Disclaimer: Please note that the following is a general guideline/ discussion only. For a full assessment, exclusion of any other underlying cause for your symptoms and an individualised treatment approach, you will need to be seen by a qualified specialist.
Voice disorders can occur due to a large number of pathologies in the larynx and is far too complex to be discussed under a single heading. This is an outline on how one could think of possible diagnosis and understand principles of assessment and treatment.
DEFINITION
Dysphonia is anomaly in phonation as apposed to disarthria which is difficulty in articulation. This need to be differentiated. Dysarthria occur due CNS pathology.
AETIOLOGY
Voice occur as air from the lungs flow thru the glottic opening causing a vocal fold wave. The sound get the specific quality due to resonance by the shape of the larynx and the skull. One may equate the vocal cord a a guitar string and the skull to the guitar box. For phonation one needs good lung function for air flow, ability for vocal cords to move and meet in the middle and compliant vocal cords as well as resonance by the skull.
Most importantly one should be able to readily identify the common causes of dysphonia as well as potential sinister causes.
(VC= vocal cords)
Common Causes
-URTI/ Laryngitis (affects the VC compliance) - Typically a short history (less than 4 weeks) responds to antibiotics.
-Laryngo Pharyngeal Reflux (LPR- affect ts the VC complience)- Typically a long hx with with other typical symptoms of laryngeal reflux (see article on laryngeal reflux). Patient may or may not have GORD symptoms, however having GORD increases the likelihood of LPR.
Sinister Causes
-Laryngeal carcinoma ( may affect the compliance or mobility) : Suspicion should be raised if a smoker and some symptoms include progressive disphonia over months, dysphagia, odynophagia, haemoptasis, difficulty breathing.
Rest can be discussed under
1) Neurological affecting apposition of VC
2) Structural affecting apposition of VC
3) Pathology on the VC surface it self
4) Functional and psychological. Following is a brief outline.
1 Neurological Issues
-RLN palsy-The VC can not meet to create the wave-hence the voice becomes breathy if a patient coughs there is no impulse- hence bovine cough. One must try and identify the reason for the RLN palsy along its course and differentiate it from a bulbar palsy which affects other carnival nerves.
- Spasmodic Dysphonia is when the laryngeal musculature goes in to spasm. the larynx may go in to spasm and get stuck in an adducted position - this occurs when one tries to vocalise consonants - i.e. would struggle saying eighty eight. In abductor SD the vc spasm and gets stuck when saying non consonants. i.e. sixty six. This thought to be due to neurologic dysfunction.
-Other extra pyramidal conditions such as parkinson disease can also give rise to voice anomaly.
2 Structural lesions affecting movement of vocal cords
-Due to the mass affecting the vocal function. This includes laryngeal carcinoma ( see above) other laryngeal cysts
this is a laryngeal cyst as opposed to a vocal fold cyst
-Also due movement issues at the aretenoid joint- i.e. rheumatoid arthritis or inflammatory conditions may affect the cretinoid joint movement
3 Structural Lesions of the Vocal cord surface affecting compliance
-Vocal cord nodules- can be thought of as callus of the VC. Its bilateral in the most vibrating part of the vocal cords sually settles when the cause is removed. i.e. voice training and managing reflux.
-vocal cord cysts- usually unilateral due to mucous retention and need surgical excision.
-
vocal cord polyps-uslaly unilateral due to an initiating trauma as vocal abuse,reflux and need excision and managing initiating cause i.e. reflux treatment and voice therapy
-polypoidal vocal cords (also known as rienke's oedema) - usually bilateral due to smoking also reflux. Need to control the causes, but also surgical excision to reduce mass.
-Ectatic vessels on the VC surface- possibly due to VC abuse, or reflux. Treatment is surgical including laster ablation and treating reflux and voice therapy.
-VC atrophy- de innervation or age related changes. Fails to meed in the middle. May benefit from injecting fillers in the paraglotic space and voice therapy
-Aretenoid garnuloma. This infect affects movement of the VC but listed here for simplicity. Usually caused by vocal abuse and possibly reflux. Treatment include steroids, reflux management, voice therapy and excision to rule out sinister cause if conservative approach fails.
-Systemic conditions that may affect VC surface include hormones such as thyroid dysfunction
-Medications- such as steroid inhalers also could cause VC surface issues
-Trauma- from recent intubation etc
-Infections-laryngitis, fungal infections
Laryngeal Thrush (looks like a cancer hence these must get a biopsy for diagnosis)
4 Functional Disorders
This is where there could be various levels of increase muscle tension leading to voice disorders. This could have an associated psychological condition. This is rare and example is post pubertal inappropraite falsetto or habitual hoarseness.
HISTORY
Above was just a brief outline on some of the possible causes. Therefore as the primary clinician the most important thing is to not miss anything sinister and possibly identify the common causes. Though further history may assist you in identifying other likely diagnosis, for a full diagnostic history one must be versed with all of the pathologies and presentations, which is impractical.
Overall any vocal disorder present over 4 weeks is best investigated with laryngoscopy by a qualified specialist in the field.
Sinister Cause
Cancer: History of smoking, progressive dysphonia longer than 4 weeks, other sinister features such as odynophagia, dysphagia, haemoptasis etc
Common Cause
Laryngitis: hx of URTI, symptoms of sinusitis, fever etc and responds to antibiotics
Reflux related: read discussion on reflux. Dysphonia may be intermittent, notices acid, throat clearing, nocturnal cough, long standing history, at times ppt by an URTI but not settling- however needs a laryngoscope to exclude a sinister cause.
Vocal Nodules: i.e. in a teacher or singer and intermittent loss of voice, non progressive
Other notable specific initiating events-
-commencing steroid inhalers
- vocal abuse-yelling: can cause polyp, aretenoid granuloma
- Head & Neck surgery- nerve palsy
- Trauma, intubation
Trying to identify specific presentations of various types of pathologies is impractical at a primary setting, as there is substantial symptom overlap and confirmation requires laryngoscopy, even stroboscopy and further investigations.
Profession
This may give not only give clues to the origin but also the importance to the individual
Social
Smoking, ETOH abuse
Medications
Steroid inhalers
Psychological Issues
May have associations
Systemic conditions
ie Thyroid, Pregnancy, Pulminory
EXAMINATION
Is there stridor
What is the nature of the voice (GRABS)
G -overall grade or quality
R -is it rough- could be a structural lesion on the cords such as tumour, or even reflux
A - asthenia or is it weak- could be age related atrophy
B -is it breathy: i.e. nerve palsy
S -is there a strain
Cough- is it Bovine i.e. no impulse if so it could be due to a nerve palsy
Oral Exam look at gag reflex- when gaging, does the palate elevate symmetrically, if not there could be a lower cranial nerve dysfunction
Further assessment may by done by a specialist and involves
Voiced consonants i.e. say eighty eight -do the stage to initiate -ADDuctor spasmodic dysphonia
Non voiced consonants i.e. say sixty six ABductor spasmodic dysphonia
Laryngoscopy followed by phonation and whistling to look at vocal chord movement
Look at structure of the vocal cords, the entire larynx, pharynx and hypo pharynx
Further the patient may be assessed with stroboscope in s combined speech clinic
if necessary other investigations may be carried out include imaging, if suspicious of a swallowing issue swallowing testing, if ongoing reflux -PH manometry etc
TREATMENT
If carcinoma of the larynx the treatment could be surgery, radio therapy or in advance cancer multi modality treatment
If reflux- practical measures are as important as high dose PPI treatment for 2-3 months in the least. Failed cases will need a full PH assessment and possibly a upper GI surgical input if significant reflux. More details in the discussion on reflux.
If any associated pulmonary or sinus symptoms these need to be adequately treated
iIf any offering medications as steroid inhalers these need to be adjusted accordingly.
If there are nodules or evidence of vocal abuse- need speech path input and also minimise reflux.
If Neurological issues with RLN palsy the cause need to be identified and treated. With regards to the vocal cord apposition surgery can be performed with fillers in the para glottic space to bring the affected Vc to midline
If spasmodic dysphonia the patients may be treated with boutox to relax the affected muscle group
Other structural lesions on the vocal cords may be treated with a combination of surgical excision, vocal training, minimising reflux and maximising vocal hygiene with speech pathology input.
Any functional or psychological diagnosis these need to be treated with a combination of psychiatric in put and speech pathology input along with maximising vocal hygiene.