Microscopic clusters of sensory neurons in C1 spinal nerve roots and in the C1 level of the spinal accessory nerve in adult humans.

This study examined C1 spinal nerve roots and their anastomotic connections with the spinal accessory nerve for histological evidence of sensory neurons in adult humans. C1 spinal nerves and roots with the adjacent segments of the spinal accessory nerve and the spinal cord were dissected en bloc from cadaveric specimens, and prepared for histological study. Results show that in 39.