3 - Radiculopathy & Pelexopathy Flashcards
List 6 Muscles With Dual Innervation 🔑
Cuccurollo 4th Edition Chapter 5 EDX pg382
Describe the difference between the dorsal and ventral rami of the spinal cord.
Origin
Both (dorsal roots and ventral roots) exist from spinal cord
They join beyond the dorsal root ganglion.
Dorsal Rami
Innervate the paraspinal muscles
Carry sensory information from overlying skin
Ventral Rami
Innervate anterior horn motor neurons of muscles of the cervical, brachial, or lumbosacral plexus.
Contains axons originating from sensory and sympathetic ganglia
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95
At which level do the lumbar nerve roots exit? Which root is most likely to be injured in a disc herniation? for i.e. L5/S1 🔑🔑 EXAM 2021
Lateral L3-L4 disc → L3 nerve root affected
- Pain and sensory changes in anterior thigh
- Weakness in hip flexors/knee extensors
- Decreased patellar tendon reflex
Central L5-S1 disc herniation → S1 nerve root affected
- Pain and sensory changes to posterior thigh/leg
- Weakness to plantar flexion, hamstrings
- Decreased ankle jerk reflex
Cuccurollo 4th Edition Chapter 4 MSK pg289
What is the distinction between spondylosis, spondylolisthesis, and spondylolysis? 🔑🔑 EXAM
Spondylosis
Nonspecific degenerative process of the spine, often due to osteoarthritis with osteophyte formation
Spondylolisthesis
Anterior subluxation of one vertebral body on another
Spondylolysis
Defect in the pars interarticularis that allows the vertebra to slip upward
Neurology Secrets 6th Eiditon Chapter 7 Radiculopathy pg95
What is the difference between a disc bulge, protrusion, and herniation 🔑🔑
Cuccurollo 4th Edition Chapter 4 MSK pg288-289
Spinal Cord Abutment
Epidural extension without cord compression
https://radiopaedia.org/articles/epidural-spinal-cord-compression-escc-scale-2
What are the non-discogenic non-spondylitic causes of radiculopathy? 🔑🔑
- Tumors
- Abcess
- Hermorrhage
- Cysts
- Infection: TB, Syphilis, HIV infection
- Arachnoiditis
PMR Secrets 3rd Edition Chapter 17 pg142
List 8 causes of radiculogpthy.
What are the two most common?
💡 Non-traumatic Cervical Myelopathy 1) Spondylosis 2) Stenosis.
Causes of radiculogpthy:
- Herniated nucleus pulposus (HNP) < 50 years
- Spinal stenosis > 50 years old
- Mass in the spine: lipoma
- Abscess
- Hematoma
- Metastasis
- Inflammation Tuberculosis (TB)
- Infection Arachnoiditis
- Diabetes mellitus
Cuccurollo 4th Edition Chapter 5 EDX pg380
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg142 Q2
What condition can mimic cervical radiculopathy? 🔑
💡 C5-C6 radicular pain from shoulder to thumb passing elbow.
1- Fibromyalgia
Pain all over, female predominance, sleep problems, tender to palpation in multiple areas
2- Regional myofascial pain
Trigger point reproducing localized or radiating pain syndrome
3- Polymyalgia rheumatica
Age >50 yr; pain and stiffness in neck, shoulders, and hips; high ESR, responde to steroid
4- Acromioclavicular joint arthropathy
Pain in anterior chest with shoulder movement, tender on palpation & crossed adduction
5- Sternoclavicular joint arthropathy
Pain in anterior chest, pain with shoulder movement, pain on direct palpation
6- Shoulder bursitis, impingement syndrome, bicipital tendonitis
Pain with palpation, positive impingement signs, pain in C5 distribution
7- Lateral epicondylitis, Tennis elbow
Pain in lateral forearm, pain with palpation and resisted wrist extension
8- de Quervain’s tenosynovitis
Lateral wrist and forearm pain, tender at APL & EPB tendons; positive Finkelstein test
9- Trigger finger, stenosing, tenosynovitis of finger flexor tendons
Intermittent pain and locking of digit in flexion
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg145 Q7 Table 17-2
What condition can mimic lumbar radiculopathy? 🔑
💡 Think 3D from anterio-lateral-poaterior hip down to soles passing knees.
1- Fibromyalgia
Pain all over, female predominance, sleep problems, tender to palpation in multiple areas
2- Myofascial pain syndrome
Trigger point reproducing localized or radiating pain syndrome
3- Polymyalgia rheumatica
Age >50 yr; pain and stiffness in neck, shoulders, and hips; high ESR, response to steroid
4- Hip arthritis
Pain in groin, anterior thigh and weight-bearing, positive Patrick’s test
5- Trochanteric bursitis
Lateral hip pain, pain with palpation over lateral and posterior hip
6- Knee arthritis
7- Patellofemoral Pain
Anterior knee pain, worse with prolonged sitting, positive patellar compression test
8- Pes anserinus bursitis
Medial proximal tibia pain, tender to palpation
9- Hamstring tendinitis, chronic strain
Posterior knee and thigh pain, can mimic positive straight-leg raise, common in runners
10- Baker’s cyst
Posterior knee pain and swelling
11- Plantar fasciitis
Pain in sole of foot, worse with weight-bearing activities, tender to palpation
12- Gastrocnemius-soleus tendonitis, chronic strain
Calf pain, worse with sports activities, usually limited range of motion
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg146 Q8 Table 17-3
Clinical Findings of Radiculopathies 3 marks 🔑🔑
LMN Syndrome:
- Sensory loss
- Radicular pain
- Muscle weakness
- Reduced reflexes
- Retention or Incontinence
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg143 Q4
Cuccurollo 4th Edition Chapter 5 EDX pg380
60 yo man with neck pain, fasciculation on right deltoid and biceps. Mention the nerve root.
You evaluated a 60 year old man who has recurrent neck pain. On examination he has fasiculations of the right deltoid and biceps. What root represents the abnormalities seen in this man? (one mark)
C5 Motor root
MRI L4-L5 Disc, mention the root affected 🔑🔑
Motor Examination for Lumbar Radiculopathy (from L3 to S1) 🔑🔑
L3 Root
Power: hip adduction & knee extension weakness
L4 Root
Power: ankle dorsiflexion weakness (L4 > L5) test by having patient walk on heels
Reflex: decreased patellar reflex
L5 Root
Power: EHL weakness (L5), ankle inversion weakness
Trendelenburg gait & Abduction : gluteus medius weakness (L5)
Reflex: decreased Hamstring reflex
S1 Root
Ankle plantar flexion weakness (S1) have patient do 10 single leg toes stands
Reflex: decreased Achilles tendon reflex
What are the signs of an L4 radiculopathy?
- Sensory: Pain and paresthesias radiating to the hip, anterior thigh, and medial aspects of the knee and calf. Sensation is impaired over the medial calf. (L4 dermatome)
- Motor: Weakness occurs in the quadriceps and hip adductors.
- Reflex: Knee jerk is diminished
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95
What are signs of an L5 radiculopathy? 🔑🔑
💡 It is most easily identified by weakness in the extensor hallucis longus (EHL)
- Sensory: Pain radiating to the posterolateral buttock, lateral posterior thigh, and lateral leg.
- Motor: Weakness in gluteus medius, tibialis anterior and posterior, peronei, and extensor hallucis longus. Result in difficulty in ankle dorsiflexion, eversion, inversion, and hip abduction.
- Reflex: Ankle reflex is usually normal
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95
What are the signs of an S1 radiculopathy?
- Sensory: Pain radiating to posterior buttock, posterior calf, and lateral foot (classic sciatica). Sensory loss in the third, fourth, and fifth toes.
- Motor: Weakness may occur in the gluteus maximus (hip flexor) and plantar flexors.
- Reflex: Ankle jerk is usually diminished
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg95
What are the clinical features of lumbar stenosis?
- Neurogenic intermittent claudication or pseudoclaudication
- Pain is provoked by walking and standing, due increase in lordotic posture.
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg96
List 4 Indications to refer LBP for surgical assessment. 🔑🔑
- Cauda Equina Syndrom
- Cervical Myelopathy (Compression)
- Progressive motor deficits
- Pain not responsive to treatment
Which categories of medication may be of help during acute phases of pain?
1- NSAIDS
musculoskeletal inflammation or inflammation or nerve root swelling
2- Muscle relaxants
Muscle spasms and improve sleep
3- Antidepressant drugs (e.g., tricyclics) and antiepileptic drugs (e.g., gabapentin)
For neuropathic pain
Neurology Secrets 6th Edition Chapter 7 Radiculopathy pg101
EDX findings in radiculoapthy
List 4 conditions where EMG is normal in radiculopathy
Positive EDX Study for Radiculopathy
FIBs or PSWs should be found in two different muscles innervated by two different peripheral nerves originating from the same root
Normal EMG in Radiculopathy (Remember 1st two common causes)
- Acute Lesion: maybe decreased recruitment of MUAPs in weak muscles.
- Pure sensory: proximal to DRG
- Pure demyelinating: unless conduction block → weakness → low MUAP recruitment
- Spinal Stenosis
- Proximal Muscles
Cuccurollo 4th Edition Chapter 5 pg381
Findings of EDX study in Radiculopathy? 🔑🔑
Abnormal
- Only motor weakness with axonal lesion will show reduced CMAP
Normal
- Sensory symptoms
- Purely demyelinating
- Incomplete
- Chronic reinnervation
NCS
- SNAP: Normal since lesion is located proximal to the DRG (pre-ganglionic)
- CMAP: Normal or reduced amplitude if axonal degeneration occurs
- H-reflex: Abnormal in an S1 radiculopathy (not pathognomonic)
- F-waves: Muscles have more than one root innervation, which can result in a normal latency
EMG (mixed picture)
- Large MUAP at reduced recruitment pattern.
Cuccurollo 4th Edition Chapter 5 EDX pg380
Needle EMG criteria for diagnosing a radiculopathy? 🔑 What is the positive findings indicating present of radiculopathy in EMG study?
EMG criteria for Radiculopathy
- FIBs or PSWs should be found in two different muscles innervated by same root but two different peripheral nerves
- Six muscles (five peripheral muscles + paraspinals)
Normal in
- Demyelinating neuropathies
- Pure sensory nerve injuries
- Chronic nerve injuries
- Missed by random sampling
Cuccurollo 4th Edition Chapter 5 EDX pg381
Muscles for sampling
Upper Limb: deltoid, triceps, pronator teres, abductor pollicis brevis, extensor digitorum communis, and cervical paraspinal muscles. (pointing forward)
Lower Limb: vasts medialis, anterior tibialis, posterior tibialis, short head of biceps femoris, medial gastrocnemius, and lumbar paraspinal muscles.
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg147 Q16
Why is the EMG normal for many people with radiculopathy? 🔑
1- Sensory radiculopathy:
Affects sensory nerve roots and causes radicular pain and numbness will demonstrate a normal EMG.
2- Motor radiculopathy (motor neurapraxia)
Demyelination lesion will result in normal study
3- Chronic Radiculopathies
Slow axonal loss that is balanced with reinnervation may show polyphasic motor units or large motor units firing in a reduced recruitment pattern.
PMR Secrets 3rd Edition Chapter 17 Radiculopathy pg147 Q15
4- Some muscles are dual innervated, resulting in normal study
C6 Radiculopathy. What would you be the CMAP in the ulnar and median nerve? 🔑🔑 EXAM
Give 3 reasons for normal CMAP result even with clinical findings.
Reduced CMAP
- Radiculopathy with severe axonal lesions (specially with clinical motor weakness)
Normal CMAP
- Purely demyelinating (Result in abnormal sensory study only, motor will be normal)
- Incomplete
- Reinnervation has occurred (chronic injury)
Cuccurollo 4th Edition Chapter 5 EDX pg380
https://now.aapmr.org/electrodiagnosis-of-radiculopathies-cervical-thoracic-and-lumbar/
What is the most commonly affected level with cervical radiculopathy?🔑🔑
C7 (C6-C7 disc herniation)
Draw the brachial plexus 🔑🔑 EXAM
The only muscle of the arm that is a flexor and that is innervated by the posterior trunk of the plexus 🔑🔑
Brachioradialis, Radial nerve (C5-C6)
List 5 sensory branches of upper trunk and 3 sensory branches of lower trunk. List the peripheral branches affected in upper vs lower trunk injury. 🔑🔑
List 4 causes of plexopathy.
- Trauma: Traction, transection, obstetrical injuries, compression.
- Cancer (Pancoast tumor)
- Radiation therapy
- Idiopathic (neuralgic amyotrophy)
Cuccurollo 4th Edition Chapter 5 EDX pg383
List 4 muscles innervated by C5-C6
💡 Axillary, MSK & Supinator
- Deltoid (Axillary n.)
- Teres Major (Axillary n.)
- Biceps (MSK n.)
- Brachialis (MSK n.)
- Supinator (Radial n.)
What is the difference between C7-C8 vs C8-T1 in relation to hand function? 🔑
C7-C8 → wrist and finger drop
Radial
- Abd. poll. longus
- Ext. poll. brevis
- ECR brevis
- Ext. poll. longus
- EIP
- Ext. dig
- EDM
- ECU
C8-T1 → weak wrist, thumb & fingers flexion and grip functional.
Median:
Finger Flexors
- FDS—4 muscles
AIN “OK Sign”
- FDP—2 muscles
- Pronator quad
- FPL
LOAF
- Lumbricals—2 muscles
- Opponens pollicis
- Abductor pollicis brevis
- Flex poll. brevis 1/2
Ulner:
- FDP—2 muscles
- Dorsal interossei—4 muscles
- Palmar interossei—3 muscles
- Lumbricals—2 muscles
- Add poll.—1 muscle
- Flex poll. brevis 1/2
- Hypothenar muscles – Oppon. dig. min. – Abd. dig. min. – Flex. dig. min.
- Palmaris brevis
What muscle and nerves if cut cant do shoulder external rotation, flexion & abduction?🔑🔑
Deltoid, Axillary nerve
Rule of EDX study in plexopathy? what is the most important finding?
Benefits of EDX in plexopathy
- Localization of the lesion in relation to DRG
- Determining axonal or demyelination lesion or both
- Determining severity of lesion (axonal > demyelination)
- Rule out radiculopathy
Sensory Study
- Decreased SNAP = axon loss distal to DRG
- Normal SNAP = injury is proximal to DRG
Motor Study
- Distal CMAP amplitude is the main prognostic factor in a plexopathy
- It represents AXONAL LOSS
Late responses
- F-waves may be delayed or absent in plexopathies
- H-reflex to evaluate the S1 pathway but not pathognomonic
- Nonspecific, as they cannot localize a focal lesion.
EMG in plexopathy
- To rule out radiculopathy, and rule in plexopathy
- Abnormal peripheral muscles
- Normal paraspinal muscles
Cuccurollo 4th Edition Chapter 5 EDX pg383
How to differentiate plexopathy and root avulsion in EDX?
Plexus lesion is post-ganglionic
Sensory nerve potentials are reduced
Root avulsion is pre-ganglionic
Sensory nerve potentials are normal
List 3 Reasons for normal SNAP with +ve physical examination
- Lesion is hyperacute (less than 2 weeks), wallerian degeneration hasn’t occur
- Lesion is proximal to the dorsal root ganglion (DRG)
- Lesion is demyelination, possibly conduction block, leaving the axon relatively intact.
EDX Nerve Root Avulsion 🔑
NCS
- Normal SNAPs (even with clinical sensory loss, Injury proximal to DRG, pre-ganglionic)
- Absent CMAPs
Needle EMG
- Absent recruitment including the paraspinals.
1) Affected root in Erb’s Palsy or Stinger. 🔑
2) Common causes
3) Erbs’ Palsy – list 8 muscles affected 🔑🔑
What nerves & muscles are affected in an Erb’s Palsy? 🔑🔑
4) EDX findings
5) Treatment
💡 Nerve traction C5–C6 nerve roots of the upper trunk
Causes:
Pediatrics: shoulder dystocia, forceps delivery
Adult: blow to the head, neck, or shoulder, sports related stinger or burner
Presentation
- Adducted arm (deltoid and supraspinatus [SS] weakness)
- Internally rotated (teres minor and infraspinatus [IS] weakness)
- Extended (bicep and brachioradialis [BR] weakness)
- Pronated (Supinator and BR weakness)
- Wrist flexed (extensor carpi radialis longus [ECR-L] and brevis weakness)
EDX
- Stimulate at Erb’s point
- Abnormal lateral cutanous n. of arm and forearm.
Treatment
- Rehabilitation
- Intermittent splinting
- Activity restriction
Cuccurollo 4th Edition Chapter 5 EDX pg385
Errbs’ Palsy
List 4 sensory nerves affected 🔑🔑
List 3 motor nerves affected
Sensory Nerves
- Upper lateral cutaneous nerve of the arm (Axillary n.)
- Lower lateral cutaneous nerve of the arm (Radial n.)
- Lateral cutaneous nerve of the forearm (MSK n.)
- Superficial branch of the radial nerve
- Median Nerve
- Palmar cutaneous branch of the median n.
- Digital cutaneous branch of the median n.
Motor Nerves
- Axillary nerve
- Suprascapular nerve
- Musculocutaneus nerve
How to differentiate Erb’s palsy from C5-C6 root injury in EDX? 🔑🔑
💡 Go back to anatomy, we know that Erb’s palsy is UPPER TRUNK plexopathy, so it’s AFTER THE ROOT, which spares some of the muscles. Also it can be AFTER THE DRG.
NCS
- C5-C6: Normal SNAPs (Proximal to DRG)
- Erb’s: Abnormal SNAP
EMG, Muscle involvement in Root but not Erb’s Palsy:
- Rhomboid (Dorsal Scapular n.)
- Serratus Anterior (Long Thoracic n.)
- Paraspinals
Neck traction injury, complains of
- A burning or electric shock sensation
- Arm numbness and weakness immediately following the injury
- A warm sensation Give three differential diagnoses. 🔑🔑 EXAM
- Upper trunk brachial plexus injury
- Cervical spine injury or stenosis
- Cervical disc injury
26-year-old gentleman who was involved in a wrestling incident 2 days ago. 🔑🔑 EXAM 🟦
He complained of a burning pain radiating down his right arm, which started at the incident. The pain was followed by numbness and weakness of the same arm. He had to hold his arm against his body to relief the discomfort. His symptoms were resolved within few minutes without any residual complaints. Physical examination showed no neurological deficit.
(a) What is the most likely diagnosis?
(b) What is the pathophysiology of this condition?
Diagnosis
Stinger or burner
Pathology
Sudden forceful stretch in the nerve roots and brachial plexus as they emerge from the cervical spine.
PMR Secrets pg321
Football player complaining of ‘dead arm’. List 4 DDx. What are 4 ‘red flags’ that would lead to further investigation? 🔑🔑 EXAM
DDx
- Stinger Traction Injury
- SLAP tear
- Shoulder dislocation
- Neuralgic Amyotrophy
- Thoracic outlet syndrome ( axillary artery + medial cord of BP)
Red flags:
- Recurrent stinger
- Persistent neurological deficit
Not sure about Q&A.
1) Affected root in Klumpke’s Palsy. 🔑 EXAM
2) Common causes
3) Presentation
4) EDX findings
5) Treatment
Causes:
- Forced adduction seen in an MVA, falls
- Shoulder dislocations
- Pancoast tumor
- Thoracic outlet syndrome (TOS).
Presentation
- Shoulder girdle muscle function is preserved
- Wasting of the small hand muscles
- Claw hand deformity (lumbrical weakness)
- Horner syndrome
💡 Normal SNAP for proximal lesion even with clinical sensory loss. Abnormal CMAP in case of axonal loss
EDX
- Normal SNAP indicate a nerve root avulsion
- Reduced Medial antebrachial cutaneous sensory response
Treatment
- Rehabilitation with incomplete lesions
- Surgical exploration with a nerve root avulsion
Cuccurollo 4th Edition Chapter 5 EDX pg385
What is Adson’s test?🔑🔑
The examiner locates the radial pulse. The patient’s head is rotated to face the test shoulder. The patient then extends the head while the examiner laterally rotates and extends the patient’s shoulder. The patient is instructed to take a deep breath and hold it.
A disappearance of the pulse and reproduction of symptoms indicates a positive test.
Orthopedic Physical Assessment, 7th Edition (Magee)
1) Common causes of Thoracic Outlet Syndrome (TOS) 🔑🔑
2) Presentations & Examination 🔑🔑
3) EDX findings 🔑🔑
4) Treatment
Compression Sites
- Between the medial and anterior scalene muscles over the first rib (hypertrophied scalene muscles)
- Between the first rib and the clavicle (cervical rib, fibrous bands)
- Beneath the insertion pectoralis muscle on coracoid process (postural factors)
Vasogenic
- Subclavian artery, subclavian vein, or axillary vein
- Artery: Ischemia, necrosis, vague pain, fatigue, with decreased color and temperature.
- Vein: bluish, swollen, achy limb.
- Positive Adson’s test (subclavian artery) - Allan test - Roos test
Neurogenic
- Pain and numbness along the medial aspect of the forearm and hand
- Worsen with overhead activity.
- Hand muscle wasting may also be noted (median thenar > ulnar intrinsics).
C8-T1 Lower Trunk Plexopathy
- Median & Ulnar n. injury
- Sensory and motor affection
NCS
- Decreased SNAP for medial cutaneous n. of forearm (Lower trunk)
- Median SNAP is spared (Upper and Lower Trunk)
- Decreased CMAP of median n. (Hand weakness)
- Decreased CMAP & SNAP of ulnar n. (Branches from lower trunk only)
EMG
- Abnormal spontaneous activity for median and ulnar hand muscles (lower trunk) EMG.
Treatment
- Rehabilitation with a focus on ROM exercises
- Stretching of tight muscles
- Strengthening of the scapular stabilizers
- Surgery can be indicated for a first rib or fibrous band resection
- Botulinum toxin injection to the scalene, subclavius, and/or pectoralis minor muscles
- Scalenectomy with or without first rib resection, is required.
Cuccurollo 4th Edition Chapter 5 EDX pg385-386
1) Common causes of Neuralgic Amyotrophy (Acute Brachial Neuritis)
2) Presentation
3) List 5 Nerves for EDX study 🔑🔑 EXAM
4) Treatment
Causes
- Idiopathic, inflammatory, immune-mediated process
- After immunization, infection, surgery, or pregnancy
Presentation:
- Pain in shoulder or periscapular region, exacerbated by abduction and rotation.
- Weakness in a patchy patchy or multifocal involvement, asymmetrically bilateral.
- Lasting 2-3 weeks then slowly improves
- Fasciculations and atrophy may be seen (LMN)
- Autonomic dysregulation
- Trophic skin changes
- Temperature dysregulation
- Increased sweating
- Altered nail/hair growth
EDX
- Spinal accessory nerve
- Suprascapular nerve
- Long thoracic nerve
- Axillary nerve
- Anterior interosseus nerve [AIN]
💡 Acute deinnervation with positive sharp waves and fibrillation potentials Reduced amplitude, preserved conduction velocity and distal latency
Treatment
- Observation and pain control with recovery taking up to 3 years.
- Operative nerve exploration, neurolysis, nerve transfer or tendon transfer be be indicated if there is no evidence of EMG recovery by 9-12 months.
Cuccurollo 4th ed - Chapter 5 EDX pg386
How to differentiate between neoplastic and radiation plexopathy? 🔑🔑 EXAM 🟦
Cuccurollo 4th Edition Chapter 5 EDX pg387 Table 5-28
Braddom 6th Edition Chapter 41 Table 41.3
Patient who is post-mastectomy and treated with chemotherapy and radiation.
Presented with thenar/hypothenar wasting.
What is the most likely diagnosis?
What are two likely causes of muscle wasting? 🔑🔑 EXAM
Diagnosis
- Breast tumor metastasis
- Secondary carcinoma from history of radiation
- Radiation induced plexopathy (less likely b/c involves upper trunks)
Causes of wasting
- Ulnar neuropathy (Hypothenar)
- Median neuropathy (Thena = LOAF)
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