Lec 30 Spinal Cord Lesions Flashcards
What is monoplegia?
paralysis of one limb
what is diplegia?
paralysis of both upper or lower limbs
what is paraplegia?
paralysis of both lower limbs
what is hemiplegia?
paralysis of upper limb, torso, and lower leg on one side
what is quadriplegia?
paralysis of all four limbs
How do you determine the sensory level of a neurologic injury?
- sensory level = lowest dermatomal level with normal sensation to pinprick and light touch [all dermatomes above being normal]
What root value for elbow flexors [biceps, brachialis]?
C5
what root value for wrist extensors [extensor carpi radialis]?
C6
what root value for elbow extensors [triceps]?
C7
what root value for finger flexors [flexor digitorum profundus]?
C8
what root value for finger abductors [abductor digiti minimi]?
T1
What root value for hip flexors [iliopsoas]
L2
What root value for knee extensors [quadriceps]?
L3
What root value for ankle dorsiflexors [tibialis anterior]?
L4
What root value for great toe extensors?
L5
What root value for anal sphincter?
S4-5
What is the motor level of neuro injury?
lowest innervated muscle wtih grade 3 or better strength where all muscles above are 5
Increased muscle tone [spasticity] and reflexes – is it UMN or LMN?
UMN!
LMN = decreased muscle tone and absent reflexes
What is spinal shock?
loss of sensation accompanied by motor paralysis with initial loss but gradual recovery of reflexes –> occurs following spinal cord injury
- slow HR, low BP, flaccid paralysis, urinary bladder dysfunction
What is syringomyelia?
- generic term, referrs to disorder where cyst [called a syrinx] forms in spinal cord
- syrinx expands and damages anterior white commissure of spinothalamic tract
- -> get bilateral loss of pain/temp [usually C8-T1] = “cape-like”
- -> as it grows: weakness of muscles in arms, atrophy, hyporeflexia
What are signs of a central cord lesions? cause?
- due to damage to anterior white commissure + spinothalamic tract
signs: bilateral pain/temp loss, preserved mechanosensation
as it grows larger –> motor weakness in upper limbs, variable bowel/bladder involvement
usually cervical
cause: syringomyelia, tumors, anterior spinal artery ischemia
What is syringobulbia?
- syrinxes [cavities] grow in brainstem
- can affect one or more crania nerves –> facial palsies, vocal cord paralysis, etc
- usually due to congenital abnormality, trauma or growth
What is brown sequard syndrome? signs?
hemisection of spinal cord [from vascular injury, tumor, trauma, etc]
signs:
below level of lesion: ipsilateral UMN signs [spastic], ipsilateral impaired proprioception, vibration, contralateral pain/temp impairment
1-2 levels down from level of lesion: loss of sensation ipsilaterally, ipsilateral LMN signs [flaccid]
1-2 levels down = because when spinothalamic enters the cord it travels 1-2 up before crossing over. so the part that got cut in lesion originates from 1-2 levels down
What is horner’s syndrome? signs?
- lesion of spinal cord above T1 –> interrupts path from hypothalamus to superior cervical ganglion
signs = PAM is horny
Ptosis: drooping eyelid
Anhidrosis: absence of sweat + flushing of affected side of face
Miosis: pupil constrictioin
What is blood supply to the spinal cord?
- posterior spinal arteries
- anterior spinal arteries [artery of adamkiewicz is largest]
What is anterior cord syndrome? cause? signs?
infarction of anterior 2/3 of spinal cord due to vascular injury of anterior spinal artery
signs: bilateral loss of motor control, bilateral loss of pain/temp sensation with preserved light touch and joint position
occurs in upper thoracic cord = watershed area
What is posterolateral column disease?
- demyelination of drosal
What happens to spinal column with vit B12 or vit E deficiency?
subacute combined degeneration = demyelination of dorsal columns, lateral corticospinal tracts, spinocerebellar tracts
- ataxic gait, paresthesia, impaired position and vibration, + romberg
What should you think if you see loss of reflexes due to peripheral neuropathy and + babinski
posteriolateral column disease = B12 or # deficiency
What is cauda equina syndrome?
occurs with central disk herniation
- gradual asymmetric onset at L4, L5, S1 nerve roots
signs:
- asymmetric flaccid paralysis
- asymmetric saddle anesthesia, sharp radicular pain
- LMN bladder/bowel develop late
What is conus medullaris syndrome?
occurs with central disk herniation - sudden, bilateral onset at L1, L2 signs - symmetric weakness - symmetric saddle anesthesia - dull pain - LMN bladder/bowel develop early
What happens in poliomyelitis? signs?
- caused by poliovirus –> goes to bloodstream to CNS
- destroyrs cells in anterior horn of spinal cord
symptoms: weakness, hypotonia, flaccid paralysis, fasciulations, muscle atrophy + malaise, headache, fever, nausea
findings: high WBC and slight high protein in CSF, virus in stool or throat
What is spondylolisthesis? treat?
anterior/posterior displacement of vertebrae relative to its neighbors
treat: NSAIDs, steroids, PT, spinal fusion surgery
What is lumbar spinal stenosis?
- spinal canal narrows and compresses cords/nerves
- due to aging or spinal disk herniation
signs: low back pain, abnormal sensation in legs/thighs/feet/buttoks, loss of bladder control
What happens in spinal disc herniation?
- nucleus pulposus bulges out beyond annulus fibrosus postero-laterally
- may cause severe pain due to release of inflammatory chemical mediators
What is tabes dorsalis? cause? signs?
due to tertiary neurosyphilis
- demyelination/degeneration of dorsal columns and roots
- impaired sensation and proprioception, progressive sensory ataxia
- areflexia, + romberg
- argyll robertson pupils = small bilateral pupils that further constrict to accomodation and convergence not to light
What causes autonomic dysreflexia? what is it?
spinal cord injuries above T6
- stimulus activated nociceptors below level of injury –> afferent impulses –> sympathetic neurons activated –> generalized sympathetic response –> PNS output prevails
–> bradycardia,
What are signs of spinal tumor?
usually thoracic, due to metastatic cancer
sensory: pain, numbness
motor: UMN spasticity, bowel/bladder
what are signs of epidural abscess?
due to infection, causes spinal cord/nerve root compression
back pain, radiculopathy [sharp, shooting pain]
what are signs of disc prolapse?
spinal cord/nerve root compression
signs: radiculopathy, numbness, weakness, bowel/bladder disruption
What are signs of UMN vs LMN bladder?
UMN = hyperactivity of bladder and urinary sphincter, difficulty emptying
LMN –> weak urethral sphincter, prone to leakage of urine
What are signs of UMN vs LMN bowel?
UMN: defacation cannot be initiated by voluntary relaxation of external anal sphincter
LMN: anal sphincter atonic, prone to leakage
