Heavy Left Arm Without Sensory Loss: Evaluation and Management
Primary Recommendation
Given your history of partial radial nerve injury and the new symptom of arm heaviness without sensory loss, you should undergo MRI of the cervical spine to evaluate for cervical radiculopathy or myelopathy, as this presentation suggests a neurological process distinct from your known radial nerve pathology. 1
Clinical Reasoning
Your symptom pattern is atypical for isolated radial nerve injury and warrants systematic evaluation:
Why This Isn't Typical Radial Nerve Pathology
- Radial nerve injuries characteristically cause motor weakness (wrist drop, finger extension weakness) and sensory deficits in specific distributions, not generalized arm heaviness 2, 3
- The absence of sensory loss makes isolated radial nerve pathology less likely as the primary cause of your current symptoms 4
- Radial nerve compression typically presents with neuropathic pain described as "electric" in quality, rather than heaviness 1
What This Pattern Suggests
Cervical radiculopathy or early myelopathy is the primary concern when arm heaviness occurs without sensory loss, particularly with a history of nerve injury 1:
- Motor weakness manifesting as heaviness can occur from cervical nerve root compression affecting C5-C6 levels 1
- The preserved sensation distinguishes this from acute limb ischemia, which would show progressive sensory and motor deficits together 5
- Atypical presentations of cervical pathology may not follow classic dermatomal patterns initially 1
Diagnostic Approach
Immediate Imaging Required
- MRI of the cervical spine without contrast is the appropriate first-line imaging for evaluating suspected cervical radiculopathy with atypical presentations 1
- This provides superior soft tissue visualization for detecting disc herniations and nerve root compression 1
- If symptoms involve both arm and leg, MRI of both cervical and lumbar spine may be necessary 1
Additional Evaluation
- Electrodiagnostic studies should be considered to differentiate radiculopathy from plexopathy or peripheral nerve lesions 6, 7
- Assess for motor deficits beyond just heaviness: test shoulder abduction, elbow flexion, and grip strength to localize the affected nerve root 1
- Evaluate reflexes bilaterally, as asymmetric reflex changes provide localizing value 1
Red Flags Requiring Urgent Evaluation
Watch for these concerning features that necessitate immediate assessment 1:
- Progressive neurological deficits
- Bilateral symptoms developing
- New bladder or bowel dysfunction
- Loss of perineal sensation
- Symptoms affecting both upper and lower extremities (suggesting possible myelopathy)
Management Strategy
Conservative Management (First-Line)
Most cases respond to conservative treatment with a 75-90% success rate 1:
- Cervical collar immobilization
- Head traction
- Nonsteroidal anti-inflammatory drugs
- Physical therapy with strengthening and stretching exercises
When to Consider Surgery
Surgical intervention (anterior cervical decompression) should be considered if 1:
- Conservative treatment fails after 4-6 weeks
- Progressive neurological deficit develops
- Surgical outcomes for arm pain relief range from 80-90%
Important Distinction from Vascular Pathology
Your presentation differs from acute limb ischemia, which would show 5:
- Loss of arterial signals on Doppler examination
- Progressive sensory loss starting in the toes/fingers
- Muscle weakness progressing to complete motor loss
- Pallor and absent pulses
The absence of these features makes vascular compromise unlikely as the primary etiology.
Neurology Consultation
Consider neurology consultation for comprehensive evaluation, particularly given your history of partial radial nerve injury and this new atypical presentation 1. Multiple sites of pathology or non-spinal causes (such as brachial plexopathy) should be considered when symptoms don't fit classic patterns 1, 6.