Neurogenic Communication Disorders 1 2024 PDF

Neurogenic Communication Disorders I CSD 4411a Introduction to Speech and Language Disorders BJ Cunningham, PhD, SLP(C), Reg. CASLPO  Learning Objectives 1. Understand the neuroanatomy and physiology of the central and peripheral nervous system and explain...

Neurogenic Communication Disorders I CSD 4411a Introduction to Speech and Language Disorders BJ Cunningham, PhD, SLP(C), Reg. CASLPO  Learning Objectives 1. Understand the neuroanatomy and physiology of the central and peripheral nervous system and explain their relationship to speech and language 2. Differentiate and describe the characteristics of the major neurogenic speech disorders 3. Explain the etiologies of the major neurogenic speech disorders Neuroanatomy  Overview 1. Nervous System Anatomy & Physiology 2. Neurogenic Communication Disorders i. Acquired/motor speech disorders ii. Aphasia iii. Cognitive-communication disorders Nervous System Anatomy & Physiology A. Central Nervous System – Brain and spinal cord B. Peripheral Nervous System – Nerves that connect body to brain and spinal cord  A. Central Nervous System Brain enables high-level functions – Damage can lead to many types of communication disorders Brainstem and spinal cord provide sensory and motor pathways between body and brain – Damage can disrupt biological support for speech 1. Brain 2. Central nervous system (brain and spinal cord) 3. Spinal cord  Image is for A. Central Nervous System illustrative purposes only Brain 1. Cerebrum Majority of brain Right and left hemispheres – Left hemisphere controls right side of the body tasks linked to language and logic – Right hemisphere controls left side of the body tasks linked to creativity, cognition  Image is for A. Central Nervous System illustrative purposes only Brain 2. Cerebellum Below cerebrum, behind brainstem Helps coordinate and regulate neural impulses Regulates balance, posture, and fine motor movements  A. Central Nervous System Know red arrow structures Cerebrum Lobes 1. Frontal ⚫ Primary motor cortex ⚫ Executive functions Parietal ⚫ Primary sensory ⚫ Cognitive functions 3. Occipital ⚫ Visual processing 4. Temporal ⚫ Primary auditory cortex ⚫ Language comprehension  A. Central Nervous System Know 4 listed structures Cortical regions of interest 1. Primary auditory cortex 2. Primary motor cortex 3. Broca’s area 4. Wernicke’s area © Psychology Press 2007  A. Central Nervous System 1. Primary auditory cortex – In temporal lobe – Bilateral – Includes Heschl’s gyrus the first area of cortex to process auditory information awareness or perception of sound  Fir illustrative A. Central Nervous System purposes only 2. Primary Motor Cortex – In frontal lobe along precentral gyrus – Bilateral – Controls muscles (including for speech)  A. Central Nervous System 3. Broca’s Area – In frontal lobe – Involved in speech production and expressive language Also plays a role in language comprehension – Unilateral In left hemisphere in most people  A. Central Nervous System 4. Wernicke’s Area – Temporal lobe, beside primary auditory cortex – Involved in language comprehension Also plays a role in language production – Unilateral In left hemisphere in most people  Image is for A. Central Nervous System illustrative purposes only Subcortical regions of interest 1. Basal ganglia Involved in movement Connected to cerebellum and cortex 2. Thalamus Relay area between parts of cortex Many functions, including motor and sensory  B. Peripheral Nervous System Helps CNS communicate with body 1. Cranial nerves – 12 pairs of nerves – Enter/exit brain and brainstem 2. Spinal nerves – 31 pairs of nerves – Enter/exit spinal cord Cranial Nerves  For illustrative Cranial Nerves purposes only  B. Peripheral Nervous System Spinal nerves 1. Ascending nerve tract – Sensory From glands, tissues, joints, etc. – Posterior (exit back portion of spinal cord) 2. Descending nerve tracts – Motor Innervate muscles of chest, abdomen, limbs – Anterior (exit front portion of spinal cord)  Video http://www.braininjury101.org/ (see Chapter 2) Neurogenic Speech Disorders Neurogenic Communication Disorders Usually brain-based, acquired disorder 1. Acquired motor speech disorders – Dysarthria – Apraxia 2. Acquired language disorders – Aphasia 3. Cognitive-communication disorders Distribution of Neurogenic Concepts not Communication Disorders numbers on exam  Acquired Motor Speech Disorders A. Dysarthria – Caused by weakness, paralysis, slowness, or incoordination of muscles responsible for speech – Impairment in speed, force, range, direction, or timing of motor control for speech – May also have involuntary movements or alterations in muscle tone – Different types based on lesion location within CNS/PNS – Common causes: stroke, Parkinson’s Huntington’s, ALS, cerebellar disease  Six Major Types of Dysarthria TYPE NEURAL SYSTEM INVOLVED 1. Hyperkinetic Basal Ganglia 2. Hypokinetic (Parkinson’s) Basal Ganglia (substantia nigra) 3. Spastic Brain/brainstem motor neurons 4. Flaccid Cranial nerves 5. Ataxic Cerebellum 6. Mixed ≥ 2 nervous system components  1. Hyperkinetic Dysarthria Hyperkinetic: Involuntary movements Several subtypes A. Chorea Fast, unpredictable, random and arrhythmic involuntary movements Some common causes: Huntington's disease, stroke, HIV infection Distinctive speech characteristics: variable speech rate, excess loudness variation, rapid and unpredictable consonant and vowel distortions  1. Hyperkinetic Dysarthrias Hyperkinetic: Involuntary movements Several subtypes B. Oromandibular Dystonia Slow, sustained involuntary movements and spasms of face, lips, jaw, tongue, and velum Some common causes: unknown (idiopathic), drugs, head trauma Distinctive speech characteristics: voice stoppages, voice tremor, prolonged consonant and vowel distortion  1. Hyperkinetic Dysarthrias Chorea Oromandibular dystonia https://youtu.be/U4BSZ4FlGRg https://youtu.be/ngxrfDJBBbg  Concepts, not 1. Hyperkinetic Dysarthrias numbers, on exam Several subtypes cont. C. Spasmodic Dysphonia Strained, effortful phonation or irregular voice stoppage due to hyperadduction or hyperabduction of vocal folds Cause: Unknown D. Essential Voice Tremor Rhythmic tremor in voice intensity or voice pitch, regular voice stoppages Cause: Unknown, 30% have family history  2. Hypokinetic Dysarthria Hypokinetic: reduced ability to move, rigidity, reduced range of motion, slowness Most common cause: Parkinson’s disease and related Parkinson-like disorders Distinctive speech characteristics Hypophonia (soft speech) Imprecise consonant articulation Short rushes and rapid rate of speech Monotone pitch and monoloudness  3. Spastic Dysarthria Increased tone (stiffness, tightness) in muscles with reduced fine motor control, weakness, and slowness of movement Some common causes: stroke, ALS, TBI, MS Distinctive speech characteristics – Slow rate – Low pitch – Harsh and strained-strangled vocal quality – Imprecise production and distortion of consonants and vowels  3. Spastic Dysarthria https://youtu.be/EHNSBo3SsmY  4. Flaccid Dysarthria Flaccid: Muscle weakness, reduced muscle tone Some common causes: trauma, neurosurgery, ALS, muscular dystrophy, tumour, stroke Distinctive speech characteristics – Hypernasality – Breathiness – Nasal emission – Audible inspiration 4. Flaccid Dysarthria https://youtu.be/dy8WvykiLto  5. Ataxic Dysarthria Impaired coordination of movement Some common causes: stroke, TBI, MS, brain tumours Distinctive speech characteristics – Sounds “slurred,” “intoxicated” – Imprecise consonant and vowel production – Irregular breakdown in articulation accuracy – Excess and equal stress (metering out syllables)  5. Ataxic Dysarthria https://youtu.be/7BnGxeMAM_s  6. Mixed Dysarthria Most common dysarthria type Two or more pure dysarthria types Causes – More diffuse damage than other dysarthrias – Commonly associated with degenerative disorders (e.g., ALS, MS) E.g., ALS commonly presents with spastic-flaccid dysarthria)  Dysarthria Summary Dysarthria Damage to… Motor difficulties Speech characteristics Type Hyperkinetic basil ganglia Involuntary movements (e.g., Irregular bursts of speech, tics, chorea), variable prosody, variable loudness, tremor-like voice breaks voice Hypokinetic basil ganglia Reduced range of motion, Monotone, fast rate, reduced rigidity, slowness volume, imprecise articulation Spastic motor neurons Muscle stiffness (spasticity), Harsh, strained, and slow reduced range of motion, slow speech; tight voice speech Flaccid cranial nerves Muscle weakness, reduced tone, Breathy, weak, hypernasal nasal speech, reduced volume speech with slow rate Ataxic cerebellum Lack of coordination, irregular Irregular and imprecise rhythm and rate, errors in timing articulation, drunken- sounding speech Mixed Combination of Varies based on the specific Combination of features structures combination of damaged areas  Acquired Speech Disorders B. Apraxia – Acquired neurological impairment in motor speech planning and programming – Inability to voluntarily select and program skilled motor movements for speech – Unrelated to weakness, slowness, paralysis – Speech characteristics Groping attempts and great variability Repeated attempts to correct errors Complex, long words are difficult  Apraxia of Speech https://www.youtube.com/watch? v=OPjDo03rUd0  Concepts, not numbers, on Distribution of Acquired Motor Speech Disorders exam