Which finding is most supportive of radiculopathy rather than a peripheral neuropathy?

Which finding is most supportive of radiculopathy rather than a peripheral neuropathy?

• A. Widespread distal sensory loss with normal reflexes
• B. Isolated nerve-specific deficits in a single dermatome
• C. Weakness and sensory loss following a dermatomal/myotomal pattern with reflex changes
• D. Symmetric proximal weakness without dermatomal pattern

Answer: (C)

Radiculopathy involves pathology at a nerve root, so the deficits follow the root’s distribution: a dermatomal area for sensation and a myotomal pattern for weakness, often with reflex changes at the involved spinal level. The described finding—weakness and sensory loss that line up with a specific dermatomal/myotomal distribution and accompanying reflex changes—is the hallmark of root-level involvement, distinguishing it from peripheral neuropathies or primary muscle diseases. In contrast, widespread distal sensory loss with normal reflexes points toward a distal polyneuropathy or another non–root-site process, not a single-root radiculopathy. Symmetric proximal weakness without a dermatomal pattern fits a myopathy rather than a nerve-root problem, and isolated deficits in a single dermatome without motor or reflex changes are less specific for radiculopathy and could reflect other localized nerve or nerve-branch issues.

Radiculopathy involves pathology at a nerve root, so the deficits follow the root’s distribution: a dermatomal area for sensation and a myotomal pattern for weakness, often with reflex changes at the involved spinal level. The described finding—weakness and sensory loss that line up with a specific dermatomal/myotomal distribution and accompanying reflex changes—is the hallmark of root-level involvement, distinguishing it from peripheral neuropathies or primary muscle diseases.

In contrast, widespread distal sensory loss with normal reflexes points toward a distal polyneuropathy or another non–root-site process, not a single-root radiculopathy. Symmetric proximal weakness without a dermatomal pattern fits a myopathy rather than a nerve-root problem, and isolated deficits in a single dermatome without motor or reflex changes are less specific for radiculopathy and could reflect other localized nerve or nerve-branch issues.