Exam 2 Motor Speech

Flaccid dysarthria is

a motor speech disorder caused by a disruption of the flow of neural impulses along the lower motor neurons

What are the characterizing speech features of Flaccid Dysarthria?

Slow-labored articulation, marked degrees of hypernasal resonance, and hoarse-breathy phonation.

What is the Final Common Pathway in relation to Flaccid Dysarthria?

The last and only 'road' neural impulses from upper motor neurons travel to reach muscles.

Which cranial nerves play a vital role in speech production?

Trigeminal, facial, glossopharyngeal, vagus, accessory, hypoglossal.

What can cause damage to the cranial nerves?

Brainstem stroke, growing tumor, viral or bacterial infections, physical trauma, surgical accidents

Which muscles are innervated by the mandibular branch of the trigeminal nerve?

Masseter, pterygoid, mylohyoid (elevates jaw) and tensor veli palatini in the velum

What can damage to the facial nerve cause?

Weakness or paralysis in all muscles on the same side of face, resulting in drooping of the eyelid, mouth, cheek, and other structures.

What is the role of the stylopharyngeus and superior pharyngeal constrictor muscles, innervated by the glossopharyngeal cranial nerve?

Elevate and open upper pharynx

What aspect of speech production can be affected by the pharyngeal branch of the vagus nerve?

Movement of the velum and resonance.

What motor innervation does the recurrent laryngeal nerve branch supply?

All the motor innervation for all adductor and abductor muscles of the vocal folds.

What are the primary characteristics of hypoglossal nerve damage?

Weakness of the tongue or paralysis, resulting in imprecise articulation, phoneme distortion, or slow lingual movements.

What is the function of the phrenic nerve?

Motor innervation to the diaphragm.

What conditions can damage lower motor neurons and cause Flaccid Dysarthria?

Physical trauma, brainstem stroke, myasthenia gravis, Guillain-Barré syndrome, and polio.

What is a brainstem stroke?

Interruption of blood flow to the brain as an artery breaks or is blocked.

What is Myasthenia Gravis?

Fluctuating weakness and fatigue affecting the neuromuscular junction.

What are the symptoms of Myasthenia Gravis?

Rapid fatigue of muscular contractions over a short time, with recovery after rest.

What is Guillain-Barré Syndrome?

Immune system attacks nerves, progressive inflammatory loss of the myelin sheath around the axon.

How does Polio affect the motor neurons?

Attacks cell bodies of lower motor neurons.

What are speech characteristics of Flaccid Dysarthria?

Hypernasality, imprecise consonant production, breathy voice quality

Damage to which nerves can cause articulation problems?

Damage to facial and hypoglossal nerves, bilateral damage to facial nerve, damage to trigeminal nerve

What is phonatory incompetence in the context of Flaccid Dysarthria?

An incomplete adduction of vocal folds during phonation, caused by damage to recurrent branch of vagus nerve.

What is a productive method of treating of Flaccid Dysarthria?

May be more productive to work on strategies that concentrate directly on increasing intelligibility of patient’s speech

With bilateral damage, what nerve can have serious effects on articulation, as the patient may not be able to sufficiently raise the jaw to produce most consonant and vowel phonemes, particularly those requiring bilabial, linguadental, and linguapalatal contact?

trigeminal

What type of neural damage causes spastic dysarthria?

Bilateral damage to upper motor neuron (UMN) tracts.

Which systems are affected in spastic dysarthria?

Both pyramidal and extrapyramidal systems.

What are common characteristics of spastic dysarthria?

Slow, effortful speech; harsh vocal quality; hyperactive and abnormal reflexes; increased tone with weakness and decreased ROM.

What does damage to the pyramidal system cause?

Weak, slow, and reduced skilled movement, especially in lips, tongue, velum.

What does damage to the extrapyramidal system cause?

Spasticity, abnormal reflexes, and increased muscle tone.

What are the two main tracts in the pyramidal system?

Corticobulbar (to cranial nerves) and corticospinal (to spinal nerves).

Why is bilateral damage necessary to cause spastic dysarthria?

Because it produces combined symptoms of weakness, slowness, spasticity, and abnormal reflexes not seen in unilateral damage.

Which muscle group shows the most noticeable spasticity?

Laryngeal muscles (often causing hyperadduction of vocal folds).

What is the most common cause of spastic dysarthria?

Stroke.

What type of strokes result in spastic dysarthria?

Brainstem strokes or bilateral cerebral hemisphere strokes.

How can ALS lead to spastic dysarthria?

When upper motor neurons are predominantly affected.

How can traumatic brain injury cause spastic dysarthria?

Through widespread bilateral brain damage.

How can multiple sclerosis cause spastic dysarthria?

If there is bilateral involvement of UMNs.

What causes speech errors in spastic dysarthria?

Spasticity, slowness, and weakness in vocal tract muscles.

Which speech components are most affected?

Articulation, phonation, resonance, prosody (more than respiration).

What is the most common articulation error in spastic dysarthria?

Imprecise consonants.

What causes imprecise consonants in spastic dysarthria?

Short voice onset time, incomplete contact, and consonant clusters.

What is the most common phonatory error in spastic dysarthria?

Harsh vocal quality.

What causes harsh or strained-strangled voice in spastic dysarthria?

Hyperadduction of vocal folds and tight larynx.

Why is low pitch often present in SD?

Due to increased muscle tone in the larynx.

What causes hypernasality in spastic dysarthria?

Spasticity in velar muscles, reducing soft palate movement.

Is nasal emission usually present in spastic dysarthria?

No.

What prosodic issues are common in spastic dysarthria?

Monopitch, monoloudness, reduced stress, and slow rate due to vocal fold tightness.

Do respiratory problems play a major role in spastic dysarthria?

No; phonation/prosody issues are more due to vocal fold spasticity.

What is pseudobulbar affect?

Uncontrollable laughing or crying due to UMN damage.

Why is drooling common in spastic dysarthria?

Impaired oral control and infrequent swallowing.

Causes of flaccid vs spastic dysarthria

Flaccid is caused by Lower motor neuron (LMN) damage and spastic is caused by Bilateral UMN damage.

How does phonation differ between spastic and flaccid dysarthria?

Spastic = strained-strangled; Flaccid = breathy.

How does reflexes differ between spastic and flaccid dysarthria?

Spastic = hyperreflexive; Flaccid = absent/reduced reflexes.

Which condition is associated with pseudobulbar affect and drooling?

Spastic dysarthria.

What is the treatment focus for spastic dysarthria?

Reducing increased muscle tone and targeting articulation.

What does treatment for phonation deficits involve IN SD?

Reducing hyperadduction of vocal folds.

How are prosodic deficits treated in SD?

Techniques to increase pitch and loudness variation.

What does resonance treatment focus on in SD?

Velopharyngeal closure and reducing hypernasality.

What are the six pairs of cranial nerves of speech production?

trigeminal, facial, glossopharyngeal, vagus, accessory, and hypoglossal

Key Evaluation Tasks for Spastic Dysarthria

-conversational speech and reading

-AMR tasks

-vowel prolongation

conversational speech and reading

Assesses resonance (hypernasal) , articulation (imprecise consonants), prosody (monopitch, monoloudness, short phrases)

AMR tasks

•Demonstrates slow rate of phoneme production

vowel prolongation

Evokes phonatory deficits = assess phonatory deficits

•Harsh voice

• Strained –strangled

• Low pitch 

Which cranial nerve originates in the brainstem at the medulla and courses out to the pharynx, where it innervates the stylopharyngeus and superior pharyngeal constrictor muscles, which assist in elevating and opening the upper pharynx?

vagus

Which cranial nerve has three branches, each having a special importance for speech production?

trigemineal

What cranial nerve’s neurons are so closely integrated with those of the vagus nerve?

accessory

The spinal nerve that is one of the most important nerves of respiration is the

phrenic nerve

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

10-30

The combined presence of what two symptoms is the strongest confirmatory sign that flaccid dysarthria is the correct diagnosis?

hypernasality and phonatory incompetence

Surgical treatments options for damage to the vagus nerve are

a pharyngeal flap and Teflon injection

The _______ branch travels a “double back” route from the brainstem to the larynx. It branches from the vagus nerve after leaving the cranium and then courses down near the heart before turning upward, traveling up along the trachea, finally reaching the larynx.

recurrent laryngeal nerve

The cranial motor neurons from the _____ help innervate the intrinsic muscles of the velum, pharynx, and larynx.

accessory nerve

The ___ nerves play an important role in speech production because they provide motor innervations for the muscles of diaphragm.

spinal

A prosthetic treatment that is essentially a dental retainer with a rear extension to help push upward on the velum is called a _____

palatal lift

What causes Unilateral Upper Motor Neuron (UUMN) dysarthria?

Damage to the upper motor neurons on one side of the brain that supply cranial and spinal nerves involved in speech.

What are the primary characteristics of UUMN dysarthria?

Weakness in the lower face, lips, and tongue on the opposite side of the lesion, leading to imprecise consonants.

How severe is UUMN dysarthria typically?

Usually mild and can sometimes be temporary or resolve on its own.

Which speech muscles receive bilateral innervation?

Most speech muscles except those of the lower face and tongue.

Why are speech deficits usually less severe in UUMN damage?

Because most speech muscles are bilaterally innervated, so the unaffected hemisphere can compensate.

What parts are most affected by UUMN damage?

The lower face and tongue.

Can bilaterally innervated structures still be affected?

Yes, they may show subtle deficits even with compensation from the undamaged hemisphere.

What is the most common cause of UUMN dysarthria?

Stroke

Why is the internal capsule a common stroke site causing UUMN dysarthria?

It contains a high concentration of descending UMNs between the thalamus and basal ganglia.

Can tumors cause UUMN dysarthria?

Yes, though rare. They can damage, compress, or disrupt blood flow to UMNs.

Is traumatic brain injury a common cause?

No. Most TBIs are diffuse, but localized damage can occasionally cause it.

What is the most prominent speech feature of UUMN dysarthria?

Imprecise consonant production due to tongue and lower face involvement.

What causes the articulation deficits?

Weakness, reduced range of motion, and decreased fine motor control.

What phonation issue may be present?

Mild to moderate harsh vocal quality (39% of patients).

Why might harsh vocal quality occur?

Mild vocal fold weakness/spasticity, lesions, or age-related dysphonia.

is resonance, respiration, and prosody an issue in UUMN

usually not

What tools are used to identify UUMN dysarthria?

Medical records (CT/MRI), conversational speech/reading, AMR tasks, and prolonged vowels.

What will conversational speech and reading tasks reveal?

Imprecise consonants and irregular articulatory breakdowns.

What does a prolonged vowel task assess?

harshness of phonation

What is ataxic dysarthria?

A motor speech disorder resulting from damage to the cerebellum or its neural pathways, primarily affecting articulation and prosody, giving speech an unsteady, slurred quality.

What does the term “ataxia” mean?

It is a Greek word meaning “lack of order,”

What is the cerebellum’s primary function?

To coordinate the timing and force of muscular contractions.

How does the cerebellum connect to the CNS?

Through three cerebellar peduncles: inferior, middle, and superior.

What are the cerebellar peduncles made of?

Bundles of neural tracts (not upper motor neurons).

What is the input/output fiber ratio for the cerebellum?

For every 1 fiber conveying info out, about 40 convey info in.

What does the inferior peduncle do?

Receives sensory info from the body, monitors ongoing movements, and checks if the motor commands are achieving intended results.