Transcutaneous neuromuscular electrical stimulation (VitalStim) curative therapy for severe dysphagia: myth or reality?

OBJECTIVES: VitalStim therapy was approved by the US Food and Drug Administration in 2001 for the treatment of dysphagia through the application of neuromuscular electrical stimulation to cervical swallowing muscles. This approval was based upon submission of data on more than 800 patients who received this therapy collected by the principal developer and patent-holder of the device. The therapy is marketed as successful in restoring long-term swallowing function in 97.5% of dysphagic patients past the point of requiring a feeding tube and as significantly better than existing therapies. More than 2,500 speech-language pathologists have taken the certification course, and thousands of devices have been sold. To date, however, aside from the developer's own studies, there are no peer-reviewed publications supporting these claims. We sought to evaluate the effectiveness of VitalStim therapy in a heterogeneous group of dysphagic patients. METHODS: We performed a retrospective analysis of 18 patients who received this therapy at an urban tertiary referral center. All patients underwent pretherapy evaluation by speech-language pathologists, including modified barium swallow and/or functional endoscopic evaluation of swallowing and clinical evaluation of swallowing that included assessment of laryngeal elevation, diet tolerance, and swallowing delay, and were then assigned an overall dysphagia severity score. After therapy, all patients underwent the same assessments. Twelve of the 18 also underwent a functional swallowing telephone survey months (range, 1 to 21 months) after their therapy to assess whether the improvement was worthwhile and sustained. RESULTS: Eleven of the 18 patients (61%) demonstrated some improvement in their swallowing. Six of the 18 patients (33%) were improved enough to no longer require a feeding tube. However, of the 5 patients categorized as having "severe dysphagia" before therapy, only 2 showed any improvement, and these patients still required a feeding tube for adequate nutrition. Telephone surveys did confirm that those who improved with their therapy seemed to maintain their progress and that most patients were satisfied with their therapy. CONCLUSIONS: VitalStim therapy seems to help those with mild to moderate dysphagia. However, the patients with the most severe dysphagia in our study did not gain independence from their feeding tubes. The authors conclude that VitalStim therapy clearly has a place in the management of dysphagia, but that the most severely afflicted are unlikely to gain dramatic improvement.

Predictors of laryngeal complications in patients implanted with the Cyberonics vagal nerve stimulator.

OBJECTIVES: Since its approval by the US Food and Drug Administration in 1997 for management of medically refractory seizures, more than 35,000 patients have been implanted with the Cyberonics vagal nerve stimulator. Preliminary reports described transient vocal changes in the majority of subjects, which were thought to be short-term. However, these reports were for the most part based upon perceptual evaluations by the subjects themselves. Later reports described possibly more permanent recurrent laryngeal nerve injury and recommended measuring the nerve diameter to use the safest spiral cuff electrode. To date, no study has systematically evaluated vocal fold mobility in subjects before and after implantation. The objectives of this study were to determine the true incidence of both short- and long-term recurrent laryngeal nerve injuries and determine whether there are any potential indicators to predict in which patients long-term nerve deficits may develop. METHODS: Thirteen subjects underwent preimplantation laryngeal electromyography, videolaryngoscopy, measurement of the maximum phonation time, Voice Handicap Index determination, and Consensus Auditory-Perceptual Evaluation of Voice. Two weeks after implantation, all subjects underwent videolaryngoscopy. Three months after implantation and activation of the device, all subjects were reevaluated. RESULTS: Six of the 13 subjects had significant vocal fold mobility abnormalities at 2 weeks. Significant electromyographic abnormalities were detected before implantation in 5 subjects. All 5 of these subjects, at 3 months after implantation, had prolonged left vocal fold paresis. CONCLUSIONS: The authors conclude that perioperative vocal fold paresis occurs in approximately 50% of subjects. Further, laryngeal electromyography performed before implantation of the vagal nerve stimulator is a statistically significant predictor (p < .05) of which patients may be at risk for extended vocal fold abnormalities. Possible explanations for this phenomenon are offered. Surgical modifications to limit vagal nerve injury are offered.