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

Abstract

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.

Fig. 1

Distribution of numbers of cumulated pulmonary infiltrates over time. See Table 3 for numbers. Average was 4.6 before, 1.4 during and 2.8 after stimulation for all patients. There was no infiltrate during stimulation in patients #s 1 and 2, and marked reduction in the others except for patient # 3 where infiltrates increased in numbers with time. Note high prestim number in patient # 4 followed by sharp decline. X² test indicates statistically significant differences between pre vs. stim and post stim (p = .001) when calculated for roughly equal observation times.

Fig. 2

Stimulation outcomes on aspiration (%) in patients #s 1–5 based on SLP (I, II, ORIG) information. Aspiration decreased with stimulation ON in all cases except for minor differences in patients # 1 (SLP II), # 2 (no differences for SLP II) and # 3 (SLP II). ORIG SLP data also indicate decrease (See table 5 for numbers).

Fig. 3

Up: Stimulation of right vocal fold resulting in tight glottic seal (right) in patient # 5. Down: Stimulation of left vocal fold resulting in incomplete adduction insufficient for tight glottic closure (right). Note poor abduction in patients #3 (CVABGBSC) in resting position (left).