If only one sensory root is severed, does a complete loss of sensation result in that area?

Question

A. Yes. Sensation does not depend on multiple dermatomes.
B. No. Overlapping dermatomes ensure not all sensation is lost.
C. No. Multiple sensory roots must be severed for complete sensory loss to occur.
D. Yes. Overlapping dermatomes will not prevent complete sensation loss.

Answer 1

ANS: B
Rationale: The results of somatosensory testing procedures can be used to map a person's pattern of sensory loss. The resulting map can be compared with standardized maps of peripheral nerve distribution and of dermatome distributions to determine whether the person's pattern of sensory loss is consistent with a peripheral nerve or a spinal region pattern. Because every individual is unique and adjacent dermatomes overlap one another, the maps presented represent common but not definitive nerve distributions. The overlap of adjacent dermatomes also ensures that if only one sensory root is severed, then a complete loss of sensation does not occur in any area.