# Central modulation-paired motor rehabilitation for recurrent laryngeal nerve injury

> **NIH NIH R01** · UNIVERSITY OF TEXAS DALLAS · 2024 · $618,001

## Abstract

PROJECT SUMMARY/ABSTRACT
Recurrent laryngeal nerve (RLN) injury causes vocal fold motion impairments (e.g., vocal fold paralysis). The
inability to adduct (close) the vocal folds has consequences for airway protection during swallowing (deglutition)
and vocal communication. These laryngeal motor deficits result in increased risk of aspiration pneumonia and
have profound effects on vocal communication required for vocation, safety, and social encounters. The result
is also significant economic burden, psychosocial consequences, and reduced quality of life. Current surgical
approaches focus on medializing the vocal folds to improve glottic closure, but they do little to restore functional
mobility to the vocal fold muscles within the larynx. The key issue is that current treatments rarely recover vocal
fold movement after RLN injuries due to nerve synkinesis at the periphery and upstream corticobulbar somato-
topic disorganization after spontaneous reinnervation.
One solution is to reorganize upstream motor pathways in the central nervous system to improve downstream
restoration of laryngeal muscle function after RLN injury. Electrical stimulation to the vagus nerve has previously
been shown to release neuromodulators in the brain that excite task-specific neural circuits and down-regulate
less important circuits to improve motor input to the forelimb after median-ulnar nerve injury in a rat forelimb
injury model. Similarly, our preliminary data in a rat model of right RLN injury has shown that temporal pairing of
enhanced central neuromodulation in the brain with a motor-specific laryngeal behavior, like deglutition, may
also restore laryngeal motor function.
The objective of this proposal is to determine the effects of neuromodulation-paired deglutition on recovery of
laryngeal motor function and central neuroplasticity in a rat model of RLN injury. Capitalizing on our promising
preliminary data, animals will be divided into one of three groups: enhanced neuromodulation paired with deglu-
tition, deglutition training only, and neuromodulation only. Enhanced neuromodulation outcomes across acute
and chronic RLN injury will be determined in Aim 1 and across ipsilateral and contralateral injury in Aim 2. Func-
tional effects of neuromodulation/deglutition combinations will be evaluated using laryngoscopy to quantify vocal
fold movement essential for airway protection and vocalization. We will also record ultrasonic vocalizations to
characterize changes in vocal intensity and tonality across the groups. Central neuroplastic effects will be eluci-
dated with retrograde tracing and somatotopic corticobulbar mapping. Effects of ipsilateral simulation on the RLN
will also be elucidated in Aim 2 using laryngeal muscle neuromuscular junction count and morphology analysis.
Expected outcomes will be known functional and mechanistic effects of neuromodulation-paired deglutition. Re-
sults will provide a springboard for novel treatment approaches for patients ...

## Key facts

- **NIH application ID:** 10936848
- **Project number:** 1R01DC021990-01
- **Recipient organization:** UNIVERSITY OF TEXAS DALLAS
- **Principal Investigator:** Adrianna Shembel
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $618,001
- **Award type:** 1
- **Project period:** 2024-08-01 → 2029-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10936848

## Citation

> US National Institutes of Health, RePORTER application 10936848, Central modulation-paired motor rehabilitation for recurrent laryngeal nerve injury (1R01DC021990-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10936848. Licensed CC0.

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