CH2-Neurobases of Motor Speech & Its Disorders Flashcards
1
Q
Major Anatomic Levels of the Nervous System
A
- Supratentorial Level
- Posterior Fossa
- Spinal
- Peripheral
2
Q
Supratentorial
Anatomic, Skeleton, Meninges
A
- located above tentorium cerebelli, lateral to falx cerebri
- Skull - anterior and middle fossa
- Meninges-horizontal membrane forms upper border of posterior fossa,covers upper surface of cerebellum and separates anterior and middle fossae from posterior fossa
- Includes :
- paired frontal
- temporal
- parietal
- occipital lobes
- basal ganglia
- thalamus
- hypothalamus
- cranial nerves I (olfactory)
- cranial nerve II (optic)
3
Q
Supratentorial
Ventricular
System
A
- lateral & third ventricles
- Subarachnoid space
4
Q
Supratentorial
Vascular
System
A
- Carotid arterial system
- Opthalmic arteries
- Middle Cerebral Arteries
- Anterior Cerebral Arteries
- Vertebrobasilar system
- Posterior Cerebral Arteries
5
Q
Supratentorial
Motor Speech Disorders
A
- Apraxia of speech
- Dysarthrias
- Spastic
- Unilateral
- UMN
- Hypokinetic
- Hyperkinetic
6
Q
Posterior Fossa
Anatomic, Skeleton,
& Meninges
A
- Anatomic - Brainstem (pons, medulla, midbrain, and cerebellum)
- origin of cranial nerves III - XII (oculomotor, Trochlear, Trigeminal, Abducens, Facial, Cochleovestibular, Glossopharyngeal, Vagus, Accessory, Hypoglossal
- several represent the last neural link or final common pathway (FCP)
- Cranial nerves serving speech are part of PNS - crucial to understanding flassic dysarthria with stems from PNS, not CNS dysfunction like all other types.
- origin of cranial nerves III - XII (oculomotor, Trochlear, Trigeminal, Abducens, Facial, Cochleovestibular, Glossopharyngeal, Vagus, Accessory, Hypoglossal
- Meninges - Below Tentorium Cerebelli
7
Q
Posterior Fossa
Ventricular System
A
- Fourth Ventricle
- Subarachnoid Space
8
Q
Posterior Fossa
Vascular System
A
- Vertebrobasilar system
- vertebral arteries
- basilar artery
9
Q
Posterior Fossa
Motor Speech
Disorders
A
- Dysarthrias
- spastic
- unilateral upper motor neuron
- hyperkinetic
- ataxic
- flaccid
10
Q
Spinal
Anatomic, Skeleton & Meninges
A
- Skeleton - Vertebral Column
- begins at foramen magnum, large opening in posterior fossa
- surrounded by bony vertebral column
- 7 cervical, 12 thoracic, 5 lumbar vertebrae
- 31 pairs of spinal nerves (attached by dorsal and ventral nerve roots)
- Meninges - Spinal Meninges
11
Q
Dorsal
Roots
A
Dorsal = posterior
Posterior nerve roots that are sensory in function
12
Q
Ventral
Nerve Roots
A
- Ventral - anterior
- Ventral nerve roots are motor in function.
13
Q
Peripheral
anatomic, skeleton
& meninges
A
- Anatomic- cranial and spinal nerves
- most of cranial nerves originate in the brainstem, exit through skull and travel to muscle destinations.
- spinal nerves contain joined dorsal and ventral roots, enter peripheral level as they emerge from the vertebral column to travel to their muscle destinations.
- Skeleton -
- Face and skull
- Noncranial & nonspinal bones
- Meninges - none
14
Q
Peripheral
Ventricular
System
A
None!!
15
Q
Peripheral
Vascular System
A
- Branches of major extremity vessels
16
Q
Peripheral
Motor Speech Disorders
A
Dysarthria:
- Flaccid
17
Q
Major Functional
Longitudinal Systems
A
- neurological diagnosis begins with linking clinical signs and symptoms to one or more of major longitudinal systems of nervous system.
- Systems contain groups of structures with specific functions
- called longitudinal = activities of the system are evident over the length of nervous system (from supratentorial to the peripheral level)
- Internal Regulation System (Visceral System)
- Cerebrospinal Fluid Sstem (Ventricular System)
- Vascular System
- Consciousness System
- Sensory system
- Motor system
18
Q
Internal Regulation System
(Visceral System)
A
- represented at all major anatomic levels of nervous system.
- Includes
- hypothalamus
- parts of limbic lobe supratentorially
- reticular formation
- portions of some cranial nerves in posterior fossa
- longitudinal pathways in brainstem & spinal cord
- ganglia
- receptors & effectors at periphery.
- contains afferent & efferent components that interact to maintain homeostasis through regulation of visceral glands and organs.
19
Q
Cerebrospinal Fluid System
(Ventricular System)
A
- Comprised of:
- ventricular system and subarachnoid space
- Ventricular system - in depths of brain
- ventricles - cavities that contain CSF, produced by choroid plexuses in each ventricle.
- CSF- circulates through ventricles & subarachnoid space and absorbed by arachnoid villi in brain or leptomeninges in spinal cord subarachnoid space.
20
Q
Cerebrospinal Fluid (CSF)
function & location
A
- Function - to cushion the CNS against physical trauma
- help maintain a stable environment for neural activity.
- Location -
- supratentorial
- posterior fossa
- spinal levels
21
Q
Vascular System
A
- lifeblood of nervous system
- found within all major anatomic levels
- provides oxygen and other nutrients to neural structures and removes metablic waste from them.
- Major locus of abnormalities that can lead to MSDs.
- blood vessels that supply brainstem and cerebral hemispheres arise from aortic arch in chest.
- Bloodenters brain through:
- Carotid system
- Vertebrobasilar system
- two systems communicate with each other through channels in brainstem (Circle of Willis)
22
Q
Vascular disturbances
in
Vascular System
A
Vascular disturbances :
L or R carotid artery = Dysarthrias
L or R anterior and middle cerebral arteries = Dysarthrias
L middle cerebral artery = common cause of apraxia of speech and aphasia
vertebrobasilar system = often leads to MSDs
23
Q
Consciousness
System
A
- crucial to maintaining wakefulness, consciousness, awareness of environment, selective & sustained attention
- Malfunctions - contribute to cognitive deficits
- in language & communication
- indirectly affect motor functions, including speech
- structures- found only at supratentorial and posterior fossa levels
- includes:
- reticular formation
- ascending projection pathways
- portions of thalamus
- pathways to widespread areas of cerebral cortex
- portions of all lobes of cerebral cortex
- includes:
24
Q
Sensory
System
A
- Found in all major anatomic levels of the nervous system
- includes:
- peripheral receptor organs
- afferent fibers in cranial, spinal and peripheral nerves
- dorsal root ganglia (spinal level)
- ascending pathways in spinal cord and brain stem
- portions of thalamus
- thalamocortical connections
- sensory cortex in temporal, parietal, and occipital lobes
- includes:
- special sensory systems such as hearing and vision, are also located at peripheral, posterior fossa, and supratentorial levels
25
Q
The Motor System
A
- present at all major anatomic levels of nervous system
- directly responsible for all motor activity involving striated muscle
- Includes:
- efferent connections of cortex, esp. frontal lobes
- basal ganglia
- cerebellum
- related CNS pathways
- descending pathways to motor nuclei of cranial and spinal nerves
- efferent fibers within cranial and spinal nerves
- striated muscle
- Essential to : normal reflexes
- maintaining normal muscle tone & posture
- planning, control and executions of voluntary movement (incl. speech)
- Lesions in nonmotor areas of nervous system can produce alterations in speech by indirect effects on motor system.
26
Q
Localizing Nervous System Disease &
Determining Its Course
A
- neurologic signs and symptoms generally reflect the location of a lesion, not necessarily its specific cause.
- Disease can be localized on the basis of history and clinical examination.
- Broad Categories for describing localization & history of disease
- Localization
- Focal
- Multifocal
- Diffuse
- Development
- Acute
- Subacute
- Chronic
- Evolution
- Transient
- Improving
- Progressive
- Exacerbating-remitting
- Stationary (or chronic)
51
Q
Trigeminal
Nerve
V
A
- largest of cranial nerves
- sensory functions -
- transmission of pain
- thermal & tactile sensation from face and forehead
- mucous membranes of nose and mouth
- teeth
- portions of cranial dura
- conveys deep pressure and kinesthetic information from teeth, gums, hard palate and temporomandibular joint & jaw
- innervates:
- muscles of mastication & mylohyoid
- anterior belly of digastric
- tensor tympani
- tensor veli palatini muscles
-
Effects of damage:
- LMN lesions of masticatory nucleus/axons = paresis/paralysis and eventual atrophy of masticatory muscles on paralyzed side
- Unilateral trigeminal nerve lesions = no major effects on speech
- Bilateral lesions = devastating; jaw hangs open, cannot be closed, moves with limited range–>preventing facial, bilabial & lingual articulatory movements from achieving accurate place & manner of articulation.
52
Q
Facial Nerve
VII
A
- paired; mixed motor and sensory nerve
- motor component - supplies muscles of facial expression & stapedius muscle (only clear role in speech)
- sensory component - innervate submandibular, sublingual, lacrimal glands, taste receptors on anterior 2/3 of tongue, & nasopharynx
-
Effect of Damage-
-
LMN lesions - weaken or paralyze muscles of entire ipsilateral side of face
- affects all voluntary, emotional, & reflex movements
- atrophy = facial asymmetry; fasciculations in perioral area & chin
-
LMN lesions - weaken or paralyze muscles of entire ipsilateral side of face
53
Q
Vagus Nerve
X
A
- paired; complex & lengthy
- mixed motor & sensory nerve
- important functions for speech
- Motor functions include innervation of :
- striated muscles of soft palate
- pharynx
- larynx
- Sensory role:
- transmission of sensation from same motor structures
- Additional functions:
- parasympathetic innervation to & sensation from thorax and abdominal viscera
- sensory innervation from external auditory meatus & taste receptors in posterior pharynx
-
3 branches relevant to speech - at exit from skull through jugular foramen
- pharyngeal branch - responsible for pharyngeal constriction & retraction and elevation of soft palate during velopharyngeal closure for speech and swallowing.
-
superior laryngeal nerve branch -
- internal - sensory; carries sensation from mucous membrane linicng larynx down to level of vocal folds, epiglottis, base of tongue, aryepiglottic folds & dorsum of arytenoid cartilages; transmits info from muscle spindles and stretch receptors to larynx
- external- supplies inferior pharyngeal constricor & cricothyroid muscles; especially important for phonation; cause cricothyroid lengthens voal folds for pitch adjustments.
-
recurrent laryngeal branch - doubles back on itself before reaching larynx
- responsible for laryngeal sensory & motor activiites involved in phonation & swallowing
-
Effects of damage - effects depend on branch of nerve where damage is
- all branches - weakness of soft palate, pharynx, larynx
- Unilateral LMN lesions - affects resonance, voice quality, and swallowing but usually affect phonation more prominantly than resonance
-
Bilateral LMN lesions - devastating effects on resonance & phonation
- secondary significant effects on prosody and precision of articulation
- swallowing may be significantly impaired
54
Q
Accessory Nerve
XI
A
- also called spinal accessory nerve
- has cranial and spinal portion
- cranial - contributes fibers to uvula, levator veli palatini & intrinsci laryngeal muscles, while intermingled with vagus nerve fibers
- spinal - innervates sternocleidomastoid & trapezius muscles
-
Effects of damage -
- Foramen magnum area lesions (where ascending nerve enters skull) or Jugular foramen (where it exits skull) = weakens head rotation toward side opposite of leasion (sternocleidomastoid weakness)
- also reduces ability to elevate or shrug shoulder on side of lesion
- Foramen magnum area lesions (where ascending nerve enters skull) or Jugular foramen (where it exits skull) = weakens head rotation toward side opposite of leasion (sternocleidomastoid weakness)
55
Q
Hypoglossal Nerve
XII
A
- paired motor nerve
- innervates all intrinsic and all but one of the extrinsic muscles of tongue (exception is palatoglossus, supplied by vagus nerve).
-
Function: receives taste and tactile information from nucleus of tractus solitarius & sensory trigeminal nucleus
- important for speech, chewing, swallowing & sucking
-
Effects of damage:
- atrophy, weakness, & fasciculations of tongue on side of lesion
- unilateral weakness = tongue deviates to side of lesion when protuded.
60
Q
Cerebellar Control Circuit & Speech-
Structures
A
- Two components:
- flocculonodular lobe - has primary connections to vestibular mechanism for modulating equilibrium & orientation of head & eyes
- primary function - control of eye movement
- body of cerebellum includes:
- midportion (vermis)
- lateral cerebellar hemispheres
- both can be subdivided into anterior and posterior lobes
- anterior - projection area for spinocerebellar proprioceptive information; important for regulating posture, gait, and truncal tone
- posterior lobe- hemispheres important for coordinating skilled, sequential voluntary muscle activity.
- Somatotopic organization invuding of speech structures (lips & tongue) is evident in portions of both lobes
- each hemisphere is connected to contralateral thalamus & cerebral hemisphere - each helps control movements on ipsilateral side of body.
- flocculonodular lobe - has primary connections to vestibular mechanism for modulating equilibrium & orientation of head & eyes
-
Purkinje cells - output neurons of cerebellar cortex;
- purkinje cell axons synapse deep cerebellar nuclei, structures form whih cerebellar output departs through the peduncles
- nuclei includes: dentate, globose, emboliform and fastigial nuclei
- Dentate - important for speech; active in initiating movement, executing preplanned motor tasks, and regulating posture
- damage: associated with persisting dysarthria
- Dentate - important for speech; active in initiating movement, executing preplanned motor tasks, and regulating posture
62
Q
Cerebellar Control
Circuit -
Effects of Damage
A
- Flocculonodular lesions - truncal ataxia (inability to stand or sit without swaying or falling), gait disturbances, nystagmus (repetitive, jerky eye movements), & other ocular movement abnormalities
- Lesions of caudal vermis - gait ataxia
- Lesions in lateral and paravermal cerebellar hemisperes - associated with intention tremor & incoordination of voluntary movements
- incoordination reflected in dysmetria (impaired estimation of range of motion)
- dyssynergy or decomposition of movement (parts of movement are produced in segmented sequences instead of smoothly)
- dysdiodokinesia (abnormal timing & velocity of alternate movements)
- lesions affect limb movements (limb ataxia) and can lead to dysarthria.
- effects on speech of cerebellar lesions = inccordination & hypotonia (ataxic dysarthria)
- Bilateral Vermis/cerebellar hemisphere damage or cerebellar output pathways in brainstem = more serious consequences for speech than damage elsewhere in circuit.
