VOICE DISORDERS

AIMS AND OBJECTIVES

1. Understand the basic anatomy and function of the larynx and in particular how voice and speech are produced

2. Know the key features that help distinguish benign from malignant causes of hoarseness i.e. the significance of smoking, age, change in voice quality, and associated stridor, otalgia and dysphagia

3. Be able to list the common causes of voice problems i.e. inflammation, muscular tension dysphonia, benign and malignant vocal cord lesions and reduced or absent vocal cord mobility

4. Know the common symptoms associated with voice disorders

5. Know the principles of the multidisciplinary treatment of the common voice problems including recurrent laryngeal nerve palsy i.e. vocal hygiene advice and reassurance, voice therapy, medical treatments, phonosurgery (microlaryngoscopy) and medialisation procedures

NOTESExamples of voice conditions will be shown in lectures and images will be place on NLE over the next few months

THE LARYNX AND THROAT

In general the head and neck anatomy for a patient is nose, mouth and throat. The throat for the patient is what in anatomy is called the pharynx and larynx (that bit of anatomy that goes from the skull base down to the clavicle).

The Pharynx:The pharynx is a chamber with a bony and fibromuscular walls serving as thoroughfare common to the respiratory and alimentary systems. It functions both as a conducting airway for the ventilation of the lungs, and as a channel for fluids and food and other swallowed materials down to the oesophagus. Thus the pharyngeal cavity communicates with the nasal chambers, the pharyngotympanic tubes, the oral cavity, the larynx and the oesophagus. These openings are guarded by functional muscular mechanisms including:1) the palatal and salpingopharyngeal muscles at the pharyngeal ostium of the

eustachian tube2) the soft palate and sphincter muscle of the nasopharyngeal isthmus3) the base of the tongue and palatoglossal folds4) the aryepiglottic folds and muscles which form the first of the triple sphincters

of the larynx (the others being the false cords and vocal folds)5) the cricopharyngeal sphincter

Functions of the Pharynx:The pharynx is involved in a number of physiological activities. It is part of the pathway for air and food. The pharyngeal muscles are concerned in the movements of the pharyngeal phase of swallowing. They are also concerned in

other acts like sneezing, coughing and vomiting and in the production of speech sounds. Sensory receptors are located in the pharyngeal mucosal. These include: 1) those of general somatic sensations like touch, pain and temperature and

some special receptors of taste2) afferent receptors concerned with the reflexes of swallowing and vomiting3) sensation in conditions of depletion of body water is usually associated with

or referred to the pharynx.

The pharynx is also related to the opening of the eustachian tube and the equalisation of pressure on the two surfaces of the tympanic membrane.

Anatomically the pharynx is divided into three areas: nasopharynx, oropharynx and hypopharynx: 1) The nasopharynx is located posterior to the nasal cavity and sinuses and its

postero/superior aspect is the skull base and clivus, and is limited inferiorly by a horizontal line from the hard palate posterior to the posterior wall of the nasopharynx. The contents of this area are the pad of adenoidal tissue, and the orifices of the Eustachian tube, which connect to the middle ear clefts.

2) The oropharynx is located between the nasopharynx above and the hypopharynx below. The upper dividing line is a horizontal from the hard palate posterior, and a horizontal line posterior from the hyoid bone posterior. The anterior separation of the oropharynx from the oral cavity is the anterior faucal pillar of the palatine tonsil, and the circumvallate papillae, which separates the anterior 2/3 tongue from the posterior 1/3 tongue. This area therefore contains the soft palate and uvula, the anterior and posterior faucal pillar and the palatine tonsil, as well as the posterior 1/3 of tongue.

3) The hypopharynx is located below the oropharynx and is that space continuous below with the oesophagus. The lower limit of the hypopharynx is the cricoid cartilage. This space is clinically divided into two lateral recesses called the piriform fossae (Greek – pear shaped), the posterior pharyngeal wall, which is an inverted triangle with the base superiorly, and the postcricoid space. Its function is to channel food from the oropharynx into the oesophagus and act as a resonance chamber for the voice

The larynx is in between and in front of the hypopharynx. It is divided into three clinical regions (Figure 1):

1) the glottis: the region of the larynx between the upper and lower limits of the vocal cords including the anterior and posterior commissures

2) the supraglottis: the region of the larynx from the vocal cords to the level of the hyoid bone. It includes the false cords, the aryepiglottic folds, and the epiglottis

3) the subglottis: the region of the larynx below the vocal cords to the level of the cricoid cartilage.

The functions of the larynx are:1. Protection of the lower airway2. Helps generate cough and expel matter from the airways3. Produces sound vibration for voice

Figure 1: Regions of the larynx

The cricoid cartilage is therefore the lower anatomical landmark, which separates the pharynx from the oesophagus and the larynx from the trachea. In the adult

this line of separation is said to be at the sixth cervical vertebra. This is only when looking at a lateral neck x-ray. In the child the larynx is located higher in the neck.

VOICE PRODUCTION:

Voice is the acoustic output of the vocal tract as a result of vocal fold vibration (Figure 2)I

In physical terms voice is a repeating (periodic) longitudinal sound wave consisting of compressions and rarefactions of the air molecules

Energy (kinetic) from the movement of air molecules causes the mucosa of the membranous part of the vocal folds to be set in oscillation

This oscillation results on the generation of a sound wave Having two vocal folds apposing and oscillating in synchrony results in a

more efficient mechanism for voice production This oscillation of the mucosa is possible due to the layered structure of

the vocal cord (more correctly known as a vocal fold) (Figure 3)

It is Reinke's space (or superficial lamina propria) that allows the epithelial layer to oscillate backwards and forwards in a superior-inferior direction

The sound produced by the vocal folds is periodic and has a fundamental frequency (F0) of vibration (measured in Hertz) and intensity or pressure (measured in dB)

Frequency (perceived by a listener as the pitch of the voice)o is determined by the mass per unit length of the vocal folds which

in turn is changed by tensioning of the vocal fold and muscle contraction

o adult males speak at a lower F0 than women as their vocal folds are bigger (i.e. have a greater mass per unit length)

o any pathological condition which increase the mass per unit length e.g. Reinke's oedema (q.v.) will lower the F0

o Average F0 during speech: Adult male 110Hz Adult female 190Hz Child 300Hz High soprano (top end > 1000Hz)

Intensity or sound pressure level (perceived by a listener as the loudness of the voice)

Figure 2

Figure 3

o is determined by subglottic pressure i.e. the pressure beneath the vocal folds which in turn is determined by the degree and length of time of vocal fold closure during a vibratory cycle

o any pathological condition that reduces the contact between the vocal folds i.e. a recurrent laryngeal nerve palsy will result in a reduced subglottic pressure as air escape resulting in a weak voice which is difficult to hear

Vocal fold vibration leads to the vowel production (and contributes to some consonants e.g. sonorants (see Table 1).

o The actual vowel sound (a,e,i,o,u) that is projected from the speaker's mouth is determined by the modulation of the sound by the vocal tract

o This is in turn is determined by the shaping of the tongue in the mouth, pharynx and the shaping of the lips

Consonants are produced by air being 'squirted' through narrowings in the vocal tract producing turbulent airflow

o This has no regularity (periodicity) to it and is perceived by a listening as noise.

o These patterns of noise however are recognisable as consonant sounds

o When these consonant sounds are produced in conjunction with the vowels speech is produced (see Figure 4)

An experiment to try on yourself:1.Say the vowel sounds in turn to yourself (i.e. a,e,i,o,u) slowly keeping the pitch and loudness the same. Feel where you tongue is in your mouth and how your lips change shape.

2. Say the word 'Speech Matters' to yourself firstly at normal conversational speed and then syllable by syllable. Which part of your vocal tract are you using to produce each of the sounds?

Table 1

Figure 4A spectrogram of a speaker saying the words 'Speech matters'. X axis (time ms), Y axis (frequency KHz). Where there points across a wide range of frequencies for a given point in time this means that it had no regularity and is perceived as noise (say the letter 's' to yourself). Where there are distinct bands at certain frequencies (i.e. there are at least 3 for the letter 'e') this represents the fundamental frequency and resonances (dominant harmonics) which are determined by the shape of the vocal tract.

KEY POINTS:o Normal voice production requires the vocal folds to vibrate in a

coordinated manner and there to be adequate subglottic pressure generated from the lungs to make the vocal folds vibrate

o The actual sound that radiates from the speaker's mouth is determined by the shaping of the vocal tract

o This all requires coordinated control by the braino When assessing patients with voice and speech disorders each part of the

mechanism needs to be analysed to see whether it is causing or contributing to the problem

DEFINITIONS:Dysphonia: Any impairment of the voice or difficulty speakingDysarthria: Imperfect articulation of speech due to disturbances of muscular control or incoordinationDysphasia: Impairment of speech and verbal comprehension (sensory dysphasia) or speech and verbal production (expressive dysphasia) especially when associated with brain injuryHoarseness: a perceived rough, harsh or breathy quality to the voice

QUESTIONS TO ASK IN GENERAL PRACTICE: Could the patient have cancer?

o Are they at risk i.e. smoker, ex-smoker or are exposed to smoke

occupationally/socially difficulty breathing or swallowing family history of throat/laryngeal cancer complaining of pain or referred otalgia have a lump in the neck

o If Yes refer on the '2 week wait cancer referral' Could the patient have infective laryngitis?

o Are there other symptoms and signs of an upper respiratory tract infection?

Is the voice problem related to voice use/’abuse’ &/or poor vocal hygiene?o What does the patient do for a living, socially or domestically with

their voice?o What is their lifestyle and diet like?

How much tea, coffee, cola do they drink? Do they drink any water? Do they eat irregularly or late at night, have large meals

before going to bed? Eat a lot of spicy, fatty food? Suffer from heartburn, indigestion, acid regurgitation, throat

clearing, coughing or choking episodes? Has the voice problem persisted for > 6/52?

o They need referring for a laryngeal examinationo If at risk of cancer: via the 2 week wait

ASSESSMENT OF A VOICE PROBLEM (SECONDARY CARE) History Listen to voice:

o Rough or breathy?o Constant/variable?o Pitch too low or too high?o Voice too loud or difficulty hearing it?

Visualize the larynxo Fibreoptic or rigid telescopes or laryngeal mirroro Stroboscopy allows wave motion of mucosa to be observed

Identify contributing factors

TYPES OF VOICE DISORDER More than one of following conditions below may be present Carcinomas must be excluded Viral infectious group relatively common in general population but don't

usually reach secondary care Muscle tension imbalance probably biggest group in secondary care Nodules, polyps and Reinke's oedema most common non-malignant

neoplasms

Structural/Neoplastico Malignant

Carcinomao Benign

Nodules Polyps Reinke’s oedema

Cysts Inflammatory

o Infectious Viral Bacterial Fungi

o Non-infectious Extra-oesophageal reflux Allergies (rare)

Neuromuscularo Underactive

Recurrent laryngeal nerve palsy Myaesthenia (rare)

o Overactive Spasmodic dysphonia (rare)

Muscle Tension Imbalanceo Primary

Vocal demands/strain Occupational

Inadequate vocal skills Psychogenic

Anxiety/’stress’ Conversion dysphonia/aphonia Puberphonia/ Mutational voice disorder

Presbylaryngis Gender identity

o Secondary Inflammation

Incl. post-infection problems Structural/neoplastic

Incl. end-stage hyperfunction Neuromuscular Breathing disorders Postural abnormalities Congenital laryngeal anatomical abnormalities

STRUCTURAL/NEOPLASTIC MALIGNANT

Laryngeal carcinoma- always consider in patients with persistent hoarseness lasting >6 weeks

Causes smoking, genetic

Symptoms progressive hoarseness or change in voice stridor, referred otalgia, difficulty swallowing and cervical

lymphadenopathy in late cases Signs

raised, thickened, irregular mass with leukoplakia (white patch) and redness

narrowing of airway +/- vocal cord fixation on laryngeal visual examination, cervical lymphadenopathy

Treatment Radiotherapy, partial or total surgical excision (laryngectomy)

BENIGNNodules

Causes Voice abuse, shouting, talking above background noise, ?reflux Boys = girls, in young adults (<40): women>>>men

Symptoms Husky voice worsens with use, loss of higher range of voice Peri-laryngeal discomfort

Signs Bilateral swellings in mid-membranous portion of vocal fold giving

hourglass appearance Treatment

Voice therapy or surgical excision if unresponsive

Polyps Causes

Shouting when suffering with a cold or extra-oesophageal reflux men>women 30s-50s

Symptoms Husky voice worsens with use, may be deeper Voice cuts out during speaking, choking episodes if very large

Signs Usually unilateral grey or haemorrhagic swelling arising from mid-

membranous portion of the vocal fold, smooth edge Treatment

Surgical excision +/- medical treatment +/-voice therapy

Reinke’s oedema Causes

Smoking +/- a lot of talking! +/- extra-oesophageal reflux Men=women (more noticeable in women)

Symptoms Deep pitched gravelly voice (women often mistaken for men on

'phone) If severe may cause choking episodes

Signs Usually bilateral grey or erythematous swellings along whole length

of membranous portion of the vocal fold Treatment

May be happy knowing haven't got cancer! Stop smoking! Surgical reduction of polypoid swelling +/- medical treatment of

reflux +/-voice therapy

Cysts Causes

Not known, some may develop after laryngeal inflammation, some may be congenital

2 types: mucus retention cysts and epidermoid cysts Men=women

Symptoms Husky voice, pitch breaks, loss of range of voice, increased effort to

produce voice Signs

Unilateral nodular swelling or localised bulge or stiffness of vocal fold

Treatment Voice therapy can help reduce secondary muscle tension Surgical excision

INFLAMMATORY ('LARYNGITIS')Infectious

Causes Viral

Part of an upper respiratory tract infection (URTI) Recurrent respiratory papillomatosis (RRP) due to Human

Papilloma Virus Bacterial

rare Fungi

Candida secondary to steroid inhalers or immunosuppression

Symptoms Acute viral or bacterial laryngitis

Hoarse or croaky voice Complete loss of voice (aphonia) in severe cases Pain on voice use, coughing or swallowing Irritant paroxysmal coughing Generally other symptoms of an URTI

Fungal laryngitis Above without symptoms of URTI

RRP Can affect infants and children when can be quite

aggressive and cause severe dysphonia and airway problems

In adults usually less aggressive but can cause severe dysphonia

Signs Acute viral or bacterial cases: erythematous or sloughy vocal folds Papillomas are usually multiple, raised erythematous lesions on the

vocal folds and anywhere in the larynx Candida appears as white dots of leukoplakia

Treatment Acute viral or bacterial laryngitis

Condition usually self-limiting and settles with: Voice rest Analgesia Fluid hydration Steam inhalations Cough suppressants as necessary

Occasionally antibiotics required RRP

Usually needs surgical excision with a laser or microdebrider

Non-infectious Causes

Extra-oesophageal (or "silent") reflux: damage from acid and pepsin Allergies (rare)

Symptoms Variable huskiness, voice may worsen with use, loss of higher range

of voice Associated throat symptoms

Chronic throat clearing, cough, excessive mucus in throat, choking episodes, globus sensation, difficulty swallowing food or pills (no true dysphagia)

Only 40% will have heartburn hence term "silent reflux" Signs

General erythema and oedema of vocal folds and larynx

Treatment Vocal hygiene and dietary advice Proton pump inhibitor twice daily before breakfast and evening

meal for a minimum of 2 months +/- alginates and H2 antagonists

NEUROMUSCULARRecurrent laryngeal nerve palsy or paresis

Causes Miscellaneous 35% Surgical trauma 23%

Thyroidectomy 10% Malignant disease 22%

Ca bronchus 10.6% Ca thyroid 3.5% Ca oesophagus 1.8%

Idiopathic 16% Neurological disorders 4%

Symptoms Weak voice Tires on prolonged talking Perilaryngeal discomfort Choking with fluids Higher pitched voice Diplophonia ('two tone' voice) Weak (‘bovine’) cough

Signs Immobile vocal cord

Left side 75% Right side 15% Both sides 10%

Listen to voice Listen to cough Check for other cranial nerve lesions

Investigations CXR

Exclude mediastinal mass CT scan skull base to midthorax

Check for lesions along path of nerve ?Ba swallow

If oesophageal lesion or aspiration suspected Treatment

None –await spontaneous recovery (up to 1 year) Voice therapy- encourages compensation Vocal cord medialization

Injection Synthetic polymer (Bioplastique) Collagen Autologous fat Fascia Hydroxyapatite (Teflon not used now)

Thyroplasty

Figure 5: Showing course or recurrent and superior laryngeal nerves and their relationships

MUSCLE TENSION IMBALANCE (MTI) or DYSPHONIA

Abnormal biomechanics: Causes

Primary imbalance of ‘pull’ or excessive tension of the laryngeal

muscles synergists and antagonists Multifactorial aetiologies

Stress, anxiety, depression Conversion disorders Neck/back problems Poor vocal hygiene Life style/dietary

Talking above background noise for prolonged periods

Having to project voice for prolonged periods Working in dusty, smoky, noisy environments

or where poor acoustics Not drinking enough fluids particularly water Too much tea, coffee and colas Eating late at night, eating large and/or fatty

meals Poor acoustic environments for working requiring

talking above background noise for prolonged periods, working in dusty, smoky, noisy environments or where poor acoustics

Secondary

Excessive tension required to overcome a deficiency in the voice producing mechanism e.g. poor respiratory function, structural defect of vocal folds, nasal blockage affecting resonance

Symptoms Variable huskiness of voice, usually worsens with use May be a little deeper or higher than expected for age and sex Voice unstable, perilaryngeal soreness, dryness/uncomfortable

sensation in throat Signs

Voice may be croaky/husky, breathy, bizarre or aphonic (no voice) Variable voice quality may occasionally be normal Cough often normal even when voice aphonic Vocal folds usually normal in appearance and movement but either

constriction of false cords, antero-posterior constriction or extreme sphincteric closure when the vocal folds disappear from view beneath false cords

Treatment Vocal hygiene and life style advice Voice therapy Address underlying causative factors