Quiz 2 Flashcards
do we expect to see UMN or LMN signs with PNS injuries?
LMN signs
what does the endoneurium surround?
individual axons
what does the perineurium surround?
fascicles (bundles of neurons)
what does the epineurium cover?
bundle of fascicles
what is the point of dynamic protective mechanisms in nerve mobility?
provide adequate blood flow for nutrition, oxygen, and removal of waste
movement of the nerve against adjacent structures allows for health of the nerve
t/f: axoplasm flows easily throughout the axon with movement
true!
what if dynamic protective mechanisms fail?
immobility=numbness
try gentle lengthening and shortening of the nerve
what do nerves look like in resting?
folding with wrinkles in endoneurium
stretch gets rid of wrinkles
what are the sensory signs of peripheral nerve injury?
decreased/lost sensation
abnormal sensations (dysesthesia, algesia, hyperalgesia)
what are the motor signs of peripheral nerve injury?
paralysis/paresis
muscle atrophy (neurogenic)
fasciculation/fibrillation
what are the autonomic signs of peripheral nerve injury?
single nerve severance signs are less severe
multiple nerves damaged-difficulty regulating BP, HR, sweating, b/b fxns, impotence
what are the trophic signs of peripheral nerve injury?
abnormalities in the lesion of the nerve injury
what are the trophic changes in muscles with peripheral nerve injury?
muscle atrophy
what are the trophic changes in skin with peripheral nerve injury?
shiny, dry, pigmentation changes
what are the trophic changes in nails with peripheral nerve injury?
brittle
what are the trophic changes in subcutaneous tissue in peripheral nerve injury?
thicken, ulceration, poor healing of wounds
what are the trophic changes in joints in peripheral nerve injury?
neurogenic damage from lack of movement
what are the classifications of peripheral nerve injuries?
mononeuropathies, multiple mononeuropathies, and polyneuropathies
what are the 3 mononeuropathies?
1) truamatic myelinopathy (neuropraxia)
2) traumatic axonopathy (axonatmesis)
3) traumatic severence (neurotmesis)
what is the usual cause of all 3 mononeuropathies?
trauma
what is the pathology of neuropraxia?
demyelination
what is the pathology of axonatmesis?
axon damage
what is the pathology of neurotmesis?
axon and myelin degeneration
what is multiple mononeuropathy?
sporadic, non symmetrical pattern of single neuropathy in many places
what is polyneuropathy?
symmetric
often complication of diabetes
what is neuropraxia?
loss of myelin at the site of injury with no axon damage
temporary impairment of nerve conduction (recovery within hours/weeks)
complete recovery via re-myelination
neuropathic pain
impaired discriminitive touch, proprioception, motor, and DTRs
how long does recovery in neuropraxia take?
hours to weeks
what is the least severe mononeuropathy?
neuropraxia
what axons are affected first in neuropraxia?
large myelinated axons
is there complete recovery with neuropraxia?
yes!
what is the prognosis for neuropraxia?
good, bc there is complete and rapid recovery via re-myelination
what is axonotmesis?
axon and myelin sheath damage with intact endo, peri, and epineurium
Wallerian degeneration at/below level
impaired discriminitive touch, proprioception, motor, DTRs, and autonomic (if severe enough)
decreased nerve conduction velocity and amplitude
complete recovery (1 mm/day of growth)
are the endo, peri, and epineurium intact in axonotmesis?
yes!
what size axons are affected in axonotmesis?
all sizes
is there complete recovery with axonotmesis?
yes!
how long does recovery take in axonotmesis?
1 mm/day (1 inch/month)
what is a common cause of neuropraxia and axonotmesis?
entrapment or mechanical contriction
what does myelin damage lead to?
inflammation in the NS, ectopic foci, and decreased nerve conduction velocity
what is Tinnel’s sign?
oversensitivity of the nerve to mechanical stimuli
tapping a superficial nerve may elicit pain
what is neurotmesis?
axon, myelin sheath, and CT damaged
wallerian degeneration
incomplete recovery
no nerve conduction
neuroma-hypersensitivity
from severe trauma (gunshot, stabbing)
why is there incomplete recovery in neurotmesis?
no covering is guiding the axon growth
what are common UE mononeuropathies?
axillary neuropathy
“saturday night” or “honeymooner’s” palsy (radial nerve)
crutch palsy (radial nerve or brachial plexus)
carpal tunnel syndrome (median nerve)
cubital tunnel syndrome (ulnar nerve)
what are common LE mononeuropathies?
femoral neuropathy
sciatic neuropathy
peroneal nerve palsy
obturator nerve palsy
morton’s neuroma-wrist drop from radial nerve palsy, atrophy of instrinsic muscles of the hand
what does peroneal nerve palsy cause?
foot drop
what does Morton’s neuroma cause?
wrist drop and atrophy of intrinsics
what nerve is affected in Morton’s neuroma?
radial nerve
what is sciatic neuropathy?
compression/irritation of the sciatic nerve causing motor and sensory symptoms
what are some causes of sciatic neuropathy?
herniated disc
spinal stenosis/spondylosis
piriformis syndrome
what are the motor symptoms associated with sciatic neuropathy?
weakness (specific to the supplied muscles)
severe cramping
reduced DTRs in L4-S1
what are the sensory symptoms associated with sciatic neuropathy?
numbness, burning, tingling (specific to the involved dermatome)
sharp shooting pain
what makes sciatic neuropathy worse?
prolonged sitting, standing, sneezing, coughing
what are multiple mononeuropathies?
involvement of 2/more nerves in dif parts of the body
asymmetric, random presentation of symptoms
occurs with ischemic nerve damages caused by DM or vasculitis (can occur with RA, lupus, and HIV as well)
are multiple mononeuropathies symmetrical or asymmetrical?
asymmetrical
what are polyneuropathies?
symmetric involvement of sensory, motor, and autonomic fibers that progresses distal to proximal in glove and stocking pattern
what axons are affected first in polyneuropathy?
large myelinated
what neuropathy can be metabolic, hereditary, inflammatory, idiopathic, or toxic (alcoholism)?
polyneuropathy
what is the most common polyneuropathy?
diabetic polyneuropathy
what are some polyneuropathies?
diabetic polyneuropathy
GBS
hereditary motor and sensory polyneuropathy (HMSN)-Charcot Marie Tooth disease
chronic inflammatory demyelinating polyneuropathy (CIDP)
idiopathic polyneuropathy
what is the difference b/w GBS and CIDP?
s/s are very similar but CIDP is more chronic than GBS and can take years to progress and recover
what is diabetic polyneuropathy?
a metabolic disorder compromises microvascular blood supply causing oxidative stress, autoimmunity, and chemical disturbances
what is the damage to structures in diabetic polyneuropathy?
demyelination and axonal damage=orthostatic hypotension symptoms
greater sensory involvement than motor
glove and stocking pattern of loss
hyporeflexia
why can there be orthostatic hypotension in diabetic polyneuropathy?
bc there is a loss of autonomic regulation of blood flow with the demyelination and axon damage
is there a greater motor or sensory involvement in diabetic polyneuropathy?
sensory
what is the pattern of loss in diabetic polyneuropathy?
glove and stocking
what is Charcot Marie Tooth disease?
hereditary motor and sensory neuropathy (HMSN) causing muscle atrophy and paresis distal to the knee and progressing to hands
what is the sensory involvement associated with Charcot Marie Tooth disease?
↓ thermal and pain sensation
neuropathic pain
numbness, tingling, burning-not severe
t/f: with charcot marie tooth disease, there is early inflammation, joint dislocation/subluxation, pathological fractures of the foot
true
what are the symptoms of Charcot Marie Tooth disease?
midfoot swelling (one of the most prominent signs)
shorter 1st metatarsal bone
laterally curved foot
uni or bilateral
hammer toe
high arch/flat foot
what are the neuromuscular junction disorders?
myasthenia gravis and botulism
what is myasthenia gravis?
decreased amplitude of AP on EMG
repetative use-weaker muscles
what is botulism?
acute, progressive weakness
loss of stretch reflexes
usually therapeutically used to decrease spasticity
what are myopathies?
degeneration of muscle fibers leading to muscle atrophy and weakness
is there greater weakness proximally or distally with myopathies?
proximally
is there sensory or autonomic involvement in myopathies?
nope!
what are the 3 myopathies?
1) Duchenne’s muscular dystrophy
2) dermatomyositis
3) polymyositis
what are the immune related myopathies?
dermatomyosititis and polymyositis
what are the 2 pediatric plexus disorders?
Erb’s palsy and Klumpke’s palsy
what roots are involved in Erb’s palsy?
C5-6
what is the pathophysiology of Erb’s palsy?
fall or traumatic birth
what roots are involved in Klumpke’s palsy?
C8-T1
what is the pathophysiology of Klumpke’s palsy?
traction of abducted arm
may present with Horner’s disease is severe
is the neurologic level above or below the vertebral level?
below
what vertebral bodies are associated with C8 SC segment?
C6-7
what vertebral bodies are associated with T1 SC segment?
C7-T1
what vertebral bodies are associated with T10-11 SC segment?
T9
what vertebral bodies are associated with L2-5 SC segment?
T12
what vertebral bodies are associated with S1-5 SC segment?
L1
what are the nerve roots of the diaphragm?
C3-5
if there is a lesion above C4, is there independent breathing?
no
if there is a lesion b/w C4 and C5, is there independent breathing?
yes, but heavily rely on accessory muscles
what does the pudendal nerve control?
b/b sphincters
does the pudendal nerve excite or inhibit the sphincters?
excites them to hold in pee
what are the 2 fxns of the SC?
1) motor coordination
2) pelvic organ fxn
how does the SC control motor coordination?
reflexes are integrated into normal functioning
locomotor CPGs
reciprocal inhibition
recurrent (autogenic) inhibition
how does recurrent (autogenic) inhibition work?
collateral branch of the alpha motor neuron innervates the Renshaw cells
are Renshaw cells excitatory or inhibitory?
inhibitory
what are Renshaw cells innervated by?
descending inputs
what is the purpose of Renshaw cells?
regualte the firing of motor neurons by keeping in check how fast the motor neuron is going
contributes to fine motor fxn
dampens the effects of it own motor neuron, its synergists, and motor neurons to slow them down
if there is damage to the descending system what is the effect on Renshaw cells?
they are no longer regulated to slow down motor neurons
how many anterior arteries supply the SC?
just 1
how many posterior arteries supply the SC?
2
how much of the SC is supplied by the anterior artery?
2/3 of the SC
how much of the SC is supplied by the posterior arteries?
1/3 of the SC
what is a segmental lesion?
a lesion affecting a single level of the SC
focal lesion of the dorsal/ventral root (radiculopathy) or spinal nerve (peripheral neuropathy)
are there UMN or LMN signs with a segmental lesion?
LMN signs
what are the LMN signs associated with a segmental lesion?
hypotonia, hyporeflexia, flacidity, fasciculation/fibrillation, paralysis
does a segmental lesion affect the levels above and below it?
nope!
what is a vertical tract lesion?
interruption of ascending and descending tracts below the lesion
are there UMN or LMN signs with vertical tract lesions?
UMN signs
what are the UMN signs associated with vertical tract lesions?
hypertonicity, spaticity/rigidity, hyperreflexia, Babinski, clasp-knife, CLONUS
does a vertical tract lesion affect that segments above/below it?
yes, it affects below the lesion
if there is both a segmental and vertical tract lesion, are there UMN signs of LMN signs?
both
UMN signs below the lesion
LMN signs at the lesion
are there significant autonomic s/s with a segmental lesion?
no bc there is redundancy in autonomic efferents
what is anterior cord syndrome?
a lesion of the anterior 2/3 of the SC causing a loss of pain, temp, motor fxn due to disruption in the anterior spinal artery
spinothalamic (sensory) and lateral corticospinal (motor) damage
fxn lost bilaterally
is there damage to the DCML or dorsal horn in anterior cord syndrome?
no
why is proprioception, light touch, and vibration intact in anterior cord syndrome?
bc the DCML is not damaged
is the ventral horn motor, sensory, or autonomic?
motor
is the dorsal horn motor, sensory, or autonomic?
sensory
is the lateral horn motor, sensory, or autonomic?
autonomic
is anterior cord syndrome bilateral?
yes
what is central cord syndrome?
a centrally located, smaller lesion causes cape-like distribution of loss of pain and temp at the level of the lesion
what usually causes central cord syndrome?
cervical trauma (hyperextension)
usually upper cervical
why is there a loss of pain and temp in central cord syndrome?
bc the spinothalamic tract is damaged by of its proximity to the anterior commissure
if the lesion in central cord syndrome is larger, what is the order in which lateral corticospinal damage will occur?
cervical–>thoracic–>lumbar–>sacrum
if the lesion is larger in central cord syndrome, what other tract will be affected?
lateral corticospinal
what is Brown-Sequard syndrome?
hemisection of the SC causing ipsilateral loss of motor fxn, proprioceptionm and discriminitive touch, and contralateral loss of pain and temp
is anterior cord syndrome segmental or vertical?
vertical
is central cord syndrome segmental or vertical?
segmental
is Brown-Sequad syndrome segmental or vertical?
both
what is cauda equina syndrome?
damage to the lumbar and/or sacral spinal roots causing sensory impairments
does cauda equina syndrome cause UMN or LMN signs?
LMN signs
t/f: cauda equine syndrome causes flaccid paresis
true
what are the MOIs for traumatic SCI?
MVAs, falls, and sports injuries
penetrating wounds
with MVAs, falls, and sports injuries, what is the damage due to?
crush, hemorrhage, edema, or infarction
is there typically a cord severance with MVAs, falls, adn sports injuries?
no, so there is some remaining fxn below the lesion
is there typically cord severance with penetrating wounds?
yes, so there is a complete disconnect b/w above and below the lesion
which has more severe presentation of sensory/motor/autonomic symptoms: MVAs, fall and sports injuries; or penetrating wounds?
penetrating wounds
what is spinal (cerebral) shock?
acute UMN lesion interrupts descending motor commands, affecting LMNs to become temporarily inactive
early=LMN
later=UMN
how long does it take for LMN signs to leave with spinal (cerebral) shock?
days or weeks
what are the temporary LMN of spinal (cerebral shock)?
paralysis
loss of sensation
somatic reflexes lost
autonomic reflexes lost or impaired
autonomic regulation of blood pressure impaired
control of sweating and piloerection lost
what % of pts develop spasticity following spinal shock?
80%
what is the difference b/w spinal and cerebral shock?
spinal chock=SCI
cerebral shock=stroke
where is a lesion with presentation of tetraplegia?
upper or lower cervical lesion
what is the presentation of tetraplegia?
loss below head or shoulders depending on lesion location
where is the lesion with presentation of paraplegia?
thoracic or lumbar lesion
does paraplegia have to include the trunk?
no, it may just be LEs
do higher or lower lesions have greater autonomic impairments?
higher
what are autonomic dysfunctions associated with SCIs?
b/b and sexual dysfxn
paralysis of diaphragm/trunk/abdominals/ intercostals
pressure ulcers
autonomic dysreflexia
VERY frequent UTIs
if the lesion is above T6, what is a pt at risk for?
autonomic dysreflexia
what is autonomic dysreflexia?
lesions at or above T6 causing serious abnormalities in autonomic regulation due to loss of descending sympathetic control
if the lesion is above C4, is a ventilator required?
yes
is the lesion is b/w C4-6, is there a need for a ventilator?
no
if the lesion is b/w T6-S2, is there b/b control?
no
why may orthostatic hypotension be present in lesions between C4-T6?
bc there is inadequate vasoconstriction in the LEs
t/f: a pt with a lesion b/w C4-6 is prone to heart stroke bc they can’t sweat below the lesion
true
t/f: with a lesion b/w C4-5 a pt can pass out just sitting bc of poor BP control
true
what is autonomic dysreflexia?
SCI at or above T6
vasomotor response to noxious stimuli below the level of injury
HTN with bradycardia, excessive sweating above the lesion, flushed face, pounding headache
how is autonomic dysreflexia treated?
remove the noxious stimulus if possible and get pt into sitting (DO NOT LAY THEM DOWN)
how is the bladder voluntarily controlled?
the frontal cortex disinhibits the pontine micturation center which facilitates the sacral micturation center and causes contraction of the bladder wall and relaxation of the sphincters and pelvic floor muscles for voiding
where is the sacral micturation center?
b/w S2-4
if the lesion is above S2, is the bladder UMN type or LMN type?
UMN type bladder
what is an UMN type bladder?
hyperreflexive bladder
reflexive voiding with little urine in the bladder
causes bladder to shrink
if the lesion is at/below S2-4, is the bladder UMN type or LMN type?
LMN type bladder
what is a LMN type bladder?
areflexive bladder
the bladder won’t void even when full, so voiding schedule is important
what is the purpose of the NS?
speed of communication b/w the body and brain
what are 3 causes of nerve impairments?
1) trauma
2) autoimmune disease
3) compression
what are pt symptoms of nerve impairment and how do we differentiate them b/w other conditions with similar s/s?
pain, weakness, paresthesias
differentiate by using diagnositic medical tests
what are the ancillary lab tests?
EMG/NCS
MRI
x-ray
bone scan
CAT scan
why are the EMG/NCS combined?
bc they have weaknesses on their own
t/f: EMG and NCS study must be completed sequentially or on the same day for Medicare coverage
true
what does NCS test?
sensory and motor neurons
how long and how strong they conduct
is there wallerian degneration with axon damage or myelin damage?
axon damage
site of lesion with axon damage
distal
is nerve damage usually a slowing or loss of AP
both
what is the goal of EMG testing?
read electricity inside muscle tissue that may suggest nerve damage
are abnormalities above or below the lesion in EMG testing?
below
t/f: you can evaluate the age of a nerve injury with EMG testing
true (but after 2 years, there are limited findings)
what does a snap sound and/or positive sharp wave on an EMG indicate?
acute motor axon nerve damage
t/f: grading EMGs is objective
false, it can be subjective
how are EMGs graded?
+1–>+4; large/small; inc/dec; long/short
does NCS or EMG measure sensory and motor nerves?
NCS
does NCS or EMG measure motor axons?
EMG
what are common UE peripheral entrapment neuropathies (in order)
carpal tunnel
cubital tunnel
radial tunnel
axillary nerve
suprascapular nerve
t/f: the PT is free to choose the test based on clinical suspicion, pt age, sex, and comorbidities
true
when myelin is impaired, the AP is slowed or gone?
slowed
when the axon is damaged, the AP is slowed or gone?
gone
what does a slowed/prolonged segment on an EMG indidcate?
that is the problem area
what are the hyperkinetic disorders?
dystonia, Tourette’s, and dyskinesia
what is dystonia?
abnormal postures or twisting caused by involuntary, sustained muscle contractions
genetic, non-progressive
increases w/stress, decreases w/sleep
what is focal dystonia?
dystonia affecting just one area
what is the most common dystonia?
focal dystonia
what is cervical dystonia?
spasmotic torticollis
tight neck muscles like the SCM
head off midline
who is focal hand dystonia most common in?
ppl who play an instrument
what is Tourrette’s disorder?
hyperkinetic disorder causing vocal and motor tics that increase with stress, and decrease with sleep
abrupt involuntary and repetitive
tics last longer than a year
what is dyskinesia?
abnormal involuntary movement
can be medication induced
what is a basal ganglia stroke?
supplied by deep branch of the middle cerebral artery (MCA)
contralateral s/s (mostly affecting lateral corticospinal)
what is post-hemiplegic athetosis?
lesions in the internal capsule and GP
what is post-hemiplegic hemiballismus?
lesions in the STN (rare)
involuntary, jerky movements, not rhythmic
severe form of chorea
what is flaccid paralysis?
extensive lesions in the lenticular nucleus (not what we would normally expect in the basal ganglia which is usually rigidity)
what is the msot common pediatric condition seen by PTs?
cerebral palsy
can all people with CP walk?
some can, some can’t
what is CP?
permanent, non-progressive brain damage perinatally (80% of cases b4 labor)
movement and postural disorder
especially traumatic to white matter
cognitive, somatosensory, visual, auditory, and/or speech deficits
is growing into the deficit common in CP?
yes, very common
is CP progressive?
only if seizures are involved
when are fetuses most susecptible to CP?
in the 3rd trimester when a lot of sulci and gyri are being made
what are the 5 types of CP?
1) spastic
2) dyskinetic
3) ataxic
4) hypotonic
5) mixed
what is spastic CP?
mainly shows increased muscle tone
motor cortex lesion
what is dyskinetic CP?
basal ganglia lesion
when trying to do one motion, there’s a lot of involuntary accessory motions
non-rhythmic, abrupt, involuntary movement
atypical, abnormal muscle tone
choreoathetoid - fluctuating muscle tone
what is choreatic movement?
jerky, non-rhythmic movement, lot of twisting
what is athetotic movement?
slow and complex movements with twisting
what is ataxic CP?
cerebellar lesion
uncoordinated movement
dysmetria
what is hypotonic CP?
no specific lesion location, more extensive lesion
more extensive cognitive dysfunction
more difficult to treat
what is mixed CP?
dyskinetic and ataxic, hypotnoic and ataxic
what are the types of CP reflecting the body parts invovled?
quadriplegic, diplegic, hemiplegic
what is quadriplegic CP?
includes lack of control of head, arms, legs, and trunk
no walking
what is diplegic CP?
leg motor control is more severly affected than UE control
may walk
what is hemiplegic CP?
half the body (L/R) involved
can walk most times
what type of CP is being described?: spasticity of UE and LE, worse in the LE
spastic diplegic
what is spastic diplegic gait?
toe walking, flexed knees, speed up scissoring gait, shortening adductors
if no Botox or release=don’t walk very long due to energy use
is spastic hemiplegic or spastic diplegic gait smoother?
spastic hemiplegic
what is the most common visual problem in CP?
strabismus (asymmetric crossed eyes/lazy eye)
what does uncorrected strabismus result in?
the brain learns to block input from the one eye -no depth perception if young
is CP frequently associated with intellectual disability and language deficits?
yes
what is the result of synaptic pruning not happening correctly in CP?
greater motor dysfunction
