Lesions

Question 1

Cerebellar lesion

Answer 1

ipsilateral symptoms eg

nystagmus, diplopia when look to right = right cerebellar lesion

Question 2

Brainstem lesion

Answer 2

ipsilateral face and contralater limb eg

left facial weakness, right arm and leg weakness = left brainstem lesion

Question 3

Brain lesion

Answer 3

contralateral symptoms

eg lesion on right side of cortex = left weakness and hemiparesis

Question 4

Which root is typically compressed by L5/S1 disc prolapse?

Answer 4

S1

L5 is above the disc and S1 just underneath so it gets compressed

in most cases the nerve root below is affected eg C5/C6 herniation affects root C6

Question 5

Brown sequard syndrome

Answer 5

• hemisection of the cord / unilateral cord lesion
• contralateral spinothalamic (pain and temperature) loss
• ipsilateral weakness (UMN lesion - can have clonus, extensor plantar response etc)
• dorsal column loss below lesion (fine touch, vibration, proprioception)
• may be caused by injury to the spinal cord (most commonly) from trauma (fall or injury from gunshot or puncture), spinal cord tumour, ischemia or infectious or inflammatory diseases such as TB, or MS.

Question 6

Transverse cord lesion

Answer 6

loss of all modalities, including motor, below lesion

- eg transverse myelitis

Question 7

Dorsal column

Answer 7

• decussates at medial lemniscus (medulla)
• sensation of fine touch, vibration and proprioception
• more distal > cuneate fasciculus = upper limbs, head and neck
• more proximal > graciate fasciculus = lower limbs

Question 8

Spinothalamic tract

Answer 8

• decussates at spinal cord level
• sensation of pain and temperature
• anterior spinothalamic = crude touch
• lateral spinothalamic = pain and T

Question 9

Corticospinal tract

Answer 9

• controls movement of skeletal muscles
• anterior corticospinal = trunk and proximal limbs
• lateral corticospinal = distal parts of limbs

Question 10

Lesion at right dorsal column at L1 produces what signs?

Answer 10

Loss of vibration, light touch and proprioception on the right leg

(decussation only at medulla)

Question 11

Lesion at right fasciculus cuneatus at C3 produces what signs?

Answer 11

Loss of vibration, light touch and proprioception on the right upper limb and trunk

Question 12

Lesion at right lateral corticospinal tract at L1 produces what signs?

Answer 12

UMN lesion
- weakness of right leg, + hypertonia, hyperreflexia etc

(decussation happens above the spinal cord)

Question 13

Lesion at the right lateral spinothalamic tract at L1 produces what signs?

Answer 13

• loss of pain and temperature sensation on the left leg

decussation happens at the level of spinal cord

Question 14

Lesion at anterior gray and white commissures at C5/C6?

Answer 14

• Central cord syndrome
• loss of pain and temperature sensation on both upper extremities

(commissures found in the middle of the cord where spinothalamic tract decussates. decussation of spinothalamic tract prevented bilaterally)

Question 15

Complete transection of dorsal column, bilaterally, at cervical spine?

Answer 15

Posterior cord syndrome

- loss of light touch, vibration and proprioception bilaterally from the neck down

Question 16

Complete transection of lateral corticospinal and lateral spinothalamic with sparing of dorsal column at cervical region?

Answer 16

Antierior cord syndrome

• UMN bilaterally from neck down
• LMN bilaterally of upper limb (affected level only) (damage to ventral horns of LMN)
• loss of pain and temperature from neck down