Differentiating Cervical Radiculopathy and

Peripheral Neuropathy

Adam P. Smith, MD

I have no financial, personal, or professional conflicts of interest to report

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

Key Features of Differentiation

Neurologic examination Neurologic examination Neurologic examination

Supplement exam with tests Willie Sutton

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

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

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 muscles in forearm (flexor carpis ulnaris and flexor digitorum profundus 3 & 4) Majority of hand intrinsic muscles, except LOAF (median)

Sensory Exam

Sensory distribution of spinal nerve roots overlap Sensory distribution of peripheral nerve branches are very discrete

Branches Roots

C8 versus Ulnar nerve- Sensory

C8 Dermatome based

Sensation to entire ring finger affected (and pinky finger)

Total sensory loss virtually never occurs

C8 versus Ulnar nerve- Sensory

Ulnar nerve (C8 and T1) Sensation to only ulnar half of ring finger affected (and pinky

finger)

Reflexes

Radiculopathy Appropriate DTRs depressed or absent early

Neuropathy Rare reflex changes Depends on location of entrapment

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

Maneuvers/ Signs Spurlings test

Tinels test Phalens test

Clawing Froments Wartenbergs

Radiculopathy

Neuropathy

Neuropathy

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

Electrodiagnostic Studies

Neuropathy Conduction delay often at site of compression

Absence of denervation in posterior myotomes (paraspinal muscles)

EMG usually normal

Imaging

Radiculopathy MRI or CT myelogram Require clinical and electrodiagnostic

correlation Nearly 28% of asymptomatic adults >40yo have

abnormal imaging

Neuropathy Rarely useful

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 Tinels sign at point of entrapment or compression

Case Examples

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

+ Spurlings test to the right

Spurlings Test

C5

C6

Right Left

C5-6

Key Factors Neck pain and radiculopathy

Weakness in muscles supplied by same spinal nerve root (C6), but different peripheral nerve branches (deltoid- axillary n., bicep- musculocutaneous n.)

Sensory disturbance concordant with C6

Reflexes normal

Positive Spurlings test

Concordant MRI

1.5cm

C5 C6 C6

C5 C6 C5

Case Example

64 yo female with diffuse neck pain Radiates bilateral arms

No weakness or numbness Slightly hyperactive reflexes Negative Spurlings

C5-6

C6-7 C5

C6

C7

Discography

Discography

Discography

Key Factors Neck pain and radiculopathy into arms

Interscapular pain Cloward 1959- Disc herniations of lower cervical levels induced spasms of para-scapular

muscles

Motor/sensory exam not localizing

Myelopathic with hyperactive reflexes

Negative Spurlings

Positive discogram Reproduced pain at levels and no pain at adjacent levels

Concordant MRI

Anterior Cervical Discectomy and Fusion

C5

C6

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 digits No reflex abnormalities Negative Spurlings sign, +Phalens/Tinels

Tinels Test

Phalens Test

Courtesy of Simon Oh, MD Colorado Neurology Specialists

Normal Abnormal

Latency < 2.3 ms or difference 15V (ulnar) or >50V (median)

axonal

NCS

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 Tinels and Phalens

Concordant NCS

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 Spurlings

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

Wartenbergs 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

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)

Froments 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

Testing flexor digitorum profundus 3 and 4

Tinels Test

C5-6

C4-5

C7-T1

C6-7 C5 C6

C7

T1

C4

Stimulate ulnar nerve transcutaneously and record EMG/NCS of abductor digiti minimi

Across wrist

Across elbow

Courtesy of Simon Oh, MD Colorado Neurology Specialists

Decreased amplitude (>6mV) Conduction velocity delayed (>51m/sec)

NCS

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 +Tinels test at elbow

NCS concordant with ulnar neuropathy at elbow

Non-concordant MRI with spinal root palsy

Olecrenon

Distal

Proximal

Tricepts m.

Ulnar nerve Medial epicondyle

Two heads of flexor carpis ulnaris m.

Biceps m.

Tricepts m.

Biceps m. Medial epicondyle

Olecrenon

Preoperative Postoperative Courtesy of Simon Oh, MD Colorado Neurology Specialists

NCS

Preoperative Postoperative

Thank You

DifferentiatingCervical Radiculopathy and Peripheral NeuropathySlide Number 2Radiculopathy versus NeuropathySlide Number 4Key Features of DifferentiationRoots versus BranchesC8 versus Ulnar nerve- MotorC8 versus Ulnar nerve- MotorSensory ExamC8 versus Ulnar nerve- SensoryC8 versus Ulnar nerve- SensoryReflexesPainManeuvers/ SignsElectrodiagnostic StudiesSlide Number 16Electrodiagnostic StudiesImagingMost Crucial DifferentiationsCase ExamplesCase ExampleSlide Number 22Spurlings TestSlide Number 24Slide Number 25Key FactorsSlide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Case ExampleSlide Number 33DiscographyDiscographyDiscographyKey FactorsAnterior Cervical Discectomyand FusionSlide Number 39Slide Number 40Slide Number 41Case ExampleTinels TestPhalens TestSlide Number 45NCSKey FactorsSlide Number 48Slide Number 49Slide Number 50Slide Number 51Case ExampleWartenbergs SignUlnar ClawingFroments SignSlide Number 56Slide Number 57Tinels TestSlide Number 59Slide Number 60NCSKey FactorsSlide Number 63Slide Number 64Slide Number 65Slide Number 66Slide Number 67Slide Number 68Slide Number 69NCSSlide Number 71Slide Number 72Thank You