scholarly journals Influence of tongue muscle contraction and dynamic airway pressure on velopharyngeal volume in the rat

2008 ◽  
Vol 104 (3) ◽  
pp. 682-693 ◽  
Author(s):  
Ralph F. Fregosi
Keyword(s):  
Muscle Contraction ◽  
Soft Palate ◽  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Transmural Pressure ◽  
Positive Pressure ◽  
Medial Branch ◽  
Hypoglossal Nerve Stimulation ◽  
Tongue Muscle ◽  
Pharyngeal Airway

The mammalian pharynx is a collapsible tube that narrows during inspiration as transmural pressure becomes negative. The velopharynx (VP), which lies posterior to the soft palate, is considered to be one of the most collapsible pharyngeal regions. I tested the hypothesis that negative transmural pressure would narrow the VP, and that electrical stimulation of extrinsic tongue muscles would reverse this effect. Pressure (−6, −3, 3, and 6 cmH2O) was applied to the isolated pharyngeal airway of anesthetized rats that were positioned in a 4.7-T MRI scanner. The volume of eight axial slices encompassing the length of the VP was computed at each level of pressure, with and without bilateral hypoglossal nerve stimulation (0.1-ms pulse, one-third maximum force, 80 Hz). Negative pressure narrowed the VP, and either whole hypoglossal nerve stimulation (coactivation of protrudor and retractor muscles) or medial nerve branch stimulation (independent activation of tongue protrudor muscles) reversed this effect, with the greatest impact in the caudal one-third of the VP. The dilating effects of medial branch stimulation were slightly larger than whole nerve stimulation. Positive pressure dilated the VP, but tongue muscle contraction did not cause further dilation under these conditions. I conclude that the narrowest and most collapsible segment of the rat pharynx is in the caudal VP, posterior to the tip of the soft palate. Either coactivation of protrudor and retractor muscles or independent contraction of protrudor muscles caused dilation of this region, but the latter was slightly more effective.

Clinical Radiographic Predictors of Response to Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

2020 ◽  
pp. 019459982096314
Author(s):  
Clara H. Lee ◽  
Everett G. Seay ◽  
James W. Reese ◽  
Xin Wu ◽  
Richard J. Schwab ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Soft Palate ◽  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Categorical Variables ◽  
Apnea Hypopnea Index ◽  
Hypoglossal Nerve Stimulation ◽  
Index Reduction ◽  
Obstructive Sleep

Objective To determine if clinically acquired cephalometric measurements, specifically soft palate size, can predict hypoglossal nerve stimulation outcomes. Study Design Combined prospective cohort study and retrospective review. Setting US sleep otolaryngology training program. Methods Adults with obstructive sleep apnea and apneahypopnea index greater than 15 events/h who underwent hypoglossal nerve stimulation. Eligible subjects had diagnostic preoperative sleep studies and full-night efficacy postoperative studies for analysis. Lateral neck x-rays were obtained as part of routine clinical care and measured for key cephalometric variables by trained head and neck radiologists. Continuous variables were compared using the Student t test, while χ2 testing was used for categorical variables. Results Fifty-one patients met all study criteria. On average, patients were white, middle aged, and overweight. Following hypoglossal nerve stimulation, the overall cohort achieved a significant apnea-hypopnea index reduction from 36.7 events/h to 20.6 events/h ( P < .01) and a response rate of 47% (defined as apnea-hypopnea index reduction >50% and apnea-hypopnea index <20 events/h). On average, therapy responders had significantly thinner soft palates than nonresponders (13.4 ± 3.8 mm vs 16.0 ± 3.4 mm, P = .045). Conclusions Patient-specific anatomic factors, specifically soft palate thickness, may help identify optimal candidates for hypoglossal nerve stimulation. A larger, prospective study including both anatomic and physiologic variables is required to validate these findings.

Contralateral Tongue Muscle Activation during Hypoglossal Nerve Stimulation

2020 ◽  
Vol 162 (6) ◽  
pp. 985-992 ◽  
Author(s):  
Joshua J. Sturm ◽  
Oleg Modik ◽  
Ioannis Koutsourelakis ◽  
Maria V. Suurna
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Nerve Stimulation ◽  
Muscle Activation ◽  
Hypoglossal Nerve ◽  
Oxygen Desaturation ◽  
Apnea Hypopnea Index ◽  
Hypoglossal Nerve Stimulation ◽  
Tongue Muscle ◽  
Obstructive Sleep

Objective The effectiveness of upper airway stimulation via hypoglossal nerve stimulation for obstructive sleep apnea depends upon the pattern of tongue muscle activation produced. This study investigated the nature of contralateral tongue muscle activation by unilateral hypoglossal nerve stimulation using intraoperative nerve integrity monitoring in conjunction with electromyography and explored the relationship between contralateral tongue muscle activation and polysomnographic measures of obstructive sleep apnea severity. Study Design Prospective case series. Setting Tertiary care medical center. Subjects and Methods Fifty-one patients underwent unilateral (right) hypoglossal nerve stimulator implantation for obstructive sleep apnea. Neurophysiological data included electromyographic responses in ipsilateral (right) and contralateral (left) genioglossus muscles in response to intraoperative bipolar probe stimulation (0.3 mA) of medial hypoglossal nerve branches. Clinical data included pre- and postoperative apnea-hypopnea indices and oxygen desaturation levels. Results A subset of patients (20/51, 39%) exhibited electromyographic responses in both the ipsilateral and contralateral genioglossus (bilateral), whereas the remaining patients (31/51, 61%) exhibited electromyographic responses only in the ipsilateral genioglossus (unilateral). The baseline characteristics of bilateral and unilateral responders were similar. Both groups exhibited significant and comparable improvements in apnea-hypopnea index and oxygen desaturations after hypoglossal nerve stimulation. Neither the amplitude nor the latency of contralateral genioglossus responses was predictive of clinical outcomes. Conclusion A subset of patients undergoing unilateral hypoglossal nerve stimulation exhibits activation of contralateral genioglossus muscles. Patients with unilateral and bilateral genioglossus responses exhibit comparable, robust improvements in apnea-hypopnea index and oxygen desaturation levels.

scholarly journals Tongue muscle plasticity following hypoglossal nerve stimulation in aged rats

2012 ◽  
Vol 47 (2) ◽  
pp. 230-240 ◽  
Author(s):  
Nadine P. Connor ◽  
John A. Russell ◽  
Michelle A. Jackson ◽  
Heidi Kletzien ◽  
Hao Wang ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Aged Rats ◽  
Hypoglossal Nerve Stimulation ◽  
Tongue Muscle ◽  
Muscle Plasticity

scholarly journals Obstruction level associated with outcome in hypoglossal nerve stimulation

2021 ◽  
Author(s):  
Markus Wirth ◽  
Maximilian Bautz ◽  
Franziska von Meyer ◽  
Benedikt Hofauer ◽  
Ulrich Strassen ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Soft Palate ◽  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Hypoglossal Nerve Stimulation ◽  
Base Level ◽  
Obstructive Sleep ◽  
Before And After ◽  
Good Treatment Response ◽  
Selection Of

Abstract Purpose Selective hypoglossal nerve stimulation (sHNS) constitutes an effective surgical alternative for patients with obstructive sleep apnea (OSA). sHNS results in tongue protrusion and consecutive alleviation of obstructions at the tongue base level (lower obstructions). Furthermore, obstructions at the soft palate level (upper obstructions) may be prevented through palatoglossal coupling as seen on sleep endoscopy. However, it has not been studied if the distribution of obstruction level during a whole night measurement is a relevant factor for the treatment outcome. Methods Obstruction levels were measured with a manometry system during a whole night of sleep in 26 patients with OSA (f = 1, m = 25; age 59.4 ± 11.3; BMI = 29.6 ± 3.6) either before (n = 9) or after sHNS implantation (n = 12). Five patients received a measurement before and after implantation. Obstructions were categorized into velar (soft palate and above), infravelar (below soft palate), and multilevel obstructions. An association between obstruction level and treatment outcome was calculated. Results The mean distribution of preoperative obstruction level could be divided into the following: 38% velar, 46% multilevel, and 16% infravelar obstructions. Patients with a good treatment response (defined as AHI < 15/h and AHI reduction of 50%) had fewer preoperative velar obstructions compared to non-responder (17% vs. 54%, p-value = 0.006). In patients measured after sHNS implantation, a significantly higher rate of multilevel obstructions per hour was measured in non-responders (p-value = 0.012). Conclusions Selective hypoglossal nerve stimulation was more effective in patients with fewer obstructions at the soft palate level. Manometry may be a complementary diagnostic procedure for the selection of patients for HNS.

Tongue-Based Procedures in Treating Refractory Obstructive Sleep Apnea in Down Syndrome Patients: A Systematic Review and Meta-Analysis

FACE ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 65-70
Author(s):  
Paul B. Lee ◽  
Michael T. Chung ◽  
Jared Johnson ◽  
Jordyn Lucas ◽  
Caitlin R. Priest ◽  
...  
Keyword(s):  
Systematic Review ◽  
Obstructive Sleep Apnea ◽  
Down Syndrome ◽  
Sleep Apnea ◽  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Meta Analysis ◽  
Apnea Hypopnea Index ◽  
Hypoglossal Nerve Stimulation ◽  
Obstructive Sleep

Objective: There is a high prevalence of obstructive sleep apnea (OSA) in pediatric and adult Down Syndrome (DS) patients that is refractory to adenotonsillectomy and continuous positive airway pressure. Newer treatment modalities have emerged with improved outcomes. The objective is to provide an updated systematic review and meta-analysis to analyze the clinical outcomes of OSA in pediatric and adult DS patients with hypoglossal nerve stimulation using Inspire, midline posterior glossectomy plus lingual tonsillectomy (MPG + LT), and combined genioglossus advancement plus radiofrequency (GGS + RF). Methods: A comprehensive literature search of PubMed and Google Scholar was performed followed by a meta-analysis. Studies with preoperative and post-operative Apnea Hypopnea Index (AHI) values were included with patients serving as their own control. Results: Across 5 studies, 56 patients were analyzed. The mean reduction in AHI was statistically significant before vs. after procedure ( P < .001 for hypoglossal nerve stimulation using Inspire with a paired 2-tailed t-test and P = .031 for MPG + LT). Although individual patient AHI values were unavailable in the GGS + RF study, the standard difference in mean AHI was also significant for GGS + RF with P = .001. Device malfunction was the most common complication for Inspire while postoperative bleeding was observed for MPG + LT and nasopharyngeal obstruction and retropalatal collapse were observed for GGS + RF. Conclusion: This review reveals significant improvement in AHI with Inspire, MPG + LT, and GGS + RF for DS patients with refractory OSA. Further investigation is needed for comparison between these 3 therapies.

Sign in / Sign up

Export Citation Format

Share Document