Section 4 Flashcards
Describe the neurological response for listening.
The sound signal travels to the pinna and through the external acoustic meatus (EAM), which amplifies the
sound signal. From here, sound is transmitted through the tympanic membrane, which then vibrates, and causes the subsequent vibration of the ossicles (incus, malleus, stapes). The footplate of the stapes hits the oval window of the inner ear, which causes displacement of fluid. This fluid displacement disturbs the hair cells along the basilar membrane, and results in neuronal
activation of the 8th cranial nerve (CN VIII - Vestibulocochlear) to the cochlear nucleus,
otherwise known as the Central Auditory Pathway to the temporal lobe in the brain. Here, auditory processing and comprehension occurs. Wernicke’s area plays a vital role in language
comprehension and processing.
What occurs after you hear something and want to respond?
Information processed in Wernicke’s area is now transmitted to the frontal lobe of the brain, whereby language production and the cognitive skills required for memory recall are stimulated. Broca’s area is responsible for language and production of coherent
speech. This information is then transmitted from Broca’s area in the frontal cortex, to the association cortex, basal ganglia, and cerebellum, whereby the motor hierarchy begins.
Describe the motor control hierarchy.
Upper motor neuron -> LMN -> peripheral nerve -> neuromuscular junction -> muscle
How are the basal ganglia association cortex and cerebellum involved in speech?
The association cortex, basal ganglia and cerebellum are related to quality of movement and tell
the muscle how to move. The association cortex regards the appropriation of movement, the basal ganglia is related to initiation of movement, and the cerebellum relates to smooth trajectory of movement, or coordination. The motor thalamus is also involved at this level of the
hierarchy. It is responsible to relay information between the cerebellum and the motor cortex, and between the basal ganglia and the motor cortex.
What is the use of the LMNs in the motor control hierarchy?
The remaining components of the pathway are related to the quantity of movement and overall muscle strength. Lower motor neurons are called the “final common pathway” because they are the most distal connection between theCNS and the muscle.
How might damage to Broca’s area impact speech?
Difficulty processing ideas into tangible language outputs, word finding difficulties
Influences the content of what is able to be spoken
A left hemisphere stroke can cause damage to Broca’s area, and result in Broca’s type aphasia
How might damage to the pyramidal/extrapyramidal system impact speech?
Extrapyramidal system affects posture and tone; as well as the regulation of reflexes [which are involuntary in nature]
Can result in dysarthria if damaged
How might damage to the basal ganglia impact speech?
Problems with initiating movements
Can result in abnormal, involuntary movements, or abnormal, involuntary postures
Disorders such as Parkinson’s disease and Huntington’s disease can cause involuntary tremors and continuous writhing
movements of the extremities
Long term use of antipsychotic drugs that target the dopamine
system can result in involuntary movements of the tongue, face, arms, lips and other body parts
How might damage to the association cortex impact speech?
Difficulties with the appropriateness of movements
Fine motor movements and approximation of articulators will be impacted
How might damage to the cerebellum impact speech?
Abnormal trajectory of movements, lack of coordination
Lesions to the vestibulocerebellum can affect posture
Can result in a staccato nature of speech, slow and disjointed
How might damage to the UMN impact speech?
Weakness with heightened muscle tendon reflexes, hypertonia
How might damage to the LMN impact speech?
Muscle fasciculations, atrophy
Decreased muscle tone
Muscle weakness is often profound in LMN disorders, in localized regions of the body
Damage can arise from diseases such as polio, or localized lesions near the spinal cord
How might damage to the neuromuscular junction impact speech?
Decreases nerve-cell activity, and results in muscle weakness
This does not impact sensation of muscles (ie. tingling)
How might damage to the muscle impact speech?
Muscle weakness, increased fatigue
Results in poor intelligibility, difficulty with articulation, muscle control of the tongue
Any damage directly to the muscles themselves will have limitations on movement, coordination and timing
What causes dysarthria?
An impairment to either the cerebellum, basal ganglia, cerebral cortex or white matter tracts, pyramidal and extrapyramidal systems, cranial nerves, and lower motor neurons. Characterized by a difficulty with motor execution.
What causes apraxia of speech?
An impairment to the left hemisphere (Broca’s area, motor cortex). Characterized by a difficulty with motor planning.
What are the different disorders associated with difficulties with motor execution and their site of impairment?
Ataxic dysarthria: cerebellum
Hypokinetic dysarthria: basal ganglia control circuit, including substantia nigra
Hyperkinetic dysarthria: same as hypo kinetic.
Spastic dysarthria: cerebral cortex or white matter tracts, pyramidal and extrapyramidal systems.
Flaccid Dysarthria: cranial nerves, LMNs
How might damage to an area of the motor hierarchy impact respiration?
Slow, restricted, weak, or uncoordinated muscle activity used in breathing for
speech
How might damage to an area of the motor hierarchy impact phonation?
Difficulties producing smooth sound in the larynx
How might damage to an area of the motor hierarchy impact resonance?
Difficulty to selectively amplify sound by changing the size, shape, or number of cavities through which it must pass
How might damage to an area of the motor hierarchy impact articulation?
Difficulty with the movement or approximation of speech structures to each other when producing sounds of speech
How might damage to an area of the motor hierarchy impact prosody?
Lack of intonation, stress, or rhythm during speech
What is the motor speech treatment hierarchy?
The hierarchy stipulates that the speech subsystems do NOT act independently. Rather, adequate respiratory support and velopharyngeal valving supports phonation, and articulatory precision is supported by respiratory, resonatory, and phonatory competence. In other words, reflecting on the characteristics of dysarthria, there is no condition where only one subsystem is affected without impacting the functionality of the other systems.
Describe the motor speech treatment hierarchy.
First order targets: respiration and resonation
Second order targets: phonation
Third order targets: articulation, prosody
What are the motor learning principles for treatment?
Amount: the more opportunities for practice, the better
Distribution: distributed practice results in better long term learning, while massed practice enhances performance
Variability: different contexts are beneficial for learning (ie. a phoneme with different
vowels)
Schedule: randomizing the targets rather than doing blocks of massed practice has benefit for learning (ie. ACBCAB vs. AABBCC)
Mediating variables include severity, cognitive level, and stage of practice
What are the key principles to neuroplasticity?
Use it or lose it: If a neural substrate is not biologically active, its function can degrade; disuse leads to weakening of synapses of neglected function, strengthening of synapses involved in more consistent behaviours.
Use it and improved: must consider what and how we are using and engaging the system to maximize functional outcomes.
Reprition matters: success typically corresponds with number of repetitions, treatment sessions, and duration.
Time matters: brain is often most amenable to change early on
Intensity matters: skeletal muscle does not adapt unless it is forced beyond to typical range of activity (overload principle)
Specificity matters: what is being repeated
Salience matters: important for therapist to know what is important and what pt takes away.
Difficulty matters: targets must be achievable, challenging, progress in difficulty (load, duration, skill)
Transference
Interference: may involve unlearning
Age matters: younger brains better
What is different about prosody in the motor speech hierarchy?
Prosody should be encouraged at each level, not just at the third. It could also be considered a first level target.
Sumarize motor speech development.
I: tone (body and facial tone, reflexes)
II: Phonatory control (airstreams, phonation, resonance)
III: jaw control vertical movement (range, grading, mid-line mov’t)
IV: labial facial control horizontal (bilabials, rounding, retraction, individual lip)
V: tongue control (anterior/ posterior - independent mov’t from jaw)
VI: Sequenced movement
VII: Prosody
Describe typical jaw movements.
Range needs to allow for the lips and tongue to move and make contact with other structures.
Jaw needs to be stable, with no sliding or thrusting. This allows for the development of controlled movement in other articulators and allows for development of differentiated and refined movement in other articulators. movement needs to be controlled in order to open and close, and grade movement in fine increments between the positions.
How must the lips move for development?
Lips must move independently without the help of the jaw to achieve closure,
rounding, retraction, and individual lip movement (ie. /f/)
How must the tongue be able to move for speech?
Must move independently without the help of the jaw to elevate the tip, elevate
the back, and create tension or constrictions at specific points from front to back
Describe the various aetiologies and speech characteristics of flaccid dysarthria.
Etiologies: surgical trauma, neuropathies (bell’s palsy), muscle disease, myasthenia graves, degenerative disease, brainstem stroke.
Primary deficit: weakness
Characteristics: hyper nasality, nasal emissions, slow and slurred DDKs, tongue fasciculations, imprecise consonants, breathy, wet, horse voice, mono pitch/loudness
Describe the various aetiologies and speech characteristics of spastic dysarthria.
Etiologies: cerebrovascular (CVA), degenerative disease, TBI, infection (meningitis), CP
Primary deficit: spasticity
Characteristics: hyper nasality, harsh, breathy voice, strained and strangled voice, mono loudness, low or mono pitch, imprecise consonants, excess and equal stress.
Describe the various aetiologies and speech characteristics of ataxic dysarthria.
Etiologies: cerebellar stroke or injury, cerebellum atrophy.
Primary deficit: incoordination
Characteristics: slow, slurred speech, excess and equal stress, irregular incoordination, imprecise consonants, distorted vowels, mono pitch/loudness, prolonged phonemes
Describe the various aetiologies and speech characteristics of hypokinetic dysarthria.
Etiologies: parkinson’s disease
Primary deficit: rigidity & decreased ROM
Characteristics: mono pitch/loudness, short rushes of speech, low, flat pitch, breathy, harsh voice, reduced stress, inappropriate silences, fast and imprecise DDK.
Describe the various aetiologies and speech characteristics of hyperkinetic dysarthria.
Etiologies: huntington’s
Primary deficit:: involuntary movements
Characteristics: involuntary movements at rest and during speech, articulatory breakdowns, voice stoppages.
Describe the various aetiologies and speech characteristics of unilateral UMN dysarthria.
Etiologies: unilateral stroke
Primary deficit: weakness, incoordination, spacticity
Characteristics: unilateral facial weakness, harsh voice, articulatory imprecision.
Differentiate the types of dysarthria based on respiration symptoms.
Ataxic: Excessive loudness variation Hypokinetic: reduced loudness Hyper: interruptions, excessive loudness variation Spastic: short phrases, reduced loudness Flaccid: short phrases UMN: reduced loudness
Differentiate the types of dysarthria based on phonatory symptoms.
Ataxic: may be harsh
Hypokinetic: tight, breathiness
Hyper: strain, tremor, voice interruptions
Spastic: strained, strangled
Flaccid: breathiness, diplophonia, flutter
UMN: weak, strained or hoarse.
Differentiate the types of dysarthria based on articulatory symptoms.
Ataxic: irregular articulatory breakdowns
Hypokinetic: imprecise, usually with reduced ROM during speech movements
Hyper: distortions, interruptions
Spastic: imprecise
Flaccid: imprecise, articulation
UMN: imprecise, irregular breakdowns.
Differentiate the types of dysarthria based on resontary symptoms.
Ataxic: often normal, otherwise may be variable
Hypokinetic: often normal
Hyper: constant or variable
Spastic: hypernasal
Flaccid: hypernasality, nasal air emissions
UMN: hyper nasality
Differentiate the types of dysarthria based on prosody symptoms.
Ataxic: slow rate, scanning speech, excess and equal stress
Hypokinetic: rapid rate, short rushes of speech, mono pitch, mono loudness.
Hyper: often slow
Spastic: slow rate, mono pitch, mono loudness
Flaccid: mono pitch, often normal rate
UMN: slow rate, reduced stress
Describe apraxia of speech.
a problem in assembling the appropriate sequence of movements for speech production or executing the appropriate serial ordering of sounds for speech. These problems cannot be explained by significant slowness, weakness, restricted range of movement or incoordination of the articulators. There is also no significant muscle involvement, and resonation is considered normal.
Lesions may be in two areas: broca’s or the primary motor cortex.
Describe the typical articulation characteristics of apraxia.
Articulation difficulties are also characterized by inconsistent errors, prolonged vowels, and a heightened difficulty with consonants rather than vowels.
Groping to find the correct articulatory postures and sequences
Facial grimaces, moments of silence, and phonated movements
Consonant phonemes are involved more often than vowel phonemes
Articulation errors are inconsistent and highly variable
Articulatory errors are primarily substitutions, additions, repetitions,
and prolongations
Describe the typical prosody characteristics of apraxia.
Durational relationships of vowels and consonants are distorted
Rate of production is slow
Alterations of the intonation
What is CAS?
The difficulty executing the volitional motor plan for speech
in the absence of paralysis or neuromuscular deficits. It is characterized by many, many speech
errors (predominantly substitutions, omissions, and additions), a difficulty imitating, poor DDKs,
and inconsistencies in errors across productions.
What are the three core features of CAS?
Inconsistent errors on consonants and vowels in repeated productions of syllables or
words
Lengthened and disrupted coarticulatory transitions between sounds and syllables
Inappropriate prosody, especially in the realization of lexical or phrasal stress
More specifically:
Vowel distortions (allows you to rule out a phonological disorder)
Vowels are based on positioning/grading
Prosodic errors- equal stress and segmentation. Awkward/imprecise transitions
Groping and/or trial and error behavior
What must be true for a diagnosis of CAS?
Must be older than 36 months of age
Must have received a block of early speech intervention prior to 36 months, followed by at least one block of motor speech therapy after 36 months
Compare and contrast CAS, motor speech, and dysarthria in terms of number of errors, prodominant error type, ability to imitate, diadochokinesis, and error consistency.
: much more (CAS), minimal-moderate (MS), moderate (dys)
Type: substitutions, omissions, and additions, substitutions, omissions, distortions, and additions, mostly omissions and distortions
Imitate: difficulty, easy to moderate, easy
DDK: poor, normal, slow
Consistency: no, yes, yes
What are the different aetiologies of neurologically based speech disorders?
Acute causes may be more likely to improve (such as a stroke or TBI)
Chronic conditions may be stable or worsen (dementia, tumor)
Acquired causes may worsen over time
Congenital may be stable, but is dependent on the condition, trajectory etc.
Describe how ALS might impact speech.
Progressive/degenerative nervous system disease that affects nerve cells in the
brain and spinal cord, causing loss of muscle control
Neurologically based speech disorders will worsen overtime
How might brain injury impact speech?
Dependent on the injury and localization of blow to head. Generally towards
improvement during the first few months, then stabilizes
Neurologically based speech disorders will: likely improve during early stages of
recovery, may or may not permanently improve.
