Ch 5 - EDX: Radiculopathy Flashcards
What is a Radiculopathy?
Pathologic process affecting the nerves at the root level
What is the presentation of Radiculopathy?
Pure sensory > sensorimotor complaints> pure motor complaints
Why are sensory complaints MC in Radiculopathy?
Larger size of sensory fibers rendering more prone to injury
Describe NCS of Radiculopathy.
Typically normal due to sparing of DRG
What is the MCC of radiculopathy <50 yo?
Herniated nucleus pulposus (HNP)
What is the MCC of radiculopathy >50 yo?
Spinal stenosis
What are uncommon causes of radiculopathy?
“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
What is the clinic presentation of a C5 radiculopathy?
Reduced reflex: Biceps
Weakness: Elbow flexion
Numbness: lateral arm
What is the clinic presentation of a C6 radiculopathy?
Reduced reflex: Brachioradialis
Weakness: Elbow flexion
Numbness: lateral arm
What is the clinic presentation of a C7 radiculopathy?
Reduced reflex: Triceps
Weakness: Elbow extension
Numbness: middle finger
What is the clinic presentation of a C8 radiculopathy?
Reduced reflex: None
Weakness: Finger flexion
Numbness: medial forearm
What is the clinic presentation of a T1 radiculopathy?
Reduced reflex: None
Weakness: Finger abduction
Numbness: medial elbow
What is the clinic presentation of a L4 radiculopathy?
Reduced reflex: Patellar tendon
Weakness: Knee extension
Numbness: Anterolateral thigh/medial ankle
What is the clinic presentation of a L5 radiculopathy?
Reduced reflex: Lateral hamstring
Weakness: Hallux extension
Numbness: Posterolateral thigh/calf and dorsal foot
What is the clinic presentation of a S1 radiculopathy?
Reduced reflex: Achilles tendon
Weakness: Plantar flexion
Numbness: Posterior high/calf and lateral ankle
Describe the SNAP in Radiculopathy.
Normal if the lesion is located proximal to the DRG
Describe the CMAP in Radiculopathy.
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
Describe H-reflex in Radiculopathy.
Possibly abnormal in an S1 radiculopathy but not pathognomonic
Describe F-waves in Radiculopathy.
Not sensitive or specific for a radiculopathy. Muscles have more than one root innervation, which can result in a normal latency.
What are the optimal # of muscles to needle for EMG when screening for radiculopathy?
6 including paraspinals
If 1 is ABN, then more muscles should be evaluated
What is found on EMG in Radiculopathy?
FIBs or PSWs should be found in two different muscles innervated by two different peripheral nerves originating from the same root
When would radiculopathy not be found on EMG?
Lesion is demylinating, purely sensory, postreinnervation, or missed by random sampling
What is the clinical finding of C3/C4 radiculopathy?
HA
Innervate posterior and lateral scalp
C2 and C3 nerves become greater and lesser occipital nerves
Which muscles are involved in a C5 radiculopathy?
Rhomboids Deltoid Biceps Supraspinatus Infraspinatus Brachialis BR Supinator Paraspinals
Which muscles are involved in a C6 radiculopathy?
Deltoid Biceps BR Supraspinatus Infraspinatus Supinator PT FCR EDC Paraspinals
Which muscles are involved in a C7 radiculopathy?
PT FCR EDC Triceps Paraspinals
Which muscles are involved in a C8 radiculopathy?
Triceps FCU FDP Abductor digiti minimi First dorsal interossei PQ Abductor pollicus brevis Paraspinals
Which muscles are involved in a L2/3/4 radiculopathy?
Iliopsoas Iliacus Gracilis Adductor longus Vastus medialis TA Paraspinals Difficult to distinguish between radiculopathy and alternate lesions due to only two peripheral nerves
Which muscles are involved in a L5 radiculopathy?
Gluteus maximus Gluteus medius TFL TA MG Medial hamstring TP Peroneus longus Paraspinals
Which muscles are involved in a S1 radiculopathy?
Gluteus maximus Gluteus medius TFL MG Medial hamstring PL TP Paraspinals
What is the etiology of a S2/3/4 radiculopathy?
Iatrogenic
Cauda equina
Spinal stenosis
Which muscles are involved in a S2/3/4 radiculopathy?
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
Which nerves innervate the Pectoralis major?
Medial and lateral pectoral nerves
Which nerves innervate the Brachialis?
Musculocutaneous and Radial nerve
Which nerves innervate Flexor digitorum profundus?
Median (AIN) and Ulnar nerves
Which nerves innervate the Lumbricals?
Median and Ulnar nerves
Which nerves innervate Flexor pollicis brevis?
Median and Ulnar nerves
Which nerves innervate Pectineus?
Femoral and obturator nerves
Which nerves innervate Adductor magnus?
Sciatic (tibial portion) and Obturator nerves
Which nerves innervate Biceps femoris?
Sciatic (tibial portion) and Sciatic (peroneal portion) nerve
Describe EDX findings in Radiculopathy at time of injury.
Decreased recruitment
Decreased recruitment interval
Prolonged F-wave
Abnormal H-reflex (S1 radiculopathy)
Describe EDX findings in Radiculopathy 4 days after injury.
~50% Dec CMAP compared to opposite side in severe cases
Describe EDX findings in Radiculopathy 1 week after injury.
ABN spontenous activity in paraspinals 1st
Normal if reinnervated or posterior rami spared
Describe EDX findings in Radiculopathy 2 weeks after injury.
ABN spontaneous activity beginning in the limbs
Describe EDX findings in Radiculopathy 3 weeks after injury.
ABN activity present in the paraspinals and limbs
Describe EDX findings in Radiculopathy 5-6 weeks after injury.
Reinnervation begins
Describe EDX findings in Radiculopathy 6 mo to 1 yr after injury.
Inc amplitude from reinnervated motor unit
Reinnervation complete
Describe EDX findings in Radiculopathy if repeated every 3-4 mo.
Serial EMG could be performed in intervals to monitor for reinnervation
Describe EMG of Radiculopathy
Pure sensory injury: negative EMG
