Nerve Lesions

Question 1

What info does the dorsal-column medial lemniscus (DCML) tract convey?

Answer 1

Proprioception, vibration and 2 point touch discrimination

Question 2

Where does the DCML decussate?

Answer 2

Medulla

Question 3

What info does the spinothalamic tract convey?

Answer 3

Pain and temperature (lateral)
Crude touch (anterior)

Question 4

Where does the spinothalamic tract decussate?

Answer 4

At level of entry of spinal cord/ 2 levels above

Question 5

What info does the spinocerebellar tract convey?

Answer 5

Balance and coordination

Question 6

Where does the spinocerebellar tract decussate?

Answer 6

Dorsal don’t, ventral double cross

Question 7

Name the ascending spinal tracts (3)

Answer 7

DCML
Spinothalamic tract
Spinocerebellar tract

Question 8

Name the descending spinal tracts (3)

Answer 8

Corticospinal tract
Rubrospinal tract
Tectospinal tract

Question 9

What does the corticospinal tract do?

Answer 9

Majority of motor functions

Question 10

Where does the corticospinal tract decussate?

Answer 10

Lateral at medulla

Anterior at level of exit on spinal cord

Question 11

What does the rubrospinal tract do?

Answer 11

Rudimentary motor function

Question 12

Where does the rubrospinal tract decussate?

Answer 12

Midbrain

Question 13

What does the tectospinal tract do?

Answer 13

Reflex head/ eye responses

Question 14

Where does the tectospinal tract decussate?

Answer 14

Midbrain

Question 15

What is myelopathy?

Answer 15

Compression of the spinal cord

Question 16

What is radiculopathy?

Answer 16

Compression of the nerve root ‘pinched nerve’

Question 17

What are the symptoms of myelopathy? (4)

Answer 17

Progressive (increasingly weak, clumsy hands)
UMN leg signs
LMN arm signs
Incontinence, hesitancy + urgency are late features

Question 18

What are the symptoms of radiculopathy? (4)

Answer 18

Pain/ electrical sensations in arms/fingers at level of compression
Numbness
LMN weakness
Eventual wasting of muscles innervated by affected root

Question 19

What are the investigations for myelopathy and radiculopathy?

Answer 19

MRI urgent

Question 20

What is the treatment for myelopathy & radiculopathy?

Answer 20

Surgical decompression and dexamethasone

Question 21

What contralateral sign is present in Brown-Sequard syndrome?

Answer 21

Loss of pain and temperature sensation below lesion

Question 22

What ipsilateral signs are present in Brown-Sequard syndrome? (2)

Answer 22

Weakness

Loss of proprioception and vibration sense

Question 23

What sign is present at the level of the lesion in Brown-Sequard syndrome? (2)

Answer 23

Flaccid paralysis

Loss of all sensation

Question 24

What are the causes of peripheral neuropathy? (5)

Answer 24

DAVID
Diabetes
Alcohol
Vitamin deficiency (B12)
Infective (GB)
Drugs (isoniazid)

Question 25

What are some of the risk factors for carpal tunnel syndrome? (4)

Answer 25

Pregnancy Obesity Hypothyroidism Rheumatoid Arthritis

Question 26

What are the symptoms of carpal tunnel syndrome? (3)

Answer 26

Pain + paresthesia in hand = wake and shake Loss of sensation in palm, medial 3 1/2 fingers Wasting of thenar eminence

Question 27

What muscle in particular shows wasting in carpal tunnel syndrome?

Answer 27

Abductor pollicis brevis

Question 28

In carpal tunnel syndrome, when are the pain and paresthesia worse?

Answer 28

Worse at night

Question 29

How do you investigate for carpal tunnel syndrome? (2)

Answer 29

Phalen's (flexing) test | Tinel's (tapping) test

Question 30

How do you treat carpal tunnel syndrome? (3)

Answer 30

Conservative: pain relief, splint at night Hydrocortisone injection Surgical decompression/ cut open flexor retinaculum

Question 31

What are the nerve roots for the sciatic nerve?

Answer 31

L4 - S1

Question 32

What are the causes of sciatica? (4)

Answer 32

Pelvic tumours Fracture to pelvis/ femur Disc prolapse Osteoarthritis

Question 33

What are the symptoms of sciatica? (3)

Answer 33

- Sensory loss or pain in back of thigh/ leg - Foot drop - Loss of sensation below the knee laterally

Question 34

How would you investigate sciatica?

Answer 34

MRI urgent

Question 35

How would you treat sciatica?

Answer 35

Conservative

Question 36

What is the cauda equina?

Answer 36

Bundle of spinal nerves from the level of L1/2

Question 37

What are the symptoms of cauda equina syndrome? (6)

Answer 37

- Lumbosacral pain - Saddle anaesthesia - Areflexia - Fasciculations - Loss of bowel/ bladder control - Urinary retention

Question 38

How would you investigate cauda equina syndrome? (2)

Answer 38

MRI spine | PR (rectal exam)

Question 39

How would you treat cauda equina syndrome? (2)

Answer 39

Surgical decompression | High dose dexamethasone

Question 40

What are the red flags to look out for in cauda equina syndrome? (6)

Answer 40

``` Bilateral sciatica Bilateral flaccid leg weakness Saddle anaesthesia Bladder + bowel dysfunction Erectile dysfunction Areflexia ```

Question 41

What does damage to the right optic nerve cause?

Answer 41

Loss of vision in right eye

Question 42

What does damage to the optic chiasm cause?

Answer 42

Bitemporal hemianopia

Question 43

What does damage to the left optic tract cause

Answer 43

Right homonymous hemianopia

Question 44

What does damage to Meyer's loop on the left (left optic radiation) cause?

Answer 44

Right homonymous superior quadrantanopia

Question 45

What does damage to Baum's loop on the left (left optic radiation) cause?

Answer 45

Right homonymous inferior quadrantanopia

Question 46

What are the clinical features of an oculomotor nerve palsy? (3)

Answer 46

- Tramp's palsy (eye down + out) - Fixed dilated pupil, doesn't react to light - Ptosis

Question 47

What nerve is affected in Bell's palsy?

Answer 47

Facial nerve (CN 7)

Question 48

What are the clinical features of Bell's palsy? (3)

Answer 48

- Drooping of mouth corner - Inability to close eyelid - Smooth, wrinkle-free forehead

Question 49

How do you treat Bell's palsy?

Answer 49

Steroid

Question 50

In CN 9/ 10 lesion, where does the uvula deviate?

Answer 50

Uvula deviates AWAY from lesion

Question 51

In CN 12 lesion, where does the tongue deviate?

Answer 51

Tongue deviated TOWARDS lesion