03.2 Ascending Pathways

Question 1

What modalities does the dorsal column medial lemniscus pathway carry?

Answer 1

Fine touch
Proprioception
Vibration

Question 2

Where do the neurones of the dorsal column medial lemniscus pathway decussate?

Answer 2

At the medulla - Above T6 at the cuneate nucleus

Below T6 at the Gacile nucleus

Question 3

Where do the 3rd order neurones begin in the dorsal column medial lemniscus pathway?

Answer 3

Thalamus

Question 4

In the dorsal column medial lemniscus pathway which fibres are the most lateral and medial?

Answer 4

Cervical are the most lateral

Sacral are the most medial

Question 5

What are the modalities carried by the spinothalamic pathway?

Answer 5

Crude touch and pressure (anterior)

Pain and temperature (lateral)

Question 6

Where do the neurones decussate?

Answer 6

At their spinal level

Question 7

In the spinothalamic pathway which fibres are the most lateral and medial?

Answer 7

Cervical are the most medial

Sacral are the most lateral

Question 8

What modalities do the spinocerebellar tracts carry?

Answer 8

Unconscious proprioception of muscles o the cerebellum

Question 9

Do the fibres of the spinocerebellar tracts decussate?

Answer 9

There is no net dessucation in any of the tracts

the anterior tract does decussate and does so twice

Question 10

What can cause loss of the dorsal column medial lemniscus pathway?

Answer 10

B12 deficiency
Tabes dorsalis (seen in neurosiphillis)

Question 11

What is lost in a spinal cord lesion of the DCLM pathway?

Answer 11

Ispilateral loss of fine touch, vibration, proprioception

Question 12

What is lost in a spinal cord lesion of the spinothalamic pathway?

Answer 12

Contralateral loss of Crude touch, pressure, pain and temperature

Question 13

What is lost in a Brown Sequard lesion?

Answer 13

Ipsilateral loss of DCLM
Contralateral loss of spinothalamic pathway
Ipsilateral loss of motor function