S3: Pathway Lesions and SX

Question 1

Ipislateral loss of epicritic sense can occur from X of the

Answer 1

Dorsal column/lemniscal sys.

1. dorsal root axons
2. gracile or cuneate fasiculus (spinal cord)
3. gracile or cuneate nuceli (medulla)

Question 2

Contralateral loss of epicritic sense can occur from X of the

Answer 2

1. medial lemniscus going up the medulla, pons, midbrain to thalamus
2. VPL in thalamus
3. post central gyrus

Question 3

what does loss of epicritic sense include?

Answer 3

loss of

1. sterogenesis (cant recognize tactile shapes in hand)
2. position sense - can lead to shuffling gait, reaching inaccuracies
3. loss of vibration - insesntive to high frequency stimulation
4. simpe touch intact but sensitivity decreased

Question 4

why is EPICRITIC information coming into the spinal cord suspectible to injury?

Answer 4

it comes in as large diameter dorsal root axons – vulnerable to insult from ischemia, toxicity, bacteria, etc

so: early sx of peripheral nerve disease shows as epicritic

Question 5

ipsilateral loss of protopathic informaiton is seen witn

Answer 5

ALS

1. dorsal root axons
2. lissaeurs tract or dorsolateral fasciulus
3. dorsal horn

Question 6

spinocerebellar carries ___ information from the ___

Answer 6

proprioceptive (muscle and joint position) from the trunk and limbs

Question 7

ipislateral loss of propathic from head and neck

caused by X of

Answer 7

1. spinal tract of CN 5

2. spinal n. of 5 in the medull

Question 8

contralateral loss of propathic from head and neck

caused by X of

Answer 8

1. after the spinal nulceus in the medulla (where it crosses) so a pons or midbrain region
2. in the vpm

Question 9

loss of proprocpetive from face on the same side can be due to

Answer 9

X trigmeminal nerve

X mescephalic nucleus of 5

X menscephalic tract of CN 5

X motor n. of 5 in the pons

X cerebellum

Question 10

loss of chewing on the same side can be caused by

Answer 10

X motor n. of 5 in the pons

X trigeminal nerve

Question 11

corticobulblar controls hypoglossal cranial nerve ncueli mostly

Answer 11

contralaterally

Question 12

corticobulblar controls facial cranial nerve ncueli mostly

Answer 12

both

Question 13

The bilateral projections from the surviving CB can sustain considerable movement on both sides of the patient

Usually only the___ and ___ are affected by a unilateral CB lesion

Answer 13

tongue and face (CN 7)

Question 14

damage to the corticospinal in the brainstem therefore impairs movement mainly on the ____ side of the body.

Answer 14

opposite

since mostly lateral corticopsinal which crosses and the pyrmida decessations

Question 15

unilateral patholgoy of the corticobulbar tract sx

Answer 15

will weaken movement of the head and neck opposite of the X

does not significantly weakend since most cn actually get bilateral input from CB

Question 16

damage to lateralc orticiospinal tract occurs with

Answer 16

X to the tract below the pyramids decussations in the medulla

Question 17

In the few surgical case studies of isolated CS damage (lesion of the medullary pyramid), the sx were

Answer 17

modest: temporary weakness, permanent Babinski’s sign, and permanent loss of independent finger movements.

mostly the pyramidal tracts are damaged with the brainstem tracts so sx area outright pralysis

Question 18

Frontal lobe lesions often cause ___

Answer 18

severe paralysis because the precentral (motor) and premotor areas of cortex contribute to both direct and indirect motor pathways

Question 19

damage to a Brainstem-spinal pathways at the level of the medulla wiill cause

Answer 19

problems with movement on the opposite side of the body

Question 20

damage to a Brainstem-spinal pathways at the level of the spinal caord wiill cause

Answer 20

problems with mvoement on the same side of the body