Motor Speech Disorders LIN381 Fall 2024 PDF

Motor Speech Disorders LIN381 Fall 2024 Ch. 10  Speech/Motor disorders with a Neurological basis Affects motor planning, programming, coordination, timing and execution of movement patterns used for speech production Primary motor cortex, Basal Ganglia, and Cerebellum are es...

Motor Speech Disorders LIN381 Fall 2024 Ch. 10  Speech/Motor disorders with a Neurological basis Affects motor planning, programming, coordination, timing and execution of movement patterns used for speech production Primary motor cortex, Basal Ganglia, and Cerebellum are especially important brain regions Two significant conditions affecting speech-motor mechanisms Dysarthria: disturbance of mechanisms that control speech musculature (but still may have language represented in the mind) Apraxia: inability to plan or program sensory and motor commands (higher- Basal Ganglia are a group of Fig. 10.3 level processing issue not neural structures located near damage/atrophy of musculature) center of the brain that connect circuitry, especially important for Structures of the brain important for Motor Speech Control Neurotransmitters are produced by cell body Brain has 15-20 billion and stored in the axon and released to the neurons synaptic junction where it binds to the target Speech musculature is cell (inhibiting, exciting, or modulating the innervated bilaterally (LH reaction). and RH); while limbs are controlled contralaterally Neural circuitry interacts with neurotransmitters (e.g., dopamine) which facilitate the signals Fig 10.1 going from nerve cells to target cells (e.g., muscle) Fig 10.2 Cerebellum (“little brain”) Helps coordinate movement by constantly monitoring all input received from parts of the brain and spinal cord Control circuits coordinate fine, complex motor activities like speech production Cerebellum damage results in discoordination of voluntary movement Too much alcohol consumption causes temporary impairment to cerebellum Cranial & Spinal Nerves Peripheral Nervous System (PNS) consists of 12 pairs of cranial nerves and 31 pairs of spinal nerves (see Fig. 10.8) Cranial nerves important for speech production Spinal nerves important for speech breathing (while brainstem controls basic breathing) Basal Ganglia (control circuits) regulate motor functioning through the primary motor cortex Regulates motor planning; automaticity of learned movement sequences UMN: Upper Motor Neuron system Part of the central nervous system, located in cerebral cortex Affects body structure on the opposite side of the body (contralateral) However, UMN innervates the speech mechanism BILATERALLY through cranial nerves (see Fig 10.8) LMN: Lower Motor Neuron system (final common pathway, located in brainstem, cranial nerves, spinal cord) Part of the peripheral nervous system that connects the Central Nervous System to the muscle-to-be-innervated on the SAME SIDE (ipsilateral)  Basal Ganglia or Cerebellum do not have direct connection to Lower Motor Neurons system (final common pathway) LMN lesion will not cause weakness or paralysis; but may affect coordination of movement as intended Damage to basal ganglia results in reduced or slowed movement (Parkinson’s) or abnormal movements (as with Huntington’s disease) Motor Speech Disorder: Dysarthria (most occur in adulthood) Disturbances in CNS and PNS that control muscles of speech production Dysarthria is not a language disorder because a person can have dysarthria, but still possess language structure in their minds. They may use another device to convey language when speech mechanism is disrupted. See Table 10.1 for summary of 5 types of Dysarthria; 10.2 for common etiologies Flaccid (weak muscles, fatigue quickly) Bells Palsy Spastic (movements of articulators are slowed and reduced in force; breathing challenges; strained speaking) Cerebral Palsy Ataxic (damage to cerebellum: incoordination of movement timing; difficulty with articulation and prosody; appearance of being drunk) Multiple Sclerosis Hypokinetic (reduced movements; feels stiff; articulators appear to be barely moving) Parkinson’s Disease Hyperkinetic (damage to basal ganglia) increase in slow, involuntary movements (Tremors, Tics, Dystonia: body twisting/movements) Huntington’s Disease, Tourette Syndrome Chorea: rapid and unpredictable movements (derived from Greek: Dance) including variable speech rate, irregular articulatory breakdown, prosodic abnormalities Mixed Dysarthria (Amyotrophic Lateral Sclerosis-ALS) Example of Hyperkinetic Dysarthria: Tic Disorders/ Tourette Syndrome (Ueda & Black, 2021) Characterized by sudden rapid recurrent movement (motor tics, gestures) or vocalization (vocal or phonic tics; throat clearing is most common). Spanning more than one year; onset before age of 18, usually between 3-8 yrs Premonitory urge (unpleasant sensation preceding tic) that is usually relieved by movement; mental energy that needs to be discharged; feels like the need to sneeze or scratch an itch Temporary Suppressibility (ability to voluntarily suppress tics for variable periods) Suggestibility (more likely to experience a tic when it is mentioned) Can be associated with psychiatric co-occurring conditions, or even anxiety or fatigue, or life changes Tics can be heightened when under emotional stress, fatigue, or even pleasant excitement Frequently accompanied by ADHD, OCD, anxiety, depression, ASD, sleep disorders, migraine, rage attacks, self-injurious behavior (35% of TS patients had SIB) In one study, 86% of adults with TS had lifetime presence of one of these other symptoms Ueda, K., & Black, K. J. (2021). Recent progress on Tourette syndrome. Faculty Reviews, 10. Tic Disorders/ Tourette Syndrome (Ueda & Black, 2021) Severity of tics, ADHD, OCD in childhood strongly predicts severity of tics in adulthood During COVID-19 pandemic clinicians saw an increase in tic disorder onset among adolescents Prevalence rates are difficult to establish due to symptom fluctuation and heterogeneous presentations but est. around.52-1.7% in children/adolescents (.0001% in adults); one study showed higher prevalence in males, but greater frequency/intensity in females Cause Neurological: Studies implicate cortical circuits and neurotransmitters; differences in functional connectivity; dopamine involvement; neuroinflammation (and immunological mechanisms) Genetic: Argued to have genetic basis, with odds ratio higher for first-degree relatives Toxic prenatal exposure: 35% risk increase of tic disorders in offspring of maternal smoking during pregnancy Therapeutic Intervention to reduce tics Behavioral Dopamine blocking medications, cannabis products, botox TMS (non-invasive brain stimulation is showing promising results in recent trials) Other alternative medicines (biofeedback, dietary supplements, hypnosis) have limited evidence because of the lack of randomized control clinical trials Ueda, K., & Black, K. J. (2021). Recent progress on Tourette syndrome. Faculty Reviews, 10.  Yale Global Tic Severity Scale-Revised (YGTSS): Gold standard for Tic Assessment Phonic tics include sniffling, throat clearing, blowing, coughing, hissing echolalia, coprolalia (less common; non-intentional obscene/socially inappropriate vocalization) https://www.youtube.com/watch?v=Ch8Jt1Zgnnc (12 min) https://www.youtube.com/watch?v=4y4CxSlHowY (2:30 min) https://www.youtube.com/watch?v=_ZfpJbjgCcI (Coprolalia; Graphic language; 5 adults with Tourette’s) Phonic Tics can also be a subvocalization just in the mind that is just as distressing Tourette Association of America Motor Speech Disorder: Apraxia Impairment of ability to plan or program the sensory and motor commands needed for speech production Not the result of damage to speech muscles or atrophy. It is a higher- level problem with motor control Retrieving “speech motor program from memory” Disordered articulation, slowed speech rate, prosodic disturbances Generally, follows damage to LH, motor and pre-motor areas of frontal left lobe (due to stroke or degenerative disease) Characteristics: groping attempts to find the correct articulatory position (aware of errors and try to correct; seems like stuttering at times) Wide variation in error types; many inconsistencies; but high- frequency words are produced with more accuracy (long, complex, unfamiliar words are most difficult to produce)  Speech sample of Apraxia “O-o-on... on... on our cavation, cavation, cacation... oh darn... vavation, oh, you know, to Ca-ca-caciporenia... no, Lacifacnia, vafacnia to Lacifacnion... on our vacation to Vacafornia, no darn it... to Ca-caliborneo... not bornia... fornia, Bornifornia... no, Balliforneo, Ballifornee, Balifornee, Californee, California. Phew, it was hard to say Cacaforneo. Oh darn.” Frequently say “I know it, but I can’t say it” “islands of fluency”: Sometimes expresses the word correctly right after having difficulty  Aphasia and Apraxia often co-occur but are not the same Aphasia is a language disorder, individual can’t express the word in any modality Apraxia is a motor speech disorder (individual may be able to write or type a word but not say it; or produce it correctly at a different time) Recovery: Stroke to Broca’s area (LH) Patient may present both apraxia and aphasia; some recovery may occur naturally Apraxia due to progressive neurological disease may need AAC options as recovery is unlikely Evaluation To begin, examine the oral peripheral mechanism and note the following with particular interest: (see video example 10.2) Symmetry, configuration, color, and general appearance of the face, jaw, lips, tongue, teeth, and hard and soft palate at rest Movement of the jaw, lips, tongue, and soft palate Range, force, speed, and direction of the jaw, lips, and tongue during movement Determine either directly (using instrumental methods) or indirectly (during nonspeech tasks or perceptual speech production tasks) the following: Respiratory function during speech production Phonatory initiation, maintenance, and cessation Pitch and pitch variability Loudness and loudness variability Volitional pitch–loudness variations Velopharyngeal function For adults who may have acquired apraxia of speech, the following speech production tasks will help in differential diagnosis: Imitation of single words of varying lengths Sentence imitation Reading aloud Spontaneous speech Rapid repetition of “puh,” “tuh,” “kuh,” and “puh-tuh- kuh” (or “buttercup”) Engage in repetitive tasks to see consistency of performance (Apraxia will likely show variable responses) Treatment/Management of Dysarthria For adults who have experienced a mild stroke, full recovery is possible May have to address difficulties with respiration, phonation, resonance, articulation, and prosody. Evidence is weak supporting non-speech oral motor treatments. (exercises, massage, blowing, cheek puffing, etc.) Read-aloud with pause training to take a breath can improve respiratory coordination Sometimes an abdominal binder helps with muscle weakness impairing respiratory muscles Voice amplifier Lee Silverman Voice Treatment (LSVT) is an intensive 4 week program to improve and self-monitor voice loudness Practice with (bio) feedback devices such as Electropalatogrophy (gives visual feedback on tongue placement on palate) Alphabet boards (to supplement speech) AAC technologies Treatment/Management of Apraxia (See Box 10.1) Integral stimulation (pairs visual-auditory cues to re- establish patient’s motor planning for functional words/phrases) Follows principles of motor learning (intensive, distributed practice) See video example 10.3 (woman with apraxia) Melodic Intonation therapy (MIT) Singing phrases, tapping out rhythm Believed to incorporate some right hemisphere functioning to support LH Contrastive stress (associated with more mild cases who have mostly prosodic difficulties)