Lec 30 Spinal Cord Lesions

Question 1

What is monoplegia?

Answer 1

paralysis of one limb

Question 2

what is diplegia?

Answer 2

paralysis of both upper or lower limbs

Question 3

what is paraplegia?

Answer 3

paralysis of both lower limbs

Question 4

what is hemiplegia?

Answer 4

paralysis of upper limb, torso, and lower leg on one side

Question 5

what is quadriplegia?

Answer 5

paralysis of all four limbs

Question 6

How do you determine the sensory level of a neurologic injury?

Answer 6

• sensory level = lowest dermatomal level with normal sensation to pinprick and light touch [all dermatomes above being normal]

Question 7

What root value for elbow flexors [biceps, brachialis]?

Answer 7

C5

Question 8

what root value for wrist extensors [extensor carpi radialis]?

Answer 8

C6

Question 9

what root value for elbow extensors [triceps]?

Answer 9

C7

Question 10

what root value for finger flexors [flexor digitorum profundus]?

Answer 10

C8

Question 11

what root value for finger abductors [abductor digiti minimi]?

Answer 11

T1

Question 12

What root value for hip flexors [iliopsoas]

Answer 12

L2

Question 13

What root value for knee extensors [quadriceps]?

Answer 13

L3

Question 14

What root value for ankle dorsiflexors [tibialis anterior]?

Answer 14

L4

Question 15

What root value for great toe extensors?

Answer 15

L5

Question 16

What root value for anal sphincter?

Answer 16

S4-5

Question 17

What is the motor level of neuro injury?

Answer 17

lowest innervated muscle wtih grade 3 or better strength where all muscles above are 5

Question 18

Increased muscle tone [spasticity] and reflexes – is it UMN or LMN?

Answer 18

UMN!

LMN = decreased muscle tone and absent reflexes

Question 19

What is spinal shock?

Answer 19

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

Question 20

What is syringomyelia?

Answer 20

• 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

Question 21

What are signs of a central cord lesions? cause?

Answer 21

• 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

Question 22

What is syringobulbia?

Answer 22

• 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

Question 23

What is brown sequard syndrome? signs?

Answer 23

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

Question 24

What is horner’s syndrome? signs?

Answer 24

• 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

Question 25

What is blood supply to the spinal cord?

Answer 25

- posterior spinal arteries | - anterior spinal arteries [artery of adamkiewicz is largest]

Question 26

What is anterior cord syndrome? cause? signs?

Answer 26

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

Question 27

What is posterolateral column disease?

Answer 27

- demyelination of drosal

Question 28

What happens to spinal column with vit B12 or vit E deficiency?

Answer 28

subacute combined degeneration = demyelination of dorsal columns, lateral corticospinal tracts, spinocerebellar tracts - ataxic gait, paresthesia, impaired position and vibration, + romberg

Question 29

What should you think if you see loss of reflexes due to peripheral neuropathy and + babinski

Answer 29

posteriolateral column disease = B12 or # deficiency

Question 30

What is cauda equina syndrome?

Answer 30

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

Question 31

What is conus medullaris syndrome?

Answer 31

``` occurs with central disk herniation - sudden, bilateral onset at L1, L2 signs - symmetric weakness - symmetric saddle anesthesia - dull pain - LMN bladder/bowel develop early ```

Question 32

What happens in poliomyelitis? signs?

Answer 32

- 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

Question 33

What is spondylolisthesis? treat?

Answer 33

anterior/posterior displacement of vertebrae relative to its neighbors treat: NSAIDs, steroids, PT, spinal fusion surgery

Question 34

What is lumbar spinal stenosis?

Answer 34

- 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

Question 35

What happens in spinal disc herniation?

Answer 35

- nucleus pulposus bulges out beyond annulus fibrosus postero-laterally - may cause severe pain due to release of inflammatory chemical mediators

Question 36

What is tabes dorsalis? cause? signs?

Answer 36

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

Question 37

What causes autonomic dysreflexia? what is it?

Answer 37

spinal cord injuries above T6 - stimulus activated nociceptors below level of injury --> afferent impulses --> sympathetic neurons activated --> generalized sympathetic response --> PNS output prevails --> bradycardia,

Question 38

What are signs of spinal tumor?

Answer 38

usually thoracic, due to metastatic cancer sensory: pain, numbness motor: UMN spasticity, bowel/bladder

Question 39

what are signs of epidural abscess?

Answer 39

due to infection, causes spinal cord/nerve root compression | back pain, radiculopathy [sharp, shooting pain]

Question 40

what are signs of disc prolapse?

Answer 40

spinal cord/nerve root compression | signs: radiculopathy, numbness, weakness, bowel/bladder disruption

Question 41

What are signs of UMN vs LMN bladder?

Answer 41

UMN = hyperactivity of bladder and urinary sphincter, difficulty emptying LMN --> weak urethral sphincter, prone to leakage of urine

Question 42

What are signs of UMN vs LMN bowel?

Answer 42

UMN: defacation cannot be initiated by voluntary relaxation of external anal sphincter LMN: anal sphincter atonic, prone to leakage