MSD REVIEW MASLP
- 1. UNIT3 NEUROMOTORSPEECHDISORDERS (ReviewofdifferenttypesofDysarthriaandApraxia) Submitted to Submitted by DR. ROHILA SHETTY HIMANI BANSAL MVSCOSH MASLP IInd year
- 2. DEFINITIONS MSD: speech disorders resulting from neurologic impairments affecting the planning, programming, control, or execution of speech. MSDs include the dysarthrias and apraxia of speech. DYSARTHRIA: a group of neurologic speech disorders that reflect abnormalities in the strength, speed, range, steadiness, tone, or accuracy of movements required for the breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production. The responsible neuropathophysiologic disturbances of control or execution are due to one or more sensorimotor abnormalities, which most often include weakness, spasticity, incoordination, involuntary movements, or excessive, reduced or variable muscle tone. APRAXIA: 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 abnormal speech. It can occur in the absence of physiologic disturbances associated with the dysarthrias and in the absence of disturbance in any component of language.
- 5. SPEECH SUBSYSTEMS FORSPEECH PRODUCTION Respiratory system Phonatory system Articulatory system Resonatory system The muscles and muscle groups in these subsystems must be coordinated in time and space.
- 6. RESPIRATORY SYSTEM Speech production requires airflow Pulmonary airstream mechanism: pushes air out of lungs through the trachea (windpipe) to produce airflow Ingressive – inhalation Egressive – exhalation 1:6- inhalation: exhalation ratio during speech production Exhalation cycle needs to be extended in time (for completion of utterance) and modulation (to reflect stress)
- 7. PHONATORY SYSTEM Includes various muscles and structures in the larynx, and regulates the production of voice and the intonational aspects of speech Vocal folds are brought closer together, and the airflow builds up to set the vocal folds into vibration Vocal folds are stretched lengthwise to manipulate the frequency or pitch of the voice
- 8. RESONATORY SYSTEM Regulates the vibration of the airflow as it moves from the pharynx into the oral and nasal cavity Manipulates shape and size of vocal tract for maintaining normal sound quality Manipulates the velopharyngeal port, (whether nasal cavity is used as a vibrating chamber) for determining nasality of sounds Oral vs. nasal sounds – b and p vs. m and n
- 9. ARTICULATORY SYSTEM Control of the articulators within the oral cavity to manipulate the outgoing airflow Major structures: lower jaw, lips, tongue (most important) Tongue: intrinsic muscles (fine-tuned movements) and extrinsic muscles (coarse movements – protrusion, retraction, elevation, depression) Muscles contract to create constrictions in the oral cavity to produce varying sounds
- 10. MOTOR CONTROL To maintain speed and fluency, the sequences of movements are programmed together as a single movement unit Degrees of freedom: the number of elements that can be independently controlled The greater the degrees of freedom, the greater the challenge to the speaker Speakers reduce the number of degrees of freedom by organizing motor actions into motor units
- 11. MOTORUNITS Motor unit: single control mechanism that controls more than one degree of freedom Basic pattern of movement components remains constant, while more specific aspects of movements are influenced by specific circumstances Producing speech involves producing both linguistic units and acoustic events This requires coordination of muscle groups and programming muscle activities into single motor units to ensure fluent and accurate articulation
- 12. PLANNING, PROGRAMMING &EXECUTION Motor Planning: processes that define and sequence articulatory goals (prior to initiation of movement) Motor Programming: processes that establish and prepare the flow of motor info across muscle, as well as control timing and force of movement (prior to initiation of movement) Motor Execution: processes that activate relevant muscles (during and after initiation of movement)
- 13. MOTOR LEARNING Extensive practice and experience producing speech leads to motor learning (“permanent changes in capability of movement”) Schema Theory: memory representations of motor specifications needed to reach a desired speech outcome (schemas) Becomes stronger with experience Person uses stored schema to produce desired speech outcomes
- 15. MANIFESTATION OFMSD Impairments of Planning/Programming: coordination of relevant muscles and muscle groups is disrupted (muscle physiology and movement are intact) Impairments of Execution: disruptions in muscle physiology – affected by involuntary movements and reductions in movement abilities (whether speech is programmed normally or not)
- 16. TYPESOFMSD Motor Planning/Programming Disorders: inability to group and sequence the relevant muscle with respect to each other Apraxia of speech (AOS) – acquired and developmental Motor Execution Disorders: deficits in physiology and movement abilities of muscles Dysarthria – acquired and developmental
- 17. ACQUIRED DYSARTHRIA Disruption in the execution of speech movements resulting from neuromuscular disturbances to muscle tone, reflexes, and kinematic aspects of movement Speech sounds slow, slurred, harsh or quiet, or uneven depending on the type of dysarthria Three concepts: spasticity, dyskinesia, ataxia Typically occurs because of a progressive disease or trauma
- 18. DEVELOPMENTAL DYSARTHRIA Present at birth Usually occurs along with known disturbance to neuromotor functioning Can be caused by pre-, peri-, or post-natal damage to the nervous system Most common types: -spastic -dyskinetic
- 20. LITERATUREREVIEW • Patients with PD had hypophonic monotonous speech with occasional rushes of speech while patients with MSA and PSP had mixed dysarthria with ataxic and spastic elements respectively. All quantitative parameters were affected when compared to controls ( P values <0.001, 0.012 and 0.008 respectively). Maximum phonation time was significantly less in PSP when compared to MSA and PD ( P =0.015). Reading speed also showed a similar trend which was not statistically significant. Semantic fluency was comparable in all three groups. Sachin et al (2008). Clinical speech impairment in Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy. • Results showed that the most deviant perceptual characteristics were those related to articulation and rhythm. Lower speech intelligibility and increased listener effort were observed for individuals with HD than control speakers. Speech intelligibility proved to be a strong predictor of listener effort. Experience of the listener had no effect on speech intelligibility ratings, but showed a significant effect for listener effort ratings. Maruthy et al (2014). Relationship between speech intelligibility and listener effort in Malayalam-speaking individuals with hypokinetic dysarthria
- 21. ACQUIREDAOS Inability to transform an intact linguistic representation into coordinated movements of the articulators Characteristics: slow speech, sound distortions, prolonged durations of sounds, reduced prosody, consistent errors within an utterance, difficulties initiating speech, groping of articulators Caused by neurological damage to the left frontal cortex surrounding Broca’s Area – due to stroke, brain injuries, illness, and infections
- 22. CHILDHOODAOS Salient characteristics of this disorder are the same as acquired AOS Considerable delay in speech production, limited sound inventory, unintelligibility, and progress slowly in speech therapy Causes are not well understood; some research points to hereditary components, not clear whether there is specific neurological damage Some cases caused by stroke or traumatic brain injury
- 24. LITERATUREREVIEW • At follow-up, 8 of the children with CAS demonstrated improvement in articulation scores, but all 10 continued to have difficulties in syllable sequencing, nonsense word repetition, and language abilities. The children also exhibited comorbid disorders of reading and spelling. Group comparisons revealed that the CAS group was similar to the SL group, but not the S group during the preschool years. By school age, however, the SL group made more positive changes in language skills than the CAS group. Lewis et al (2004). School-Age Follow-Up of Children With Childhood Apraxia of Speech • The most prevalent functional problems in addition to communication were attention (focus), vestibular function, temperament, fine hand use, maintaining attention, and learning to write. Four orthogonal factors accounted for 23% of the variance in functional problems: Cognitive and Learning Problems, Social Communication Difficulties, Behavioral Dysregulation, and Other Oral Motor Problems. Over half the sample had health, mental health, and developmental conditions. Almost all of the children used early intervention and speech/language therapy services. Teverovsky et al (2009). Functional Characteristics of children diagnosed with Childhood Apraxia of Speech
- 27. REFERENCES 1. Brookshire. R H (2007). Introduction to Neurogenic Communication Disorders. 7th Edn. Mosby Elsevier, Missouri. 2. Duffy J. R. (2005). Motor Speech Disorders: Substrates, Differential Diagnosis and Management. 2nd Edn. Elsevier, Mosby, Missouri. 3. Hall, P. K., Jordan, L.S., Robin, D. A. (1993). Developmental Apraxia of Speech. Pro-Ed Inc.
- 28. QUESTIONS ASKEDIN PREVIOUSYEARS 1. Short note on hyperkinetic dysarthria. 4 Marks (2021, 2017, 2018) 2. Describe the sensory motor control for speech production with schematic diagram. 16 Marks (2016, 2018) 3. Differentiate between motor planning and motor programming. 16 Marks (2016, 2018) 4. Short note on hypokinetic dysarthria. 4 Marks (2013) 5. List the characteristics of spastic dysarthria and discuss its management options. 16 Marks (2013) 6. Describe the important issues in classification of dysarthrias. 10 Marks (2011) 7. Briefly write on types of apraxias. 6 Marks (2011)
- 29. THANKYOU