Ch 5 - EDX: Radiculopathy

Question 1

What is a Radiculopathy?

Answer 1

Pathologic process affecting the nerves at the root level

Question 2

What is the presentation of Radiculopathy?

Answer 2

Pure sensory > sensorimotor complaints> pure motor complaints

Question 3

Why are sensory complaints MC in Radiculopathy?

Answer 3

Larger size of sensory fibers rendering more prone to injury

Question 4

Describe NCS of Radiculopathy.

Answer 4

Typically normal due to sparing of DRG

Question 5

What is the MCC of radiculopathy <50 yo?

Answer 5

Herniated nucleus pulposus (HNP)

Question 6

What is the MCC of radiculopathy >50 yo?

Answer 6

Spinal stenosis

Question 7

What are uncommon causes of radiculopathy?

Answer 7

“Hi Madam”
H—Herpes zoster
I—Inflammatory: TB, Lyme disease, HIV, syphilis, cryptococcus, and sarcoidosis
M—Metastasis
A—Arachnoiditis: Myelogram, surgery, steroids, and anesthesia
D—Diabetes mellitus
A—Abscess
M—Mass: Meningioma, neurofibroma, leukemia, lipoma, cysts, and hematoma

Question 8

What is the clinic presentation of a C5 radiculopathy?

Answer 8

Reduced reflex: Biceps
Weakness: Elbow flexion
Numbness: lateral arm

Question 9

What is the clinic presentation of a C6 radiculopathy?

Answer 9

Reduced reflex: Brachioradialis
Weakness: Elbow flexion
Numbness: lateral arm

Question 10

What is the clinic presentation of a C7 radiculopathy?

Answer 10

Reduced reflex: Triceps
Weakness: Elbow extension
Numbness: middle finger

Question 11

What is the clinic presentation of a C8 radiculopathy?

Answer 11

Reduced reflex: None
Weakness: Finger flexion
Numbness: medial forearm

Question 12

What is the clinic presentation of a T1 radiculopathy?

Answer 12

Reduced reflex: None
Weakness: Finger abduction
Numbness: medial elbow

Question 13

What is the clinic presentation of a L4 radiculopathy?

Answer 13

Reduced reflex: Patellar tendon
Weakness: Knee extension
Numbness: Anterolateral thigh/medial ankle

Question 14

What is the clinic presentation of a L5 radiculopathy?

Answer 14

Reduced reflex: Lateral hamstring
Weakness: Hallux extension
Numbness: Posterolateral thigh/calf and dorsal foot

Question 15

What is the clinic presentation of a S1 radiculopathy?

Answer 15

Reduced reflex: Achilles tendon
Weakness: Plantar flexion
Numbness: Posterior high/calf and lateral ankle

Question 16

Describe the SNAP in Radiculopathy.

Answer 16

Normal if the lesion is located proximal to the DRG

Question 17

Describe the CMAP in Radiculopathy.

Answer 17

Normal or reduced amplitude as lesion is distal to the motor neuron cell body.

Normal if the injury is purely demyelinating, incomplete, or reinnervation has occurred

Question 18

Describe H-reflex in Radiculopathy.

Answer 18

Possibly abnormal in an S1 radiculopathy but not pathognomonic

Question 19

Describe F-waves in Radiculopathy.

Answer 19

Not sensitive or specific for a radiculopathy. Muscles have more than one root innervation, which can result in a normal latency.

Question 20

What are the optimal # of muscles to needle for EMG when screening for radiculopathy?

Answer 20

6 including paraspinals

If 1 is ABN, then more muscles should be evaluated

Question 21

What is found on EMG in Radiculopathy?

Answer 21

FIBs or PSWs should be found in two different muscles innervated by two different peripheral nerves originating from the same root

Question 22

When would radiculopathy not be found on EMG?

Answer 22

Lesion is demylinating, purely sensory, postreinnervation, or missed by random sampling

Question 23

What is the clinical finding of C3/C4 radiculopathy?

Answer 23

HA
Innervate posterior and lateral scalp
C2 and C3 nerves become greater and lesser occipital nerves

Question 24

Which muscles are involved in a C5 radiculopathy?

Answer 24

Rhomboids
Deltoid
Biceps
Supraspinatus
Infraspinatus
Brachialis
BR
Supinator
Paraspinals

Question 25

Which muscles are involved in a C6 radiculopathy?

Answer 25

``` Deltoid Biceps BR Supraspinatus Infraspinatus Supinator PT FCR EDC Paraspinals ```

Question 26

Which muscles are involved in a C7 radiculopathy?

Answer 26

``` PT FCR EDC Triceps Paraspinals ```

Question 27

Which muscles are involved in a C8 radiculopathy?

Answer 27

``` Triceps FCU FDP Abductor digiti minimi First dorsal interossei PQ Abductor pollicus brevis Paraspinals ```

Question 28

Which muscles are involved in a L2/3/4 radiculopathy?

Answer 28

``` Iliopsoas Iliacus Gracilis Adductor longus Vastus medialis TA Paraspinals Difficult to distinguish between radiculopathy and alternate lesions due to only two peripheral nerves ```

Question 29

Which muscles are involved in a L5 radiculopathy?

Answer 29

``` Gluteus maximus Gluteus medius TFL TA MG Medial hamstring TP Peroneus longus Paraspinals ```

Question 30

Which muscles are involved in a S1 radiculopathy?

Answer 30

``` Gluteus maximus Gluteus medius TFL MG Medial hamstring PL TP Paraspinals ```

Question 31

What is the etiology of a S2/3/4 radiculopathy?

Answer 31

Iatrogenic Cauda equina Spinal stenosis

Question 32

Which muscles are involved in a S2/3/4 radiculopathy?

Answer 32

``` Abductor hallucis Abductor digiti quinti Needle exam of the external anal sphincter ``` ``` Monitor: Bulbocavernosus reflex, anal wink, external sphincter tone, and bowel and bladder function ```

Question 33

Which nerves innervate the Pectoralis major?

Answer 33

Medial and lateral pectoral nerves

Question 34

Which nerves innervate the Brachialis?

Answer 34

Musculocutaneous and Radial nerve

Question 35

Which nerves innervate Flexor digitorum profundus?

Answer 35

Median (AIN) and Ulnar nerves

Question 36

Which nerves innervate the Lumbricals?

Answer 36

Median and Ulnar nerves

Question 37

Which nerves innervate Flexor pollicis brevis?

Answer 37

Median and Ulnar nerves

Question 38

Which nerves innervate Pectineus?

Answer 38

Femoral and obturator nerves

Question 39

Which nerves innervate Adductor magnus?

Answer 39

Sciatic (tibial portion) and Obturator nerves

Question 40

Which nerves innervate Biceps femoris?

Answer 40

Sciatic (tibial portion) and Sciatic (peroneal portion) nerve

Question 41

Describe EDX findings in Radiculopathy at time of injury.

Answer 41

Decreased recruitment Decreased recruitment interval Prolonged F-wave Abnormal H-reflex (S1 radiculopathy)

Question 42

Describe EDX findings in Radiculopathy 4 days after injury.

Answer 42

~50% Dec CMAP compared to opposite side in severe cases

Question 43

Describe EDX findings in Radiculopathy 1 week after injury.

Answer 43

ABN spontenous activity in paraspinals 1st Normal if reinnervated or posterior rami spared

Question 44

Describe EDX findings in Radiculopathy 2 weeks after injury.

Answer 44

ABN spontaneous activity beginning in the limbs

Question 45

Describe EDX findings in Radiculopathy 3 weeks after injury.

Answer 45

ABN activity present in the paraspinals and limbs

Question 46

Describe EDX findings in Radiculopathy 5-6 weeks after injury.

Answer 46

Reinnervation begins

Question 47

Describe EDX findings in Radiculopathy 6 mo to 1 yr after injury.

Answer 47

Inc amplitude from reinnervated motor unit Reinnervation complete

Question 48

Describe EDX findings in Radiculopathy if repeated every 3-4 mo.

Answer 48

Serial EMG could be performed in intervals to monitor for reinnervation

Question 49

Describe EMG of Radiculopathy

Answer 49

Pure sensory injury: negative EMG