Understanding the nerve distribution along the dermatomes is helpful in determining how certain diseases, such as shingles and some other neurological conditions, target one area of the body. The letter-number combinations show the relationship between each area and its corresponding sensory nerve. The vertebrae are classified as C for cervical, T for thoracic, L for lumbar, and S for sacral. The trigeminal nerve is the fifth cranial nerve, represented by V.
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.