Motor Speech

Apraxia of Speech (AOS) and the Dysarthria's

Define **Apraxia of Speech** (AOS):

A neurogenic speech sound disorder presumably due to sensorimotor problems in creating motor plans and positioning and sequentially moving muscles for the volitional production of speech. It is primarily an articulatory-phonologic disorder.

Apraxia of Speech is characterized by…

Speech sound production errors and prosodic deficiencies.

AOS is ***NOT*** caused by:

Muscle weakness or neuromuscular slowness.

What is the **cause** of AOS?

An injury to the speech-motor programming areas in the dominant hemisphere, such as Broca’s area and the supplementary motor area.

AOS frequently coexists with what type of aphasia?

Broca’s

True or False: AOS individuals have a high variability in speech errors.

True

AOS individuals have more severe problems with…

Affricates, fricatives, and consonant clusters.

Define **Dysarthria**:

A neurologically based motor-speech disorder characterized by abnormal strength, speed, range, steadiness, tone, and accuracy of movement involved in speech production. Also results in paralysis, weakness, or incoordination of the muscles.

What is the lesion site for **Flaccid** Dysarthria?

Lower Motor Neurons (LMN)

What is the neuromotor basis for **Flaccid** Dysarthria?

Weakness and hypotonia

What are the major characteristics of **Flaccid** Dysarthria?

Diminished reflexes, fasciculations, fibrillations, atrophy.

What is the lesion site for **Spastic** Dysarthria?

Upper Motor Neurons (Bilateral)

What is the neuromotor basis for **Spastic** Dysarthria?

Weakness and spasticity

What are the major characteristics of **Spastic** Dysarthria?

__Spasticity and Weakness__: Bilateral facial weakness, less severe lower face weakness, normal or near normal jaw movement.

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__Movement Disorders__: Reduced range, force, and speed of movement, loss of fine and skilled movement, and increased muscle tone.

What is the lesion site for **Unilateral Upper Motor Neuron (UUMN)** Dysarthria?

Upper Motor Neurons (Unilateral)

What is the neuromotor basis for **Unilateral Upper Motor Neuron (UUMN)** Dysarthria?

Weakness and spasticity

What are the major characteristics of **Unilateral Upper Motor Neuron (UUMN)** Dysarthria?

__Neurological Impairments__: Unilateral lower face weakness, unilateral tongue weakness, unilateral palatal weakness, and hemiplegia/hemiparesis.

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__Associated Disorders__: Dysphagia, aphasia, apraxia, and right-hemisphere disorder.

What is the lesion site for **Ataxic** Dysarthria?

Cerebellum

What is the neuromotor basis for **Ataxic** Dysarthria?

Muscle incoordination and irregular movements

What are the major characteristics of **Ataxic** Dysarthria?

__Ataxic Gait__: Feet are broadly spread apart and step irregularly.

__Nystagmus__: Back and forth rapid eye movement.

__Dysmetria__: Overshoot or undershoot intended movements.

__Intention Tremors__

__Hypotonia__

Uncoordinated, jerky, inaccurate, slow, imprecise, and halting movements.

What is the lesion site for **Hypokinetic** Dysarthria?

Basal ganglia

What is the neuromotor basis for **Hypokinetic** Dysarthria?

Reduced range of motion, rigidity, and reduced movement.

What are the major characteristics of **Hypokinetic** Dysarthria?

__Resting Tremors__

__Mask-Like Face__: Infrequent blinking and no smiling.

__Micrographic Writing__: Excessively small print.

__Walking Disorders__: Slow to begin, then short, rapid, shuffling steps.

__Postural Disturbances__: Involuntary flexion of the head, trunk, and arm with difficulty changing positions.

__Decreased Swallowing__: Accumulation of saliva in the mouth, drooling.

__Parkinsonian__: When hypokinetic symptoms are present but are not the result of Parkinson’s Disease.

What is the lesion site for **Hyperkinetic** Dysarthria?

Basal ganglia

What is the neuromotor basis for **Hyperkinetic** Dysarthria?

Abnormal, extra movements

What are the major characteristics of **Hyperkinetic** Dysarthria?

__Orofacial Dyskinesia__: Abnormal involuntary movements of the orofacial muscles.

__Myoclonus__: Involuntary, rapidly occurring jerks of body parts.

__Tic__: Stereotyped movement that is quick and repetitive.

__Chorea__: Purposeless, random, involuntary movements.

__Athetosis__: Slow, writhing, purposeless movements.

__Ballism__: Bilateral, involuntary, and irregular movement of the extremities.

__Spasm__: Sudden, involuntary muscle contractions.

__Tremor__

What is the lesion site for **Mixed** Dysarthria?

Damage to various parts of the nervous system

What is the neuromotor basis for **Mixed** Dysarthria?

Flaccid-Spastic

Ataxic-Spastic

What are the major characteristics of **Mixed** Dysarthria?

Flaccid-Spastic is associated with ALS.

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Ataxic-Spastic is associated with MS.

Dysarthria affects both ___ and ___ utterances.

Involuntary and voluntary

In dysarthria, errors are ___ regardless of length or complexity of words.

Consistent