Spinal Cord Syndromes

Question 1

What is the name of the structure where anterolateral system axons (pain, temperature) cross the spinal cord?

Answer 1

The white comissure.

Question 2

Where do axons of proprioception / mechanoreception (touch, vibration, pressure) cross the midline?

Answer 2

The lower medulla.

Question 3

Is sympathetic innervation ipsilateral, contralateral, or a mix?

Answer 3

Ipsilateral only.

Question 4

What’s the most common sympathetic syndrome? How can you test for it?

Answer 4

Horner’s Syndrome. Dripping cocaine in the eye should make pupil dilated - if it doesn’t, sympathetics are lesioned.

Question 5

In what spinal segments do nerves controling bladder enter/exit ?

Answer 5

S2-S4

Question 6

What is an infantile bladder? What stops us from having an infantile bladder? Lesions in what location will cause it?

Answer 6

Bladder fills until stretch receptors detect fullness, then it reflexively empties. Cortical descending fibers inhibit this reflex. Lesions above pons cause it.

Question 7

What effect do lesions between the pontomesencephalic micturation center and the conus medullaris have on the bladder? (note acute vs. chronic effects) Why?

Answer 7

Acutely: acontractile bladder -> urinary retention

Chronically: spastic bladder due to loss of ihibitory signals to the detrusor

Question 8

What effects do lesions of the cauda equina and conus medullaris have on the bladder? Why?

Answer 8

Atonic (flaccid) bladder -> urine just dribbles out. Loss of motor innervation to detrusor and sphincters. Loss of sensation.

Question 9

What major arteries supply the spinal cord? What is their contribution to total blood supply?

Answer 9

One anterior spinal artery (anterior 2/3) and two posterior spinal arteries (posterior 1/3).

Question 10

What artery supplying the spinal cord is most likely to infarct?

Answer 10

The anterior spinal cord.

Question 11

Slow and stiff muscles. UMN or LMN lesion?

Answer 11

UMN

Question 12

Weak, crampy muscles. LMN or UMN lesion?

Answer 12

LMN

Question 13

Increased tone, hyperactive reflexes, pathological reflexes (eg. Babinski’s). UMN or LMN lesion?

Answer 13

UMN

Question 14

Weakness, atrophy, fasciculations, decreased tone, hypoactive lesions. UMN or LMN lesion?

Answer 14

LMN lesion.

Question 15

Do you usually get bladder and bowel symptoms from a unilateral lesion?

Answer 15

No.

Question 16

How do the acute symptoms of complete cord transection vary from the later, chronic features?

Answer 16

Acute: spinal shock with flacid plegia (weakness), numbess, urinary retention, constipation

Chronic: spastic plegia, spastic bladder and rectal sphincter with incontince

(in chronic, things are “disinhibited”)

Question 17

Sparing what spinal segment with allow indepedent transfer (ability to move self)?

Answer 17

C7

Question 18

What’s the main type of information traveling contralaterally in the spinal cord? What does this mean for spinal hemisection (Brown-Sequard Syndrome)?

Answer 18

Pain and temperature. Loss of pain and temperature will be contralateral, all else will be ipsilateral.

Question 19

In a hemisegmented spinal cord, what will be different at the level of the lesion vs. below it?

Answer 19

At the level of the roots, there can be a LMN damage (producing flaccid, not spastic, weakness/paralysis).

Question 20

What do central cord lesions affect? Why?

Answer 20

Primarily the crossing fibers of the spinothalamic tract in the white comissure (pain and temperature), because that’s where they run. If the lesion is large enoug, it make affect anterior horn cells.

Question 21

What are some causes of central cord lesions? (3 things)

Answer 21

Syringomyelia (CSF-filled cavity in spinal cord), hematomyelia, intramedullary tumor)

Question 22

What is Tabes Dorsalis? Symptoms? Common cause?

Answer 22

Destruction of posterior columns. Impaired propriosensation (especially in the dark), impaired mechanoreception, inabiilty to detect bladder fullness, shooting pains while walking. Syphilis.

Question 23

What’s the Romberg test? Why does this happen?

Answer 23

Patient with balance loses balance when eyes are closed. Visual data can compensate for lack of proprioception and be sufficient for balance.

Question 24

Is a positive Romberg test indicative of a problem with the cerebellum?

Answer 24

No! It doesn’t show a problem with the cerebellum. If it were, patient wouldn’t have balance with eyes open.

Question 25

What are Argyl Robinson pupils?

Answer 25

Pupils accomodate but don’t react (to light)… like a prostitute… from whom you got syphilis / Tabes Dorsalis.

Hey, I didn’t make this up.

Question 26

What regions of the spinal cord are affected in posterolateral column syndrome?

Answer 26

Dorsal columns and corticospinal tracts.

Question 27

What’s the pathophysiology of posterolateral column syndrome (aka subacture combined degeneration)? Most common cause?

Answer 27

Myelin degeneration without inflammation. B12 deficiency.

Question 28

What are the signs/symptoms of posterolateral column syndrome?

Answer 28

Combination of tabes dorsalis (sensory loss, positive Romberg sign) and corticospinal tract dysfunction (spasticity, hyperactive reflexes).

Question 29

What’s one notable pathological reflex seen posterolateral column syndrome?

Answer 29

Babinski sign - upgoing toes when bottom of foot stroked (normally they should flex).

Question 30

What do patients with anterior horn cell disease experience? Is the disease focal or widespread?

Answer 30

Flaccid paralysis and atrophy of affected muscles. Can be either focal or widespread, depending on cause.

Question 31

What are the main causes of anterior horn disease? (name 3)

Answer 31

Spinal Muscular Atrophy (inherited or aquired)

Infectious (esp. Polio, but others as well)

Benign focal forms (less important)

Question 32

What is combined anterior horn cell - pyramidal tract syndrome?

Answer 32

Amyotrophic Lateral Sclerosis (ALS)

Question 33

In anterior spinal artery occlusion, what area of the spinal cord is spared?

Answer 33

Dorsal columns (proprioception, mechanoreception (makes seense)

Question 34

What is lost in anterior spinal artery occlusion? (4 things)

Answer 34

Below lesion: initial flaccid weakness -> spastic paraparesis

At lesion -> LMN abnormalities

Pain and temperature below lesion.

Bowel / bladder control.

Question 35

What does it mean for a tumor to be intramedullary? What spinal cord syndrome will it probably mimic?

Answer 35

Within the parenchyma of the spinal cord. Will probably mimic complete cord transection.

Question 36

How do symptoms of an intradural extramedullary lesion evolve?

Answer 36

Initially -> root compression

Increasing size -> more areas, until complete cord transection

Question 37

What two tumor types tend to cause intradural extramedullary tumors?

Answer 37

Schwannomas and meningiomas

Question 38

Contrast the symptoms of extradural tumors from intradural extramedullary tumors. Contrast their appearance on MRI.

Answer 38

Trick question - extradural and intradural extramedullary tumors have essentially the same symptoms. They do appear very distinct on imaging though.

Question 39

Causes of extradural lesions: list 5.

Answer 39

Disc disease (esp. herniation)

Epidural metastasis

Primary bone tumor

Lymphoma

Epidural Abcess

(note 3/5 of list are cancer)

Question 40

Why are we all going to be stiff and incontinent in our old age?

Answer 40

Cervical myelopathy

Question 41

What is cervical spondylosis?

Answer 41

Chronic degenerative change to bony structuresand ligaments secondary to loss of elasticity in discs and surrounding structures.

Question 42

Does L5 disc herniation cause a spinal cord syndrome? What do lumbar disc herniations cause?

Answer 42

No! There’s no spinal cord at L5. Typically lumbar disc herniations cause LMN lesion, dermatomal sensory loss (making loss/depression of reflexes at the level make sense), and radicular pain.