In distinguishing cervical radiculopathy from a peripheral nerve lesion in the upper limb, which pattern is most characteristic of radiculopathy?

• A. Dermatomal and myotomal patterns with reflex changes
• B. Isolated nerve-specific sensory loss in a single nerve distribution
• C. Symmetric distal weakness with normal reflexes
• D. Proximal muscle weakness affecting many myotomes

Answer: (A)

Radiculopathy is a problem at a spinal nerve root, so the deficits it produces follow a dermatomal pattern for sensation and a myotomal pattern for movement, often with reflex changes tied to the affected root. This means you’ll see sensory loss and weakness that map to the same spinal level (for example, a C6 pattern with lateral forearm/thumb sensation and specific elbow/wrist movements) and a diminished reflex corresponding to that root. A peripheral nerve lesion, by contrast, follows the distribution of a specific nerve, which can cut across multiple dermatomes or myotomes, and may spare the root-level reflex pattern. The hallmark then is a dermatomal and myotomal pattern with reflex changes, rather than a localized nerve distribution.