Dysarthria Introduction

Question 1

Define Dysarthria

Answer 1

Dysarthria is a motor speech disorder.
It is a collective name for a group of speech disorders resulting from disturbances in muscular control over the speech mechanism due to damage of the central or peripheral nervous system.
(Darley, Aranson and Brown, 1969)

Question 2

In dysarthria what is disrupted?

Answer 2

In simple words…The signals from the brain to the muscles required for speech is disrupted.

Question 3

What does dysarthria impact?

Answer 3

This impacts…How speech sounds.

Question 4

What can dysarthria range from?

Answer 4

It can range from mild to severe- remaining fully intelligible to being anarthric (Stephen Hawking- no sound).

Question 5

What does speech require?

Answer 5

Speech is a complex behaviour that requires the co-ordinated contraction of a large number of muscles for it’s production. This contraction is controlled by nerve impulses that originate in the cerebral cortex and pass to the muscles by the way of motor pathways.
(Murdoch, 1998)

Question 6

Name the components of speech.

Answer 6

Prosody
Resonance
Articulation
Phonation
Respiration

Question 7

Respiration

Answer 7

Air for speech from the lungs- correct volume of air and appropriate & coordinated patterns for speech.

Question 8

Phonation

Answer 8

Voicing in the larynx- the vibration of the vocal folds via the exhaled air stream to produce sound

Question 9

Articulation

Answer 9

Movements of the articulators/ muscles for speech.

Question 10

Resonance

Answer 10

Where the air goes e.g. oral and nasal resonance.

Question 11

Prosody

Answer 11

Stress, intonation, rhythm and rate.

Question 12

Causes of dysarthria

Answer 12

Lots of causes- anything that affects brain signals really
CP
Stroke (25%)
TBI (33%)
Infection
Parkinson's Disease (90% at some point)
Huntington's Disease
Motor Neuron Disease
Friedrich's Ataxia
Multiple Sclerosis

Question 13

Speech is a complex behaviour…

Answer 13

Which is controlled by nerve impulses originating from motor areas in the cerebral cortex, which pass to the muscles by motor pathways.
(Murdoch, 1998)

Question 14

What’s important for us to understand?

Answer 14

The underlying neurology behind speech.

Question 15

What are upper motor neurons?

Answer 15

These are at the highest level and send impulses to cranial nerves via pyramidal or extrapyramidal pathways.

Question 16

What are lower motor neurons?

Answer 16

These are the final common pathway/lowest level, connecting the CNS to the muscles.

Question 17

Near to the junction of the medulla oblongata and the spinal cord…

Answer 17

the majority of nerve fibres cross to the other side of the body, some uncrossed connections also exist.

Question 18

All cranial nerves for speech have..

Answer 18

Bilateral Upper Motor Neuron Innervation, except the hypoglossal nerve and lower part of the face- these just have contralateral innervation.

Question 19

Why is it important to understand underlying neurology?

Answer 19

• helps us understand when things go wrong.
• helps with differential diagnosis of dsarthria type and likely localisation of neurologic disease.
• identify deviant speech characteristic and relate them to various levels of the speech system.
• helps to inform management

Question 20

UMN facial lesion

Answer 20

Raise both eyebrows
Can’t smile on opposite side of lesion.
AKA. paralysis of contralateral lower facial musculature.

Question 21

LMN facial lesion.

Answer 21

Can’t raise eyebrow on affected side.
Can’t smile on affected side.
Paralysis of ipsilateral upper and lower facial musculature.

Question 22

What are the cranial nerves for speech?

Answer 22

Trigeminal- facial sensation, jaw movement
Facial (upper)- facial movement, bilateral.
Facial (lower)- facial movement, contralateral.
Glossopharyngeal- sensation in pharynx, posterior tonge and soft palate.
Vagus and accessory- supply muscles of larynx and pharynx.
Hypoglossal- tongue movement, contralateral.