Dysarthria

Introduction to Dysarthria 

- Is a Motor Speech Disorder (MSD) -  Speech dis­orders resulting from neurologic impairments affecting the planning, programming, control, or execution of speech.

Definition

Group of neurogenic speech disorders characterized by 

è   Abnormalities in 1. strength, 2. speed, 3. range, 4. steadiness, 5. tone, or 6. accuracy of movements required for breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production 

NB. Anarthria – severe form of dysarthria – total loss of speech due to muscle weakness


Incidence & Prevalence:

-        Not fully known. Estimates and ranges vary based on the location of lesion, the nature and course of the underlying condition, and the assessment criteria used. 

-        Prevalence of dysarthria associated with some common neurologic conditions are as follows:

Stroke

8-60%

Multiple Sclerosis

25-50%

TBI

10-65%

Amyotrophic lateral sclerosis

30% as initial sign

Parkinson’s disease

70-100%

~100% at late stages

 

Adverse Effect on :

-        Intelligibility of speech, naturalness of speech, or both


General Signs & Symptoms

 

 

Physical Signs:

E.g.

1

Weakness

tongue, lower face, velum

2

Muscle wasting 

hypo- or hyperactive gag reflex, jaw jerk, sucking, snout reflexes

3

Abnormal reflexes

head, jaw, face, tongue, velum

4

Involuntary movements

 

4a

Tremor

head, jaw, lip, tongue, velum

4b

Fasciculations

 

5

Abnormal muscle tone at rest

 


References:

Duffy, J. R. (2020). Motor speech disorders: Substrates, differential diagnosis, and management (4th ed.). St. Louis, MO: Elsevier Mosby. 


Next: Dysarthria - Etiologies