Improvement in Swallowing Function in Patients with Previous Irradiation for Nasopharyngeal Carcinoma by Expiratory Muscle Strength Training

Dysphagia and chronic aspiration are common post-irradiation complications in nasopharyngeal carcinoma (NPC) survivors. Expiratory Muscle Strength Training (EMST) is a simple device-driven exercise therapy for swallowing training. This study investigates the effectiveness of EMST in a group of post-irradiated NPC patients. This prospective cohort, including twelve patients with previous irradiation for NPC and with swallowing disturbance, was performed between 2019 and 2021 in a single institution. Patients were trained with EMST for 8 weeks. Non-parametric analyses examined effects of EMST on primary outcome, maximum expiratory pressure. Secondary outcomes were measured with Penetration-aspiration scale, Yale pharyngeal residue severity rating scale (YPRSRS) by flexible endoscopic evaluation of swallowing, and Eating Assessment Tool (EAT-10) and M.D. Anderson Dysphagia Inventory questionnaire. Twelve patients, with a mean (SD) age of 64.3 (8.2) were recruited. There was no patient dropout with 88.9% overall compliance of training. Maximum expiratory pressure improved by 41% (median 94.5 to 133.5 cmH2O, p = 0.003). There was reduction in Penetration-aspiration scale with thin liquid (median 4 to 3, p = 0.026), and in YPRSRS at pyriform fossa with mildly thick liquid (p = 0.021) and at vallecula with thin liquid (p = 0.034), mildly thick liquid (p = 0.014) and pureed meat congee (p = 0.016). Questionnaire scores did not significantly change statistically. EMST is an easy-to-use and effective exercise therapy to improve airway safety and swallowing function in post-irradiated NPC survivors.

Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report

We report the first case of bilateral hypoglossal nerve stimulator implantation in a patient with Treacher Collins syndrome and very severe obstructive sleep apnea, who was initially intolerant of continuous positive airway pressure (CPAP) treatment. Novel bilateral hypoglossal nerve stimulation in combination with CPAP allowed near obliteration of snoring, improved sleep quality, and ability to maintain the CPAP mask in position in the setting of craniofacial changes associated with this condition.

CITATION

Wong ACL, Jones A, Stone A, MacKay SG. Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report. J Clin Sleep Med. 2023;19(1):197-199.

Sensorineural Hearing Loss in Nasopharyngeal Carcinoma Survivors in the Modern Treatment Era - The Early and Late Effects of Radiation and Cisplatin

AIMS

Hearing loss is a common debilitating complication in nasopharyngeal carcinoma (NPC) survivors. The aim of the present study was to investigate the impact of inner ear/cochlear radiation dose and cisplatin use on early and late sensorineural hearing loss (SNHL) in NPC patients treated with radiotherapy alone, concurrent chemoradiation (cCRT) and induction chemotherapy followed by cCRT (iCRT) in the intensity-modulated radiotherapy era.

MATERIALS AND METHODS

The study included 81 NPC patients treated with intensity-modulated radiotherapy between 2014 and 2016. Pure tone audiometry was carried out at baseline and follow-up. The effects of cochlear/inner ear radiation and cisplatin doses on early (<12 months) and late (≥24 months) SNHL were analysed using multivariable regression after adjusting for important predictors.

RESULTS

In total, 156 ears were examined. In early SNHL (n = 136), cisplatin use predicted the incidence of early high-frequency SHNL (HF-SNHL) (odds ratio 6.4, 95% confidence interval 1.7-23.9, P = 0.005). Ninety ears were analysed for late SNHL (median follow-up 38 months). Inner ear/cochlear radiation and cisplatin doses and better pre-treatment hearing were independent predictors of threshold change at 4 kHz. Every 10 Gy increase in inner ear/cochlear Dmean resulted in 5-dB and 6-dB threshold changes, respectively (cochlear Dmean: B = 0.005, 95% confidence interval 0.0004-0.009, P = 0.031; inner ear Dmean: B = 0.006, 95% confidence interval 0.001-0.010, P = 0.014). Cisplatin use was associated with late HF-SNHL (odds ratio 3.74, 95% confidence interval 1.1-12.3, P = 0.031). In the cCRT and iCRT subgroups, no cisplatin dose-dependent ototoxicity was observed. Severe (≥30 dB) late HF-SNHL occurred in 14% and 25% of the patients when the cochlear dose constraints were 40 Gy and 44 Gy, respectively. The radiotherapy-alone group did not develop severe late HF-SNHL.

CONCLUSION

Cochlear/inner ear radiation dose and cisplatin use showed differential and independent ototoxicity in early and late SNHL. As cochlear/inner ear dose-dependent ototoxicity was demonstrated, the cochlear dose constraint should be as low as reasonably achievable, especially when cisplatin is also administered.

Multiplexing of polarization-maintaining photonic crystal fiber based Sagnac interferometric sensors

Three multiplexing schemes are presented for polarization-maintaining photonic crystal fiber based Sagnac interferometric sensors. The first technique is wavelength division multiplexing using coarse wavelength division multiplexers (CWDMs) to distinguish signals from each multiplexed sensor in different wavelength channels. The other two schemes are to multiplex sensors in series along a single fiber link and in parallel by using fiber-optic couplers. While for the CWDM scheme, the multiplexed sensing signal can be obtained by direct measurement; for the other two multiplexing techniques, the sensing signal is more complex and cannot be easily demultiplexed. Thus, some signal processing methods are required. In this regard, two mathematical transformations, namely the discrete wavelet transform and Fourier transform, have been independently and successfully implemented into these two schemes. The operating principles, experimental setup, and overall performance are discussed.

Plasma-enhanced synthesis of bactericidal quaternary ammonium thin layers on stainless steel and cellulose surfaces

We have investigated bottom-up chemical synthesis of quaternary ammonium (QA) groups exhibiting antibacterial properties on stainless steel (SS) and filter paper surfaces via nonequilibrium, low-pressure plasma-enhanced functionalization. Ethylenediamine (ED) plasma under suitable conditions generated films rich in secondary and tertiary amines. These functional structures were covalently attached to the SS surface by treating SS with O 2 and hexamethyldisiloxane plasma prior to ED plasma treatment. QA structures were formed by reaction of the plasma-deposited amines with hexyl bromide and subsequently with methyl iodide. Structural compositions were examined by electron spectroscopy for chemical analysis and Fourier transform infrared spectroscopy, and surface topography was investigated with atomic force microscopy and water contact angle measurements. Modified SS surfaces exhibited greater than a 99.9% decrease in Staphylococcus aureus counts and 98% in the case of Klebsiella pneumoniae. The porous filter paper surfaces with immobilized QA groups inactivated 98.7% and 96.8% of S. aureus and K. pneumoniae, respectively. This technique will open up a novel way for the synthesis of stable and very efficient bactericidal surfaces with potential applications in development of advanced medical devices and implants with antimicrobial surfaces.