Neurogenic Speech Disorders Final

Eighty key vocabulary terms drawn from the lecture notes on neurogenic motor speech disorders, each paired with a concise definition to support exam preparation.

Akinetic Mutism

Profound apathy and lack of initiative resulting in little or no spontaneous movement or speech, usually from frontal-limbic damage.

Alternating Motion Rates (AMRs)

Rapid, repetitive articulatory movements (e.g., /pʌpʌpʌ/) used to gauge speed and regularity of speech movements.

Amyotrophic Lateral Sclerosis (ALS)

Progressive degeneration of upper and lower motor neurons, typically producing a mixed flaccid-spastic dysarthria.

Anarthria

Complete or near-complete loss of intelligible speech due to severe neuromuscular impairment.

Apraxia of Speech (AOS)

Impaired capacity to plan or program sensorimotor commands for phonetically and prosodically normal speech, despite intact basic motor abilities.

Aprosodia

Loss or impairment of prosodic features (intonation, stress, rhythm) often from right-hemisphere damage.

Ataxic Dysarthria

Speech disorder from cerebellar control-circuit damage causing incoordination, irregular breakdowns, and “drunken”-sounding speech.

Athetosis

Slow, writhing, purposeless involuntary movements that flow into one another.

Basal Ganglia Control Circuit

Subcortical loop (basal ganglia–thalamus–cortex) that generates motor programs and stabilizes posture; dysfunction yields hypo- or hyperkinetic dysarthrias.

Bell's Palsy

Acute idiopathic facial nerve (CN VII) paralysis, often linked to latent herpes virus.

Biopercular Syndrome

Severe dysarthria or mutism from bilateral damage to the rolandic operculum.

Bradykinesia

Slowness of movement initiation and execution, typical in Parkinsonian disorders.

Cerebellar Control Circuit

Network that times, scales, and sequences movements; damage leads to ataxic dysarthria.

Chorea

Rapid, unpredictable, dance-like involuntary movements; hallmark of Huntington’s disease.

Corticobasal Degeneration (CBD)

Asymmetric neurodegenerative disease with apraxia, rigidity, and mixed dysarthria.

Corticobulbar Tract

Direct activation fibers from cortex to brainstem cranial-nerve nuclei controlling skilled speech movements.

Corticospinal Tract

Direct activation pathway from cortex to spinal nerves controlling skilled limb and trunk movement.

Conversion Disorder

Psychological conflict manifests as physical symptoms (e.g., aphonia) without organic cause.

Darley, Aronson, and Brown (DAB) Approach

Foundational auditory-perceptual classification that links speech characteristics to lesion sites in dysarthria.

Deep Brain Stimulation (DBS)

Implanted electrodes deliver pulses (e.g., to STN, GPi) to treat tremor, dystonia, or Parkinsonian speech deficits.

Demyelinating Disease

Disorders (e.g., MS, Guillain-Barré) causing myelin loss and impaired conduction, often producing mixed dysarthrias.

Direct Activation Pathway (Pyramidal Tract)

UMN system mediating finely controlled, voluntary movement via corticobulbar and corticospinal tracts.

Dyskinesia

Generic term for abnormal involuntary movements, including drug-induced tardive dyskinesia.

Dysmetria

Cerebellar sign of overshooting or undershooting movement targets.

Dysphonia

Any impairment of voice quality, pitch, or loudness.

Dystonia

Sustained muscle contractions causing abnormal postures or repetitive movements.

Echolalia

Unsolicited repetition of another’s utterances, linked to diffuse cortical or severe aphasic pathology.

Essential Voice Tremor

Rhythmic oscillation of vocal folds producing voice tremor, often with limb/head tremor.

Factitious Disorder

Intentional feigning of illness for psychological gain (sick-role), without external incentives.

Fasciculations

Visible, brief muscle twitches signifying LMN disease.

Fibrillation

Invisible, spontaneous contractions of denervated muscle fibers detected by EMG.

Final Common Pathway (FCP)

Lower motor neurons, neuromuscular junctions, and muscle fibers—the last link between CNS and muscle.

Flaccid Dysarthria

Speech disorder from LMN or motor-unit damage, marked by weakness and hypotonia.

Guillain-Barré Syndrome (GBS)

Acute autoimmune demyelinating neuropathy causing rapid weakness, frequently affecting speech and respiration.

Hemiballismus

Violent, flailing unilateral limb movements due to subthalamic nucleus lesion.

Huntington's Disease (HD)

Inherited neurodegenerative disorder with chorea, dementia, and hyperkinetic dysarthria.

Hyperkinetic Dysarthrias

Dysarthria group with irregular, unpredictable involuntary movements from basal ganglia dysfunction.

Hypokinetic Dysarthria

Dysarthria linked to dopamine-deficient basal ganglia, featuring reduced loudness, monopitch, rapid rate, and rigidity.

Hypotonia

Reduced muscle tone or resistance to passive movement, seen in LMN or cerebellar lesions.

Indirect Activation Pathway (Extrapyramidal Tract)

UMN system that modulates reflexes, posture, and tone via multisynaptic brainstem/basal ganglia routes.

Lee Silverman Voice Treatment (LSVT)

Intensive program for Parkinsonian hypokinetic dysarthria that uses high-effort loud phonation to recalibrate vocal output.

Locked-in Syndrome (LiS)

Quadriplegia and anarthria with preserved consciousness and vertical eye movement, usually from ventral pontine infarct.

Lower Motor Neuron (LMN)

Neuron directly innervating muscle; damage causes flaccid weakness, atrophy, and fasciculations.

Malingering

Deliberate fabrication of symptoms for external incentives (money, avoidance of duty).

Medialization Laryngoplasty (Type I Thyroplasty)

Framework surgery that medializes a paralyzed vocal fold to improve glottal closure and voice.

Melodic Intonation Therapy (MIT)

Treatment that uses melody, rhythm, and stress to facilitate speech in severe aphasia or AOS.

Motor Speech Disorders (MSDs)

Neurologic disorders affecting motor control of speech, encompassing dysarthrias and apraxia of speech.

Motor Speech Programmer (MSP)

Hypothesized left-hemisphere network that organizes and sequences neuromotor commands for speech.

Multiple Sclerosis (MS)

Acquired CNS demyelinating disease often producing mixed ataxic-spastic dysarthria.

Multiple System Atrophy (MSA)

Degenerative disease with parkinsonian, cerebellar, and autonomic features, leading to mixed dysarthrias.

Muscular Dystrophy (MD)

Inherited progressive muscle-fiber degeneration that can cause flaccid dysarthria.

Myasthenia Gravis (MG)

Autoimmune disorder of neuromuscular junction causing fatigable weakness and flaccid dysarthria.

Myoclonus

Sudden, brief lightning-like jerks from muscle contraction or inhibition; can affect speech muscles.

Neurofibromatosis (NF)

Genetic disorder producing peripheral or central tumors that may cause flaccid dysarthria.

Neurogenic Mutism

Absence of speech due to severe dysarthria, apraxia, aphasia, or diminished drive/awareness.

Neurogenic Stuttering (NS)

Acquired dysfluency (repetitions, prolongations) stemming from CNS damage rather than developmental origins.

Nonverbal Oral Apraxia (NVOA)

Inability to perform volitional oral movements (e.g., cough) despite intact comprehension and strength.

Palatal Lift Prosthesis

Device that elevates a weak soft palate to improve velopharyngeal closure and resonance.

Palatopharyngolaryngeal Myoclonus (PM)

Rhythmic jerks of soft palate, pharynx, and larynx causing voice tremor.

Palilalia

Compulsive repetition of words/phrases with fading loudness and accelerating rate; basal ganglia related.

Parkinson's Disease (PD)

Dopamine-depleting neurodegenerative disorder causing tremor, rigidity, bradykinesia, and hypokinetic dysarthria.

Progressive Bulbar Palsy (PBP)

Motor neuron disease primarily affecting LMNs of cranial nerves, leading to flaccid dysarthria and dysphagia.

Progressive Supranuclear Palsy (PSP)

Degenerative disease with gaze palsy, axial rigidity, and mixed spastic-hypokinetic-ataxic dysarthria.

Pseudobulbar Affect

Involuntary, inappropriate laughing or crying episodes due to bilateral UMN lesions.

Psychogenic Speech Disorders (PNSDs)

Speech impairments of psychological or nonorganic origin that can mimic neurogenic conditions.

Rigidity

Non-velocity-dependent hypertonia with resistance to passive movement, typical in basal ganglia disorders.

Sequential Motion Rates (SMRs)

Rapid sequences of different articulatory gestures (e.g., /pʌtʌkʌ/) assessing planning and sequencing.

Somatization Disorder

Multiple physical complaints without clear medical cause, beginning before age 30.

Spasmodic Dysphonia (SD)

Laryngeal dystonia causing strained-strangled (adductor) or breathy (abductor) voice interruptions.

Spastic Dysarthria

Speech disorder from bilateral UMN damage yielding spasticity, strained voice, and slow, regular AMRs.

Supplementary Motor Area (SMA)

Frontal-lobe region critical for movement preparation; lesions can reduce or abolish speech output.

Tardive Dyskinesia (TD)

Involuntary orofacial movements arising after long-term antipsychotic use.

Traumatic Brain Injury (TBI)

Penetrating or closed-head trauma producing various, often mixed, dysarthrias.

Tremor

Rhythmic oscillatory movement; may be resting, postural, action, or terminal.

Unilateral Upper Motor Neuron (UUMN) Dysarthria

Dysarthria reflecting unilateral UMN damage, chiefly affecting articulation and phonation.

Upper Motor Neuron (UMN)

Cortical or brainstem neurons that modulate LMNs; damage causes spasticity and loss of skilled movement.

Vascular Parkinsonism

Parkinsonian features due to vascular lesions in basal ganglia/white matter, often levodopa-resistant.

Wallenberg's Lateral Medullary Syndrome

Brainstem stroke causing ipsilateral cerebellar signs and CN IX/X involvement with dysarthria/dysphagia.

Wilson's Disease

Inherited copper-metabolism disorder affecting basal ganglia and cerebellum, causing mixed dysarthria.

Auditory-Perceptual Assessment

Clinician’s systematic listening that remains the primary and most salient tool for diagnosing MSDs.

Instrumental Analyses

Acoustic, physiologic, or imaging measures (e.g., EMG, MRI) that quantify and visualize speech processes.

Intelligibility, Comprehensibility, and Efficiency (ICE)

Outcome measures describing how well speech is understood, in context, and with what effort or speed.