NEUROLOGICAL LESIONS OF

LARYNXDr Manpreet Singh Nanda

Associate Professor ENTMMMC&H Solan

ETIOLOGY Supranuclear – tumours, trauma, stroke Nuclear – tumours, stroke High vagal – above inferior ganglion A – intracranial – tumours, meningitis, head injury B – jugular foramen – fractures, NP Cancer,

glomus tumour C – parapharyngeal space – tumours, surgery,

glomus Low vagal 1 – SLN – neck trauma, thyroid surgery 2 – RLN – Neck trauma, thyroid surgery, tumours,

mediastinal lesions (left)

Systemic Diabetes Diptheria Typhoid OP/Lead poisoning Viral Syphilis IDIOPATHIC , MALIGNANCY (MC)

AND SURGICAL TRAUMA (30% EACH)

THEORIES Semon’s law – fibres supplying the abductors

get affected much earlier than adductors and reverse for recovery in RLN paralysis result in vc earlier in paramedian position

Wagner’s and Grossman hypothesis – In absence of cricoarytenoid fixation vocal cords are in median and paramedian position in RLN paralysis due to continued function of cricothyroid muscle.

Negus – Supported Semon law. Since post cricoarytenoid is a only abductor supplied by RLN so abductors are more vulnerable in RLN paralysis..

POSITIONS OF VC Median (midline) – phonation, RLN

paralysis Paramedian – vc 1.5 mm away from

midline – strong whisper, RLN paralysis Intermediate/cadaveric/lateral – vc 3.5

mm away from midline – combined paralysis

Gentle/slight abduction – vc 7mm away from midline – quiet respiration, adductor paralysis

Full abduction – vc 9.5 mm away from midline – deep inspiration

UNILATERAL RLN PARALYSIS U/L paralysis of all muscles except

cricothyroid Etiology – Bronchogenic carcinoma, thyroid

surgery (mc) C/F Asymptomatic - one third Change in voice which gradually improves

due to compensation by healthy cord.. Tiring voice Diplophonia O/E Affected VC in median/paramedian position

Treatment Asymptomatic – spontaneous recovery Speech therapy Intracordal inj of teflon paste Medialization thyroplasty

BILATERAL RLN PARALYSIS Abductor paralysis. There is unopposed action of

cricothyroid muscle Etiology – thyroidectomy (mc), trauma,

neoplasm C/F Acute onset Dyspnoea and inspiratory stridor which becomes

worst on exertion or infection.. Aspiration in elderly Patient may retain good voice O/E – both vc in median or paramedian position Diagnosis – CT, MRI ,Chest X Ray,

Panendoscopy..

Intubation/emergency tracheostomy Permanent tracheostomy with a

speaking valve – to retain good voice Lateralisation of vc – vc is moved and

fixed in lateral position which improves airway. Not preferred in patients with good voice as good voice is lost

LATERALISATION PROCEDURES Arytenoidectomy – removal of

arytenoid by external approach (woodman’s operation), by endoscopic approach (thornell operation)

Endoscopic CO2 LASER cordectomy Laterialisation thyroplasty Nerve muscle implant – sternohyoid

muscle with nerve supply is transplanted into post cricoarytenoid

UNILATERAL SLN PARALYSIS Rare Paralysis of unilateral cricothyroid muscle Unilateral supraglottic anaesthesia Etiology – thyroid surgery, tumours, trauma,

neuritis C/F Weak and low pitch voice (loss of tension) Occasional aspiration (anaesthesia) O/E I/L VC flabby and bowed, wavy appearance Oblique laryngeal inlet Post commissure deviated medially towards

affected side

Prognosis Voice recovered by compensation from

healthy cord Singers cant produce high pitch voice Treatment Speech therapy

BILATERAL SLN PARALYSIS Least common Both cricothyroid paralysed Anaesthesia of supraglottic larynx Etiology – surgical trauma, RTA, neoplasm C/F Coughing and choking during swallowing

due to aspiration Weak and husky/breathy voice Short phonation time O/E B/L flaccid and bowed vc

Treatment Ryle’s/NG tube feed Tracheostomy with cuffed tube Thyroplasty Injection teflon/collagen for

medialization Epiglottoplexy – reversible procedure

where in laryngeal inlet is closed to protect the lungs from aspiration. Epiglottis is fixed to arytenoids

UNILATERAL COMBINED PARALYSIS OF SLN AND RLN Paralysis of all unilateral muscles except

interarytenoid which receive innervation from other side

Etiology – high vagal lesions, thyroid surgery C/F Hoarseness of voice Aspiration of fluids Inadequate cough O/E Unilateral paralysed vc in cadaveric position Prognosis No compensation by healthy cord

Treatment Speech therapy Medialisation of paralysed vc by teflon

injection or thyroplasty

BILATERAL COMBINED PARALYSIS OF SLN AND RLN Rare Total anaesthesia of larynx All laryngeal muscles paralysed Etiology Neoplasm in skull base, medulla, upper neck CNS disorder C/F Aphonia – vc dont approximate Aspiration – laryngeal anaesthesia Inability to cough leading to collection of

secretions Bronchopneumonia due to aspiration and

secretions

O/E Both vc in cadaveric position Treatment Ryle’s tube feed Reversible Tracheostomy with cuffed tube Epiglottoplexy VC plication – approximation of vc with sutures Irreversible Total laryngectomy – for progessive and

irreversible disease, when voice is lost- to protect lungs

CONGENITAL VC PARALYSIS Second mc cause of stridor in neonates (1st

laryngomalacia) Unilateral mc, Right VC Etiology Idiopathic U/L – birth trauma, congenital anomaly of heart or

vessel B/L – anomalies of CNS, hydrocephalus, meningitis C/F Weak or hoarse cry Inspiratory or biphasic stridor Difficulty in feeding Prognosis – 70% U/L and 50% B/L recover

spontaneously within six months

Diagnosis Awake flexible laryngoscopy MRI X Ray Neck/Chest Treatment- NG tube feed U/L (if severe aspiration or dyspnoea) Inj teflon/thyroplasty B/L (after 5 yrs of age if recovery has not

happened) Arytenoidectomy (endoscopic/external) Endoscopic lateral cordotomy

PHONOSURGERY Microlaryngeal surgery Excision of vc lesion under operating microscope

using LASER, microdebrider, forceps Local intralesional injections .. To medialize the vocal cords Done percutaneously/transorally under operating

microscope using Teflon paste (PTFE) Gelfoam Collagen Autologous fat Collagen derivatives

Thyroplasty (laryngeal framework surgery) Isshiki’s thyroplasty I – Medial displacement of vc to improve

quality of life (Medialisation thyroplasty) – window created below thyroid notch and silastic block fitted through window

II – Lateral displacement of vc to improve airway (Lateralisation thyroplasty)

III – Relaxation or shortening of vc To produce male low pitched voice Puberphonia/gender transformation

IV – Tension or lengthening of vc To produce female high pitched voice Cricothyroid palsy Gender transformation Laryngeal innervation procedure Window made in thyroid cartilage and

segment of superior belly of omohyoid with its nerve supply is implanted into vocalis muscle

To innervate paralysed vocalis muscle

FIXED VC Etiology Malignancy Adhesions/mass Cricoarytenoid joint arthritis Diagnosis Swelling around cricoarytenoid joint Straight or shortened vc – no bowing No deviation of arytenoid cartilage On phonation no flicker Probe test – press the arytenoid with a large

probe. No vibration of vc or change in position