Speech (Motor speech disorders) Flashcards
Motor Speech Disorders:
A group of disorders that in adults are aquired following…
- Neurological event
- Neurological degenerative process
- structural change (ie surgery)
- > Divided into 2 categories:
1) Dysarthrias
2) Dyspraxia
Dysarthria
Difficulty producing clear speech (individual sounds or connected speech) because of damage affecting muscle tone/co-ordination.
*Dysarthria is a broad term for a range of acquired speech difficulties varying in presentation, dependant on cause.
Hypokinetic Dysarthria
Caused by basal ganglia impairment (often Parkinson’s, or Parkinsonianism)
Basal Ganglia
finetune motor movements. If not working properly, amplitude and range of movement decreased. Reduced feedback, so person may not sense it or can’t change it.
Hypokinetic Dysarthria symptoms:
Often with Parkinson’s/Parkinsonionism
- reduced volume
- Breathy, rough voice (dysphonia)
- reduced articulation (unclear, underarticulation)
- reduced intonation (monotone)
- difficulty with timing
- reduced feedback -> they don’t know they have an issue and/or can’t fix it.
- > sounds like mumbling
Hyperkinetic Dysarthria - causes:
Excess movement of speech aperatus: - Huntington’s, Tardive dyskenesia, Progressive supranuclear palsy, tourette’s, tremor, excess L-dopa.
*Basal ganglia origin
Hyperkinetic Dysarthria symptoms:
- Speech often normal, but with excess movement of jaw, tongue, face etc
- Whole body movements can affect control of respiration and phonation -> affects speech.
Spastic Dysarthria cause:
Bilateral upper motor neurone impairment (must be bilateral, because upper motor neurones inervate both sides).
- Not usually single stroke, except brainstem stroke or multiple strokes.
- maybe traumatic brain injury, CP, MND, tumours…
Spastic Dysarthria symptoms:
- High muscle tone (upper motor neurones receive proprioceptive feedback from muscle spindle fibres, and compensate accordingly. Damage interferes with this feedback - no compensation to relax muscles -> high tone)
- speech sounds tight and slow. Finely controlled movements affected.
- Phonation affected - speech sounds strained/strangled.
- Articulation slow, effortful, imprecise.
- prolonged phonemes, transitions
- Prosody affected because of slow change of transitions.
- May have hyperactive gag reflex.
- Increased emotional lability (laughing/crying at unexpected moment or out of proportion to the moment).
Unilateral Upper Motor Neuron Dysarthria causes:
- Stroke (cortial, subcortical, brainstem)
- Tumors
- surgical damage
Unilateral Upper Motor Neuron Dysarthria symptoms:
CN V, IX and X bilateral innervation (no shoudn’t be effect from single stroke affecting these upper motor neurons)
CN VII Bilateral innervation on upper side of face, but unilateral on lower
CN XII bilateral innervation except for genioglossus muscle (muscle of tongue protrusion).
so: generally respiration, phonation, resonance OK but phonemes at the front of the tongue are affected (/s/, interdentals, /t/ and with CN VII affected, possiblly with /f/ and /v/))
*saying: t-t-t-p-p-p more difficult than k-g (genioglossus) [slowed but not terrible - quite mild effect, slight distortion of some sounds. Good intelligibility].
BUT can see weakness of CN VII and XII so facial weakness and tongue deviation on protrusion.
Clues:
*Tongue deviation -> mild-moderate laminal distortion due to impaired genioglossus (s, +/- V th, t)
*Lower facial weakness -> mild labiodental distortion.
*sudden dysarthria (not progressive, not getting worse)
Dysarthria
Motor speech disorder due to disfunction at motor programming and execution level of speech output.
- can cause disterbance to all subsystems of speech including articulation, resonance, etc..
- 6 different types of dysarthria
Differential diagnosis of dysarthria:
- Case history, lesion site of neurological disturbance…
* Initial observations from the client –> (start creating hypothesis, then test the hypothesis)
Types of Dysarthria:
1) Flaccid Dysarthria (lower motor neurons affected)
2) Spastic Dysarthria (Bilateral upper motor neuron affected)
3) Ataxic Dysarthria (cerebellar lesion)
4) Hypokinetic Dysarthria (Basal Ganglia issue, typically with PD)
5) Hyperkinetic Dysarthria (Basal Ganglia issue)
5) Unilateral Upper Motor Neuron Dysarthria (One sided upper motor lesion)
7) Mixed Dysarthria (Damage at multiple levels)
Flaccid Dysarthria presentation:
- weakened reflexes
- weaker automatic and voluntary movements
- possible hypotonia
- possibly fasiculations of tongue or facial muscles
- hypernasality, breathyness, inhalation stridor, monopitch, mono-loudness
Spastic Dysarthria presentation:
Bilateral upper motor neurons affected:
- negative symptoms: loss of function: loss of skilled movement, effortful, strained or strangled sounding harsh speech with slow rate, maybe drooling and/or dysphagia. short vowel prolongation (evident on sustained ‘ahh’)
- Positive symptoms: hyperactivity of muscles, increased tone of muscles
- Positive Babinski sign (extension of toes instead of flexion)
- clonus
- snout reflex, jaw jerk
- psudo-bulbar affect: involuntary laughing or crying - struggle to control that.
Ataxic Dysarthria presentation:
Due to cerebellar lesion.
- “Drunk speech”
- Broad/wide stance/gait
- abnormal eye movement
- May exhibit hypotonia
- Often normal OMA but maybe abnormal bite marks on tongue or inside of cheeks.
- incoordination and reduced muscle tone resulting in slowness and inaccuracy in force, range and timing of speech movements –> irregular articulatory breakdowns cause ‘drunk’ sounding speech. Varying pitch and loudness, possible hypernasality.
- examine sustained ‘Ahh’ (looking for irregularities in pitch and loudness) - won’t be the same twice.
- finger to nose - won’t quite get there.
Hypokinetic Dysarthria presentation:
[if Parkinsons: *resting tremor, rigidity, bradykinesia (slow movement), loss of postural reflexes (maintaining posture, balance, fluidity of movement)
- Reduced loudness
- reduced pitch range
- short rushes of speech at an accelarated rate
- sometimes inappropriate repetative movements and repetative silences
Hyperkinetic Dysarthria presentation:
[often seen with movement disorders ie Huntington’s, Tourettes…]
- Abnormal rhythmic or irregular/unpredictable rapid or slow involuntary movements superimposed onto and interfere with speech.
- May have loudness variability (maybe in sustained ‘Ahhh’)
- maybe unpredictable articulatory breakdown.
Unilateral Upper Motor Neuron Dysarthria presentation:
- Contralateral hemiplegia or hemiparesis
- Contralateral lingual weakness
- maybe harsh, strained voice that may sound hoarse, but never breathy
- some imprecise consonants, maybe irregular articulatory breakdowns, slow rate
Speech disorders that may be confused with dysarthria:
*Apraxia of speech
*stuttering
BUT…–>Dysarthria will always be cause by a lesion somewhere
(Flowchart) Function: Ideas
Domain: Cognition
Possible Disorders?
- Dementia
- Confusion
- Developmental Delay
(Flowchart)
Function: Sounds, words, grammar
Domain: Language
Possible Disorders:?
- Aphasia
* Language delay
(Flowchart)
Function: Motor Plan
Domain: [Speech] Motor Planning
Possible Disorders:?
- Acquired Apraxia
* Developmental Apraxia
(Flowchart)
Function: Speech Movements
Domain: Speech Execution
Possible Disorders: ?
*Dysarthria
Speech motor planning (motor programming):
Translating linguistic code into speech units. Moving from abstract components into actual speech.
Motor execution:
The process whereby the motor plan results in motor movements (ie. muscle contractions). So motor plan must first be good, to get good execution. And muscles must also behave to get final good execution.
What are the 5 ‘subsystems’ of speech relating to different levels of physiological, anatomical and neurological involvement?
- Respiration
- Phonation
- Resonance
- Articulation
- Prosody
Role of Respiration in Speech:
Provides the subglottic air pressure that is needed to set the vocal folds into vibration.
Phonation:
The production of voice phonemes through vocal fold vibrations in the larynx.
Resonance:
The proper placement of oral or nasal tonality onto phonemes during speech.
Articulation:
The shaping of the vocal airstream into phonemes.
Prosody:
The melody of speech…In most instances, prosody conveys meaning within an utterance through the use of stress and intonation.
What areas does the Association Cortex feed into?
- Basal Ganglia
* Cerebellum
Basal Ganglia (role in motor speech)
Plans and programmes postural, supportive components of motor activity.
Cerebellum and Thalamus (role in motor speech)
Integrates and coordinates the execution of smooth, directed movements.
Extra-pyramidal system (indirect pathway):
Indirect pathway. Mediates involuntary (subconscious) movement - tone, posture… provides essential base for voluntary movements.
Pyramidal (direct pathway) system:
Voluntary movements
All higher systems must go through the Lower motor neuron system to make things move. The lower motor neurons are…?
Cranial and spinal nerves.
Upper motor neurons originate in the motor region of the brain stem. They…
carry information from brain centres that control the muscles of the body, but they can’t leave the CNS, so they synapse with the lower motor neurons which interface with muscle fibres.
What are Motor Speech Disorders (MSDs)?
Speech disorders resulting from neurologic impairments affecting the planning, programming, control, or exectuaion of speech. Include dysarthrias and apraxia of speech. Collection of speech production deficits caused by abnormal functioning of motor system. 7 types of dysarthria and 1 type of apraxia.
What is Dysarthria?
A collective name for a group of neurologic speech disorders that reflect abnormalities in the strength, speed, range, steadiness, tone or accuracy of movement required for the breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production (Duffy, 2013:4).
Apraxia of speech:
A neurologic speech disorder that reflects an impaired capacity to plan or program sensorimotor commands necessary for directing movements that result in phonetically and prosodically normal speech (Duffy, 2013:269)
This is an impairment to planning speech movements, not an impairment at the muscle (execution) level:
Apraxia of speech (AOS).
Motor planning disorder –>
Apraxia of speech
Motor execution disorder –>
Dysarthria
These are generally part of a larger disorder of movement. Patterns and characteristics of movement may be somewhat predictable based on where neurological damage has occured/is ocurring:
Dysarthrias
Reduced range of movement (shuffle gait, mumbling), slowness… Basal ganglia being damaged…
Parkinson’s Disease
Common to find expressive language problems (aphasia) together with this motor disorder of speech:
Apraxia of speech.
Primary Cortex:
Made up of different parts of the cerebrum. Dedicated to recieving single types of neural inputs ie primary visual cortex, primary auditory cortex, primary sensory cortex, primary motor cortex. These feed into the association cortex.
Association cortex:
Reception and integration of sensory information fed in from primary cortices. Formulates initial planning of movement. 4 different areas: Temporal, parietal, occipital and frontal association areas. These areas formulate planning of movements (take the desire and turn it into a rough, basic plan). Then sends that information to the basal ganglia and cerebellum.
Which area of the brain receives and integrates sensory information and formulates the initial planning of movements, then sends that rough plan to the Basal ganglia and the Cerebellum?
Association cortex
These are several sub-cortical structures involved in planning slow, continuous movements and regulation of uncontrolled movements. They also produce and regulate neurotransmitters ie dopamine, glutamate
Basal ganglia
Caudate nucleus, Globus Palidus and Putamen together make up the…?
Basal ganglia
The Basal ganglia take the rough plan forwarded by the Association cortex, refine it, then send the refined plan….
…via the Thalamus up to the primary motor cortex.
This brain structure functions to regulate muscle tone, maintain balance, coordinate skilled movements….
Cerebellum
Integrates sensory feedback with information recieved from the association cortex, then adjusts motor impulses according to what the body currently needs. and sends that info via the thalamus to the primary motor cortex.
Cerebellum
This brain structure also has links with the extra-pyramidal system which controls posture, so it also has a role in regulating background posture….
Cerebellum
Damage to the cerebellum can result in an ataxia, which presents like…
drunkenness (kind of).
This brain structure is sometimes called “The Doorway”:
Thalamus
This brain structure further refines information it recieves from the Basal ganglia and Cerebellum:
Thalamus
This brain area recieves impulses from subcortical structures and begins transmission along descending motor tracts:
Primary motor cortex
What are the pyramidal and extrapyramidal systems also know as?
The direct and indirect pathways.
What are the pyramidal and extrapyramidal systems?
Descending motor tracts: Tracts/pathways of nerves originating from the motor cortex. They have variable termination points.
The pyramidal system are the tracts responsible for:
Fine motor movements
The pyramidal system consists of which 2 tracts, with which terminus and interface?
1) Corticospinal tract: Terminates - spinal cord Interface: Spinal nerves (SN). 2) Corticobulbar tract: Terminates: Brainstem (the bulb). Interface: cranial nerves (CN)
The Extra-pyramidal system are tracts responsible for:
involuntary movements (ie postural adjustment, balance plus lots more).
Where do the extra-pyramidal stystem tracts originate?
Usually at the brainstem.
Which tracts make up the extra-pyramidal system?
1) Rubrospinal tracts
2) Reticulospinal tracts
3) Vestibulospinal tract
4) Tectospinal tract
What are the descending motor tracts?
Pyramidal and extrapyramidal systems. Pathways (tracts) of nerves originating from the motor cortex, with variable termination points.
CN responsible for jaw movement:
CN V (Trigeminal)
CN responsible for upper and lower face movement:
CN VII (Facial)
CN responsible for elevation of larynx:
CN IX (Glossopharyngeal)
CN responsible for palate and intrinsic laryngeal function:
CN X (Vagus)
CN responsible for head movement:
CN XI (Accessory)
CN responsible for intrinsic and extrinsic tonge movements:
CN XII (Hypoglossal)
Neuromuscular junction:
The point at which cranial/spinal nerves synapse with muscles via neurotransmitter emmission and reception.
Upper motor neurons:
Neurons found in central nervous system, i.e. brain, brainstem and spinal cord.
Lower motor neurons:
Neurons found in peripheral nervous system, i.e. cranial and spinal nerves
What are neurons found in the central nervous system, called?
Upper motor neurons.
What are neurons found in the peripheral nervous system, i.e. cranial and spinal nerves, called?
Lower motor neurons.
A lower motor neuron dysarthria is always a…?
Flaccid dysarthria
Bilateral damage in the cortex produces what kind of dysarthria?
Spastic dysarthria.
Single sided damage to the cortex (very common in stroke) can result in what kind of dysarthria?
Unilateral Upper Motor Neuron lesion Dysarthria
To much going on in the basal ganglia results in what kind of dysarthria?
Hyperkinetic dysarthria.
To little going on in the basal ganglis results in what kind of dysarthria?
Hypokinetic dysarthria.
Damage to the cerebellum can result in what kind of dysarthria?
Ataxic dysarthria.
Damage to multiple levels of the motor neuron pathway, this can result in what kind of dysarthria?
Mixed dysarthria.
Damage to the motor speech areas (part of the primary motor cortex) may result in which motor speech disorder?
Apraxia of speech
Multiple sclerosis is associated with which kind of motor speech disorder?
Flaccid dysarthria (MS reduces efficiency with which neuronal impulses travel along axon. Leads to weakness, especially if fatigued).
What kind of injury can lead to spastic dysarthria?
- Brainstem stroke (bilateral damage of upper motor neurons leads to disruption to pyramidal and extrapyramidal descending motor tracts -> weaknesses, spaciticity/rigidity).
- Multiple strokes (damage on both sides).
What kind of injury can lead to unilateral upper motor neuron dysarthria?
- Stroke (cortical stroke can disrupt upper motor neurons in one hemisphere only)
- unilateral weakness of movements (pyramidal systems)
- **Extrapyramidal systems usually supported by innervation on contrlateral side, limiting spaciticiy/rigidity in most cases. Presents as weakness.
- can be mild, reasonable prognosis.
- Can present with other characteristics (aphasia, apraxia of speech, hemiplegia..)
Which kind of dysarthria is associated with cerebellar stroke?
Ataxic dysarthria
What does cerebellar stroke look like?
- drunken speech dysarthria.
* Incoordination of movements (speech, gait, limbs). Prototypical ‘slurred speech’.
This kind of dysarthria is associated with Parkinson’s disease:
Kypokinetic dysarthria.
Characteristics of Parkinson’s Disease:
Disorder of the Basal ganglia
- Reduction in dopamine production
- Reduced ability to initiate and sustain movement through faulty feedback systems.
- resting tremor
- bradykinesia (slowed movement with reduced amplitude)
- Rigidity
- posture and gait
This motor speech disorder is associated with Huntington’s disease:
Hyperkinetic dysarthria
Some characteristics of Huntington’s Disease:
Disorder of the basal ganglia (precise mechanism unknown)
- leads to inability to suppress involuntary movements.
- possible chorea (i.e., writhing movements)
- Dystonia (i.e., rigid movements and sustained postures).
Motor neuron disease is associated with which kind of motor speech disorder?
Mixed dysarthria (degeneration of upper and lower motor neurons may eventually lead to mixed pattern of dysarthria, often spastic-flaccid.)
Apraxia of speech can be caused by which kind of injury?
Stroke affecting left inferior frontal lobe (Broca’s area) MAY be associated with AoS.
Apraxia of speech caused by stroke, may co-occur with which other speech/language disorders?
Dysarthria and/or aphasia.
