Understanding Dysarthria and Related Speech Disorders

Spastic dysarthria

Imprecise articulation of bilabial and labiodental sounds.

Hoarseness

Reduced vocal fold adduction causing voice changes.

Hypernasality

Weak velar movement leading to excessive nasal resonance.

Dysarthria classification

Distinguished by perceptual speech characteristics and neuropathology.

Apraxia

Presence of speech motor planning difficulties.

Vagus Nerve (CN X)

Impairment leads to hypernasality and weak closure.

Spastic dysarthria characteristics

Slow rate, strained voice, and reduced prosody.

Hypokinetic dysarthria

Associated with Parkinson's disease symptoms.

Apraxia of speech

Characterized by groping movements during speech.

Ataxic dysarthria

Result of cerebellar damage affecting coordination.

Lower motor neuron lesion

Causes hypernasality and nasal emission in speech.

Flaccid dysarthria

Primarily affects respiration and phonation subsystems.

Hyperkinetic dysarthria

Commonly associated with Huntington's disease symptoms.

Myasthenia Gravis speech

Increased effort with speech deterioration over time.

Glossopharyngeal nerve (CN IX)

Damage leads to loss of taste and swallowing issues.

Ataxic dysarthria treatment

Prosody modification through pacing and rhythmic cues.

Neuromotor control of speech

Theoretical basis for understanding dysarthria development.

Trigeminal Nerve (CN V)

Involved in facial sensation and mastication.

Facial Nerve (CN VII)

Controls muscles of facial expression and taste.

Cranial Nerve IX function

Involved in swallowing and taste from posterior tongue.

Articulation breakdowns

Irregularities in speech clarity and coordination.

Respiration subsystem

Involved in airflow during speech production.

Phonation subsystem

Involves vocal fold vibration for sound generation.

Prosody

Rhythm and intonation patterns in speech.

Velopharyngeal closure

Essential for preventing nasal airflow during speech.

Speech intelligibility

Severity of clarity and understandability in speech.

Dysarthria

Speech disorder from motor control deficits.

Ataxic dysarthria

Irregular speech with excessive stress, uncoordinated.

Hyperkinetic dysarthria

Involuntary movements causing unpredictable speech interruptions.

Flaccid dysarthria

Weak muscle tone leading to breathy phonation.

Spastic dysarthria

Imprecise consonants with hypernasality.

Apraxia of speech (AOS)

Consistent speech errors, unlike dysarthria's prosodic deficits.

Hypoglossal Nerve (CN XII)

Controls tongue movement; damage causes deviation.

Glossopharyngeal Nerve (CN IX)

Taste sensation from posterior tongue; stylopharyngeus motor.

Vagus Nerve (CN X)

Controls vocal fold adduction; vital for phonation.

Cerebellum damage

Leads to ataxic dysarthria affecting speech coordination.

Broca's area

Involved in speech production and motor planning.

Supplementary motor cortex

Coordinates complex movements for speech.

Velopharyngeal port

Closure prevents hypernasal speech; controlled by CN IX, X.

Irregular articulatory breakdown

Characteristic of ataxic dysarthria.

Strained-strangled voice

Associated with spastic dysarthria.

Breathy voice

Common in flaccid dysarthria due to muscle weakness.

Monopitch

Characteristic of hypokinetic dysarthria.

Reduced loudness

Common in hypokinetic dysarthria.

Involuntary movements

Characteristic of hyperkinetic dysarthria.

Dysphagia

Difficulty swallowing, often from laryngeal muscle damage.

Motor speech subsystems

Impaired control leads to dysarthria.

Auditory feedback loops

Essential for motor learning in speech.

Prosodic deficits

Dysarthria affects rhythm and rate of speech.

Cranial nerves

Control various speech and swallowing functions.

Vocal fold adduction

Essential for voice production, controlled by CN X.

Tongue deviation

Occurs with unilateral hypoglossal nerve damage.

Laryngeal muscles

Muscles affecting voice quality and pitch.

Tongue muscles

Muscles responsible for articulation of sounds.

Facial muscles

Muscles aiding in bilabial and labiodental sounds.

Pharyngeal muscles

Muscles linked to resonance and hypernasality.

Hypokinetic dysarthria

Speech disorder often seen in Parkinson's disease.

Lee Silverman Voice Treatment (LSVT LOUD)

Therapy focusing on vocal loudness and effort.

Spastic dysarthria

Speech disorder from bilateral upper motor neuron damage.

Flaccid dysarthria

Speech disorder due to lower motor neuron damage.

Motor execution deficits

Impaired muscle activation for speech movements.

Motor control deficits

Inability to regulate ongoing speech production.

Motor coordination deficits

Disruptions in timing and synchronization of speech.

Common features of Parkinson's Disease

Monopitch, reduced loudness, increased speech rate.

Brainstem stroke effects

Impaired eye movement and severe dysphagia.

Oculomotor nerve (CN III)

Controls eye movement and pupillary reflexes.

Vagus nerve (CN X)

Involved in swallowing and voice production.

Facial nerve (CN VII)

Responsible for taste sensation in anterior tongue.

Trigeminal nerve (CN V)

Controls mastication and facial sensation.

Hypernasality

Excessive nasal resonance in speech.

Breathy voice

Soft voice quality with airflow leakage.

Strained-strangled voice

Tense voice quality with effortful speech.

Increased muscle tone

Characteristic of spastic dysarthria.

Reduced muscle tone

Characteristic of flaccid dysarthria.

Multiple Sclerosis (MS)

Can cause various types of dysarthria.

Hallmark of spastic dysarthria

Slow rate, strained voice, imprecise articulation.

Hallmark of flaccid dysarthria

Breathy voice, hypernasality, reduced loudness.

Hallmark of ataxic dysarthria

Irregular breakdown, excessive stress, scanning speech.

Hallmark of hypokinetic dysarthria

Monopitch, rapid speech, reduced loudness.