Neurogenic Voice Disorders Flashcards
CNS:
- Motor cortex, primary motor strip, midbrain, brainstem
- Broca’s area
- Insula
- Precentral gyrus
- Basal ganglia/thalamus
- Temporal lobes (Heschyl’s gyrus)
Function of the Motor Cortex, Primary Motor Strip, Midbrain, and Brainstem (for voice, CNS):
motor control of larynx
Function of Broca’s area (for voice, CNS):
voice response (preplanning)
Function of the Insula (for voice, CNS):
motor planning for voice
Function of the Precentral Gyrus (for voice, CNS):
voice production
Function of the Basal ganglia/thalamus (for voice, CNS):
sensory info for vocalizing (motor)
Function of the Temporal lobes (Heschyl’s gyrus) (for voice, CNS):
audition
PNS (important for voice):
Cranial Nerves
Which CN’s are important for phonation/voice? (4)
- Glossopharyngeal (IX)
- Vagus (X)
- Spinal Accessory (XI)
- Hypoglossal (XII)
Glossopharyngeal (IX) and phonation/voice:
Motor to stylopharyngeus m. (elevates larynx)
Vagus (X) and phonation/voice:
SLN, RLN: sensory & motor to larynx, motor to thorax
Spinal Accessory (XI):
Neck accessory m.’s (SCM & trap), levator veli palatini & uvula
Hypoglossal (XII):
Depression/elevation of larynx (via tongue m.’s), neck strap m.’s
3 Branches of the Vagus:
Pharyngeal Branch
Superior Laryngeal Branch
Recurrent Laryngeal Branch
Superior Laryngeal Branch of the Vagus:
Sensory: (internal branch) mucous membrane supraglottal larynx
Motor: (external branch) CT m.
Recurrent Laryngeal Branch of the Vagus:
Right – loops behind R carotid & R subclavian
Left – loops around aortic arch
Motor: TA of vf, PCA (abductor), LCA (adductor), transverse arytenoids (adduction), oblique arytenoids (adduction) + all other laryngeal m.’s
*Very concerned with recurrent laryngeal nerve bc can cause vocal fold paralysis
Neurogenic Etiologies (3):
- Congenital (Huntington’s)
- Lesion/tumor/disease (dysarthrias [can be caused by ALS or Parkinson’s], stroke, cancer)
- Trauma (TBI, n. trauma)
Neurogenic Disorders can be:
- Lower motor neuron
- Upper motor neuron
- Mixed (upper + lower motor neuron type)
ALS (most common), TBI, MS
Lower motor neuron damage can cause (4):
- Vocal fold paralysis - part 2
- MG
- Guillaine-Barré
- Flaccid dysarthria
Upper motor neuron damage can cause (4):
- Spastic dysarthria
- Hypokinetic dysarthria (PD)
- Hyperkinetic dysarthria (Spasmodic dysphonia - SD voice samples - NPRs Diane Rehm, essential tremor Huntington’s)
- Ataxic dysarthria
Mixed (upper + lower motor neuron type) (3):
- ALS (most common)
- TBI
- MS
Paramedial Position:
if a vocal fold is paralyzed in this position, the other vocal fold can compensate
Spasmodic dysphonia can look a lot like muscle tension dysphonia. How do you tell the difference?
Muscle Tension Dysphonia isn’t neurological
Test the difference by looking at them while they laugh or yawn. MTD will back off when the patient is relaxed, SD will not bc it is neurological
Types of Spasmodic Dysphonia (3):
Abductor Spasmodic dysphonia
Adductor Spasmodic dysphonia
OR Mixed Spasmodic dysphonia
- can also get laryngeal tremor with these
- not painful, but AD type can feel the strain
- usually do not get a functional disorder on top of this disorder
- proximal dyskinesia: movements not done on purpose also can coincide
- treat with Botox injected in the thyroarytenoid muscles
- Diane NPR has Adductor Spasmodic Dysphonia (hyperkinetic dysarthria)
Abductor Spasmodic dysphonia:
vocal folds spasm open, breathy voice not common
Adductor Spasmodic dysphonia:
vocal folds spasm closed (similar to how a spastic dysarthria patient sounds) most common
OR Mixed Spasmodic dysphonia:
where they spasm open and they spasm closed
Lower Motor Neuron Damage can cause (5):
- Flaccidity, weakness, reduced m. contraction, reduced ROM
- Flaccid dysarthria
- Vf paralysis or paresis (damage to recurrent laryngeal will result in paresis (sluggish or slow movement of the VF) OR paralysis)
- MG
- Guillaine-Barré
*Generally unilateral and will be ipsilateral
Why should you wait a year to do permanent surgery for vocal fold paralysis?
- A paralysis CAN turn into a paresis through regeneration (nerves CAN regenerate but it is VERY slow [up to a year])
- Wait a year to do permanent surgery for vocal fold paralysis: putting a silicone thingy in there to push the vocal fold
UMN Damage can cause (4):
- Spastic dysarthria
- Hypokinetic dysarthria
- Hyperkinetic dysarthria
- Ataxic dysarthria
Spastic dysarthria
- Spasticity/hypertonicity
- Strain/strangle
- Short phonation time
- Monopitch
Hypokinetic dysarthria
- Rigidity
- Bradykinesia
- Limited ROM
- Resting tremor
- Parkinson’s
- reduced loudness, short phonation time (effects both laryngeal and respiratory muscles), vocal fold muscles are not getting input for muscle tone—get boding of the muscles
Hyperkinetic dysarthria
- Uncontrolled movements
- Strain/strangle
- Chorea
- Huntington’s
Ataxic dysarthria
- Cerebellar lesion
- Prosodic slowdown
- Resonance changes
- Inarticulation
- “intoxicated”
- cerebellum is affected (not precise movements), can affect gait (goes towards the affected side, stumbbling like drunk)
What is bradykinesia?
slow movement
Parkinson’s (hypokinetic dysarthria):
- hunched gait
- bode appearance of the vocal folds. Basal ganglia is not making dopamine (Nuerotrasmitter), so tone is not there.
- This causes resting tremor, some rigidity, muscle weakness, muscles have weakened and vocal folds will bode, and incomplete vocal fold closure bc of the lack of dopamine going to the muscles.
Mixed Dysarthria (types):
Mix of dysarthria types (usually spastic & flaccid)
- ALS – UMN & LMN
- MS – myelin sheath degeneration
- TBI - variable
Why do we need myelin and what happens when it degenerates? (like in MS)
- Need myelin for protection of the axon AND rapid transmission (like needed for speech):
- Muscles will start atrophying if the axon is getting damaged
