Flaccid Dysarthria: Profile

Etiology of Flaccid dysarthria

Large Broad Cause: LMN damage at the level of execution

Mostly Degenerative Origin: e.g., ALS (flaccid then spastic), motor neuron disease. Also traumatic: neurosurgical, neuromuscular disease (myasthenia gravis)

Any damage to cranial nerves of speech production can result in flaccid dysarthria: e.g., brainstem stroke in either pons (CN V and CN VII) or medulla (CN IX, CN X, CN XI, CN XII)

CN V: trigeminal, CN VII: facial, CN IX: glossopharyngeal, CN:X vagus, CN XI: accessory, CN XII: hypoglossal.

Usual Presentations of Flaccid Dysarthria

Slow and labored articulation

Hypernasality

Hoarsy-breathy Phonation

CN V: Trigeminal Nerve DAMAGE

level of pons

• Unilateral damage: very mild impact on speech production; can result in weakness or paralysis in the jaw on the same side as the damage; jaw might slightly deviate toward the affected side when it is opened.

• Bilateral damage:

• BIG impact on articulation: b/c of jaw weakness and imprecise consonants; cannot raise jaw to produce most consonants and vowel phonemes, especially bilabials.

  • SLOW RATE OF SPEECH (prosody)

    • FOR AMRS/SMRs; imprecise PUH first then tuh and kuh

CN VII: Facial Nerve damage

level of medulla

• Unilateral damage: e.g., Bells palsy; inability to close eyes, nasolabial fold, asymmetrical smile; distortion of bilabials and labiodentals

• Bilateral damage:

  • Articulation: Distortion of bilabials, labiodentals, and lip rounding vowels.

  • Prosody: SLOW rate of SPEECH

AMRS: PUHs will be worse then TUH which is worse than KUH

consonants difficult for facial nerve damage; P, B, M, F, V, W,

CN X: VAGUS NERVE DAMAGE

Level of medulla in brainstem

note:

Pharyngeal: controls hypernasality→ innervation of velopharyngeal port aka velum

Superior laryngeal: Controls pitch→ inneervation of cricothyroid muscles

Recurrent branch: vocal quality→ adduction/abduction of vocal folds

general rule: if lesion above pharyngeal branch=hypernasality and voice changes, if lesion below pharyngeal branch=voice changes only.

Lesion above pharyngeal branch (hypernasality +voice changes)

• unilateral:

  • respiration/phonation=breathy voice, reduced loudness

  • resonance: mild hypernasality, nasal emission

  • mildly weak pressure consonants (stops, fricatives, affricates)

  • reduced pitch and loudness variation

• Bilateral:

  • respiration/phonation: severely breathy voice, markedly reduced loudness

  • resonance: moderate-severe hypernasality, nasal emission

  • weak pressure consonants

  • monopitch and monoloudness

Lesion Below Pharyngeal branch: Voice changes ONLY, no hypernasality

• what happened: velum cannot rise sufficiently

• Unilateral:

  • respiration/phonation: breathy voice, hoarseness, reduced loudness, reduced pitch range, short phrases, diplophonia (double pitch), short phrases

  • Prosody: short phrases

• Bilateral:

  • respiratory/phonation: severe breathiness, short phrases, inspiratory stridor

  • Prosody: short phrases

Lesion to Superior Laryngeal Branch

• what happened: inefficient stretching and tensing of cricothryoid muscles

• Unilateral:

  • respiratory/phonation: reduced pitch range, difficulty producing high pitch

• Bilateral:

  • respiratory/phonation: Markedly reduced pitch and pitch range

Lesion to Recurrent branch only

• what happened: inefficient vocal fold closure: unilateral=paralysis of one of vocal folds; bilateral: complete vocal fold paralysis stuck in midline position.

• Unilateral:

  • respiratory/phonation: breathiness, hoarsness, reduced loudness,

  • prosody: short phrases

• Bilateral:

  • respiration/phonation: severe breathiness, reduced loudness, possible stridor

  • prosody: short phrases

CN XII: Hypoglossal Nerve damage

level of medulla

Imprecise articulation is the primary characteristic of an indi- vidual with hypoglossal nerve damage.

• unilateral: weakness or paralysis in the half of the tongue that is on the same side as the nerve damage.

  • articulatory distortion will probably be mild because the unaf- fected side of the tongue can usually compensate for the weakened movements of the impaired side

• Bilateral: much more significant effect on articulation. In these cases, phonemes requiring elevation of the tip or back of the tongue will be notably distorted

Articulation: trouble with lingual consonants: TUHS will be worse than KUHS which will be worse than PUHs

MOST COMMON SPEECH FEATURES of Flaccid Dysarthria

REMEMBER: presentation will be fully dependent on where the damage is (i.e., maybe which cranial nerve)

1. Hypernasality

2. Imprecise consonants

3. breathiness

4. monopitch

5. monoloudness

6. nasal emission

7. audible inspiration

8. harsh voice quality

9. short phrases

HOW to Evaluate Flaccid Dysarthria

1. Conversational speech and reading:

   1. can tell you about:

      1. Resonance (hypernasality), articulation (imprecise consonants), respiration (shortened phrases), prosody (monopitch, monoloudness)

         1. in other words: Connected speech during conversation or while reading aloud can evoke a client’s monopitch and monoloud prosody, short- ened phrases, articulation distortions, and hypernasality.

2. Alternate Motion Rate (AMRs): (e.g., pa-pa-pa-pa) + also SMRs (pa-ta-kuh)

   1. Will tell you about: Articulation, slow rate of speech

3. Prolonged Vowel (/a/)

   1. Will tell you about: Breathy voice quality, respiratory weakness (e.g., maybe poor breath support and can’t sustain /a/ for that long)

Speech stress test: (counting 1-100) For suspected case of myasthenia gravis (neuromuscular junction disease which causes muscles to get weaker the more you use it)

General treatment of motor speech disorders

1. Use assessment data to identify deficits

2. make appropriate treatment goals based on them

3. increase complexity of tasks as patient improve

4. work toward generalization of improvement

5. make sure patients are talking therapeutically aka utilizing taught strategies to support their speech productions in all parts of sessions to promote generalization. (maybe verbal reminders to pause and use breathing techniques)

6. make sure you teach them to self-evaluate and self-correct their speech ( example: a 3-point self- evaluation scale to describe moments of talking therapeutically. A score of 1 on the scale is for an utterance that is shows no improve- ment over the first day of treatment. A 2 is given for an utterance that is improved but not as good as possible. A 3 is assigned for an utterance that is the best possible).

7. Progressively add cognitive linguistic load to promote generalization:

   1. He recommended, for example, requiring faster or longer responses, introducing visual or auditory distractions, and formulating complex responses or questions. He suggested bringing family members or volunteers into the clinic room so that they can converse with patients during the sessions. During all of these tasks of increased cognitive-linguistic load, the expectation is that patients will consistently talk therapeutically.

8. work on creating new feedforward patterns through repeated practice

Treatment of flaccid Dysarthria

Should also be based on which cranial nerve or combination of nerves are damaged

Treatment benefits eachother (2): rule of all of the arthrias

1. Improving PROSODY: can benefit naturalness and intelligibility; aka have carryover on articulation and vocal quality

2. Increasing LOUDNESS improves everything: induce changes in articulation, resonance, prosody, stc.

Examples of treatment goals that are smart

Respiratory: Pt will maintain adequate breath support to produce 5–7 word utterances in 80% of opportunities during structured conversation, given minimal cues.

Resonance: Pt will produce words with plosive sounds in the initial position in with minimal nasal emission (as measured by absence of fog on the mirror) in 80% of trials and minimal cues.

Articulation: Pt will accurately produce lingual sounds at the word level using overarticulation strategy in 60% of opportunities provided modA.

Phonation: Pt will maintain increased vocal loudness (3–5 dB above baseline) during sentence-level conversation in 4/5 opportunities.

Prosody: Pt will use appropriate contrastive stress to clarify meaning during structured task (e.g., correcting misunderstandings or emphasizing key information) in 4 out of 5 opportunities and minimal cues.

Treatment of FLACID DYSARTHRIA

Treatment of trigeminal nerve CN 5

jaw sling: A jaw sling is one way to compensate for bilateral trigeminal nerve damage. This prosthetic device is placed under the jaw and lifts it close to the maxilla. By adjusting the amount of supportive jaw elevation provided, appropriate articulatory contact can be provided for the lower lip and the tongue

Treatment of CNX: VAGUS

resonance:

velopharyngeal Resistence Exercises:

1. Continuous positive airway pressure (CPAP)

   1. aim: reduce hypernasality by strengthening velopharyngeal muscles

   2. For this procedure, the patient wears a nasal mask that sends a continuous flow of air through the nasal cavity and into the upper pharynx. As the air flows downward through the velopharyngeal port, the patient engages in speech tasks requiring a variety of velar movements. As the patient speaks, the velum is forced to work against the resistance of the downward flowing air throughout the time the patient is speaking.

smart goal: client will produce functional phrases containing initial pressure consonants (stops/fricatives) with no audible nasal emission in 80% of opportunities during structured tasks, given minimal verbal cues, within eight weeks following a daily CPAP resistance training protocol

2. Visual/biofeedback:

   1. dental mirror under nose

mild hypernasality:

3. Increase loudness—The perception of hypernasality can sometimes be minimized by having the patient speak more loudly. Louder speech tends to mask the hypernasal resonance in individuals with flaccid dysarthria. Equally important, the louder speech can often increase intelligibility by simply making it easier for a listener to hear what is being said. Mod- eling appropriate loudness levels is a key component of this treatment. Visual feedback on loudness is also helpful for most patients. A sound pressure level meter (either as a stand-alone instrument or an app on a smartphone) can give patients a visual cue as to what the desired loudness should be.

PHONATION:

Laryngeal Adduction exercises:

• goal is to bring vocal folds together

  • tasks: coughing, throat clearing, vocal fry→ all help bring vocal folds together.

• Holding breath—Holding a deep breath of air requires the ability to fully adduct the vocal folds. The tighter the adduc- tion, the better the air will be held in the lungs. Ask the patient to inhale deeply and hold his or her breath. Use a small mirror under the nostrils to detect leaking air. Work to the point at which the patient can hold a breath for about 15 s over 10 consecutive trials. Be sure to give sufficient rest periods between the trials.

  n Hard glottal attack—Some patients can demonstrate a better quality phonation when they begin an utterance with a hard glottal attack (Dworkin & Meleca, 1997; Spencer et al., 2003). Dworkin (1991) described a complete exercise for this pro- cedure. The basic steps are to have the patient hold a deep breath, bear down, and attempt to phonate a tight /a/. This tight phonation should be modified into a more normal vocal quality as soon as possible to avoid the negative side effects of consistent hard glottal attacks during speech.

Prosody aka for pitch:

Contrastive stress drills—These tasks are designed for the clinician to ask a question, with the patient answering it by adding stress on key words to convey the intended meaning of the answer (McHenry, 1998). For example, the clinician might ask the following question about a picture of a man playing football: “Is the man playing basketball?” The patient will answer, “No. The man is playing football.” The clinician’s next question might be, “Is the woman playing football?” The patient’s answer to this question would be, “No, the man is playing football.” A third question might be, “Is the man watch- ing football?” The patient would answer, “No, the man is play- ing football.” The length of the questions and the complexity of the pictures for this task can easily be varied to match the abilities of the patient.

●The emphasis on specific words in a sentence.

Inpatient: Patient will produce constrastive stress by emphasizing target words in structured practice with 70% accuracy given moderate visual and verbal cues.

Outpatient: Patient will independently use constrastive stress by emphasizing target sentences with 80% accuracy given moderate visual and verbal cues.

Chunking or phrase grouping:

Dividing utterances according to normal pauses within/between sentences.

Natural pauses after phrases, introductory clauses, between short sentences.

Inhalations at points at which normal pauses occur in an utterance.

the client will inhale at natural syntactic boundaries every 3–5 words during structured tasks in 70% of opportunities, given moderate verbal and visual cues,