What causes variation between dermatome maps?

Updated: Oct 13, 2017
  • Author: Stephen Kishner, MD, MHA; Chief Editor: Thomas R Gest, PhD  more...
  • Print


The dermatome is a basic concept, yet much variability exists between dermatome maps in standard anatomy and medical guideline textbooks. A review of 14 different dermatome maps by Lee et al showed striking variations within each individual map. [7] Nearly all maps reviewed were based on 2 primary sources, Foerster [8] and/or Keegan and Garrett. [9]

Most areas of the skin are innervated by 2 or more spinal nerve roots, which may be the reason for variability between individuals. Other possibilities of such variability could be due to intrathecal intersegmental anastomoses of dorsal spinal rootlets, allowing sensory neurons at one dorsal root ganglion to enter the spinal cord at a different level. [7]

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!