The Thesis deals with the problem of quality diagnostic improving, disease prognosis of larynx motility disorders and analysis of the effectiveness of voice restoration in patients after conservative treatment and laryngeal reinnervation with unilateral paralysis in thyroid surgery.
The dissertation is based on complex clinical and instrumental examination of larynx and vocal function of 227 patients with laryngeal motility disorders, including patients with laryngeal paresis (n=131), with laryngeal paralysis (n=33) and patients after laryngeal reinnervation (n =63). The control group consisted of practically healthy individuals (n=295) without complaints of voice disorders and visible disorders of the motor function of the larynx, who were studied for the indicators of the acoustic analysis of the voice by gender and age, and the determination of the reference values of these indicators.
All studied patients underwent general clinical examination, otolaryngological examination, videolaryngostroboscopy, acoustic voice analysis with determination of maximum phonation time parameters (MPT), laryngeal fundamental tone frequency (F0), harmonic/noise ratio (HNR), Jitter, Shimmer.
The frequency of laryngeal paresis (9,1 %) and paralysis (0,8 %) in thyroid surgery was determined.
The highest frequency of post – thyroidectomy paresis and paralysis was observed in various forms of thyroid cancer: papillary thyroid cancer (paresis – 10,6 %, paralysis – 0,8 %), medullary thyroid cancer (paresis – 10,3 %, paralysis – 3,4 %), follicular thyroid cancer (paresis – 14,3 %, paralysis – not detected).
Using of central and lateral dissection of the neck with total thyroidectomy (paresis – 11,7 %, paralysis – 1,2 %) or partial thyroidectomy (paresis – 8,1 %, paralysis – 1,6 %) increases the frequency of RLN damage.
The most significant laryngoscopic signs in patients with vocal cord motion disorders were determined using the ANOVA one-factor analysis. The analysis of laryngoscopic signs regarding the development of laryngeal paresis and paralysis in patients after thyroid surgery was carried out with methods of Wald and binary logistic regression. Based on the ranking of two highly significant laryngoscopic signs (p<0,05), a prognostic model of the course of paresis and paralysis of the larynx in patients undergoing thyroid surgery was created (Area under curve (AUC) 0,863 (95 % CI 0,794–0,931)). The increase in rank corresponded to the strengthening of the negative relationship with the presence of laryngeal paralysis:
- motion of arytenoid paralyzed vocal fold (present – rank 1, slight mobility – rank 2, absent mobility – rank 3);
- flotation of the paralyzed vocal fold (absent – rank 1, slightly expressed – rank 2, expressed – rank 3).
If the value of the rank sum is ≥4, patients belong to the group with a high risk of laryngeal paralysis.
The voice of persons without motion disorders of the larynx by gender and age was studied. The indicators of the spectral analysis of the voice in young and middle-aged women and men (18–59 years old) are relatively stable and do not change significantly in this time period. In elderly men and women, there is a significant decrease in MPT (p<0,01), a decrease in HNR (p<0,001), and increase in Jitter (p<0,001) and Shimmer (p<0,001) indicators after 60 years. With age, there is a slight decrease in Fo in women and a significant increase F0 (p<0,001) in men over 60 years of age.
The reference intervals of the MPT indicator in women aged 18–59 are: 13,3– 28,5 sec, in women 60–74 years old: 12,3–25,6 sec, in men aged 18–59: 16,7–37,
4 sec and men aged 60–74: 14,2–36,2 sec.
The reference intervals of the F0 indicator in women 18–59 years old are: 132,6–300,2 Hz, 60–74 years old: 121,9–289,4 Hz, in men 18–59 years old:
118,2–185,6 Hz and 60–74 years: 116,8–239,1 Hz.
The reference intervals of the HNR indicator in women aged 18–59 are: 19,25–25,90 dB, aged 60–74: 18,01–22,98 dB, in men aged 18–59: 19,16–
27,46 dB, aged 60–74 years: 17,98–23,11 dB.
The reference intervals of the Jitter indicator (loc, %) in women aged 18–59 are: 0,151–0,401 %, 60–74 years: 0,158–0,611 %, in men 18–59 years:
0,141–0,483 %, aged 60–74: 0,146–0,598 %.
The reference intervals of the Shimmer indicator (loc, %) in women 18–59 years old are: 1,818–2,139 %, in women 60–74 years old: 1,821–2,342 %, in men 18–59 years old – 1,832–2,128 % and 60–74 years old – 1,839–2,416 %.
Developed indicators of reference intervals requires further study and refinement.
