculty of Medicine, Jordan University of Science and Technology, P O Box 3030, Irbid 22110, Jordan.
authors.forename: Diala T
authors.initials: DT
authors.lastname: Mardini
authors.affiliation: Department of Neurosciences, Faculty of Medicine, Jordan University of Science and Technology, P O Box 3030, Irbid 22110, Jordan.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Castellanos
mesh_terms: D000293:Adolescent; D000328:Adult; D001291:Attitude of Health Personnel; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006801:Humans; D007818:Laryngeal Diseases / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D008297:Male; D010036:Otolaryngology; D010819:Physician's Role; D012189:Retrospective Studies; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000009:adverse effects*; D055815:Young Adult
keywords: Refractory epilepsy; Status epilepticus; Supraglottic muscle tension; Vagal nerve stimulator; Voice complications