Neuro VI Flashcards Preview

STEP > Neuro VI > Flashcards

Flashcards in Neuro VI Deck (59):
1

Common causes of noncommunicating hydrocephalus?

1) stenosis of aqueduct of Sylvius
2) colloid cyst blocking foramen of monro
3) tumors

2

Differentiating ex vacuo ventriculomegaly from hydrocephalus

ICP normal in ex vacuo ventriculomegaly

3

Common causes of ex vacuo ventriculomegaly

1) AD
2) advanced HIV
3) Pick disease

4

Total # of spinal nerves and breakdown

31
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

5

Rules about where nerves exit

1) C1-C7 exit above corresponding vertebra.
2) C8 exits below C7 and above T1.
3) All other nerves exit below (eg C3 exits above 3rd cervical vertebra; L2 exits below 2nd lumbar vertebra)

6

most common locations of herniated disc

L4-L5
L5-S1

7

Where does spinal cord end in adults?

Lower border of L1-L2

8

Where does subarachnoid space extend to in adults?

Lower border of S2 vertebra.

9

LP location?

L3-L5, keep the cord alive.

10

Gracilis vs. cuneatus

Organized as you are with Arms and hands outside, legs inside.

11

If you see a sympathetic horn what does that tell you?

Between T1 and L2/L3

12

Tract locations in spinal column...

FA 472

13

Organization of lateral spinothalamic tract...

Sacral out wide, cervical medial.
*Legs lateral.

14

anterior vs. lateral spinothalamic tract

Lateral = pain, temperature
anterior = crude touch, pressure.

15

lateral corticospinal tract organization

sacral lateral, cervical medial.
*legs are lateral

16

ascending vs. descending pathways

dorsal column + spinothalamic tracts carry ascending information.
CS tract carries descending information.

17

location of crosses in tracts

Ascending tracts (dorsal column, spinothalamic) synapse and then cross.

18

Dorsal column pathway

1st order neurons are sensory neurons with cell body in DRG --> enters spinal cord, ascends ipsilaterally in dorsal column --> synapses with ipsilateral nucleus cuneatus or gracilis in the medulla --> 2nd order neuron decussates in medulla --> ascends contralaterally in medial lemniscus --> synapse 2 on VPL in thalamus) --> 3rd order neuron projects to sensory cortex.

19

Spinothalamic tract pathway

sensory nerve ending (alpha delta or C fibers) has cell body in dorsal root ganglion, enters spinal cord --> synapse 1 in ipsilateral gray matter in spinal cord --> decussates at anterior white commissure --> ascends contra laterally --> synapses on VPL in the thalamus --> 3rd order neuron projects to sensory cortex.

20

Lateral CS tract pathway

UMN neurons have cell bodies in motor cortex --> descend ipsilaterally through IC --> most fibers decussate at caudal medulla (pyramidal decussation) --> descends contra laterally --> synapses on cell body of anterior horn in spinal cord --> LMN leaves spinal cord and synapses at NMJ.
**2 neuron pathway.

21

Weakness: UMN or LMN sign?

both

22

Muscle tone in UMN and LMN

Increased with UMN, decreased with LMN

23

spastic and flaccid paralysis for UMN and LMN

spastic paralysis = UMN lesion
flaccid paralysis = LMN lesion

24

syndromes affecting anterior horn?

1) polio
2) werdnig-Hoffmann

25

werdnig-Hoffmann prognosis

Median age of death of 7 months

26

Difference in presentation with polio vs. werdnig-Hoffmann

Polio --> asymmetric weakness
werdnig-Hoffmann --> symmetric weakness

27

Where will ALS affect spinal cord?

Combined UMN and LMN, so anterior horn + lateral CS tract

28

ALS presentation

1) asymmetric limb weakness (hands/feet)
2) fasciculations
3) eventual atrophy
4) *preserved sensory and bowel/bladder functions

29

ASA occlusion presentation on spinal cord cutout?

Everything affected except dorsal columns and Lissauer tract

30

What is the watershed area with ASA and why?

Upper thoracic territory because artery of Adamkiewicz supplies ASA below T8

31

Tabes dorsalis affects...

posterior column.

32

Tabes dorsalis pathophys

demyelination of dorsal columns and roots leading to progressive ataxia.

33

tabes dorsalis exam

1) positive romberg sign
2) absence of DTRs

34

tabes dorsalis associations

1) charcot joints
2) shooting pain
3) Argyll Robertson pupils

35

subacute combined degeneration presentation

1) ataxia
2) paresthesia
3) impaired position/vibration sense

36

How does polio virus get around?

Replicates in oropharynx and small intestine then spreads via bloodstream to CNS.

37

How do you recover polio virus?

from stool or throat.

38

CSF findings in poliomyelitis?

1) increased WBCs
2) slight increase of protein

39

What is frataxin?

iron binding protein

40

cell bio problem with Friedrich's?

impaired mitochondrial functioninig

41

Childhood presentation of Friedrich's?

Kyphoscoliosis

42

What is brown-sequard?

Hemisection of spinal cord

43

brown-sequard presentation

1) ipsilateral UMN signs below level of lesion
2) ipsilateral loss of tactile, vibration, proprioception sense below level of lesion
3) contralateral pain and temp loss below level of lesion (due to spinothalamic tract damage)
4) Ipsilateral loss of all sensation at level of lesion
5) Ipsilateral LMN signs at level of lesion
6) Horner syndrome if above T1

44

Horner syndrome and brown-sequard pathophys

Due to damage of oculosympathetic pahway

45

Whee is gallbladder pain referred to?

right shoulder via phrenic nerve.

46

Referred right shoulder pain think...

Diaphragm or gallbladder

47

C2 dermatome

posterior half a skull cap

48

C3 dermatome

high turtleneck shirt

49

C4 dermatome

low-collar shirt

50

C6 distribution

thumbs

51

T4

nipple

52

T7

xiphoid process

53

T10

umbilicus

54

L1 location

inguinal ligament

55

kneecap dermatome

L4

56

Dermatomes related to erection and sensation of penile and anal zones?

S2,3,4.
(S2,3,4 keep the penis off the floor)

57

triceps reflex

C7,8 "C7,8 lay them straight

58

cremaster reflex nerves

L1,L2-- "testicles move"

59

anal wink reflex nerves

S3,S4 "winks galore"