Assessment of spine and spinal cord Flashcards
define paresthesia
abnormal sensation = burning, pricking, tingling tickling
define dysesthesia
impairment of sensation short of anesthesia
define paresis
partial loss of movement or impaired movement
define dermatome
cutanoeus area served by individual sensory root
define myotome
muscles innerv by individual motor root
define radiculopathy
sensory and/or motor dysfunction due to injury to a nerve root from lateral herniation
define myelopathy
disorder resulting in spinal cord dysfunction from central herniation
spinothalamic tract
function
cross
function = pain and temp (cold/hot)
cross = 2-3 segments above root entry level in anterior cord
posterior column
function
cross
function = vibration, position, 2-point discrim
cross = medulla (brain stem)
corticospinal tract
function
cross
function = motor cross = lower medulla (brain stem)
where nerve roots exit
c1-7
exit above same numbered vertebra
c7 above c7
where nerve roots exit
c8
c8 exits below c7 vertebra
t1 below t1
where nerve roots exit
t1-s5
exit below same number vertebra
know cord level each vertebral body overlies
upper cervical
vertebra number overlies cord segment of same number
know cord level each vertebral body overlies
lower cervical
vertebra number overlies cord segment number + 1
c6 bone = c7 cord
know cord level each vertebral body overlies
upper thoracic
vertebra number overlies cord segment number + 2
T4 bone = T6 cord
know cord level each vertebral body overlies
lower thoracic/lumbar
vertebra number overlies cord segment number +2/3
t11 bone, L1-2 cord
know cord level each vertebral body overlies
lower edge of l1 vertebral body
overlies cord tip (conus medullaris)
where is conus medullaris
what does it supply
s2-s5 = supplies bladder, rectum, genitalia
what happen if lesion conus medullaris
late pain in thighs and butt, pelvic floor weakness
symmetric saddle anesthesia
early bladder dysfunction, bowel, sex
cauda equina formed by
what happens if lesion
Lumbar sacral roots within lumbosacral cistern
early root pain radiating to legs (conus = late), leg weakness, decr DTR, patchy, asymm “saddle
late bladder dysfunction (conus = early), bowel, sex dysfunction
if lesion extramedullary (outside cord)
if lesion intramedullary (inside cord)
early pain
UMN signs
early bladder dysfunction
extaspinal blood supply includes
paired posterior spinal arteries (supplies posterior column)
single anterior artery (supplies spinothal and corticospinal tracts and watershed T1-T4 or L1)
intraspinal blood supply includes
gray matter require more blood than white
define radiculopathy pain
variable- shooting, burning, tingling, numb
radiates into dermatome or myotome
exam for radiculopathy
localization
exercabation
possible LMN signs
localization based on root of muscles/dermatome
exacerbation by neck flex/ext/rot, shoulder movement, cough
exam for radiculopathy
relieving factors
rest, immob, graded therapy, NSAIDs +/- muscle relaxant
common causes of radiculopathy
direction of herniated disc
posterior herniation causes –>
compression by DJD –> bony prolif or herniated disc near intervertebral foramen
other = herpes zoster, cancer, lymphoma
discs herniated laterally
posterior herniation –> myelopathy
describe lhermitte’s symptom
due to
neck flxion –> “electric shock” sensation down back and/or arms
due to posterior column disease (MS, disc, B12 deficiency, mass)
LMN vs UMN signs
LMN = atrophy, fasciculations, decr tone, decr DTR
UMN = spasticity, hyperreflexia, babinski
voiding controlled by
higher cortical centers developing as continence and achieved in childhood
define incontinence
neuro pathways that innerv bladder interrupted or when problem with pelvic floor/sphincter
assoc with spinal cord damage
bladder controlled by
neurons terminate where?
1) areas of brain/brainstem sending axons down cord medial to LCST
2) terminate on preganglionic parasympathetic at S2-S4
3) synapse on postgangl parasymp near bladder
4) innerv detrusor (smooth muscle) for voiding
muscle spindles, nociceptors, and receptors in detrusor and bladder wall have cell bodies where?
involved in what?
DRG at S2-S4
involved in reflex arc and ascend nervous system via AL path and dorsal column
what happens when bladder fills?
1) muscle spindle of detrusor/bladder stretched
2) incr firing –> incr neuronal firing of symp preganglionic neurons in IML cell column from T11-L1
3) constriction of internal urethral sphincter
decr firing of pregangl symp at S2-S4 to inhib contract of detrusor
4) then activates higher centers in bain
5) inhib of symp tone and activ of parasymp contraction of detrusor
if PNS LMNs injured
if sensory afferents affect
if intact sensory with damaged motor
weakness, atrophy, hyporeflexia
bladder does not contract = overflow incontinence
no sensation of full bladder
urge to void but detrusor can’t contract
where can LMN injury occur
preganglionic neuron at S2-S4
sacral root of cauda equina, pelvic nerve
pelvic plexus
2ndary postgangl, parasymp neuron innerv detrusor
if UMN lesions injuured
to affect bladder, must be bilateral
detrusor flaccid –> urinary retention –> flaccid bladder
over time, get spasticity and bladder hyper contracts causing freq and urgency (activ parasymp motor neuron with little stretch and cause spastic bladder)
c5 sensory
motor
reflex
sensory = shoulder, upper lat arm motor = deltoid, infraspinatus, bicep
reflex = biceps
c6
sensory
motor
reflex
sensory = 1st and 2nd digits of hand motor = wrist extension, biceps
reflex = biceps, brachioradialis
c7
sensory
motor
reflex
sensory = 3rd digit motor = triceps reflex = triceps
L4
sensory
motor
reflex
sensory = knee, medial leg motor = psoas, quad reflex = patellar
L5
sensory
motor
reflex
sensory = dorsal foot, great toe motor = foot dorsiflex, big toe ext, foot eversion/inversion
reflex = none
S1
sensory
motor
reflex
sensory = lat foot, small toe, sole of foot
motor = foot plantarfelx reflex = achilles
dermatomes for
nipple line
xyphoid
umbilicus
nipple = T4 xyphoid = T6 umbilicus = T10
Lhermitte’s sign
with cervical stonosis and flex head —> shock extend down spine and compression
of spinal cord acutely (cervical myelopathy)
spurling’s sign
turn head towards nerve root (foramen
narrows) —> shock sensation along
the tract of nerve root
Lasegue’s sign
in lumbosacral spine, narrowed neural foramen and raise
leg and dorsiflex ankle —> stretch sciatic nerve, shooting
pain in distrib of nerve root of sciatic nerve
dysestheia vs paresthesia
dysesthesia is more unpleasant
