Neurogenic Voice Disorders Flashcards
RLN innervates which intrinsic laryngeal muscles?
All but the CT
SLN innervates which laryngeal muscle?
CT
If there is a lesion at the level of the hyoid which branches of the Vagus nerve will be affected?
Both the RLN and SLN
If there is a lesion at the level of the cricoid which branches of the Vagus nerve will be affected?
RLN only
Peripheral nerve damage cause paralyses that are _______ in nature
flaccid
Isolated SLN paralysis (low) leads to what type of paralysis?
CT paralysis, laryngeal asymmetry
Isolated RLN paralysis (low) leads to what type of paralysis?
abductor VF paralysis
Combined RLN and SLN paralysis (high) leads to what type of paralysis?
adductor VF paralysis
Describe bilateral abductor paralysis and its Tx
- VFs cannot abduct. Both VFs are paralyzed in an adducted (closed) position
- The most severe form of vocal fold paralysis
- May cause severe respiratory compromise
- Vocal function and airway protection are usually good
- Tx: tracheotomy if necessary. Phonosurgery involving lateral suturing or complete removal of one arytenoid to open the airway. Post op voice and swallowing therapy.
Describe bilateral adductor paralysis and its Tx
- VFs are paralyzed in the abducted (open) position
- Good respiration, poor phonation or complete aphonia
- High risk of aspiration, gastrostomy tubes are necessary in many patients
- Tx: feeding tube, AAC devices. Fibrosis and contraction of glottis starts 6-9 months post onset and can reduce the glottal opening considerably. This approximation facilitates breathy, hoarse phonation and increases airway protection but may decrease the air production
Describe unilateral abductor paralysis
- paralyzed fold remains in median or paramedian position
- Usually relatively good respiration, phonation and protection against aspiration because of the fully functional contra-lateral fold
- The flaccid paralysis of the affected fold will decrease patients dynamic range
- airway diameter is reduced which may lead to inspiratory stridor during heavy physical activity.
- May have some diplophonia but will be able to produce some voice
- Tx: usually very little therapy necessary. Voice therapy to increase dynamic range
Describe unilateral adductor paralysis
- the paralyzed fold is frozen in intermediate, abducted or wide abducted position
- The most common type of VF paralysis
- The position and vertical height of the abducted fold and the resulting gap determine the severity of the resulting voice disorder
- Voice quality is breathy and can be diplophonic. Vocal intensity and range are decreased
- physical fatigue because of increased vocal effort
- Tx:: voice therapy and possible phonosurgery to bring the paralyzed VF towards midline
T or F: RLN paralysis is much more common than SLN paralysis
True
Describe bilateral SLN paralysis
-CT paralysis leads to decreased lengthening of the VFs, reduced pitch and intensity ranges
Describe unilateral SLN paralysis
- asymmetrical approximation of cricoid and thyroid cartilages leads to an oblique position of the VFs, resulting in a vertical gap
- Despite the incomplete VF closure, many speakers have good conversational speech
- Pitch and intensity range are decreased
- Vocal fatigue
What is the therapy for both unilateral and bilateral SLN paralysis?
no medical treatment, voice therapy, education and voice conservation
describe myasthenia graves and its Tx
– a lower motor neuron impairment resulting in rapid muscle fatigue. Usually generalized throughout the whole body but can be isolated to vocal fatigue (myasthenia larynges) or velar fatigue with hyper nasality
- Voice loss after a few minutes of speech, but their voice ‘recharges’ after a few minutes of rest
- Treatment: refer to a neurologist. Voice therapy in individuals who continue to exhibit symptoms. In severe cases, voice amplification
It is currently thought that spasmodic dysphonia is a type of __________
focal dystonia (a movement disorder that is involuntary, task specific and action induced)
Describe abductor spasmodic dysphonia and Tx
- involuntary abduction movements (opening)
- Phonation interrupted by sudden intermittent or prolonged phases of aphonia. Breathy phonation
- Spasms mostly on unvoiced consonants
- Tx: botox injection in PCAs (results unpredictable)
Describe adductor type spasmodic dysphonia and Tx
- involuntary adduction movements (closing) More common
- Vocal hyperfunction. Increased muscle tone.
- Effortful, pressed and distorted voice quality
- Pitch and voice breaks, intermittent voice blocks
- Struggling voice initiation
- Patients suffer from physical fatigue and strain because air needs to be forced through the closed glottis
- Tx: botox injection in vocalis (mostly successful)
Describe voice therapy for spasmodic dysphonia
soft phonation onsets using /h/. Relaxation techniques to reduce vocal effort and secondary behaviours. May prolong benefits of botox.
describe organic (essential) vocal tremor/ laryngeal tremor and it’s treatment
- most noticeable on prolonged vowels as a rhythmic warble. -
- Conversational speech may also be affected. Severe tremor can lead to voice breaks and complete aphonia which may sound like spasmodic dysphonia in connected speech!
- Tx: no known treatment
How to differentiate between spasmodic dysphonia and essential tremor?
on phonation of a sustained vowel SD has normal phonation or intermittent spasms, an essential tremor has rhythmical modulation of the sustained vowel.
