[revised 15 Jan 2019 to update a url in a link]
This is a comment on two articles:
- Kirshblum SC, Burns SP, Biering-Sorensen F, Donovan W, Graves DE, Jha A, Johansen M, Jones L, Krassioukov A, Mulcahey MJ, Schmidt-Read M, Waring W. International standards for neurological classification of spinal cord injury (revised 2011). J Spinal Cord Med. 2011 Nov;34(6):535-46.
- Kirshblum SC, Waring W, Biering-Sorensen F, Burns SP, Johansen M, Schmidt-Read M, Donovan W, Graves D, Jha A, Jones L, Mulcahey MJ, Krassioukov A. Reference for the 2011 revision of the International Standards for Neurological Classification of Spinal Cord Injury. J Spinal Cord Med. 2011 Nov;34(6):547-54.
The international standards for neurological classification of spinal cord injury were originally developed in 1982. In 2011, the International Standards Committee of the American Spinal Injury Association (ASIA) published these two articles: a revised guide to the classification of spinal cord injuries; and a reference article providing explanation and details on the revisions. The reference article also includes many examples illustrating the use of the classification system. Anyone with an interest in answers to any of the following questions, or in myriad related questions, should read these articles:
- What are dermatomes and myotomes, and how do they relate to the sensory and motor levels of spinal cord injuries?
- How is the neurological level (C1-C8, T1-T12, L1-L5, S1-S4/5) of a spinal cord injury determined, and how does this relate to the motor and sensory levels of the injury?
- How can an injury have sensory level C1 when the C1 nerve root does not have a sensory component that is tested on the International Standards Examination?
- How is the ASIA Impairment Scale (AIS) grade of injury severity (AIS A, B, C, D) determined?
- What is the difference between a complete and an incomplete injury? (Hint: no matter what the level of injury, this question boils down to sensory and motor function preservation at S4-S5.)
- Which spinal cord nerve roots affect which key muscles?
- How can there be 8 cervical level injuries (C1-C8) when there are only 7 cervical vertebrae?
- Since myotomes at C1 to C3 are not clinically testable by a manual muscle exam, how can such an exam result in a motor level designation of C3?
- What is a zone of partial preservation, and how does it relate to level and AIS grade of injury?
- What are central cord, Brown-Sequard, anterior cord, cauda equina, and conus medullaris syndromes?
Further information on the ASIA classification system is available at the ASIA web site, and free tutorials for practitioners on the use of the classification system are available at the ASIA Learning Center.