unit 1 Flashcards
Apraxia of Speech
neurologic disorder that reflects an impaired ability to plan or program movements for speech
dysarthria
collective name for group of neurologic speech disorders*, reflect abnormalities in strength, speed, range, steadiness, tone, or accuracy of speech movements
CNS (composed of what?)
brain and spinal cord
PNS (composed of what?)
cranial, spinal, and peripheral autonomic nerves
strong membranes (meninges) anchor the brain and spinal cord to the skull and vertebrae
dura mater, arachnoid, pia mater
spaces around the meninges
epidural, subdural, subarachnoid spaces
diseases capable of producing MSDs involving meninges and spaces stem from what?
infection, venous vascular disorders, hydrocephalus, or trauma w/ hemorrhage & edema
tracts
bundles of axons following similar path
nuclei
functionally related nerve cell clusters
damage in response to ischemia (deprivation of o2… ex/ stroke)
2-5 mins.. may be acute swelling of neurons followed by shrinkage, then cell loss
damage in response to motor neuron diseases
degeneration of motor neurons (ex/ ALS, progressive bulbar palsy)
damage in response to demyelinating disease
myelin is attacked/broken down; MS, guillain-barre syndrome
CNS structures
diencephalon, basal ganglia, brainstem, cerebellum, spinal cord
diencephalon structures
thalamus, hypothalamus, epithalamus
thalamus
integrates sensation from all sensory systems (except olfaction); also serves motor and autonomic fx’s
hypothalamus
controls emotional bx (rage, aggression); regulates body temp; controls pituitary gland & hormone release
basal ganglia structures
caudate nucleas, putamen, globus pallidus, substantia nigra, subthalamic nucleus,
basal ganglia fx’s for motor activity depend on balance of…
neurotransmitters (acetylcholine, dopamine, gammaaminobutric acid)
ex’s of basal ganglia
- regulate & control motor movements and muscle tone
- initiate movement
- give expression to motor movements
- influence posture
- automatic & skilled movements
- facilitate wanted movements
- inhibit unwanted movements
results of damage to basal ganglia
- difficulty initiating/restricted voluntary movements
- muscular rigidity, tremor, gait,
- hypokinetic dysarthria
- hyperkinetic dysarthria
hypokinetic dysarthria
rigidity, difficulty initiating movement (Parkinsons)
hyperkinetic dysarthria
involuntary movements (chorea athetosis
basic expressive comm. model (5 levels)
1) cognitive/conceptualization
2) lingustic (lang.) planning
3) motor planning/programming
4) speech production
5) feedback
3 types of motor acts
1) autonomic (beating of heart)
2) reflexes (automatic responses)
3) voluntary (speaking, walking)
acquired apraxia
lesion to broca’s or surrounding FL, CVA is common cause; characterized by groping & short automatic speech
CAS
motor planning deficit, no lesion, often difficult pregnancy/birth,
speech characteristics of CAS
groping, better short speech, young- even easy phonemes /b, m, p/ errors
speech characteristics of acquired apraxia
\groping & short automatic speech
UMNs
stay w/in CNS, originate in cerebral cortex & descend to cranial nerve nuclei in brain stem or ventral horn of spinal cord
Are UMNs part of direct or indirect motor pathways?
both!
where are synapses in coricospical tract?
1 synapse (monosynaptic) w/ spinal verves via motor nuclei in spinal cord
where are synapses in corticobulbar tract?
synapse is w/ cranial nerve nuclei at different levels of brain stem
corona radiata
fanlike mass of fibers from coricobulbar and corticospinal tracts; in basal ganglia/thalamus; converges into compact band known as internal capsule
UMN innervation
primarily bilateral (except lower face and some degree of tongue)
Why is unilateral UMN damage not as profound as with LMN lesions?
because UMNs have bilateral innervation… weakness is on opposite side of body in this type of damage
two loops
basal ganglia control circuit & cerebellar circuit
lesion in cerebellar results in
poor coordination
damage to indirect pathway results in
reflexes and spasticity
bilateral innervation occurs in these cranial nerves
vagus, trigeminal, and upper facial
unilateral innervation
lower 7 ; hypoglossal
Where does damage occur for flaccid dysarthria?
damage to cranial nerves, LMNs, or at neuromuscular junction
characteristics of flaccid dysarthria
weakness, muscles will atrophy over time… the system affected will depend on nature of disorder (ex/ peripheral trauma may only affect larynx or lower face)
