Laryngeal electromyography findings of vocal fold immobility in patients after radiotherapy for nasopharyngeal carcinoma

Voice Changes of Patients With Nasopharyngeal Carcinoma in Eleven Years After Radiotherapy: A Cross-Sectional Study

OBJECTIVES

The objective of this study was to assess voice changes in patients with nasopharyngeal carcinoma (NPC) using subjective and objective assessment tools and to make inferences regarding the underlying pathological causes for different phases of radiotherapy (RT).

METHODS

A total of 187 (123 males and 64 females) patients with post-RT NPC with no recurrence of malignancy or other voice diseases and 17 (11 males and 6 females) healthy individuals were included in this study. The patients were equally divided into 11 groups according to the number of years after RT. The acoustic analyses, GRBAS (grade, roughness, breathiness, asthenia, and strain) scales, and Voice Handicap Index (VHI)-10 scores were collected and analyzed.

RESULTS

The fundamental frequency (F0) parameters in years 1 and 2 and year 11 were significantly lower in patients with NPC than in healthy individuals. The maximum phonation times in years 1 and 11 were significantly shorter than those in healthy individuals. The jitter parameters were significantly different between year 1 and from years 8 to 11 and the healthy individuals. The shimmer parameters were significantly different between years 1, from years 9 to 11, and healthy individuals. Hoarseness was the most prominent problem compared to other items of the GRBAS. The VHI-10 scores were significantly different between years 1 and 2 and year 11 after RT in patients with NPC.

CONCLUSIONS

Voice quality was worse in the first 2 years and from years 8 to 11 but remained relatively normal from years 3 to 7 after RT. Patient-reported voice handicaps began during year 3 after RT. The most prominent problem was perceived hoarseness, which was evident in the first 2 years and from years 9 to 11 after RT. The radiation-induced mucous edema, laryngeal intrinsic muscle fibrosis, nerve injuries, upper respiratory tract changes, and decreased lung capacity might be the pathological reasons for voice changes in post-RT patients with NPC.

Electrophysiological Changes on Laryngeal Motor Neuropathways Cause Voice Disorders for Postradiotherapy Patients with Nasopharyngeal Carcinoma

OBJECTIVE

This study explored electrophysiological changes in the laryngeal motor neuropathway and determined whether lesions in the laryngeal motor cortex (LMC) and its descending tract contribute to voice deterioration and peripheral nerve palsy in patients with nasopharyngeal carcinoma (NPC) postradiotherapy (RT).

STUDY DESIGNS

Prospective cohort study.

METHODS

Twenty-two patients with NPC at 2 to 4years post-RT (8 female and 14 male), 22 patients with NPC at 8 to 10years post-RT (8 female and 14 male), and 22 healthy individuals (9 female and 13 male) were selected to test their magnetic evoked potentials (MEP), motor nerve conduction, and voice quality using transcranial magnetic stimulation, laryngeal electromyography, and the XION DiVAS acoustic analysis software. Three groups were matched according to approximate age. Multiple comparisons were performed among the three groups.

RESULTS

The voice quality of post-RT patients with NPC deteriorated compared to that of healthy individuals. Bilateral LMC and their corticonuclear tracts to the bilateral ambiguous nuclei of post-RT patients with NPC were impaired according to multigroup comparisons of MEP amplitudes, latencies, and resting motor thresholds. The vagus and recurrent laryngeal nerves (RLN) of post-RT patients with NPC were impaired according to multigroup comparisons of the amplitude and latencies of the compound muscle action potential and latencies of f-waves.

CONCLUSIONS

The voice quality of patients with NPC deteriorated after RT. The pathogenesis of post-RT voice deterioration may involve radiation-induced injuries to the vagus, RLN, and bilateral LMC. Furthermore, radiation-induced injuries to the bilateral LMC may contribute to vagus and RLN palsies. These findings support the use of transcranial approaches to treating voice disorders and peripheral nerve palsies in post-RT patients with NPC.

TRIAL REGISTRATION

ChiCTR2100054425; Electrophysiological Study of Vocal-Fold Mobility Disorders After Radiotherapy for NPC Patients via Magnetic Evoked Potential and Their Correlation with Voice Quality Assessment; https://www.chictr.org.cn/bin/project/edit?pid=144429.

Identifying the Prevalence of Dysphagia among Patients Diagnosed with Unilateral Vocal Fold Immobility

OBJECTIVE

To identify dysphagia prevalence and characteristics among patients with unilateral vocal fold immobility (UVFI) through a systematic review of current literature.

DATA SOURCES

Embase, PubMed, ScienceDirect, Wiley Online Library.

REVIEW METHODS

Four electronic databases were reviewed according to the PRISMA criteria. Original English-language studies examining dysphagia among adult patients with UVFI met eligibility. Two researchers independently analyzed qualified articles.

RESULTS

Of 227 studies discovered through the literature search, 17 satisfied eligibility criteria. The prevalence of symptomatic dysphagia ranged from 55.6% to 69.0%, and the aspiration rate was 20.0% to 50.0%. Self-reporting and clinical evaluation were used to identify symptomatic dysphagia, while videofluoroscopic swallowing study and functional endoscopic evaluation of swallowing evaluated aspiration. Left-sided UVFI predominated. The most common causes of UVFI were iatrogenic and idiopathic. Central lesions and acute-onset UVFI were each associated with more severe dysphagia. Patients were more likely to aspirate on liquids versus purées and pastes. Benefits of medialization thyroplasty and vocal cord injection were equivocal.

CONCLUSION

A significant portion of patients with UVFI present with dysphagia due to anatomic and physiologic disruptions during the swallow. Study population heterogeneity and small sample sizes in the reviewed studies may have compromised reliability, calling for large-scale studies with rigorous methodology. Future studies should not only strive to identify the mechanics of the disordered swallow but also explore patients' quality of life and the effectiveness of current treatments for dysphagia with underlying UVFI.

Delayed lower cranial neuropathy after oropharyngeal intensity-modulated radiotherapy: A cohort analysis and literature review

BACKGROUND

The purpose of this study was to examine swallowing-related lower cranial nerve palsy (LCNP) in oropharyngeal cancer (OPC) survivors after intensity-modulated radiotherapy (IMRT).

METHODS

Patients treated with definitive IMRT (66-72 Gy) were pooled from institutional trial databases. Prospective analyses on parent trials included videofluoroscopy, clinical LCNP examination, and questionnaires pre-IMRT, 6 months post-IMRT, 12 months post-IMRT, and 24 months post-IMRT. Time-to-event and incidence of LCNP was estimated with competing risk methods. Literature review (1977-2015) summarized published LCNP outcomes.

RESULTS

Three of 59 oropharyngeal cancer survivors with a minimum 2-year follow-up developed hypoglossal palsy ipsilateral to the index tumor (median latency 6.7 years; range 4.6-7.6 years). At a median of 5.7 years, cumulative incidence of LCNP was 5%. LCNP preceded progressive dysphagia in all cases. Published studies found median incidence of radiation-associated LCNP was 10.5% after NPC, but no OPC cancer-specific estimate.

CONCLUSION

Although uncommon, the potential for late LCNP preceding swallowing deterioration highlights the importance of long-term functional surveillance in OPC survivorship.

Adipose-Derived Stem Cells Alleviate Radiation-Induced Muscular Fibrosis by Suppressing the Expression of TGF-β1

We aim to investigate the effects of adipose-derived stem cells (ASCs) transplantation on irradiation-induced skeletal muscle fibrosis. Sixty-four rabbits were randomly divided into ASCs group and PBS group followed by irradiation at unilateral hip with a single dose of 80 Gy. Nonirradiated side with normal skeletal muscle served as normal control. Skeletal muscle tissues were collected from eight rabbits in each group at 1 w, 4 w, 8 w, and 26 w after irradiation. Migration of ASCs was observed in the peripheral tissues along the needle passage in the injured muscle. The proportion of the area of collagen fibers to the total area in sections of ASCs group was lower than those of PBS groups at 4 w, 8 w, and 26 w after irradiation. Significant decrease was noted in the integrated optimal density of the transforming growth factor β1 (TGF-β1) in the ASCs group compared with those of PBS group at 4 w, 8 w, and 26 w after irradiation. Moreover, the expression of TGF-β1 was lower in the ASCs group compared to those of the PBS group at each time point determined by Western blot analysis. ASCs transplantation could alleviate irradiation fibrosis by suppressing the level of TGF-β1 in the irradiated skeletal muscle.