Impairment Oriented Neuro Exam III Flashcards
what is coordination
sequence, timing, and force production of multiple ms groups to produce smooth, accurate, and controlled movement
what is coordinated movement characterized by
appropriate:
- speed
- distance
- direction
- timing
- ms tension
what are 3 types of coordinated movement
intralimb
interlimb
visual motor
what is intralimb coordination
occurring within one limb
- ex: brushing hair, shaving
need coordination of distal and proximal working together
what is interlimb coordination
bimanual movements
integrated performance of 2 or more limbs
- ex: dressing, walking
could be arm and leg, two arms, two legs, etc.
what is visual motor coordination
ability to integrate both visual and motor abilities (driving a car)
see something and then interact w it
- including force you need d/t wt of object
what is the role of the basal ganglia in coordinated movements
nuclei that regulate initiation of gross intentional movements, and complex planning and execution
what structures are responsible for coordinated movements (4)
- basal ganglia
- DCML
- motor cortex & descending pyramidal pathways
- cerebellum
what does the DCML do in terms of coordinating movement
transmission of discriminative sensations, can cause “sensory ataxia”
what is sensory ataxia
description of movement that is uncoordinated
what is the motor cortex and descending pyramidal pathways role in coordinating movements
receives info from basal ganglia and cerebellum
what is the physio behind why you see uncoordinated movement in Parkinsons
basal ganglia is interruped by parkinsons
- freezing episodes or bradykinesia
- body has trouble starting movement
external cues help bc don’t have the internal cue from body anymore
what are 5 cerebellar functions
- coordinate the range, velocity, and strength of ms contractions to produce steady, volitional movements and postures
- equilibrium in conjunction w vestib system
- ms tone regulation
- eye-head coordination
- coordination of ms for speech
what is the cerebellum’s role in eye-head coordination
ability to keep eye on something while moving head around
how is the cerebellum coordinating the range/velocity/strength of ms contractions
gets info on how you are performing and tells you how its going
- did it feel good? or not what you wanted?
then unconsciously selects right motor plan for you
how does the cerebellum coordinate ms for speech
controls tongue and lips to help regulate how you are coordinating different sounds
information comes from which prominent motor pathways for cerebellar functions
reticulospinal
vestibulospinal
not exclusively, but most commonly found in these two
what is the cycle of information traveling for cerebellar functions
PERIPHERAL feedback: GTOs, ms spindles, joint & cutaneous receptors, peripheral vestib
–>
modulated and corrected by cerebellum
–>
CENTRAL: info from motor pathways, most commonly reticulospinal and vestibulospinal tracts
what can cerebellar functions be summarized into most simply?
vast processing power
- checks and balances
- fact checker
lets you know that everything is doing what it is supposed to be doing
what anatomic part of the cerebellum has output for balance and eye movements
vestibular nuclei
- in flocculonodular lobe
what anatomic part of the cerebellum gives output for motor planning
dentate nuclei via areas 4&6
- in cerebro-cerebellum
what anatomic part of the cerebellum gives output for motor execution
fastigial nuclei - medial descending systems
interposed nuclei - lateral descending systems
both nuclei are in the spinocerebellum
what is cerebellar ataxia
disordered movements
- umbrella term used to describe motor impairments of cerebellar origin
what side is ataxia seen on relative to the cerebellar lesion
ipsilateral
what are types of causes of cerebellar ataxia
congenital
acquired
what are congenital causes of cerebellar ataxia
infection
autoimmunity
vitamin deficiencies
what are acquired causes of cerebellar ataxia
stroke
tumors
trauma
demyelination
what is the most common sign of a cerebellar lesion
ataxic gait
what does an ataxic gait look like
dec arm swing
uneven step length
inability to alter gait w change in surface
inc or dec in BOS
staggering
variable foot placement
high movement variability
someone with cerebellar ataxia will have difficulty or a delay in what
initiating volitional movements
someone with cerebellar ataxia will have errors in
rate, rhythm, and timing of ms firing
basal ganglia vs cerebellum in initiation of volitional movements
basal ganglia - immediate initiation, gross movements, fire to start the grill
cerebellum - more motor planning and coordination of how to start the movement
- more important w complicated and fine motor movements
BOTH SYSTEMS WORK SIMULTANEOUSLY
what is a common compensation for initiation of volitional movement when a cerebellar disorder is present
use of visual system
what are 6 types of coordination impairments
dysmetria
dyssynergia
intention & postural tremors
dysdiadochokinesia
rebound phenomenon (“check reflex”)
asthenia
dysdiadochokinesia & physio behind it
dec rapid alternating movements (RAM)
- cannot sustain regular rhythm or produce an even amt of force
physio behind dysdiadochokinesia
antagonistic ms firing overlaps w agonist
dysmetria
deficit in reaching a target requires corrective movement to reach target
what is dysmetria a result of
d/t loss of direction, extent, force and timing of ms contractions
what are two types of dysmetria
hypermetria - over shoot target
hypometria - under shoot target
dyssynergia
decomposition of movement
errors in relative timing of components of complex multi-joint movements
what does dyssynergia look like
movement performed in a sequence of component parts, rather than one smooth activity
movement appears robotic and stiff
everything is a bit isolated
intention tremors
oscillation of limb w volitional movement
- most pronounced w termination phase of goal directed movement
postural tremors
oscillation of head, neck, trunk
rebound phenomenon
inability to rapidly activate an antagonist muscle when resistance is removed from agonist
aka lack of “check reflex”
what are 3 additional clinical manifestations of cerebellar pathology
hypotonia
asthenia
dysarthria
hypotonia is d/t what?
less excitation of alpha and gamma motor neurons
what is an example of hypotonia manifesting in a cerebellar pathology
pendular reflexes - oscillates 6-8 times
asthenia
generalized weakness
- differs from hypotonia
how does asthenia manifest in cerebellar pathology
excessive efforts required for tasks & c/o early fatigue
dysarthria
dec melody and rhythm of speech
how does dysarthria manifest in cerebellar pathology
grammar and words selection intact
may be nasal, soft, tremulous, staccato
not regulated (tone, enunciation)
what are non-equilibrium tests looking for when assessing coordination
ability of limbs to do something
what are examples of non-equilibrium tests for assessing coordination (7)
- finger to nose
- finger opposition
- pronation/supination
- pointing, past pointing
- heel to shin
- tapping (PF/DF)
- fixation or position holding (rebound phenomenon)
what are 6 equilibrium tests for coordination
- tandem stance
- perturbations
- romberg - EO/EC
- walking on heels or toes
- figure 8
- stop-start
what are equilibrium tests looking at when assessing coordination
plays into vestibular system
mostly looking at balance
what does the vestibular system work in conjunction with and what do they do together
visual and somatosensory systems
all yield estimates of body position and motion if intact
- all happening/processed in brain
what 3 roles does the vestibular system also play
- works w sensory and motor systems
- sensor of gravity and head acceleration
- one of nervous system’s most important tools in controlling posture
what are the 3 main components of the vestibular system
- peripheral sensory apparatus
- central processor
- motor outputs
what composes the peripheral sensory apparatus as part of the vestibular system
bony labyrinth
- part of ear system
membranous labyrinth
- within the labyrinth itself
what composes the central processor of the vestibular system
vestibular nucleus complex
- one of the CN nucleus (VIII)
cerebellum
what composes motor outputs of the vestibular system
ocular ms and SC
- vestibulo-ocular reflex (VOR)
- vestibulospinal reflex (VSR)
- vestibulocollic reflex (VCR)
what do the semicircular canals in the peripheral vestibular structures detect
rotational movements
angular acceleration
describe the orientation of semicircular canals in the peripheral vestibular structures
horizontal, anterior, posterior
how do the semicircular canals in the peripheral vestibular structures detect rotational movements?
canals filled w endolymph
head motion moves the endolymph which causes hairs at the base of canals to deflect
this produces a firing of CNVIII
brain detects direction of head movement based on direction hairs move and the firing of CNVIII
what is endolymph and how does it help detect motion
viscous fluid, when moves will drag hairs with it
causes excitation on one side and inhibition on the other
- need them both bc check each other
what are otolith organs
saccule
utricle
saccule
detects vertical linear acceleration and static head tilt
ex: on escalator / elevator as you move up or down floors
utricle
detects horizontal linear acceleration
ex: stay on same level and move in any direction
- when on that flat conveyor belt in airport
what are the 3 primary functions of the peripheral vestibular system
- stabilize images on fovea of retina during head movements (VOR)
- maintain postural stability; esp w head movements (VSR)
- spatial orientation info
describe the VOR
vestibular ocular reflex
keep your eyes on something while you move your head
if there is an issue w the VOR what could this be an indication of and what does this look like
NOT AN INDICATION OF lesion w CNS or cerebellum
could indicate lack of function/firing on one side (hypofunction)
- your eyes would go w head movement and then maybe jump back after head movement
describe the VSR
vestibulospinal reflex
how you isolate your head movements
what does spatial orientation from the peripheral vestibular system look like
are you upright, on your side, prone
what might an issue w spatial w orientation present like
walking leaning sideways
don’t know what upright is or where to be in space
what are the components for central processing of vestibular input
vestibular nuclear complex
cerebellar flocculus
what is the vestibular nuclear complex
four major nuclei in pons and medulla
primary processors of vestibular input and have fast connections to motor output neurons
what is the cerebellar flocculus’s role in processing of vestibular input
monitors vestibular performance and readjusts central vestibular processing if necessary
- telling you what is going on and if something is off, will make that adjustment if needed
what are the vestibular pathways involving the vestibular nuclei
nuclei integrate info from vestibular, visual, and somatic receptors
sends collaterals to the cerebellum
the cerebellum sends corrective adjustments to motor cortex - maintenance of balance and posture
the central vestibular system has connections with:
cortex
thalamus
reticular formation
the central vestibular systems connections w the cortex, thalamus, and reticular formation allows the vestibular system to: (3)
- contribute to integration of arousal and body awareness
- discriminate b/w movement of self and environment
- control of vestibular reflexes/motor output
what specific central vestibular system function is primarily accomplished by the reticular formation
contribute to integration of arousal and body awareness
what is the function of the VOR
maintain stable vision/gaze stability during head motion
what does the VOR work w to function successfully
works closely w ocular muscles and visual system
one of the fastest reflexes in body
- how it accomplishes this
what is the ratio of eye movement to head movement amplitude associated w VOR gain? why?
1:1
ensures equal movement of head and eyes and a stable image projected to the retina
- eye and head movement need to be in opposite direction and equal speed
is the VOR gain ratio always 1:1
in some cases the VOR will need to adapt i order to ensure proper gain
how can peripheral vestibular pathology affect VOR gain?
tonic firing rate of VOR becomes disrupted
- gain is not achieved
if the VOR isn’t intact what does your body do? how do we treat this?
cervico-ocular reflex (COR) supplements the VOR
- driven by neck proprioceptors
VOR can be trained if not intact
what is the function of the VSR
stabilize the body via compensatory movement using otolithic input
- whenever moving head or eyes, keep you from falling over and keep yourself upright
VSR vs VOR speed
VOR - one of fastest reflexes in the body
VSR - slower than VOR
- still considered primary vestibular reflex
what are examples of visual disturbance presentation
oscillopsia
diplopia
what are examples of how oculomotor dysfunction present
nystagmus
ocular dysmetria
saccadic intrusions
what are 6 clinical presentations of vestibular dysfunction
dysequilibrium - balance is off
nausea
vertigo
dizziness
visual disturbances
oculomotor dysfunction
vertigo vs dizziness
vertigo - spinning sensation
- is room spinning or are you spinning
dizziness - broad term
- lightheadedness
- fuzzy foggy
what is oscillopsia
unable to stabilize and hold gaze
- just keeps bouncing around
what is diplopia
double vision, eyes aren’t working in conjunction
- eyes should together form one image
- eyes each creating a separate image
how does someone w diplopia usually compensate? what is the issue w this?
compensate w one eye closed
- problem is you lose depth perception
depth perception is gained when two images come together
what is ocular dysmetria
constant under- or over-shooting of the eyes when attempting to focus gaze on something
- eyes work together to perceive depth/distance
what are saccadic intrusions
saccades - smooth pursuit when following an object
intrusions - will see eyes jump
what are 4 ocular tests for screening vestibular dysfunction
nystagmus
smooth pursuit
saccades
VOR/gaze stabilization
how do you test/screen for nystagmus
check for ability to fixate on target
- holding gaze
how do you test smooth pursuit
ability to follow target smoothly
- no saccadic intrusion
how do you test saccades
ability to shift gaze quickly between points
- no under-shooting or over-shooting of target
how do you test VOR/gaze stabilization
image stays clear during testing
- no visual disturbances
what are 4 ex of peripheral vestibular testing
- head shake and head thrust
- positional testing for BPPV (ex dix - hallpike)
- dynamic visual acuity test for hypofunction (ex: snellen chart)
- balance and gait evals
what is the head shake and thrust testing specifically in the peripheral vestibular systme
VOR system
- quick movements and tell them to keep looking at your nose
what are 2 tests used in a central vestibular exam
VOR cancellation test
vergence test
what is the VOR cancellation test used in a central vestibular exam
ability to bypass VOR if you would like to
- have pt put their hands clasped in front and look at your thumb nails
- now rotate trunk (kinda swinging your arms)
ability to cancel out looking at something else in the distance
what would a vergence test have pts do in a central vestibular exam
putting finger up and down like pencil pushups
what are the 4 main points hit in a PT exam
subjective hx
body structures and function
activity limitations
participation
what might be asked in a subjective hx
when did sx start?
what made them worse? better?
main problem or CC?
falls? n/v?
dizziness?
what is assessed specifically in the body structure and function
coordination tests
reflexes
ms tone
strength
CNs
what is assessed in terms of activity limitations
all
- fine motor
- gross motor
- reaching
- balance
- gait
- stairs
- transfers
what is assessed in terms of participation
play
school
sport
family roles
employment
