Spinal cord pathology - myelopathy + cauda equina + sciatica

Question 1

What is myelopathy?

Answer 1

Spinal cord compression

Question 2

What spinal cord levels makes the spinal cord?

Answer 2

C1 -> L1/2

Question 3

What is the cauda equina?

Answer 3

L3 –> conus medullaris and cauda equina (lumbar and sacral nerve roots)

Question 4

What are the 2 types of paralysis and what do they indicate?

Answer 4

• Hemiplegia: one side of body (brain lesion)
• Paraplegia: both legs (cord lesion)

Question 5

What are the main tracts?

Answer 5

DCML
Spinothalamic
Corticospinal

Question 6

Which tracts are sensory?

Answer 6

DCML
Spinothalamic

Question 7

Which tract is motor?

Answer 7

Corticospinal

Question 8

What type of tract is DCML?

Answer 8

Ascending
Dorsal root –> medulla then decussates

Question 9

What is DCML responsible for?

Answer 9

Fine touch
2 point discrimination
Proprioception

Question 10

What type of tract is spinothalamic

Answer 10

Ascending
Decussates 1-2 spinal levels above dorsal entry

Question 11

What is spinothalamic tract responsible for?

Answer 11

Pain and temp

Question 12

What type of tract is corticospinal?

Answer 12

Descending UMN
Decussates at medulla –> ventral root

Question 13

Do sensory spinal cord lesions show ipsilateral or contralateral signs?

Answer 13

Ipsilateral

Question 14

Do motor spinal cord lesions show ipsilateral or contralateral signs?

Answer 14

Contralateral

Question 15

What spinal cord level is the knee jerk?

Answer 15

L3/4

Question 16

Which spinal cord level is the big toe jerk?

Answer 16

L5

Question 17

Which spinal cord level is the ankle jerk?

Answer 17

S1

Question 18

Define myelopathy/spinal cord compression

Answer 18

Compression of C1-L1/2

Question 19

What are causes of spinal cord compression?

Answer 19

• Vertebral body neoplasms (main cause- metastases from lung, breast, RCC, melanoma)
• Spinal pathology (eg disc prolapse/herniation)

Question 20

What are symptoms of spinal cord compression?

Answer 20

• Progressive leg weakness w/ UMN signs:
• eg contralateral hyperreflexia, Babuski +ve, spasticity
• Sensory loss BELOW lesion (ascending sends info up)
• Sphincter involvement uncommon (late very bad sign)

Question 21

What investigations do you do for spinal cord compression?

Answer 21

MRI of spinal cord ASAP (risk of permanent damage if not)
CXR if malignancy suspected

Question 22

How do you treat spinal cord compression?

Answer 22

Neurosurgery (laminectomy, microdiscectomy)

Question 23

Define cauda equina syndrome

Answer 23

• Compression below conus medullaris

Question 24

Describe the pathophysiology of cauda equina syndrome

Answer 24

• surgical emergency where the nerve roots of the cauda equina at the bottom of the spine are compressed
• The cauda equina is a collection of nerve roots that travel through the spinal canal after the spinal cord terminates around L2/L3

Question 25

What are causes of cauda equina syndrome?

Answer 25

→ Herniated disc - most common (occurs in 2% lumbar herniation) → tumours - mets → spondylolisthesis - anterior displacement of vertebra out of line with one below → Abscess infection → trauma

Question 26

What are the signs and symptoms for cauda equina syndrome?

Answer 26

→ Bilateral or severe motor weakness in the legs w/ LMN signs (ipsilateral hypotonia, fasciculations, hyporeflexia) →Saddle anaesthesia (loss of sensation in the perineum – around the genitals and anus) → Loss of sensation in the bladder and rectum (not knowing when they are full) + sphincter involvement common → Urinary retention or incontinence → Faecal incontinence → Bilateral sciatica → Reduced anal tone on PR examination

Question 27

What investigations do you do for cauda equina syndrome?

Answer 27

MRI cord (diagnostic) Testing nerve roots/reflexes

Question 28

How do you treat cauda equina syndrome?

Answer 28

- Neurosurgery ASAP (eg. microdiscectomy, spinal fixation, spinal cord decompression) - Immobilise spine

Question 29

What is sciatica?

Answer 29

- L5/S1 lesion due to spinal or non spinal causes

Question 30

What is a spinal cause of sciatica?

Answer 30

IV disc herniation/prolapse

Question 31

What are non spinal causes of sciatica?

Answer 31

Piriformis syndrome, tumours, pregnancy

Question 32

What are symptoms of sciatica?

Answer 32

- Pain from buttock down lateral leg --> pinky toe - Weak plantarflexion + absent ankle jerk

Question 33

How do you diagnose sciatica?

Answer 33

Exam: can't do straight leg raise test without pain

Question 34

What investigations do you do for sciatica?

Answer 34

MRI

Question 35

How do you treat sciatica?

Answer 35

Analgesia + physiotherapy Neurosurgery