Physiology of Larynx and Hoarseness

Physiology of Larynx and HoarsenessDr Manpreet Singh NandaAssociate Professor ENTMMMC&H Solan

Functions of LarynxProtection of lower airways (1)Phonation and Speech (2)RespirationFixation of chestHelps in promoting venous return

Protection of lower respiratory tractSPHINCTER CLOSURE OF LARYNGEAL OPENINGS DURING SWALLOWING1st tier aryepiglottic folds, epiglottis, arytenoids2nd tier false cords3rd tier true cordsDue to contraction of adductor muscles

CESSATION OF RESPIRATION TEMPORARYIX CN (Swallowing reflex when food comes into contact with oropharynx)

COUGH REFLEXBarking sensation at entry of FB and food particles which are coughed out

Phonation and SpeechTheories 1. Aerodynamic theory of phonation2. Myoelastic theory of phonation3. Neurochronaxic theory of phonationPHASES Pulmonary phaseLaryngeal phaseSupraglottic or Oral Phase

Pulmonary PhaseAir breathed inInflation of lungsIncreased air pressureExpulsion of air(due to contraction of thoracic and abdominal muscles)

Laryngeal PhaseAir pressureOpens adducted vcSmall puffs of air between vocal cordsVibration of elastic cords (oscillatory motion of membranous part of vc)Fundamental note (voice) formed

Supraglottic or oral phaseModifies laryngeal soundResonation modification/amplification of soundOral cavity, pharynx, nasal cavity, PNS (Supraglottic tract)

Articulation words of sentence (speech) formed by muscles of tongue, lips, teeth, gums, palate

Intensity of sound controlled by air pressure in lungsPitch of sound controlled by vocal cord vibration which changes with change in length, breadth and elasticity of vcQuality of speech depends on resonance and articulation

RespirationAdduction of vc expirationAbduction of vc inspirationRegulates flow of air into lungs

Fixation of chestClosed larynx -> built up of air pressure -> chest wall fixed -> main thoracic and abdominal muscles act best -> sternous work

Digging, pulling, climbing, coughing, defaecation, micturition, child birth, straining

Hoarseness of voiceDef Change in voice or rough and unpleasant voice due to vocal cord lesions leading to faulty approximation of vocal cordsM.C SymptomMuffled voice hot potato voice Seen in lesions of laryngopharynx and tongue base, vocal cords not involvedBreathy voice seen in vc paralysis due to escape of air between vc

EtiologyLaryngeal Congenital webs, cystsInfective acute, chronic, TB, syphilisTrauma injury, intubation, fumes inhalationAcid refluxTumours benign, malignant (elderly >2 weeks)Voice abuseNeurological vc paralysisPsychologicalIrradiationArthritis of cricoarytenoid jointVocal cord nodule, polyp, laryngocele

EndocrineHypothyroidism, RA, Hyperparathyroidism, DibetesOesophageal MalignancyCervical and Mediastinal RLN paralysisPATHOLOGY interference in Movement of vcApproximation of vcMass of vcTension of vc

ManagementHISTORY TAKINGAge young - infection, old malignancySex male malignancyOccupation voice users, workers (fumes)Onset sudden with gradual improvement vc paralysisDuration short inflammatoryProgression long duration slow progress (neoplastic) long duration rapid progressive (malignancy)Past history procedures, radiation therapyHabits smoking, drinking

GPENutrition cachexia malignancy, TBLymph nodes hard (malignancy)Thyroid

LOCALENTIDLCVS/RS/CNS

InvestigationsX Ray larynx, chestCT ScanFlexible laryngoscopy (OPD)DL Scopy and BiopsyMicrolaryngoscopy ( op microscope)Barium Swallow (ca oesophagus)Bronchoscopy and OesophagoscopyThyroid Scan / TFTBlood Hb, TLC, DLC, RBS, ESR, VDRLUrineMantoux test

TreatmentTreat the causeVoice rest avoid abuse and whisperingSteam inhalations with inhalant capsules (menthol, camphol, eucalyptus oil) soothes vc, reduces congestionAntibiotics - infectionAnti inflammatory oedema and congestionSpeech therapy

Voice and Speech disordersSpeech disorders - Aphasia and Dysphasia - Dysarthria - Stammering or Stuttering

Dysphasia and AphasiaDysphasia Impaired comprehension or production of speech due to lesions affecting cortical speech centre in dominant cerebral hemisphereAphasia loss of speechTYPES - Sensory or receptive- Motor or expressive- Conductive- Mixed or total- Amnesic or nominal

Sensory dysphasia or Wernickes aphasiaReceptiveImpaired comprehension of wordsPatient unawareTypes 1. Auditory (word deafness)Cant comprehend spoken words, hearing normal, lesion in auditory area2. Visual (word blindness)Cant comprehend meaning of written words, vision normal3. Agrammatism Severe

Motor dysphasia or Brocas aphasiaExpressiveDifficulty in speech production or language output (writing and sign)Knows what to say cant speakUnderstands written words cant readPatient awareLesion in cortical motor speech brocas areaCan read and hear normally

CONDUCTIVE APHASIASkips words or repeat wordsCant repeat examiner commandLesion in arcuate fasciculus (connects)PARAPHASIA Replacing one word with another AMNESIC OR NOMINAL APHASIA Difficulty in naming objects or persons seen, held or feltMIXED OR TOTAL APHASIA All aspects of speech and communication are impaired

DysarthriaDef Disturbance of articulation due to lesions affecting cranial nerves, muscles, joints, ligaments responsible for speech leading to faulty working of lips, tongue, palate, pharynx and larynxEtiology Supranuclear lesions, nuclear lesions, infranuclear lesions, muscular lesions, nerve palsy

Stammering or StutteringFunctional speech disorderNeurological movement disorder in which abnormal, involuntary and inappropriate use of speech muscles results in dysfluencyCause Psychogenic, due to increased muscle tension in 3 subsystems of speech lungs, larynx and supra laryngeal tractToo much attention or reprimands to childhood dysfluency between 2 to 4 yearsCommon in pre school yearsCommon in boys

Clinical FeaturesHesitation to initiate speechRepetitionProlongationBlocks in speech flowSecondary features facial grimacing, eye blink, abnormal head movementsRelieving factors singing, shoutingAggravating factors public speech, personal interview

TreatmentSpeech therapyPsychotherapy assurance and counselling of both parents and patients, educate not to over reactAnti depressantsBotulinum toxin inj Speech easy ear device delayed auditory feedback

Dysphonia plica ventricularisFalse cord voiceVentricular dysphoniaFalse cords take over function of true vcEtiology- Psychogenic and tense individuals- Organic causes- true vc paralysis, fixation, excision causing compensationC/F- Rough, harsh and low pitched voice- Late onset in psychogenic cause- Diplophonia (double voice)

Signs- False cords approximate on phonation partially or completely- False vc red and thickened- Obscure view of true vcInvestigation stroboscopyTreatment- Voice therapy- Psychogenic therapy- Organic cause difficult to treat ( laser excision)

Functional/hysterical aphoniaSudden complete loss of voice seen in young femalesEtiology- emotional social problems, anxiety- age gp mc 15 to 30 yrsC/FSudden and complete loss of voiceWhisper, cough, laugh and cry are normalNo aspiration ( diff from adductor palsy)Muteness ( refusal to speak)Signs vc in abducted position but adduct on coughingTreatment reassurance and psychotherapy

Puberphonia/PubophoniaMutational/Functional falsetto voiceFailure to change childhood high pitched voice to low pitched male voice after puberty in boysEtiologyEmotionally immature boys, insecure, too much attached to mother or sister Hormonal disturbanceChildhood asthma (doubtful)PathologyHyperkinetic function and spasm of cricothroid muscle C/FCracking of voice in males at pubertyHigh pitched and weak voiceThin, shy and insecure patients

SignsNormal larynxOval or elliptical slit glottisPosteriorly formed mutational triangle (due to partial closure of vocal process)Investigations StroboscopyTreatmentSpeech therapyPsychotherapyTrain to produce low pitch voice by pressing thyroid prominence backwards and downwards (relaxes vc) Gutzmann pressure test

Habitual dysphoniaGradual onset hoarseness which becomes worst after period of timeEtiologyProlonged habitual misuse or abuse of vc like shouting and screaming or long useSignsOedema and inflammation of vcTreatmentVoice therapy

MogiphoniaPhonic spasm in professional voice users when they appear in publicEtiology psychogenicC/FStarts normal but later cant speakSignsAdducted vcTreatmentPsychotherapySpeech therapyVoice rest

PhonoastheniaPhonoasthesia/Myasthenia of LarynxFunctional weakness of voice due to fatigue of phonatory muscles mainly thyroarytenoid and interarytenoidEtiology- Vocal abuse- LaryngitisC/F easy fatigue voiceIDL - Hyperaemia of vc- Elliptical space between vc (thyroarytenoid)- Triangular gap in post commissure (interarytenoid)- Keyhole appearance (both)Treatment total voice rest and vocal hygiene

RhinolaliaNasal speech or nasal intonation of speechRhinolalia clausa HyponasalityBlockage of nose or nasopharynx due to rhinosinusitis, allergic rhinitis, polyp or mass, adenoids, functionalLack of resonance of words resonated in nasal cavity like m , n , ngRhinolalia apertaHypernasalityFailure of nasopharynx to cut off from oropharynx or extra openings between oral and nasal cavities due to short soft palate, soft palate paralysis, palatal perforation, after adenoidectomy and functionalNasal resonance for all the words even those having little resonance

Spasmodic/Spastic dysphoniaFocal dystonia of larynx/ laryngeal spasmDystonia abnormal involuntary movementsDef stress induced laryngeal motion disorder resulting in alternate harsh and soft voiceTypes adductor (irregular hyperadduction), abductor (intermittent abduction), mixedC/FAt rest normal vcWhen speak abnormal functionRapid alteration in pitch and loudness of voice (vocal tremors)Adductor choked, strained, strangulated, monotonous voiceAbductor breathy and effortful voice

Aggravated by stressRelieved by sedation, alcohol, singing, yawning, shoutingAlso seen spasm of eyelids, jaw and tongueTreatment- voice therapy- sedatives- RLN sectioning- Botulinum injection

Tourettes syndromeTic disorderInvoluntary vocalization of articulate soundsAlong with other tics (nose, tongue)C/FOnset childhoood or adolescenceOCDTreatmentBenzodiazepinesPhenothiazines (haloperidol)Botulinum injections

Laryngeal vertigoAttacks of vertigo with temporary unconsciousness following spasm of vocal cordsSeen in emotionally instable malesC/FGiddiness or light headPale and cyanosisMomentary loss of consciousBut no tremors and convulsions (epilepsy)

Vocal hygieneDef Habits to maintain proper functioning of vocal cords especially those with voice disordersHabits - Voice rest- avoid voice abuse- avoid smoking and dust- avoid spicy food (LPR)- avoid whispering, forceful coughing, throat clearing- avoid drying potential medications like anti histaminics- treat mouth breathing- increased fluid intake- avoid speaking during URTI- avoid vigorous exercise leading to noisy breathing