Chapter 4: Flaccid

Question 1

What causes Flaccid Dysarthria and how is it defined?

Answer 1

Impairments of the lower motor neurons in cranial or spinal nerves (damage to PNS). This results in speech or respiratory musculature in distinctive qualities.

Question 2

Flaccid Dysarthria Characteristics & Causes

Answer 2

• Slow-labored articulation, marked degrees of hyper-nasal resonance, and hoarse-breathy phonation.
• Paralysis, weakness, hypotonicity, atrophy, and hypoactive reflexes of involved speech subsystem musculature.

Question 3

Neurologic Basis for Flaccid Dysarthria

Answer 3

• Caused by damage to LMNs (final common pathway: last and only connection to neural impulses from UMNs to reach muscles)
• Results from disorder that disrupts flow of neural impulses along LMNs that innervate muscles of respiration, phonation, articulation, prosody, or resonance

Question 4

Cranial Nerves of Speech Production

Answer 4

• Trigeminal (V), Facial (VII), Glossopharyngeal (IX), Vagus (X), Accessory (XI), Hypoglossal (XII)
• LMNs inside these nerves transmit motor impulses from UMNs to muscles used for speech

Question 5

Cranial Nerve Damage Causes

Answer 5

-Brainstem Stroke, Growing Tumor, Viral or Bacterial infections, Physical Trauma, Surgical accidents

Question 6

Trigeminal Nerve (V)

Answer 6

• Attached to brainstem at the level of pons
• Divided into 3 main branches (ophthalmic, maxillary, and mandibular) mandibular is most important for speech b/c it innervates lower jaw & tongue muscles
• Damage can be unilateral or bilateral

Question 7

Facial Nerve (VII)

Answer 7

• Branches out from brainstem just below CN V, divides into cervicofacial and temporofacial branch
• Damage results in lesion ABOVE the point where facial nerve divides –> can cause weakness or paralysis in all muscles on same side of face resulting in drooping of eyelid, mouth, cheek, and other structures.

Question 8

Glossopharyngeal Nerve (IX)

Answer 8

• Originates in brainstem at medulla, coursing out to the pharynx
• Innervates muscles that open to the pharynx, and damage will typically impact Vagus nerve as well.
• Possible role in speech resonance & phonation

Question 9

Vagus Nerve (X)

Answer 9

• Crucial cranial nerve for speech production
• Origin: Brainstem at medulla
• Contains 3 branches related to speech and if damaged can impact certain functions: Pharyngeal Branch (velum & resonance), External Superior Laryngeal Nerve Branch (pitch), Recurrent Nerve Branch (breathy phonation)

Question 10

Accessory Nerve (XI)

Answer 10

• Origin: Medulla just below Vagus (X) nerve
• Works with Vagus nerve to innervate intrinsic muscles of velum, pharynx, and larynx
• Damage to cranial components will impact Vagus nerve and vice versa

Question 11

Hypoglossal Nerve (XII)

Answer 11

• Origin: the medulla
• Provides motor innervation for ALL intrinsic and MOST extrinsic muscles of tongue
• Damage to hypoglossal CN results in weakness of tongue or paralysis. Characteristics of CN XII damage include imprecise arctic., phoneme distortion, or slow lingual movements.

Question 12

Spinal Nerves

Answer 12

• Provide motor innervation for muscles of respiration (phrenic nerve innervates the diaphragm)
• Damage is typically wide spread to impair respiration, unless the phrenic nerve is damaged (e.g., paralyzed diaphragm - decreased volume, short speech, strained vocal quality)

Question 13

Causes of Flaccid Dysarthria

Answer 13

• Can be caused by ANYTHING that disrupts flow of motor impulses along cranial or spinal nerves used for innervating muscles related to speech production
• Damage to LMNs can be caused by physical trauma, brainstem stroke, myasthenia graves, Guillain-Barré syndrome, and polio. Other causes..tumors, muscular dystrophy, progressive bulbar palsy

Question 14

Physical Trauma

Answer 14

• Surgical trauma with accidental cut of cranial nerve (e.g., carotid endarterectomy, cardiac surgery, removal of head and neck tumors, & dental surgery)
• Head and neck injury (e.g., motor vehicle accidents, blows to head, & falls)

Question 15

Brainstem Stroke

Answer 15

• Occurs with interruption of blood flow to brain (artery breaks or is blocked)
• Can affect CN directly…possible for single brainstem stroke to damage more than one CN. Degree of impairment depends on # of LMNs lost.

Question 16

Myasthenia Gravis Definition & Symptoms

Answer 16

• Affects neuromuscular junction.

- Symptoms: rapid fatigue of muscular contractions over short time, with recovery after rest

Question 17

Myasthenia Gravis Causes

Answer 17

• Antibodies that block/damage muscles tissue that receives the neurotransmitter acetylcholine from LMNs.
• Temporary Treatment: Injection of edrophonium chloride (Tensilon)

Question 18

Myasthenia Gravis Characteristics

Answer 18

• Pt. speech is hyper-nasal, decreased loudness, breathy voice quality, & decreased articulatory precision
• Assessed with a stress test (e.g., counting from 1 to 100)

Question 19

Guillain-Barré Syndrome

Answer 19

• Causes demyelization usually occurring in the PNS. Frequently occurs after certain infections and immunizations.
• Symptoms: flaccid dysarthria & dysphagia
• Recovery: High recovery rate within weeks or months

Question 20

Other Causes of Flaccid Dysarthria

Answer 20

-Tumors in or near brainstem, muscular dystrophy, Progresssive bulbar palsy, palsy & neuralgia, anatomic anomalies, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), & polio

Question 21

Speech Characteristics of Flaccid Dysarthria

Answer 21

• Not all individuals with flaccid dysarthria demonstrate deficits in all areas (severity levels vary for each pt. in each area).
• Look for clusters of symptoms when trying to diagnose particular type of dysarthria

Question 22

Resonance with Flaccid Dysarthria

Answer 22

• Reflects bilateral damage to the pharyngeal branch of the vagus nerve because innervates most muscles of the velum.
• Hypernasilty (most noticeable), nasal emission, weak pressure consonants, and shortened phrases

Question 23

Articulation with Flaccid Dysarthria

Answer 23

• Imprecise consonant production.
• Large range of severity from mild distortion to complete unintelligibility, damage to facial & hypoglossal nerves is usually cited as reasons for this problem.
• Damage to CN V could impact jaw elevation to bring articulators into contact with each other

Question 24

Phonation with Flaccid Dysarthria

Answer 24

• Phonatory imcompetence

- Incomplete adduction of vocal folds during phonation. Caused by damage to recurrent branch of Vagus (X) nerve.

Question 25

Diagnosis of Flaccid Dysarthria

Answer 25

-Combined presence of hypernasility AND phonatory incompetence is the strongest confirmatory sign of flaccid dysarthria as a correct diagnosis

Question 26

Respiration with Flaccid Dysarthria

Answer 26

• Weakened respiration may or may not be a component of flaccid dysarthria
• Symptoms: reduced loudness, shortned phrase length, strained vocal quality, may inhale frequently while speaking (potential impact on prosody)

Question 27

Prosody with Flaccid Dysarthria

Answer 27

• Weakened laryngeal muscles are unable to make many fine vocal-fold adjustments necessary for normal potch and loudness variations
• Symptoms: monopitch, monoloudness
• Not unique to flaccid dysarthria so NOT a definite marker

Question 28

Key Evaluation Tasks for Flaccid Dysarthria

Answer 28

• Conversational speech & reading (evokes hypernasality, imprecise consonants, shortened phrase length, & prosody
• Alternate motion rate (AMR) task (highlight a slowed rate of phoneme production)
• Prolonged vowel
• Speech stress test

Question 29

Treatment of Motor Speech Disorders

Answer 29

-Traditional approach is…use Ax data to ID deficits, work with pt. using appropriate Tx goals, increase complexity of tasks as pt. improves, & generalize improvements

Question 30

Rosenbek’s Treatment Approach to Motor Speech Disorders

Answer 30

1. Help pt. recognize differences in their speech
2. Help pt. have a willingness to change their speech for the better
3. Work closely with pt. when setting goals of Tx
4. Increasingly insist that pt. are talking therapeutically in session & eventually in small talk
5. Ensure pt. are leaning to listen, evaluate, & self-correct their speech
6. Be sure to progressively add cog-linguistic load to Tx tasks to ensure pt. are working toward generalization

Question 31

Treatment of Flaccid Dysarthria

Answer 31

• Tx for flaccid dysarthria are presented according to which CN or combination of nerves are damaged
• Needs & abilities of pt. vary greatly
• IF speech production in the goal, Tx activities should concentrate directly on speech production

Question 32

Damage to Trigeminal Nerve (V)

Answer 32

• Unilateral damage (typically minimal - no effect on speech production)
• Bilateral damage (rare but can leave jaw muscles very weak or in severe cases, cause inability to close jaw)

Question 33

Damage to Vagus Nerve (X)

Answer 33

• Damage affects glossopharyngeal & accessory cranial nerves d/t close proximity to each other
• Tx for resonance (e.g., pharyngeal flap procedure, posterior pharyngeal wall aug., or palatal lift)
• Mild hyper nasality Tx: rate reduction, increase loudness, more open mouth position

Question 34

Damage to Facial (VII) & Hypoglossal (XII) CN

Answer 34

• Affects speech production primarily by decreasing lip or tongue strength & range of movement.
• Traditional articulation drills often used & treatment for respiratory weakness

Question 35

Treatment for Respiratory Weakness

Answer 35

-Correct posture, compensatory prosthetic devices, speaking immediately on exhalation, & curing for complete inhalation