Motor Speech Disorders Exam #2

Flaccid Dysarthria

motor speech disorder caused by damage to the lower motor neurons of the cranial or spinal nerves (PNS)

Final common pathway

lower motor neurons are often referred to as the ____________, because they are the last only “road” that the neural impulses from the upper motor neurons can travel to reach the muscles

Six pairs of cranial nerves of speech production

1) trigeminal V

2) facial VII

3) glossopharyngeal IX

4) vagus X

5) accessory XI

6) hypoglossal XII

Bilateral damage to Trigeminal Nerve (V)

Can have a very serious effect on articulation. If severe, affected individuals cannot raise their jaw sufficiently to produce most consonant & vowel phonemes, especially those needing bilabial, linguadental, or linguapalatal contact. Rate of speech is slowed.

Unilateral damage to Trigeminal Nerve (V)

Can result in weakness or paralysis in the jaw and velar muscles that are on the same side as the damage. Patient’s jaw might deviate to the affected side when open.

unilateral damage to Facial Nerve (VII)

can affect the muscles of the entire face on the same side as the lesion if it occurs above the point where the facial nerve divides into its cervicofacial & temporofacial branches. Result will be degree of weakness and paralysis, drooping eyes, mouth, cheek, & other structures on affected side. damage to only one branch will result in damage to only those structures innervated by that branch. Unilateral UMN damage in one cerebral hemisphere will result in nearly normal upper face movements of the eyebrows, forehead, and eyelids on both sides. However, movement of the cheeks, and mouth on the opposite side of the lesion will be notably weak and have reduced range of motion. This type of damage can result in UMN dysarthria.

bilateral damage to glossopharyngeal nerve (IX)

damage will usually also affect the vagus, therefore the full importance of glossopharyngeal is hard to determine. Probably assists in resonance and phonation.

bilateral damage to vagus nerve (X)

Pharyngeal branch: affect overall movement of the velum, result in hypernasal speech External superior laryngeal nerve branch: cricothyroid’s ability to stretch & tense vfs is greatly reduced. Causes decreased loudness, increased breathiness, notable difficulty varying pitch. Recurrent nerve branch: Bilateral VF paralysis which may cause breathy and hoarse phonation, inhalatory stridor

unilateral damage to vagus nerve (IX)

Pharyngeal branch: affected side of the velum may hang lower than unaffected side, usually does not result in hypernasal speech because the other side can still lift the velum. External superior laryngeal nerve branch: modest difficulty in varying pitch. Recurrent nerve branch: Unilateral VF paralysis which may cause breathy phonation and decreased loudness

bilateral damage to accessory nerve (XI)

Because the neurons of this cranial nerve are so closely integrated with those of the vagus, it is practically impossible to differentiate the functions of the two. damage may impact the function of the velum, pharynx and larynx and will impact the vagus as well.

Unilateral damage to accessory nerve (XI)

similar to vagus bc closely integrated

bilateral damage to hypoglossal nerve (XII)

overall weakness to the tongue, reduction in range of tongue movement, and muscle atrophy on both sides of the tongue.

Imprecise articulation especially for phonemes requiring elevation of tip of tongue, and slow lingual movements.

Unilateral damage to hypoglossal nerve (XII)

weakness or paralysis in the half of the tongue on the same side as the damage. If severe, muscles on the affected side will eventually atrophy, leaving that side of the tongue shrunken. When protruded, the tongue will deviate to the affected side.

Damage to Left UMN= weakness on Right side of tongue

Damage to Right UMN = weakness on Left side

mild articulatory distortion

Phrenic nerve

a spinal nerve that originates from the cervical section of the spinal cord and provides the motor innervation of the diaphragm. damage can paralyze the diaphragm and result in significantly weakened inhalation.

causes of flaccid dysarthria

Physical/surgical trauma, brain stem CVA, myasthenia gravis, Guillian-Barre syndrome, polio, tumors, muscular dystrophy, progressive bulbar palsy

speech characteristics of flaccid dysarthria

hypernasality (most common), imprecise consonants, breathiness, monopitch, nasal emission, audible inspiration, harsh voice quality, short phrases, monoloudness

treatments for flaccid dysarthria

Melodic Intonation Therapy, Nonspeech oral strengthening excersises (pushing and pulling exercises), Respiratory muscle training (posture and how to postion yourself), EMST 150, pitch range excersises, Jaw sling

what percent of their maximum forces do the tongue and lips use for speech?

10-30%

What two symptoms, when combined, are a strong confirmatory sign that flaccid dysarthria is the correct diagnosis?

hypernasality and phonatory incompetence

Myasthenia Gravis

disease that affects the neuromuscular junction. Primary symptom is rapid fatigue of muscular contractions over a short period of time, with recovery occurring after rest.

speech characteristics: hypernasality, decreased loudness, breathy voice quality, decreased articulatory imprecision during prolonged speaking tasks.

spastic dysarthria

motor speech disorder caused by bilateral damage to the upper motor neurons.

causes of spastic dysarthria

stroke, ALS, TBI, MS, brainstem tumor, brain anoxia, viral infections, bacterial infections

which component of speech is not typically as affected in spastic dysarthria?

respiration

most common articulation disorder in spastic dysarthria

imprecise consonant production

pseudobulbar affect

uncontrollable crying or laughing that can accompany damage to the upper motor neurons of the brainstem. Appears to be caused by damage to areas of the brain that are important in inhibiting emotions. In cases of spastic dysarthria or mixed dysarthria with spastic componet, crying is more common than laughing.

bulbar palsy

general term meaning atrophy and weakness in the muscles innervated by the medulla (the bulb). This includes the muscles of the tongue, velum, larynx, and pharynx. Bulbar dysarthria was once a term used to describe flaccid dysarthria. Caused by damage to the lower motor neurons

pseudobulbar palsy

“false” bulbar palsy; means weakness and slowness in the same muscles as bulbar palsy; this term was sometimes used to describe spastic dysarthria. caused by damage to the upper motor neurons.

is hypernasality more severe in spastic or flaccid dysarthria?

flaccid dysarthria

the hypernasality seen in spastic dysarthria mis usually not as severe as that heard in flaccid dysarthria. In addition nasal emission is not common in spastic dysarthria, but may be quite evident in flaccid dysarthria.

treatments for spastic dysarthria

Phonation: Effortful closure, holding breath, hard glottal attack, head turning and sideways pressure on the larynx

Articulation: stretching exercises/beckman oral motor exercises, traditional articulation drills and teaching placements.

Prosodic: pitch range exercises, contrastive stress drills, chunking utterances into syntactic units.

Resonance: surgical treatments, palatal lifts, modifications of speech by reduced rate, more open mouth posture during speech, and increasing loudness, behavioral-based treatments via visual feedback

phonation treatments for spastic dysarthria

head and neck relaxation

easy onset phonation

yawn-sign exercises

tongue strengthening exercises

passive: in which the clinician gently grasps the patient’s tongue with a gauze pad and carefully pulls it straight forward until resistance is felt. This protruded position is held for 10 seconds. Then the clinician gently pulls the protruded tongue to theleft and the right of the mouth, and again holds it for 10 seconds.

Active: can also be used to increase strength, speed, and accuracy of tongue movements. Examples of these tasks include having the patient protrude the tongue fully, elevate the tongue tip towards the nose, lower the tongue tip toward the chin, and hold the tongue at the corners of the mouth etc.

is drooling a non speech finding in spastic dyarthria?

Yes; although drooling can happen with other dysarthrias, it appears most prominently with spastic dysarthria. Probably due to impaired oral control of saliva or perhaps to less frequent swallowing. A behavioral approach works on cueing the individual to consciously swallow more frequently than normal. Pharmaceutical treatments that reduce saliva production are also available

monopitch/monoloudness exercises for spastic dysarthria

pitch range exercises

intonation profiles

contrastive stress drills

chunking utterances into syntactic dysarthria

how does a single brainstem stroke cause spastic dysarthria?

A single stroke can cause spastic dysarthria only when it occurs in the brainstem. This is because the neural fibers in both the right and left pyramidal and extrapyramidal systems are in very close proximity to each other in the brain stem. Consequently, a single stroke in the brainstem can be extensive enough to damage the left and the right upper motor neurons in these two systems.

When was UUMN dysarthria discovered?

1980s

unilateral upper motor neuron (UUMN) dyarthria

Motor speech disorder is caused by damage to the UMN on a single side of the brain that supplies the cranial and spinal nerve involved in speech production

most common cause of UUMN dysarthria

strokes

severity of UUMN dysarthria

mild-moderate

what does UUMN dysarthria typically co-occur with?

aphasia, apraxia of speech, limb hemiparesis, visual deficits, cognitive impairments

why might UUMN dysarthria with a co-occurring language deficit be difficult to diagnose?

Because the patient’s verbal output might be limited and the dysarthria may take a “back seat” to the other deficits

speech component most affected with UUMN dysarthria?

articulation

most likely cause of prosodic deficits in UUMN dysarthria

slightly slow rate of speech

tasks for diagnostic information for UUMN dysarthria

a. The medical records may provide valuable diagnostic information. Facts about the site of lesion can be especially helpful in diagnosing UUMN. Remember that lesions may be too small for neurologic imaging procedures to detect, especially early after the onset of symptoms.

b. conversational speech or reading a paragraph are useful tasks for evoking imprecise consonant productions that are so common in this dysarthria. These tasks are also useful in detecting the irregular articulatory breakdowns that are sometimes present

c. The AMR task is helpful in highlighting a slowed rate of phoneme production. Remember that in many individuals with UUMN dysarthria, a slightly slow AMR may not reflect slow connected speech

d. a prolonged vowel will be useful in detecting the harsh voice quality heard in some patients with this dysarthria

treatments for UUMN dysarthria

traditional articulation tasks:

a. intelligibility drills

b. phonetic placement

c. exaggerating consonants

d. minimal contrast drills

site of lesion for ataxic dysarthria

damage to the cerebellum

speech components most affected with ataxic dysarthria

articulation and prosody

cerebellum

typically assigned to the motor system and is a very important part of this system. Its primary function is to coordinate the timing and force of muscular contractions so that skilled, voluntary movements appropriate for an intended task are created.

cerebellar control circuits

the neurons that course through the three peduncles; the neural tract that send information to and from the cerebellum.

how does the cerebellum influence speech production?

the planned motor impulses of a planned speech act are sent from the cortex to the cerebellum

causes of ataxic dysarthria

stroke, tumors, TBI, degenerative diseases (autosomal dominant cerebellar dysfunction, idiopathic sporadic late onset, Friedreich’s ataxia, Olivoponto cerebellar)

Toxins: lead and mercury poisioning, long term alcohol poisioning, exposure to cynaide, toxic Dilantin, vitamin E of B12 deficit.

most prevalent speech error in ataxic dysarthria

imprecise consonant production

prosodic deficits present in ataxic dysarthria

a. equal and excess stress

b. prolonged phonemes: caused by decreased muscle tone

c. prolonged intervals between phonemes: caused by decreased muscle tone

d. monopitch: caused by hypotonia

e. monoloudness: caused by hypotonia

f. slow rate: a result of the prolonged phonemes and prolonged intervals between phonemes

what do patients needing to work on respiration deficits due to ataxic dysarthria benefit from?

controlling their airflow more accurately during speech

slow and controlled exhalation

speak immediately on exhalation

stop phonation early

optimal breath group

what do patients with ataxic dysarthria need to work on regarding prosody?

slowing their rate (improve intelligibility)

a. reciting syllables to a metronome

b. finger or hand tapping to follow a tempo

c. cued reading material- marks to indicate pauses

stress and intonation (more typical speech and intonation to make their speech more natural)

a. contrastive stress drills

b. pitch range exercises

c. intonation profiles

d. chunking utterances into syntactic units

how is hypokinetic dysarthria unique?

it’s the only dysarthria that displays increased rate of speech as a symptom

causes of hypokinetic dysarthria

Parkinson’s (most common), stroke, TBI, Wilson’s disease, antipyschotic drug usage

Parkinsonism symptoms that have the greatest effect on speech

muscle rigidity, reduced range of motion, slowed movement

Site of lesion of Parkinsonism (and hypokinetic dysarthria)

basal ganglia or the basal ganglia’s neural connections with other portions of the CNS

two neurotransmitters that the basal ganglia depends upon for balanced interaction

dopamine and acetylcholine

three categories of treatment for hypokinetic dysarthria

pharacological, surgical, and behavioral

common speech characteristics of hypokinetic dysarthria

monopitch, reduced stress, monoloudness, imprecise consonants, inappropriate silence, short rushes, harsh vocal quality, breathy voice, decreased pitch range, variable rate

delayed auditory feedback (DAF)

a behavioral treatment for parkinsonism. It’s an electronic device that send “feeds” to patients of their own voice after a short delay

Deep brain stimulation

surgical treatment for parkinsonism; electrical leads are inserted into specific targets (globus pallidus or subthalamic nucleus): once activated, a low level current is sent into the surrounding neurons to disrupt activity in that part of the brain.