C5 Radiculopathy Dermatome
The C5 dermatome typically affects the lateral aspect of the shoulder and arm, extending from the lateral shoulder down to the lateral upper arm. 1
Anatomical Distribution of C5 Dermatome
- Primary location: Lateral aspect of the shoulder and upper arm 1
- Sensory pattern: Follows a band-like distribution along the lateral deltoid region
- Distinguishing features: Does not typically extend below the elbow or into the forearm
Clinical Correlation with C5 Radiculopathy
C5 radiculopathy presents with specific patterns of symptoms that correspond to its dermatome:
- Pain distribution: Primarily in the suprascapular region 2
- Sensory changes: Both superficial and deep pain sensations are typically affected in C5 radiculopathy 2
- Motor deficits: Weakness in deltoid and biceps muscles (not part of the dermatome but important for clinical diagnosis)
- Reflex changes: Diminished biceps reflex
Diagnostic Considerations
When evaluating suspected C5 radiculopathy, it's important to understand:
- MRI is the gold standard imaging modality for confirming cervical radiculopathy and visualizing nerve root compression 3
- Electrodiagnostic studies can help differentiate C5 radiculopathy from other conditions affecting the shoulder and upper arm 3
- Clinical assessment should include evaluation of:
- Shoulder abduction strength (deltoid)
- Elbow flexion strength (biceps)
- Biceps reflex
Distinguishing from Adjacent Dermatomes
Understanding the boundaries between adjacent dermatomes helps with accurate diagnosis:
- C5 vs C6: C6 primarily affects the lateral forearm and the first three fingers 1, while C5 affects the lateral shoulder and arm
- C5 vs C4: C4 affects the upper shoulder and neck region
- Overlap considerations: There is significant overlap between dermatomes, particularly between C5 and C6 4
Common Pitfalls in C5 Dermatome Assessment
- Relying solely on sensory findings can be misleading, as there is substantial overlap between C5 and adjacent dermatomes 4
- Scapular pain can be present in C5 radiculopathy but is not exclusive to it 2
- Imaging findings must be correlated with clinical presentation, as asymptomatic degenerative changes are common 3
Clinical Pearls
- C5 radiculopathy typically presents with both superficial and deep pain in the affected dermatome, unlike C6 or C7 radiculopathy which often presents with deep pain only 2
- The American College of Radiology recommends MRI as the preferred imaging modality for suspected cervical radiculopathy 5
- Sensory testing should be performed systematically across the entire upper limb to accurately map areas of impaired sensation
Understanding the C5 dermatome is essential for accurate diagnosis and appropriate management of cervical radiculopathy, which ultimately impacts patient outcomes including morbidity, mortality, and quality of life.