Stroboscopy

To understand vocal fold biomechanics
video on slide 7

1. STROBOSCOPY PRESENTER: DR. ARJUN SURESH

2. INTRODUCTION Videostroboscopy - practical and useful technique - clinical evaluation - visco -elastic properties of phonatory mucosa. Painless, OPD-based procedure Essential evaluation of laryngeal mucosa, vocal fold motion biomechanics, and mucosal vibration. Helps detect pathology - determine impact on voice and airway function.

3. STROBSCOPY Method used to visualize vocal fold vibration. Uses synchronized, flashing light passed via flexible or rigid telescope Flashes of light are synchronized to vocal fold vibration at slightly slower speed, allowing examiner to observe it during sound production in slow motion

4. Essential for planning effective phonomicrosurgery . R eal-time information - nature of vibration, image to detect vocal pathology, and permanent video record of examination. Improves sensitivity of subtle laryngeal diagnoses. Helps evaluate: 1. Vocal fold biomechanics 2. Laryngeal mucosa 3. Mucosal Vibration

5. USES : Cause of voice dysfunction or hoarseness - vocal cord swelling, irritations, misuse, growths, polyps or acid reflux. To visualize your vocal cords To evaluate or detect vocal cord lesions and other irregularities like inflammation, scar tissue or muscle tension conditions To assess swallowing issues, which could be caused by muscle abnormalities

6. CANDIDATE FOR VIDEOSTROBOSCOPY You may be a candidate for videostroboscopy if you're experiencing chronic or intermittent voice problems like: Breathiness, hoarseness, decreased or loss of vocal range or vocal fatigue Tightness, discomfort or pain or burning in your throat while talking The feeling of "something in your throat“ (foreign body sensation) Symptoms and hoarseness caused by acid reflux

7. A strobe - visualize the mucosal waves across the vocal folds. Synchronized to the frequency of the voice. The mucosal waves are too fast for the human eye to appreciate. The strobe slows this process by visualizing the mucosal wave across several cycles of vocalization. Mucosal waves originate upon contact or closure of the vocal folds and move from a medial to lateral direction Mucosal folds are at the same position on both vocal folds at any particular time

8. CONTRAINDICATIONS No absolute CI – patient should have adequate mouth opening and patent nasal airway.

9. EQUIPMENT A videostroboscopic unit: A stroboscopic light source and microphone, Video camera Endoscope Video recorder. Stroboscopy can be performed by using either rigid or flexible Endoscopes.

10. Standard 70-degree rigid strobolaryngoscope . Camera attachment with mounted microphone Laryngeal microphone flexible laryngostroboscope

11. POSITIONING Videostrobolaryngoscopy begins by seating the patient in the examination chair at a height comfortable for the examiner. The patient leans forward with the neck flexed and the head extended at the atlo -occipital joint (Kirstein position).

12. TECHNIQUE/PROCEDURE Once the patient is in appropriate position, Spray topical anesthesia – posterior part of tongue and oropharynx . Calibrate microphone and hold against thyroid lamina. To avoid condensation – dip scope in hot water. Open mouth, protrude tongue- scope is inserted. Proper focus – visualise subepithelial vasculature of vocal fold.

13. With Vocal folds in focus – ask patient to produce ‘ ee ’ sound. Should be done at low, mid and high frequency pitches and different volumes. Examiner - comment on arytenoid and vocal fold mobility, glottic closure pattern, mucosal wave, and pliability. Ulcerative lesions or masses can also be observed.

14. DIAGNOSTIC FINDINGS VOCAL CYST Encapsulated, spheroid lesions - mucus or keratin Located - lamina propria of the vocal fold. Keratin cysts - likely congenital & mucous cysts - likely acquired. Generally unilateral, though several may be present at the time of diagnosis. On stroboscopy , region of the cyst - diminished pliability - mucosal wave does not propagate normally through the region of the cyst. Mucosal-wave deficit - size and location of the cyst. Illustrated by the fact - small superior-surface cysts minimally affect vocal function.

15. VOCAL CYST

16. VOCAL FOLD POLYPS Unilateral or bilateral. Represent phonotraumatic pathology - collision forces, shearing stresses - lamina propria . Consistency - gelatinous to fibrotic. Glottic closure – compromised - gaps anterior and posterior to the lesion in maximal closure. The vibratory patterns of VC – asymmetric - diminution of vibration near the lesion. Medial surface polyp - disturbs the vibratory pattern - contralateral vocal fold during closure.

17. VOCAL POLYP

18. VOCAL FOLD NODULES Bilateral fibrovascular lesions - symmetric sessile masses. Occur in the center of the musculomembranous region - basement-membrane - between the overlying epithelium and the underlying superficial lamina propria . Glottic closure is compromised - high pitch frequencies. Mucosal wave - usually preserved bilaterally - pliability and amplitude - decreased in the region of the nodule.

19. VOCAL FOLD NODULE

20. THANK YOU