Motor Speech Disorder Module 3

Name the five purposes of the motor speech examination

Description / Diagnostic Possibilities / Diagnosis / Localization / Severity

A patient's findings are consistent with either ataxic or hypokinetic dysarthria, and the neurologic workup is pending. Which purpose are you fulfilling? Explain

You are fulfilling Diagnostic Possibilities. When clinical evidence points in more than one pathological direction and testing is still incomplete, the clinician establishes a plausible range of potential MSD types rather than declaring an absolute, single diagnosis.

Why should a clinical report section be labeled “Diagnosis/Impression” rather than “Summary”? What does each imply?

A Summary merely restates, copies, or lists the raw observations and symptoms you noted during the exam. A Diagnosis/Impression requires an active clinical interpretation of those findings to describe what they actually mean neurologically

Name the three procedural components of the motor speech examination and what each contributes.

History

Salient Features - Neuromuscular

Confirmatory signs - physical

A patient has a gait abnormality, hyperactive limb reflexes, and limb atrophy — but no speech deficit. Can you diagnose an MSD? Why or why not?

No. Per Duffy's core clinical rules, confirmatory signs alone can never diagnose an MSD. A perceptible speech deficit must be present to establish a motor speech disorder diagnosis

Why does Duffy describe many confirmatory signs as epiphenomena?

An epiphenomenon is a sign that appears alongside a disorder because it shares a common neurological injury site, but it is not casually or directly responsible for the speech deficit itself. For example, a patient may exhibit an asymmetric, abnormal walking gait due to a brain lesion. While the gait abnormality confirms neurological damage exists, the leg muscles do not physically cause or explain the speech errors occurring in the mouth

Match each dysarthria type to its tone pattern ( Flaccid)

Reduced/ decreased tone

Match each dysarthria type to its tone pattern ( spastic)

increased tone

Match each dysarthria type to its tone pattern (hypokinetic)

increased tone

Match each dysarthria type to its tone pattern (hyperkinetic)

variable tone

Tremor during limb movement, also during vowel prolongation: which dysarthria type, what level of the nervous system?

This points to Ataxic dysarthria caused by a lesion in the Cerebellar system. A tremor that occurs specifically during volitional movement is classified as an action tremor

Which dysarthria can show excessive speed? What other feature is it nearly always paired with?

Hypokinetic dysarthria is nearly always paired with a noticeably decreased range of motion (ROM)

Name the four common hyperkinesias

Dystonia, dyskinesia, chorea, and athetosis

A patient has right lower face weakness only; the forehead and eyelid are spared. Where is the lesion (level + side), and why is the upper face spared?

The lesion is located on the Left side at the Upper Motor Neuron (UMN) level. The upper face is completely spared because the cranial nerve nuclei driving the forehead and eyes receive bilateral UMN input (backup wiring) from bothcerebral hemispheres. If one hemisphere's pathway is damaged, the opposite side keeps the upper face moving symmetrically

A patient deviates their tongue left on protrusion across multiple trials. Which side is weak? Why?

The Left side is weak. The tongue is a pushing muscle driven by the genioglossus muscle. When protruded, the fully intact right side pushes normally across the midline, but because the left side is weak and cannot push back, the tongue is forced over toward the weak side

Weak cough + sharp coup. What does this suggest

This strongly points to respiratory weakness. A glottal coup purely measures the physical closing ability of the vocal folds. Because the coup is sharp, laryngeal closure is normal. The weak cough indicates the patient cannot generate the essential abdominal/chest respiratory pressure to force air out.

Can't cough on command but coughs reflexively when water is cleared. What does this suggest? Where does it localize?

This suggests Nonverbal Oral Apraxia (NVOA). It demonstrates a distinct volitional/automatic dissociation (automatic reflexes work fine, but voluntary motor commands fail). It localizes to the dominant hemisphere of the brain.

Max vowel duration = 3 seconds. What are two possibilities to consider before concluding muscle weakness?

Motor Impersistence: A sustained-attention deficit (frequently driven by right hemisphere damage) where the patient simply cannot hold a physical posture, rather than lacking physiological muscle support.

Coordination/Air Wastage Issues: Severe structural leaks, such as rapid air escaping through a weak velopharyngeal port or weak lips

What did DAB produce? How many patients, features, and dysarthria types were involved?

Darley, Aronson, and Brown (DAB) established the perceptual foundation of modern speech pathology. They evaluated 212 patients across 7 neurological conditions, tracking 38 distinct perceptual features. By analyzing how these features naturally clustered together, they defined the six classic types of dysarthria we use today.

Why are SMRs sensitive to AOS but AMRs are not?

AMRs (/pʌ pʌ pʌ/) utilize simple, repetitive movements that isolate the baseline speed and rhythm of a single muscle tract. SMRs (/pʌ tʌ kʌ/) force the brain to execute complex, rapidly changing motor planning and programming sequencing. Because Apraxia of Speech is a motor planning disorder, this high sequencing demand immediately triggers apraxic errors.

Define Intelligibility

How well a listener understands the auditory speech signal alone.

Define Comprehensibility

How well a listener understands the speaker based on the speech signal plus all surrounding non-speech context clues (gestures, drawings, topic settings).

Define Efficiency

The total rate or speed at which understandable information is successfully communicated

Which is most valid for functional limitiations ?

Intelligibility

Why are AMRs confirmatory rather than diagnostic? What is the diagnostic standard?

AMRs are artificial, isolated tasks. When a patient's AMR performance directly conflicts with how they sound talking naturally, natural conversational speech remains the true diagnostic standard. AMRs add supportive evidence but never overrule real speech

An older adult presents with easily elicited palmomental, snout, and sucking reflexes. What is the typical interpretation, and what is the caveat from Key Points 3.7?

These are primitive pathologic reflexes that usually imply a reduction in cortical inhibition, often associated with bilateral UMN damage.

Duffy's Caveat: These reflexes are actually very common in completely healthy, typically aging older adults (the palmomental reflex appears in over 37% of normal older adults and up to 60% in their 90s). They must always be interpreted with high caution

What is the FDA-2’s primary limitation? What is it best used for?

It relies heavily on non-speech oral motor design ratings (like jaw movements or tongue wiggling) and subjective patient self-reports, meaning it does not evaluate active speech production extensively. Best Used For: Determining or supporting an inference about the anatomical locus of a lesion, rather than making a fine-grained differential diagnosis between dysarthria types.

Which test focuses SOLELY on perceptual ratings of speech and refines the DAB/Mayo approach?

The BoDyS (Bogenhausen Dysarthria Scales)

Why are standardized tests considered “limited”? What remains central to MSD diagnosis?

Standardized tests give objective scores, but they cannot replace a trained clinical ear. Carefully listening to, identifying, and describing salient perceptual speech features remains the centerpiece of accurate differential diagnosis

Name one finding from a functional-impact measure that shows why clinician-judged severity alone is insufficient

Studies from tools like the Communicative Effectiveness Survey (CES) and the Dysarthria Impact Profile (DIP) prove that a patient's purely measured physical intelligibility scores do not strongly predict their real-world communication effectiveness or psychological impact. A clinician might score a patient's dysarthria as "mild," yet that patient may still experience profound social isolation, participation restrictions, and severe emotional distress in their daily life