Impairment Oriented Neuro Exam II Flashcards
what are 3 ways that muscle tone is defined
- measure of tension in muscle at rest
- resistance of ms to passive elongation or stretch
- slight residual contraction or steady-state contraction at rest in neurotypical people
why do we want our muscles to maintain a slight residual contraction at rest
allows you to initiate any movement immediately
- without this, there would be a delay to movements - like starting a car vs car is idling
what does muscle tone support functionally
posture
what is an important function that muscle tone provides
provides reflexive, energy efficient base for movement
what is muscle tone influenced by (2)
- intrinsic mechanical or elastic properties of ms and connective tissue
- reflex ms contractions / tonic stretch reflex of intrafusal fibers
what is muscle tone influenced by (2)
- intrinsic mechanical or elastic properties of ms and connective tissue
- reflex ms contractions / tonic stretch reflex of intrafusal fibers
what tracts are involved in muscle tone
motor
- reticulospinal
- vestibulospinal
- rubrospinal
- corticospinal
what are the two main categories of atypical muscle tone
hypertonia
hypotonia
what is hypertonia and what is the common cause
inc tone
UMNL (brain or SC)
what is hypotonia and what are causes of this
dec tone
LMNL
acute UMNL
cerebellar lesions
what is the physiology behind and clinical presentation of hypertonia (3)
inc excitability of alpha motor neurons
associated w inc DTRs
enhanced excitatory synaptic input
- muscle spindle
- GTO
what are two specific types of hypertonia
spasticity
rigidity
what is spasticity
involuntary, VELOCITY DEPENDENT, inc resistance to passive elongation
what cases do you typically see spasticity in
pyramidal tract lesions
- CP
- CVA
- MS
- TBI
what is the clasp-knife phenomenon associated with spasticity
strong resistance to initial passive movement followed by a releases of resistance
what is clonus
cyclical, spasmodic alternating ms contraction (aka beating) in response to sustained stretch
where is clonus typically seen and why is this significant
at ankle when achilles on stretch
- makes walking difficult bc of elongation in terminal stance
what are negative impacts of spasticity (in general terms)
secondary impairments
activity limitations
what are secondary impairments typically seen in patients w spasticity
contractures
issues at joint itself
skin breakdown
what activity limitations do you typically see in patients w spasticity
difficulty walking / exercises
hard to participate in ADLs overall
what are positive impacts of spasticity
passive postural support
may contribute to function in presence of reduced motor control
- ex: extensor tone in standing
what are exacerbating factors of spasticity
infections
pressure sores
DVT
other factors: temp, fatigue, positioning, bladder distention, bowel impaction
describe PT management of spasticity
procedural interventions:
- modalities (heat, ice, estim)
- positioning, stretching, splinting, casting
- RRo and deep pressure
TEMPORARY EFFECT
why would we want to modify spasticity tone if the effect is temporary
pain relief
improve QOL/function
keep activating ms
keep joint integrity
prevent contractures
prevent condition from getting worse
what are examples medical management of spasticity
meds
injections
surgery
what are you looking for / examining when implementing medical management interventions for spasticity
effects of dec tone on function
- find a good balance
main difference between medical management and PT management for spasticity
medical management has lasting effects
PT is temporary effects
what is rigidity
inc resistance through range and is not velocity dependent
- usually seen in both agonist and antagonist ms groups
what cases do you typically see rigidity in
basal ganglia lesions
- ex: Parkinsons Disease
cogwheel vs lead pipe rigidity
cogwheel - stops, releases for a second and then catches again
- pushing through a beating
lead pipe - not moving, can’t break a lead pipe
what are interventions for rigidity
splinting - maintain, don’t let get worse
positioning
what neurological injuries often present with a decerebrate rigidity
lesion of reticular nuclei in MEDULLA
- loss of inhibitory control of cortex and basal ganglia
what does decerebrate rigidity look like
ext head and neck, UE, LE
ankles in PF
wrist/fingers flexed or fisted
what neurological insults often present with a decorticate rigidity
severe cerebral injury above red nucleus and basal ganglia
- higher up than decerebrate (medulla level)
what does decorticate rigidity look like
UE flex
LE ext
ankle PF
which is worse: decerebrate or decorticate?
decerebrate is worse
- pts can progress from decerebrate to decorticate and it might indicate improving
what is dystonia
involuntary ms contractions/spasms
- fluctuating inc tone in one or multiple ms groups
what can dystonia look like bc of its etiology
repetitive twisting or writhing motions and abnormal postures
what causes dystonia
unknown
- may be genetic, acquired, idiopathic, SE of meds (ex: antipsychotics)
what are interventions for dystonia
music
PT to avoid sedentary lifestyle
what cases are hypotonia associated with
LMNL
UMNL
chromosomal abnormalities and genetic disorders (ex: down syndrome)
where are LMNL found specifically which cause hypotonia
anterior horn cell
peripheral nerve injury
what specific UMNL can cause hypotonia
acute and transient d/t cerebral or spinal shock
cerebellar lesions
what are clinical manifestations of hypotonia
reduced resistance to passive stretch
reduced DTRs
poor posture
weakness
dec function
hyperextensibility
altered joint integrity
pain
neurogenic atrophy
what is a common injury that presents when there is altered joint integrity d/t hypotonia
passive shoulder dislocations/subluxations
- tone of delt and biceps dec and humerus sinks bc of shallow joint
what is the examination process for observing muscle tone
posture and body position
muscle bulk
- hypotonic»_space; less definition
- hypertonic»_space; well defined
what is the examination process for palpating muscle tone
hypotonic»_space; loose, squishy
hypertonic»_space; taut, hard
to examine a person’s muscle tone, what are the steps
passively elongate the muscle/muscle groups being tested
- position: supine to start
- manual contact: over bony prominences
- limb well supported
- ask ab pain
- instruct person to relax and not resist/assist
- PROM thru entire available range avoid end feel
what are the possible findings when interpreting results from an exam of muscle tone
normal: limb easily moved, direction changes easily, responsive, light feeling
hypotonic: easy to move, little resistance, floppy, heavy
hypertonic: inc resistance to movement, stiff
what is the next step if you find that hypertonicity is detected upon a muscle tone clinical exam
further assess to determine if spasticity or rigidity present
you detected hypertonicity in your clinical exam, how do you assess for spasticity
quick stretch»_space; inc amt of resistance to passive movement
- usually unidirectional
test for presence of clonus
further assessment via modified ashworth or tardieu
you detected hypertonicity in your clinical exam, how do you assess for rigidity
amt of resistance doesn’t change w velocity of stretch
- bidirectional
test for presence of lead pipe vs. cogwheel
no standardized tests or measures (just describe)
what are the grades for the modified ashworth scale
0 - no inc in ms tone
1 - slightly inc in ms tone, catch or minimal resistance at end of ROM when affected part(s) moved in flex or ext
1+ - slight inc in ms tone, catch followed by minimal resistance throughout the remainder (less than half) of ROM
2 - more marked inc in ms tone thru most of ROM but affected part(s) easily moved
3 - considerable inc in ms tone, passive movement difficult
4 - affected part(s) rigid in flex or ext
9 - unable to test
how is the tardieu scale conducted
measurements take place at 3 velocities
V1 = slow as possible, slower than natural drop of limb under gravity
V2 = speed of limb falling under gravity
V3 = fast of possible, faster than rate of natural drop of limb under gravity
how are responses interpreted/recorded for the tardieu scale
responses are recorded at each velocity as X/Y
Y - indicates 0-5 rating
X - indicates degree of angle at which muscle reaction occurs
what are the grades of Y for the Tardieu Scale
0 - no resistance throughout course of passive movement
1 - slight resistance throughout course of passive movement, no clear catch at a precise angle
2 - clear catch at precise angle, interrupting the passive movement, followed by release
3 - fatigable clonus w <10sec when maintaining pressure and appearing at precise angle
4 - clonus >10sec when maintaining pressure and appearing at precise angle
5 - joint is immovable
what are deep tendon reflexes (DTRs)
involuntary, predictable, specific response to stimulus
what is a deep tendon reflex a result of
stretch-sensitive IA afferents of muscle spindle producing muscle contraction (reflex arc)
DTR: in UMN vs LMN syndromes
UMN syndrome: inc DTRs associated w hypertonicity
LMN syndrome: dec DTRs associated w hypotonicity
what are common sites of DTR and corresponding innervations
jaw (CN V)
biceps (C5-6)
triceps (C6-7)
patellar (L2-4)
achilles (S2)
what is the scale which assess DTRs
0 - no response, always abnormal
1+ slight but definitely present response
- may or may not be normal
2+ normal, typical reflex
3+ brisk response
- may or may not be normal
4+ very brisk, always abnormal
what are two pathological reflexes
babinski
hoffman
what are babinski and hoffman reflexes indicative of
UMNL
what is the Babinski reflex
PT strokes foot from heel up lateral side to MT heads
normal: normal plantar response (toes flex)
abnormal: extensor plantar response
- toes fan up
what does a positive Hoffman’s indicate
hyper reflexia / UMNL
how do you test for a Hoffman’s reflex
hold hand w wrist slightly ext and fingers partially flex
- hold middle finger in ext, stabilize DIP
- flick nail of middle finger
what are a negative and positive response to the Hoffman’s reflex test
negative:
- sudden flexion of DIP and then release
- eliciting stretch reflex of finger flexors
positive:
- flex and ADD of thumb and index finger (possibly other fingers too)
while subtle, when is testing for a Hoffman’s reflex helpful
in dx where not seeing typical signs
- ex: MS - can have both peripheral and central lesions
