1. Terminology - Motor speech disorders are described in four systems involved with speech production; respiratiry, phonatory, resonatory, & articulatory sistems.
2. Articulatory system- controls and regulates the articulators within oral cavity to manipulate the outgoing airflow in different ways, usually at very high speeds. The major structures involved in articulation are in the lower jaw and lips for opening and closing movements. Changes in the positions and shapes of the tongue and the other articulators result in different speech sound. Speech sounds are duvided into constants and vowels. FOr constants, the constrictions may be a complete obstruction of airflow as in the case of stop constants such as /p/ /d/ & /k/. For vowels, the airflow is never turbulent and the continuous airflow is manipluated by the tougue in the oral cavity to create the varying vowel sounds.
3. Motor Units- Sometimes called a motor program ir muscle synergy, an absrtact representation of a relativity invariant movement pattern that can be scaled in size time to meet the demands of the particular situation. Motor units are those aspects of a movement remains constant over repeated production in different contexts therefore seemed to be planned and executed as a whole, although timing and force can be vary across executions. Speech production is more complicated then kicking a ball. When an idividual is producing lingustic units- phrases, words, syllables and phonemes and is simutantiously pro ducing acoustic events- pitch and loudness varioations.
4. How are motor speech disorders classified- they maybe acquired or developed. Acquired motor speech disorders result from damage to a previously intact nervous system, most often caused by a cerebrovascular accidents or strokes, degenerative diseasse. Developmental motor speech disorders result from abnormal develpmental of nervous system or from damage to the nervous system in its early development
5. Velopharunegeal port- the opening between the velum and the back of the pharynx wall . When the velum is raised, the port is closed
6. Motor planning - refers to the processes that define that define and sequence articulatory goals prior to occurance Motor programming- refers to the processes resposible for establishing and preparing the flow of motor information across muscles for speech productions and specifying the timing and force required for the movements Motor execution- refers to the processes responsible for activation relevant muscles during the movements used in speech production Motor learning- the capability of movement
7. Treatment-Individuals with MSD often have other clinical problems suh as aphasia, limb paralysis, hypertention, or learning disability. Therefore, treatment options are typically explored and recommended by an interdisciplinary team.
8. Respiratory system - Speech production requires airflow to produce sound. The airflow for speech may be ingressive (going in) or eggresive (going out) but most languages, including english rely on eggressive .
9. Phonatory system- Humans produce speech sounds by modulating or changnning the airflow in various ways and at the various ways and at major source if sound is various points along the vocal tract. One major source of sound is vibration of the vocal folds that sit within the larynx. The various muscles and structures in larynx, including the vocal folds, form the phonatory system of speech production
10. Resonatory system- regulates the resonation or vibration of the airflow aas it moves from the pharynx into the oral or nasal cavities. Resonance refers to shape or size of the vocal tract on the sound quality and an important aspect of vocal resonance is whether the nasal cavity is used as a vibrating chamber.
11. Dysarthia- a group of speech disorders caused by disturbance of neuromuscular control of the speech production systems Muscle Tone- referes to the resistance to passive movement and reflects sustained muscle activity Muscle Strength- refers to the ability of the muscle to contract to a desired level and may be reduced as in flaccid dysarthia Movement steadiness- refers to the ability of the muscles to generate steady movements and may be disrupted by involuntary movements Movement speeds- important for speech prodecution which involves many rapid articulator movements and may be reduced Movement range- how far a structure sucj as the tongue or jaw can move and this range may be reduced Movement coordination- refers to the ability to precisely time muscle contractions so that each articulator moves the intended distance and direction at the same time
12. Spastic dysarthia- characterized by increaced muscle tone, weakness, and reduced speed and movement and state of hyppereflexes Flaccid dysarthia- involves muscle weakness atrophy and hypotonicty. These abnormalities may result in restricted speed and range of movement. Hypokinetic dysphasia- symptoms include bradykinesia, rigidy and statur tremor. Although any or all subsystems may be affected, usually the effects are most obvious on phonation, articulation and prosody. Hyperkinetic dysphasia- characterized by muscle tone and involuntary movements and also results from damage to the basal ganglia. Speech characteristics may seem sudden and irregular breathing patterns happen often Ataxic dysarthia- results from damage of the cerebellum, causing incoordination
13. Treatment goals: typically, the solution is provided by the speech-language pathologist throuth paitent and impaitant therapy. An important consideration in treatment is clear identificiation of therapy goalds. In treatment, the goal is to learn or re-learn accurate production of speech for improved speech intelligentably. In many treatment contexts professionals face great pressure to achieve maximal progress to achieve maximal progress with limited resources.
