Exam 1 Flashcards
neurologic process of speech production involves:
cognitive-linguistic process, motor speech programming, neuromuscular execution
cognitive-linguistic process
aspect of speech production involving an intention to communicate which is organized into the verbal symbols that follow the rules of language
motor speech programming
intended communication that has to be executed by the neuromuscular system. speaker selects and organizes the sensorimotor programs that cause the appropriate speech muscles to be activated at the right time
neuromuscular execution
the CNS and PNS innervate the necessary muscles of respiration, phonation, articulation, and resonance to produce desired words
def. of motor speech disorders
speech disorders resulting from neurologic impairment affecting the motor programming or neuromuscular execution of speech
what do motor speech disorders encompass?
apraxia of speech and the dysarthrias
what is dysarthria?
group of motor speech disorders resulting from disturbances in muscular control over the speech mechanism due to damage to CNS or PNS; results in paralysis, weakness, or incoordination of speech muscles
what subsystems can dysarthria affect?
ALL; respiration, phonation, resonance, artic, prosody
what is apraxia?
Neurogenic speech disorder resulting from impairment of the capacity to program sensorimotor commands for the positioning and movement of muscles for volitional production of speech. Occurs in the absence of weakness.
what subsystems can apraxia affect?
artic and prosody
what are the courses of the disease?
transient, improving, progressive, exacerbating-remitting, stationary
what are the 3 developments of symptoms?
acute (within minutes), subacute (within days), chronic (within months)
what does the cerebrum consist of?
4 lobes, cortex, gyri, sulci
what does the cerebellum do?
modifies cortical activity
what are the lobes of the cerebellum?
anterior, posterior, flocculonodular
what is the midportion of the cerebellum?
vermis
what does the brainstem consist of?
midbrain, pons, medulla
what does the midbrain do?
links cerebrum to brain stem
what does the pons do?
bridges to cerebellum
what does the medulla do?
controls respiration
what are the four main anatomical levels of the CNS?
supratentorial, posterior, spinal, peripheral
what is the supratentorial level made up of?
anterior and middle fossae, all 4 lobes, basal ganglia, thalamus, hypothalamus, CN I and II
what is the posterior level made up of?
posterior fossa, brainstem, cerebellum, CN III-XII
what are foramina?
holes in fossae where CN exit the skull
spinal anatomic level?
spinal cord begins at lower end of medulla, surrounded by bony vertebral column. ends at first lumbar vertebrae
peripheral anatomic level?
made up of 12 paiars of CN and 21 pairs of SN which exit through foramina
where do CN emerge from?
brain stem and penetrate skull through foramina to reach sensory-motor targets
what are the three layers of the meninges?
dura mater (outer membrane), arachnoid mater (loosely covers brain), pia mater (innermost layer, closely attached to surface of brain)
what are the spaces around the meninges?
epidural space (between dura and bone), subdural space (beneath dura), subarachnoid space (beneath arachnoid)
which of the three spaces around the meninges can develop infections?
subdural space
what is the subarachnoid space filled with?
CFS, connected to inner part of brain via ventricular system
what are the 6 neurologic systems?
ventricular, vasular, sensory, motor, consciousness, neurochemical
what are ventricles filled with?
cavities filled with CSF which cushions the brain
what are ventricles produced by?
choroid plexuses
are choroid plexuses found in each ventricle?
YES
what is the ventricular system made up of?
paired lateral ventricles in each hemisphere, third ventricle between 2 thalami, and 4th ventricle
what does the vascular system involve?
blood vessels which provide oxygen and nutrients to structures and removes waste
what two arterial systems does the brain receive blood from?
carotid and vertebral basilar system
where do the carotid and vertebral basilar system join?
the Circle of Willis at base of brain
what does the neurochemical system influence?
all anatomic levels of the nervous system
what does the neurochemical system include?
amino acids, ACH, neuropeptides
what is the consciousness system important for?
maintaining consciousness, attention, and awareness of environment
what structures does the consciousness system involve?
those found at the suprtentorial and posterior fossae level
what is the motor system responsible for?
all motor activity for speech
what does the motor system include?
efferent connection to cortex, basal ganglia, cerebellum, CNS/PNS pathways
what does the sensory system include?
peripheral receptor organs
nerves
collection of many nerve fibers (axons). Cell bodies stay in CNS, nerves travel between cell bodies and peripheral end organ to be innervated.
neurons
dendrites/axons projections. Axons end in synapses which release neurotransmitters. AcH is an important neurotransmitter in neuromuscular synapses. Release of AcH results in contraction of muscle fiber.
what are groups of fibers called in PNS?
nerves
what are groups of fibers called in CNS?
pathways/tracts
in PNS, where is the impulse carried?
to the end organs
what is a motor unit made up of?
axon and the muscle fiber it innervates
name and describe the supporting (glial) cells?
oligdendroglia cells (form myelin in CNS), schwann cells (form myelin in PNS), astrocytes (found in CNS, part of blood-brain barrier, keeps toxins out and nutrients in)
what diseases attack myelin?
multiple sclerosis and Guillain Barre disease
what happens in LMN innervation to muscle is lost?
muscle will atrophy
what happens if axons become separated from cell body?
motor speech problems
disruption in blood supply causes what?
neuron can be damaged due to lack of oxygen (ischemia)
what does the thalamus do?
acts as relay station, helps to mediate speech, language, and cognitive function
where is the basal ganglia located?
deep inside cerebrum
what does the basal ganglia consist of?
globus pallidus, striatum (putamen, caudate nucleus), lentiform nucleus (globus pallidus, putamen), substantia nigra, subthalamic nuclei
what is the reticular formation part of?
brain stem; important for motor control
where are the substantia nigra and subthalamic nuclei primarily located?
midbrain; important for motor control
what are the different localizations of neurologic lesions?
focal, mulitfocal, diffuse
what are the etiologies of motor speech disorders? (broad categories)
degenerative (gradual decline in neuronal function), inflammatory (meningitis), toxic (metabolic dz, vitamin deficiencies), neoplastic (tumors), traumatic (car accidents), vascular (CVA, neurons deprived of oxygen)
what are motor neurons?
nerve cells involved in motor movement
where do motor neurons originate?
brain stem or spinal cord from a cranial or spinal nerve
what are motor neurons also called?
lower motor neurons
describe what happens to the axons on lower motor neurons?
they leave cell bodies and travel to specific muscles; they subdivide into branches that connect with muscle fibers; can innervate several muscle fibers; each fiber may receive input from branches of different motor neurons
what happens to LMN without proper innervation?
muscles atrophies; may result in fasciculations
upper motor neurons
cell bodies in motor cortex and their descending axonal processes that synapse on cranial and spinal motor neurons
lower motor neurons
motor nuclei through which CNS sends impulses to muscles and glands
where do UMN originate?
upper brain levels
where do LMN originate?
brainstem or spinal cord
what are the four main parts to speech motor system?
final common pathway, direct activation pathway, indirect activation pathway, control circuits
what is the FCP also called?
LMN system or PNS
why is it called the FCP?
the last link in sequence of motor events that lead to motor movement and all other components have to go through it
what 2 nerves have unilateral innervation?
facial nerve VII to lower face and hypoglossus nerve XII to genioglossus
unilateral lesion is UMN, where does the structure deviate to ?
contralateral to side of lesion
unilateral lesion is LMN, where does the structure deviate to?
ipsilateral to side of lesion
if the lesion is bilateral, what is the result?
decreased ROM and strength
what 2 tracts make up the UMN system and DAP?
corticobulbar and corticospinal
where does the corticobulbar tract originate and terminate?
originates: cortex; mainly at primary motor cortex
terminates: brainstem at level of cranial nerve nuclei involved with speech
where does the corticospinal tract originate and terminate?
originates: cortex
terminates: level of spinal nerve nuclei
where do the corticobulbar and corticospinal tracts descend through?
descend from cortex, through corona radiata and internal capsule in brainstem
what is the DAP important for?
controlled skilled, discrete, and often rapid voluntary movements in speech
with UMN unilateral lesion, where is the weakness typically?
on the opposite side of the body
what do control circuits do?
integrate or help control the structures and pathways involved in motor movement
do control circuits have direct contact with LMN?
NO
what are the 2 control circuits?
Basal ganglia and cerebellum
what does the basal ganglia depend on?
balance among neurotransmitters (AcH, dopamine, GABA) for aiding motor activity
what does the basal ganglia provide input to?
cerebral cortex to coordinate motor movement
what is the basal ganglia involved in?
regulating muscle tone and maintaining normal posture
what can damage to the basal ganglia cause?
hypokinetic and hyperkinetic dysarthria
what does the cerebellum do?
integrates and coordinates movements for speech, including timing, size of muscular action and sequences of movement to provide smoothly flowing well-timed coordinated speech
what does damage to the cerebellum cause?
ataxic dysarthria
flaccid dysarthria is a lesion where?
LMN system
With the LMN system, it only takes one lesion to wipe out the function because it all comes together in the LMN system. True or false?
TRUE
what is the primary deficit in flaccid dysarthria?
weakness to muscles
what is a result of the palate being too weak to close?
hypernasality
what does UMN damage usually result in?
spastic dysarthria
what happens when all of the LMN input is lost to a muscle?
paralysis (partial loss leads to paresis)
what are defining characteristics of flaccid dysarthria?
hypotonia and weak reflexes, atrophy, fasciculations, fibrillations, progressive muscle weakness
what neuromuscular junction disease cause the muscle to fatigue quickly when used?
myasthenia gravis
what are etiologies of flaccid dysarthria?
neuromuscular junction disease,vascular disorders, infectious processes, demyelinating disease, muscle disease, degenerative disease, anatomic anomalies, radiation treatment
what is myasthenia gravis?
chronic disease characterized by rapid weakness in voluntary movement of muscles and improvement with rest; AcH receptors are destroyed so receptors aren’t receptive to AcH which triggers muscle contraction
with rest, muscle functions normally
what test is given for myasthenia gravis?
tensilon: injections of this after pt shows signs of fatigue when talking
what are examples of vascular disorders?
brain stem stroke, Wallenberg’s lateral medullary syndrome
what is an example of an infectious process?
polio (LMN cell bodies get infected)
what are examples of muscle diseases?
muscular dystrophy, genetic, inherited, and degenerative (muscle fibers degenerate)
what is an example of a degenerative disease?
motor neuron disease, ALS
what are examples of anatomic anomalies?
arnold chiari malformation (congenital)-results in distortion of brain stem which can result in impairment of cranial nerves
what is an example of a multiple cranial nerve lesion?
bulbar palsy (can be caused by other etiologies)
what are the best distinguishing features of flaccid dysarthria according to Duffy?
hypernasality, nasal emission, continuous breathiness, audible inspiration, isolated articulatory imprecision, atrophy, fasciculations, diplophonia
