What is Dysarthria?

Dysarthria is a motor speech disorder typically due to neurologic impairment of some kind (i.e., stroke, Parkinson’s disease, TBI, etc.) that results in an inability to properly move the muscles in charge of speech production. This inability to properly control these muscles- whether it be due to inability to coordinate movements, paralysis, or weakness- results in disordered speech production. There are 7 types of dysarthria categorized based on the location of neurologic damage and presenting speech deficits. Flaccid dysarthria presents as muscle weakness causing deterioration of articulatory precision over time along with improvement with rest. Spastic dysarthria is characterized by frequent pitch breaks, a slow rate of speech, and harsh vocal quality. Ataxic dysarthria is characterized by slurring and irregular speech sound errors. Hypokinetic dysarthria presents as limited variation in pitch, loudness, and prosody. Hyperkinetic dysarthria presents as vocal tremor, vocal harshness that comes and goes, and distorted vowels. Unilateral upper motor neuron dysarthria presents as imprecise production of speech sounds, low vocal volume, and a slow rate of speech. Lastly, mixed dysarthria is any combination of the other dysarthria types.

References:

https://www.asha.org/practice-portal/clinical-topics/dysarthria-in-adults/

https://www.asha.org/practice-portal/clinical-topics/dysarthria-in-adults/distinguishing-perceptual-characteristics/