Neurology of motor control and motor speech disorders

Explain the Van der Merwe model for the characterization of pathological speech sensorimotor control and how this supports SPs diagnosis of MSDs  Describe why we study MSDs  Understand the neurology of motor speech control and how this aids differential diagnosis

What are the 4 stages of Van Der Merwes Model?

1. Linguistic-Symbolic Planning

2. Motor planning

3. Motor programming

4. Execution

What happens in stage 1 of Van Der Merwes Model? (Linguistic Symbolic planning)

Conceptualisation: Conception of communication

intent

Linguistic-Symbolic planning: Semantic, syntactic, morphological

and phonological planning. The phonological plan is the

output of this stage.

What happens in Stage 2 of Van Der Merwes Model? (Motor planning)

Converts the phonological plan into a motor plan to guide movements for speech

What happens in Stage 3 of Van Der Merwe’s Model? (Motor programming)

Converts the motor plan into more technical instructions for movement

What happens in Stage 4 of Van Der Merwe’s Model? (Execution)

Central and peripheral nervous system activity coordinates respiratory, phonatory, resonatory and articulatory muscles to execute speech motor programs, generate sound, and use sensory feedback to detect errors.

What is the Neural Control of Speech Production?

1. Cortical and subcortical structures

2. Basal ganglia, thalamus, cerebellum, and connections

between these structures

3. Cranial nerve nuclei in the brainstem and the lower motor

neurons

4. Spinal motor neurons (respiration)

What are the Lower Motor Neurons involved in the Final Common Pathway?

1. Respiration

2. Phonation

3. Articulation

4. Resonance

What are the cranial nerves invovled in the direct activation pathway?

1. Trigeminal (V) Bilateral

2. Facial – Upper Face (VII) Bilateral

3. Facial – Lower Face (VII) Predominantly contralateral

4. Glossopharyngea l (IX) Bilateral

5. Vagus (X) Bilateral

6. Accessory (XI) Bilateral

7. Hypoglossal (XII) Contralateral > bilateral