Motor Speech Exam 1

Efferent vs. Afferent Pathways

Afferent carries sensory input to CNS; efferent carries motor commands away from CNS.

Neuron: Dendrites vs. Axon

Dendrites receive incoming signals; axons conduct nerve impulses away from soma.

Gray Matter vs. White Matter

Gray matter contains cell bodies and synapses; white matter contains myelinated axon bundles.

Primary Function of Glial Cells

Support, insulate, nourish, and protect neurons throughout the nervous system.

Oligodendrocytes vs. Schwann Cells

Oligodendrocytes produce CNS myelin; Schwann cells produce PNS myelin.

Synapse vs. Neuromuscular Junction (NMJ)

Synapse communicates neuron-to-neuron; NMJ is the synapse between motor neuron and muscle.

Acetylcholine (Role in Speech Motor Control)

Neurotransmitter released at the NMJ to activate skeletal muscle contraction.

Primary Motor Cortex (Location)

Located on the precentral gyrus of the frontal lobe, anterior to central sulcus.

Direct Activation Pathway (Pyramidal System)

Mediates rapid, discrete, skilled, voluntary motor movements via corticobulbar and corticospinal tracts.

Indirect Activation Pathway (Extrapyramidal System)

Regulates background muscle tone, posture, and supportive reflexes for skilled movement.

Upper Motor Neurons (UMN)

CNS motor neurons within direct/indirect pathways that modulate lower motor neurons.

Lower Motor Neurons (LMN)

Motor nuclei and peripheral axons directly innervating skeletal muscles; final common pathway.

UMN Damage vs. LMN Damage Signs

UMN damage causes spasticity and hyperreflexia; LMN damage causes flaccid weakness and atrophy.

Corticobulbar vs. Corticospinal Tracts

Corticobulbar innervates cranial nerve motor nuclei; corticospinal innervates spinal motor neurons.

Basal Ganglia Control Circuit (Function)

Plans, initiates, and scales movement; damage leads to hypokinetic or hyperkinetic dysarthria.

Cranial Nerve V (Trigeminal): Speech Role

Motor innervation to muscles of mastication for jaw elevation, depression, and movement.

Cranial Nerve VII (Facial): Motor Assessment

Assessed by lip pucker, smile, cheek puffing, and eye closure.

Gag Reflex: Sensory vs. Motor Limb

Afferent sensory limb is CN IX (glossopharyngeal); efferent motor limb is CN X (vagus).

Cranial Nerve X (Vagus): Speech Role

Innervates velopharyngeal, pharyngeal, and intrinsic laryngeal muscles for phonation and resonance.

Cranial Nerve XII Damage Signs

Tongue weakness, muscle atrophy, fasciculations, and deviation toward weak side upon protrusion.

Auditory Observations in Motor Speech Exam

Listening to voice, pitch, resonance, rate, and prosody to detect dysarthria signs.

Gag Reflex: Clinical Interpretation

Highly variable in healthy individuals; absent reflex alone does not indicate pathology.

Sustained Vowel (/a/) Assessment Target

Evaluates respiratory-phonatory support, voice quality, steadiness, and maximum duration.

AMRs vs. SMRs

AMRs (/pa/, /ta/, /ka/) test articulatory speed and regularity; SMRs (/pataka/) test sequencing.

Muscle Tone (Definition)

Constant resistance of muscle to passive stretch, present even during complete relaxation.

Six Salient Features of Neuromuscular Function

Strength, speed, range of motion, steadiness, muscle tone, and movement accuracy.

Functional Limitation vs. Disability (Speech)

Functional limitation = intelligibility: How well a listener recognizes spoken words without context (speech signal). Disability = comprehensibility: How well the intended message is understood in real situations using context and listener knowledge. Speech can have poor intelligibility but good comprehensibility.

Communicative Participation Item Bank (CPIB)

Self-report measuring how communication disorders interfere with participation in life activities.

Assessment of Intelligibility in Dysarthric Speakers (AIDS)

Standardized tool measuring acoustic-perceptual speech intelligibility and rate, not communicative participation.

Flaccid Dysarthria

LMN damage. Results from damage to motor units of cranial or spinal nerves that supply speech muscles

Characteristics Flaccid Dysarthria

Imprecise consonants, hypernasality, breathy continuous voice

Spastic Dysarthria

Results from bilateral damage to upper motor neurons. Lesions in multiple areas, including cortical areas, basal ganglia, internal capsule, pons, and medulla are common

Characteristics of Spastic Dysarthria

spasticity & weakness, especially bilateral facial weakness, though jaw strength may be normal & lower face weakness may be severe; movement dis, incl reduced range & slowness, loss of fine & skilled movement, & increased muscle tone; hyperactive gag reflex; hyperadduction of VFs & inadequate closure of the velopharyngeal port; prosodic dis; artic dis; phonatory dis; resonance dis with a predominant hypernasality

Ataxic Dysarthria

Results from damage to cerebellar system. Characterized predominantly by articulatory & prosodic problems

Characteristics of Ataxic Dysarthria

gait disturbance: instability of the trunk & head; tremors & rocking motions; rotated or tilted head posture; hypotonia

movement dis: over-or undershooting of targets; uncoordinated, jerky, inaccurate, slow, imprecise, & halting movements

artic dis: imprecise production of consonants; irregular artic breakdowns & distortion of vowels

prosodic dis: excessive & even stress; prolonged phonemes & intervals b/w words or syllables; slow rate of speech

phonatory dis: monopitch, monoloudness, & harshness

speech quality: impression of drunken speech

Hypokinetic Dysarthria

Results from damage to basal ganglia (extrapyramidal system)

Characteristics of Hypokinetic Dysarthria

Monopitch

Monoloudness

Reduced stress

Imprecise consonants

Short rushes of speech

What are the main structures of a neuron?

The soma is the cell body, dendrites receive information, and the axon sends impulses away.

Where and how do neurons communicate with other neurons and muscles?

Neurons communicate at synapses, where an action potential triggers neurotransmitter release into the synaptic cleft, activating receptors on the next cell. At the neuromuscular junction (NMJ), acetylcholine (ACh) signals skeletal muscles to contract.

What are neurotransmitters, and what are the functions of common neurotransmitters?

Neurotransmitters are chemical messengers. Glutamate = excitatory; GABA/glycine = inhibitory; dopamine = movement regulation (Parkinson disease); acetylcholine (ACh) = skeletal muscle contraction at NMJ (myasthenia gravis). Effects depend on receptor type.

What assessments measure communication participation, effectiveness, and functional impact in dysarthria?

CES: Communication success in everyday situations.

CPIB: How communication difficulties interfere with participation.

Living With Dysarthria: Self-reported difficulties and coping.

Dysarthria Impact Profile: Psychosocial impact.

ASHA FCM (Motor Speech): Clinician-rated functional independence and cueing.

AIDS: Speech intelligibility and rate (NOT participation).