Motor speech disorders

Muscles in your mouth, face, and throat work together to allow you to create sounds. When these muscles are damaged they result in what is called clinically as “dysarthria’’. Difficulty speaking can take many forms, and it is important to work closely with a speech-language pathologist to determine they type and severity of a persons dysarthria. There are seven types of dysarthria. Click below to learn more.

Flaccid Dysarthria

Flaccid dysarthrias are caused by injury or disease of one or more cranial or spinal nerves. The hallmark feature of flaccid dysarthria is muscle weakness and reduced muscle tone. The person with flaccid dysarthria will have difficulty coordinating speed, range, and accuracy of their speech. Systems that may be impacted include respiratory, phonatory, resonators, and articulatory. Common patient complaints include slow or slurred speech, the phrase “lazy tongue” is often used. According to the Mayo Clinic, flaccid dysarthria accounts for 8.4% of all dysarthrias.

Spastic Dysarthria

Spastic dysarthria is caused by injury or disease to neural pathways within the central nervous system (i.e. brain and spinal cord). Damage to these areas manifest in combined weakness and spasticity in a manner that slows movement and reduces its range and force. Reduced skilled and discrete movements are associated with this dysarthria. Spasticity is a hallmark of upper motor neuron disease and spastic dysarthrias account for 7.3% of dysarthrias.

Ataxic Dysarthria

Ataxic dysarthria is a result of damage to the cerebellar control circuit in the brain. It can affect all subsystems of speech but primarily are manifest in difficulties with articulation and prosody. It reflects the effects of incoordination and may include reduced muscle tone, inaccuracy in the force range, timing, and direction of speech movements. Identification helps to determine area of damage or disease to the cerebellum. Ataxic dysarthria reflects problems of motor control. Breakdowns in timing and coordination are hallmark features. Common complaints from patients include “drunken” quality to their speech or stumbling over their words. It accounts for about 10.1% of all dysarthrias.

Hypokinetic Dysarthria

Hypokinetic dysarthria is associated with damage to the basal ganglia. The basal ganglia is important in the production and regulation of dopamine. It can damage all subsystems of speech, but with primary impacts on voice, articulation and prosody. It reflects rigidity, and mix of reduced force of range of movement, but also fast repetitive movements. This type of dysarthria is associated with Parkinson’s Disease. Common complaints from patient’s family and friends include a weaker or softer voice, which the patient themselves are not aware of. Hypokinetic dysarthria accounts for 10% of all dysarthrias.

Hyperkinetic Dysarthria

Hyperkinetic dysarthria also involves damage to the basal ganglia. This type of dysarthria is associated with involuntary movements of any of the subsystems of speech. Some involuntary movements are normal for any person, as when someone is startled, tremors from fear etc. Involuntary movements associated with hyperkinetic dysarthria are the ones when motor control and steadiness is expected, such as when being still. Patient’s complaints usually include slow, slurred, or halting speech, the phrase “hard to get it out” is used. Sometimes patients are unable to describe their symptoms. Hyperkinetic dysarthria accounts for about 7% of all dysarthrias.

Apraxia of Speech (AOS)

Apraxia of speech (AOS) is different from dysarthria. It is difficulty and impairment with motor planning and execution. Damage is in located in the cerebral cortex (brain). Speech disturbances can be variable and inconsistent, which is frustrating to someone who has AOS. Think about how a car works to help differentiate between apraxia of speech and dysarthria. All the parts of the car need to be working to get to your destination smoothly, if the brakes do not work or if there is difficulty with the engine or tires, the ride could be jerky. This is similar to dysarthria. If the GPS is not working however, you will take wrong turns and indirect routes to your location. This is more similar to apraxia of speech. You need all the parts of the car working smoothly and ability to direct you to your destination to be working properly. AOS accounts for 6.9% of motor speech disorders.

Tips for speakers dysarthric speakers

If you have dysarthria, here are some tips for you:

Say one word or phrase before starting to talk in sentences. This will tell the listener what the topic is and help them understand what you say. For example, you can say "dinner" before starting to talk about what you want to eat.
Check with listeners to make sure that they understand you.
Speak slowly and loudly. Pause to let the other person think about what you have said.
Try not to talk a lot when you are tired. Your speech may be harder to understand.
Try pointing, drawing, or writing when you have trouble talking.

Source: ASHA.org