Which sensory distribution corresponds to the C6 nerve root?

Which sensory distribution corresponds to the C6 nerve root?

• A. Lateral forearm, thumb
• B. Medial forearm, pinky
• C. Medial leg, big toe
• D. Dorsum of foot, toes

Answer: (A)

The idea being tested is how sensory skin areas map to cervical nerve roots in the upper limb (dermatomes). The C6 nerve root provides sensation to the lateral forearm and the thumb. This pattern is a classic upper-limb dermatomal map, with C5 around the shoulder, C6 at the radial-lateral forearm and thumb, C7 the middle finger, and C8 with the little finger and medial forearm. So sensation on the lateral forearm and the thumb matches C6, making that option the best fit. The other regions correspond to different roots—medial forearm and pinky align with lower cervical/ulnar territories (C8-T1), while the medial leg and big toe or the dorsum of the foot/toes map to lumbar or sacral dermatomes, not cervical. In practice, a patient with numbness or a sensory deficit in the thumb and lateral forearm would point toward C6 involvement.

The idea being tested is how sensory skin areas map to cervical nerve roots in the upper limb (dermatomes). The C6 nerve root provides sensation to the lateral forearm and the thumb. This pattern is a classic upper-limb dermatomal map, with C5 around the shoulder, C6 at the radial-lateral forearm and thumb, C7 the middle finger, and C8 with the little finger and medial forearm. So sensation on the lateral forearm and the thumb matches C6, making that option the best fit. The other regions correspond to different roots—medial forearm and pinky align with lower cervical/ulnar territories (C8-T1), while the medial leg and big toe or the dorsum of the foot/toes map to lumbar or sacral dermatomes, not cervical. In practice, a patient with numbness or a sensory deficit in the thumb and lateral forearm would point toward C6 involvement.