Neuro tracts

Question 1

What does the rubrospinal tract do?

Answer 1

Originates in red nucleus of pons

Excites flexors and inhibits extensors of upper limb. Has a role in fine hand movements

Question 2

What does the vestibulospinal tract do?

Answer 2

Originates in vestibular nuclei of pons (input from CNVIII and cerebellum)

Balance and ‘anti-gravity’ extensor muscles

Question 3

What do the medial and lateral reticulospinal tracts do?

Where do each start?

Answer 3

Lateral - starts in reticular formation in MEDULLA
- does flexor movements (inhibits extensors)

Medial - starts in reticular formation in PONS
- does extensor movements (inhibits flexors)

Question 4

Verbal response in GCS scores?

Answer 4

5 - orientated
4 - confused
3 - words
2 - sounds
1 - none

Question 5

What is decorticate posturing? (5)

Answer 5

Plantarflexed ankles
Internally rotated hip
Adducted shoulder
Flexed elbow
Flexed wrist (hands on centre of chest)

Question 6

What tracts are involved in decorticate posturing?

Where might the lesion be?

Answer 6

1 - Rubrospinal, due to disinhibition of the Red Nucleus
2 - Loss of corticospinal tracts, meaning pontine (lateral) reticulospinal, and vestibulospinal tracts overwhelm the medullary (medial) reticulospinal tract, causing Extesion

Therefore lesion may be in cerebral hemisphere or cervical spine

Question 7

Decerebrate posturing indicates a lesion where?

2 potential causes?

Answer 7

Below the Red Nucleus (i.e. midbrain or pons, at mid-colliculus or below)

1 - pontine stroke
2 - uncal herniation (starts as decorticate then transition to decerebrate)

Question 8

Eye-opening response in GCS scores?

Answer 8

4 - spontaneous
3 - to speech
2 - to pain
1 - none

Question 9

Role of the tectospinal tract?

Answer 9

Head and neck reflexes in response to light