Voice Disorders Due to Nerve Damage

Vocal fold paralysis Inability of one or both folds to move because of the lack of innervation to particular intrinsic laryngeal muscles lesion may be peripheral or central; most VFP are due to peripheral lesions e.g., damage to the SLN or RLN Brodnitz (as far back as 1967) “most frequent cause…during thyroid operations”

Superior Laryngeal Nerve Paralysis If bilaterally damaged, pt can not elevate pitch if unilateral, one fold elongates for pitch change while the other is unaffected; results in hoarse voice, lacking pitch variation, and adequate loudness result is an “oblique glottis”

Recurrent Laryngeal Nerve Paralysis Can be unilateral or bilateral Adductor paralysis: involved fold(s) can not be adducted to the central position Abductor paralysis: paralyzed fold can not move laterally paresis

Adductor Paralysis Bilateral adductor form Unilateral Adductor form folds are open; usually in a paramedian position pts is aphonic Unilateral Adductor form involved fold is in paramedian position; complete glottal closure is not possible air is wasted during phonation breathy, hoarse vocal quality

Unilateral adductor con’t Tx.directed at increasing the “sharpness” of glottal attack possibly with effort closure sometimes will give the pt. a stronger,better voice Medical management: electrotherapy to stimulate the fold (muscle and nerve) and phonosurgery

Unilateral Adductor Paralysis, con’t Boone: if bilateral, voice tx is rarely effective medical tx: surgical repositioning, phonosurgery Spontaneous recovery period: approximately 6-9 months; varies physician Vs. behaviorists

Abductor Paralysis Unilateral abductor: results in the paralyzed fold lying near the midline some cases may abduct laterally to the intermediate position, but never full abduction as in deep inhalation pt complains more about SOB than dysphonia Primary symptom: usually impaired respiration with little/no voice change

Bilateral Abductor Paralysis Both folds are relatively fixed in an adducted midline position immediate surgery required to preserve the airway initially requires tracheotomy, then a second procedure to reposition the folds voice tx may be prescribed

Therapy for vocal fold paralysis Bilateral adductor: May try effort closure often result of central brain stem lesion (Boone) can have cerebral dysfunction, e.g., weakness of the tongue, palate or pharynx Boone says tx is “probably contraindicated” Surgery only if bilateral damage secondary to PNS damage, not CNS

Unilateral Adductor Paralysis Usually due to unilateral involvement of RLN Perceptual symptoms: marked dysphonia, severe breathiness. Note: breathiness is dependent upon the degree of glottal closure. Mgmt determined by MD/DO; must preserve the airway.

Airway considerations Laryngeal valving; biologic function silastic injection may be require to protect the airway

More tx considerations Boone: best voice is achieved with treatment that stresses increased breath control, increased hard glottal attack (why??) and pushing exercises

Tx for Unilateral Abductor Paralysis One fold remains fixed in a central, adducted position phonation is rarely effected since both folds approximate well quiet breathing is unaffected; during physical activity breathing becomes difficult due to narrowed airway

Unilateral Abductor tx con’t Surgery unlikely as the airway will be preserved Generally voice tx requires goo vocal hygiene, maintenance of a relaxed, open vocal tract

Tx for adductor forms (Boone, Stemple,Aronson and Case) Prognosis is better for pts with static lesion rather than degenerative PNS diseases Unilateral forms are better tx risks than bilateral Idiopathic VFP may experience spontaneous voice return masks as a conversion aphonia: SEE ENT!

More Boone, et al. Tx based upon the pt’s potential to compensate by means of adduction of the intact fold Aronson: effort closure, dec. musculoskeletal tension, digital manipulation of the affected fold, gravity, head turns

Considerations for surgical augmentation Typically “polytef” a mixture of 50% glycerin base inserted into the lateral margin of the fold

Case: reasons for teflon laryngoplasty Only if affected fold is in the paramedian, intermediate or abducted position AND unable to move toward the midline inject one cord if bilateral bowing due to SLN paralysis; bowing in the midglottic space when adduction/abduction are “normal”

Case, con’t Done after cordectomy, hemilaryngectomy or blunt laryngeal trauma when glottal incompetency occurs due to removed or damaged tissue Done when arytenoidectomy produces glottic incompetency

Contraindications of Teflon laryngoplasty Not in majority of bilateral add. Paralyses as the procedure requires one competent v.f. to work against the displaced fold can’t be done if v.f.s are paralyzed due to CNS lesion producing dysarthria and bilateral involvement NOT done to add mass to v.f. to lower fundamental frequency

Contraindications, con’t Not done before 6 mo after onset except in the case of CA-caused paralysis may experience spontaneous recovery during the 6 mo period Not done if pt is psychologically unstable Not done for dysphonia from myasthenia laryngis or hypogenesis of the vocalis muscle

More contraindications Not done for minor defects in the glottic area until vocal rehab via voice tx has been attempted Should not be done in an attempt to move the arytenoid medially; only vocalis tissue should be moved by displacing the anterior 2/3 of the glottis

Phonosurgery Any surgery designed primarily for the improvement or restoration of voice

Phonosurgery options Laryngeal injection techniques Laryngeal framework surgery Laryngeal innervation Microsurgery of benign lesions Laser Instrumental

Evaluation History and physical exam Videostroboscoy Aerodynamic analysis Maximum phonation time (MPT) Mean air flow rate (MFR) Acoustic analysis Laryngeal manual compression tests

Aerodynamic Analysis Max phonation time indication of glottic competence influenced by vital capacity use sustained /a/ women: 14-40 seconds men: 15-62 seconds

Aerodynamics, con’t Mean air flow rate indicator of degree of glottic closure Norm values women: 43-193 cm3/sec men: 46-222 cm3/sec

Lateral Compression Test Most valuable in incomplete glottic closure Unilateral RLNP Vocal Fold atrophy Sulcus vocalis Sulcus vergeture Sustain phonation using /o/ Type I thyroplasty

Injection Techniques in Vocal Fold Paralysis 1911- Wilhelm Brunings Paraffin injection Brunings syringe (0.05 ml) Paraffinoma < 46 degrees C 1957 Godfery Arnold Diced autogenous septal cartilage paste 1976-Lewy--teflon injection; 1039 procedures over 24 y ears; 96% improvement

Laryngeal Framework Surgery 1915-Erwin Payr: first thyroplasty, anteriorly based flap of the thyroid cart. 1942-Yrho Meurman: implanted costal cartilage via laryngofissure 1955-Odd Opheim: superior thyroid ala 1965- Tschiassny:approximate cricoid and thyroid cartilage to increase vocal pitch 1974-Isshiki thyroplasty

Laryngeal Framework Surgery Advantages Less vocal fold trauma Vibratory structure is preserved Reversible Intraoperative Early voice restoration

Laryngeal Framework Surgery Indications Unilateral RLNP Vocal fold atrophy Suclus vocalis Sulcus vergeture

Laryngeal Framework Surgery Isshiki Classification Type I Medialization Type II Lateralization Type III Shortening Type IV Lengthening

Combined Lateral Compression and Cricothyoroid Approximation Evaluates imperfect glottic closure due to VF atrophy and decrease in tension and stiffness RLNP and presbylaryngis CN X injury above the nodore ganglion Thyroplasty Type I and IV or arytenoid adduction

Arytenoid Adduction Procedure of choice when the glottic aperture is wide and the immobile vocal fold is at a higher level posteriorly Technically difficult Anterior placement-- junction of anterior and middle third of the thyroid ala Open cricoarytenoid joint

Cricothyroid Approximation Evaluates pitch disorders Sustained /o/ Compression should rise pitch Thyroplasty type IV

Vocal Fold Medialization Intrafold injection: transoral via indirect, transoral with direct or transcutaneous through the cricothyroid space surgical augmentation medial shift of the thyroid rotation of the arytenoid

Vocal Fold Lateralization Laterofixation of the VF: move the vocal process laterally Arytenoidectomy: removal of the arytenoid to widen the posterior glottis

Vocal Fold Tensing To raise pitch Cricothyroid approximation: permanent approximation of the cricoid arch to the thyroid cart. Anteriorly stimulates the cricothyroid m. done under local to monitor pitch anterior commissure advancement: intent is to stretch the VF by moving the anterior commissure anteriorly

Vocal Fold Slackening Reduce the tension of the VFs move the anterior commissure posteriorly, toward the arytenoids