Paced glottic closure for controlling aspiration pneumonia in patients with neurologic deficits of various causes.

OBJECTIVES: We undertook to determine whether paced vocal fold adduction can check aspiration in patients with various neurologic conditions. METHODS: Five patients with fluoroscopically documented aspiration and repeated pneumonias were enrolled. Two previously reported patients with hemispheric stroke were compared to 3 additional subjects with brain stem-basal ganglia and cerebellar stroke, cerebral palsy, and multiple sclerosis. A modified Vocare stimulator was implanted subcutaneously and linked to the ipsilateral recurrent laryngeal nerve via perineural electrodes. Vocal fold adduction and glottic closure were effected with pulse trains (42 Hz; 1.2 mA; 188 to 560 micros) and recorded with Enhanced Image J. Fluoroscopy results with and without stimulation were assessed by 2 independent blinded reviewers. Pneumonia rates were compared before, during, and after the 6- to 12-month enrollment periods. RESULTS: There was statistically significant vocal fold adduction (p < 0.05) for all patients, further verified with bolus arrest (p < 0.05 for thin liquids, thick liquids, and puree depending on the speech-language pathologist). Pneumonia was prevented in 4 of the 5 patients during enrollment. In the fifth patient, who had brain stem-basal ganglia and cerebellar stroke, we were unable to completely seal the glottis and open the cricopharyngeus enough to handle his secretions. CONCLUSIONS: Vocal fold pacing for aspiration pneumonia from a variety of neurologic insults appears to be appropriate as long as the glottis can be sealed. It is not sufficient when the cricopharyngeus must be independently opened.

Artificial manipulation of voice in the human by an implanted stimulator.

OBJECTIVES/HYPOTHESIS: Traditional approaches influencing voice quality (e.g., anatomical and chemical denervation for spasmodic dysphonia, surgical medialization for paralysis) have ignored the dynamic nature of the larynx. STUDY DESIGN: We report here the first attempt to manipulate voice using an implanted stimulator to systematically control vocal fold adduction. METHODS: Devices placed for aspiration in three subjects retaining speech after stroke, cerebral palsy, and multiple sclerosis were used to stimulate recurrent laryngeal nerves with 42 Hz, 52 to 200 microsecond pulses of incremental amplitudes during phonation with the tracheostomy tube occluded. Vocal fold adduction increased with stimulation strength (P < .05). Speech was analyzed with the Vox Metria program. RESULTS: We found highly significant differences for fundamental frequency (P < .007), jitter (P < .004), and shimmer (P < .005), between natural and stimulated voice (aah and eeh) when using higher charges. CONCLUSIONS: Dynamic vocal fold manipulation seems promising in terms of versatility lacking with static approaches to voice control.