Differentiating Cervical Radiculopathy from Cervical Myelopathy
Cervical radiculopathy presents with unilateral arm pain in a dermatomal distribution with sensory or motor deficits confined to one upper extremity, while cervical myelopathy presents with bilateral upper extremity symptoms, lower extremity involvement (gait disturbance, balance problems), and upper motor neuron signs indicating spinal cord compression. 1, 2, 3
Key Clinical Signs of Cervical Radiculopathy
Upper Extremity Findings (Unilateral):
- Neck pain radiating down one arm in a specific dermatomal pattern 1
- "Electric" quality neuropathic pain characteristic of nerve root compression 4
- Sensory deficits or paresthesias (tingling, numbness) in the affected nerve root distribution 1, 5
- Motor weakness confined to specific myotomes corresponding to the compressed nerve root 1, 5
- Diminished deep tendon reflexes, particularly triceps reflex, are the most common neurologic finding 6
- Symptoms typically affect C5-C6 or C7 nerve roots most commonly 4
Absence of Lower Extremity Involvement:
Key Clinical Signs of Cervical Myelopathy
Upper Extremity Findings (Often Bilateral):
- Difficulty with fine motor skills and hand clumsiness 3
- Hand numbness that may be bilateral 3
- Upper motor neuron signs in the upper extremities 2
Lower Extremity Involvement (Critical Distinguishing Feature):
- Difficulty walking due to loss of balance 3
- Gait abnormalities requiring detailed neurologic examination 2
- Bilateral symptoms affecting both upper and lower extremities 4, 7
- Long tract signs indicating spinal cord compression 4
Spinal Cord Compression Signs:
- Upper motor neuron signs on examination 2
- Progressive neurological deficits 4, 7
- Potential bladder or bowel dysfunction 7
- Loss of perineal sensation in severe cases 7
Critical Clinical Pitfalls
When Unilateral Arm AND Leg Symptoms Occur Together:
- This raises concern for cervical myelopathy (spinal cord compression) rather than simple radiculopathy 4
- Consider cervical cord compression with long tract signs 4
- Multiple sites of pathology affecting both cervical and lumbar spine may coexist 4
- Non-spinal causes such as multiple sclerosis must be considered 4
Rarely, cervical myelopathy may coexist with clinically significant cervical radiculopathy, requiring careful examination to identify both conditions. 1
Diagnostic Approach Algorithm
Step 1: Assess Distribution of Symptoms
- Unilateral arm pain only → suspect radiculopathy 1
- Bilateral upper extremity symptoms OR any lower extremity involvement → suspect myelopathy 4, 7
Step 2: Perform Targeted Neurologic Examination
- Test deep tendon reflexes (diminished in radiculopathy, hyperreflexia in myelopathy) 6, 2
- Assess for upper motor neuron signs (present in myelopathy, absent in radiculopathy) 2
- Evaluate gait and balance (abnormal in myelopathy, normal in radiculopathy) 2, 3
- Test fine motor skills of hands (impaired in myelopathy) 3
Step 3: Imaging Selection
- MRI cervical spine without contrast is the preferred initial diagnostic study for both conditions 2, 7
- MRI correctly predicts approximately 88% of cervical radiculopathy lesions 4
- MRI must be interpreted in clinical context as asymptomatic individuals frequently have imaging abnormalities 4
Red Flags Requiring Urgent Evaluation for Myelopathy
- Progressive neurological deficits 4, 7
- Bilateral symptoms or signs of myelopathy 4, 7
- New changes in bladder or bowel function 7
- Loss of perineal sensation 7
- Symptoms affecting both upper and lower extremities 7
- Gait disturbance or balance problems 2, 3
The presence of any lower extremity symptoms in a patient with neck and arm pain should immediately raise suspicion for myelopathy rather than isolated radiculopathy, as this distinction fundamentally changes management urgency and surgical considerations. 4, 7