Spinal cord function and dysfunction

Question 1

How many segments of the spinal cord are there?

How many vertebrae are there?

Answer 1

SC: 31 (8C,12T,5L,5S,1C)
V: 30 (7C,12T,5L,5S,1C) -> discrepancy

Be careful when speaking about spinal and vertebral levels.

Question 2

What are the spinal nerves subdivided into?

Answer 2

8 Cervical
12 Thoracic
5 Lumbar
5 Sacral
1 Coccygeal

Question 3

How do the spinal nerves exit the vertebral column?

Answer 3

Through intervertebral foramina

Question 4

Where in the spinal cord are enlargements for the innervation of limb found?

Answer 4

Cervical (C3-T1)

Lumbar (L1-S3)

Question 5

Which layer does the spinal block go into?

Answer 5

Subarachnoid space

Question 6

Which layer does an epidural nerve block go in?

Answer 6

Epidural space

Question 7

Where is CSF taken from in an LP?

Answer 7

From the subarachnoid space. (L3/L4 or L4/5)

Question 8

What is the grey and white matter in the spinal cord?

Answer 8

Grey: cell bodies (inside)
White: tracts (outside)

Question 9

Corticospinal tract

Answer 9

Main voluntary movement pathway

Question 10

What are the main sensory pathways?

Answer 10

Dorsal column pathways and spinothalamic tract

Question 11

Dorsal column pathways

Answer 11

->Discriminative touch, vibration, proprioception

fasciculus gracilis for ipsilateral lower limb
fasciculus cuneatus for ipsilateral upper limb

Question 12

Spinothalamic tract

Answer 12

Pain and temperature (from contralateral side of the body)

Question 13

Which factors affect the severity of a spinal cord lesion?

Answer 13

• Loss of neural tissue
• Vertical level
• Transverse plane

Question 14

Loss of neural Tissue in spinal cord injury

Answer 14

• Usually small if due to trauma

- Can be more extensive e.g. metastases, degenerative disease

Question 15

What is the relationship between the severity of the disability and the vertical level?

Answer 15

The higher the lesion, the greater the disability.

Question 16

Transverse plain (spinal lesions)

Answer 16

most lesions are not complete

Question 17

How many people are paralysed due to spinal cord injury every day in the UK?

Answer 17

6

Question 18

What are the most common causes of spinal cause injury?

Answer 18

a broken neck or back as a result of road traffic accidents, accidents during sports or recreation or falls (in older people)

Question 19

In principle, how many neurones are there between the skin and the brain?

Answer 19

3

Question 20

What are the major 3 pathways affected by spinal cord injury?

Answer 20

lateral corticospinal - hence paralysis
dorsal column - hence loss of sensation of touch
spinothalamic - loss of feeling pain and temperature

Question 21

What are the 2 stages of injury to the lateral corticospinal tract?

Answer 21

Stage 1. Spinal shock: loss of reflex activity below the lesion, lasting for days or weeks = flaccid paralysis

Stage 2. Return of reflexes: hyperreflexia and/or spasticity = rigid paralysis

Question 22

Brown-Sequard Syndrome

Answer 22

With unilateral lesions the relationship of the deficit to the lesion depends on where the tract decussates