2. I have no financial, personal, or professional
conflicts of interest to report
3. Radiculopathy versus Neuropathy
• Radiculopathy
– Usually involves one spinal nerve root distribution following “myotomal” and “dermatomal”
patterns
– Pathology often proximal (disc or osteophyte)
• Neuropathy
– Usually involves one peripheral nerve branch
– Pathology often entrapment distally
• “Double Crush” phenomenon
– Rare
– Both radiculopathy and neuropathy present
4.
5. Key Features of Differentiation
• Neurologic examination
• Neurologic examination
• Neurologic examination
• Supplement exam with tests
Willie Sutton
6. Roots versus Branches
• Roots
– C5
– C6
– C7
– C8
– T1
• Branches
– Musculocutaneous (C5,6,7)
– Axillary (C5,6)
– Radial (C5,6,7,8, T1)
– Median (C5,6,7,8)
– Ulnar (C8, T1)
Abundant overlap between
motor and sensory
distributions
7. C8 versus Ulnar nerve- Motor
• C8 spinal nerve root
– Present in ulnar, median, and radial peripheral nerve branches
– Myotome based
• Weakness in muscles of one spinal root but multiple peripheral nerve
branches, so usually partial or incomplete
– Atrophy rare (unless long-standing)
– Fasciculations rare (visible “motion” of muscle)
– C8 palsy will cause some weakness in nearly all intrinsic hand
muscles, including those innervated by median nerve
8. C8 versus Ulnar nerve- Motor
• Ulnar nerve (C8 and T1)
– Muscle based
• Weakness usually complete
• Worse with use and better with rest
– Atrophy “early”
– Fasciculations common
– Innervates:
• 1 ½ muscles in forearm (flexor carpis ulnaris and flexor digitorum profundus 3 & 4)
• Majority of hand intrinsic muscles, except LOAF (median)
9. Sensory Exam
• Sensory distribution of spinal nerve roots overlap
• Sensory distribution of peripheral nerve branches are very discrete
Branches Roots
10. C8 versus Ulnar nerve- Sensory
• C8
– Dermatome based
• Sensation to entire ring finger affected (and pinky finger)
– Total sensory loss virtually never occurs
11. C8 versus Ulnar nerve- Sensory
• Ulnar nerve (C8 and T1)
– Sensation to only ulnar half of ring finger affected (and pinky
finger)
13. Pain• Radiculopathy
– Common history of neck pain (abrupt-disc, slow-osteophyte)
– Occasional radiation into suboccipital area and interscapular area
– Pain down arm in spinal nerve root distribution
– Leaning head away from affected side and neck traction may
improve pain
– May worsen with valsalva
• Neuropathy
– Rarely neck or radicular pain
– Pain may be distal near joint (entrapment often proximal to joint)
– Depends on entrapment
• Carpal tunnel- Pain predominant symptom early in course
• Cubital tunnel- Pain may or may not be present
14. Maneuvers/ Signs
• Spurling’s test
• Tinel’s test
• Phalen’s test
• Clawing
• Froment’s
• Wartenberg’s
Radiculopathy
Neuropathy
Neuropathy
15. Electrodiagnostic Studies
• Radiculopathy
– NCS usually normal
• Usually sensory normal
• Motor may be abnormal
– EMG quite sensitive
• Single motor axon can innervate many muscle fibers, the loss
of only a few axons can produce detectable EMG changes
• “Fibrillations” of muscles at rest supplied by spinal nerve root
– Not seen until >3-4 weeks after compression
• “Denervation” ipsi paraspinal muscles
– Posterior rami (“sensory”) innervates paraspinal muscles
» Can only be compressed in foramen
16.
17. Electrodiagnostic Studies
• Neuropathy
– Conduction delay often at site of compression
– Absence of denervation in posterior myotomes
(paraspinal muscles)
• EMG usually normal
18. Imaging
• Radiculopathy
– MRI or CT myelogram
– Require clinical and electrodiagnostic
correlation
• Nearly 28% of asymptomatic adults >40yo have
“abnormal” imaging
• Neuropathy
– Rarely useful
19. Most Crucial Differentiations
• Difference in distribution of motor and sensory deficits
– Neuropathy has weakened muscles and disturbed sensation
solely within distribution of one peripheral nerve branch
• Discrete
• Lack of neck and radicular pain in neuropathy
• Neuropathy has absence of denervation in posterior
myotomes
• Frequent presence of Tinel’s sign at point of entrapment
or compression
21. Case Example
• 45yo male with neck pain radiating into
right arm, right deltoid/bicep weakness,
and numbness in right thumb and index
finger
• No reflex abnormality
• + Spurling’s test to the right
32. Case Example
• 64 yo female with diffuse neck pain
– Radiates bilateral arms
• No weakness or numbness
• Slightly hyperactive reflexes
• Negative Spurling’s
42. Case Example
• 58yo female with right lateral hand
numbness, and weakness
– Pain thenar eminence, no neck/arm pain
– Weakness in opponens pollicis
– Numb in first 3 ½ digits
– No reflex abnormalities
– Negative Spurling’s sign, +Phalen’s/Tinel’s
46. Courtesy of Simon Oh, MD
Colorado Neurology Specialists
Normal Abnormal
• Latency < 2.3 ms or
difference <0.3ms
• demyelination
• Amplitude >15μV
(ulnar) or >50ÎĽV
(median)
• axonal
NCS
47. Key Factors
• No neck pain or radiculopathy
– Pain present in hand
• Weakness in muscles supplied by one peripheral nerve branch
• Sensory deficit in one peripheral nerve
– More than 1 spinal root involved (C6 and C7)
• Reflexes normal
• Positive Tinel’s and Phalen’s
• Concordant NCS
48.
49.
50.
51.
52. Case Example
• 60yo female with left hand numbness and weakness
– Weakness hand intrinsics
• “Clawing” present
• Left pinky weak adduction
– Numbness 4th and medial 5th digits
– Reflexes normal
• Mild neck pain without radiculopathy
• No hand pain
• Negative Spurling’s
• PMHx- Long standing poorly controlled diabetes
• History of left hand carpal tunnel release
– No symptom improvement
4 Issues
• Neck pain
• No radiculopathy, but DM
• Prior dx carpal tunnel
• Motor/sensory findings
ulnar problem
53. Wartenberg’s Sign
• Ask patient to adduct fingers
• “Pinky” finger of affected
hand cannot adduct
• Patient may notice “pinky”
caught on pant pocket
• Ulnar innervated palmar
interossei weak
54. Ulnar Clawing
• Ask patient to leave fingers “at rest”
• 4th and 5th metacarpal-phalangeal joints
extend while interphalangeal joints
slightly flex but are somewhat paralyzed
• Weak medial lumbricales and 3rd/4th
flexor digitorum profundus (both ulnar
innervated)
55. Froment’s Sign
• Ask patient to adduct the thumb and
index finger so the finger pads touch
• Patient flexes interphalangeal joint
and finger tips touch
• Ulnar innervated adductor pollicis
weak so ulnar/median innervated
flexor pollicis brevis compensates
61. Courtesy of Simon Oh, MD
Colorado Neurology Specialists
Decreased amplitude (>6mV)
Conduction velocity delayed (>51m/sec)
NCS
62. Key Factors
• Minimal neck pain, but no radiculopathy into arms
– 60 yo so very common symptom
• Weakness of hand intrinsics supplied by ulnar nerve only
– Maintained median nerve function
• Sensory loss in ulnar nerve distribution
– Radial half of ring finger spared- not C8 palsy
• No reflex abnormalities
• No pain or numbness in median nerve distribution to suggest carpal tunnel syndrome
– Failed prior carpal tunnel release
• Negative Spurling, but +Tinel’s test at elbow
• NCS concordant with ulnar neuropathy at elbow
• Non-concordant MRI with spinal root palsy