What is TM?
* Revised 4/12/2021. This information sheet has been reviewed and approved by members of SRNA’s Medical and Scientific Council.
Myelitis roughly translates to “spinal cord inflammation,” which can result from an infection or inflammatory cause. The term transverse myelitis (TM) has been adopted to describe inflammation of the spinal cord due to a misdirected immune response, resulting in varying degrees of weakness, sensory alterations, and autonomic dysfunction (the part of the nervous system that controls involuntary activity, such as the heart, breathing, the digestive system, and reflexes). Reports describing TM date back to the 1880s, but the first known use of “transverse myelitis” is in 1931, where it was used to describe inflammatory changes across the anatomical “transverse” plane seen on autopsy. The Transverse Myelitis Consortium Working Group provided a framework to delineate TM from non-inflammatory spinal cord disorders in 2002.1
(1) Transverse Myelitis Consortium Working Group. Proposed diagnostic criteria and nosology of acute transverse myelitis. Neurology. 2002 Aug 27;59(4):499-505. doi: 10.1212/wnl.59.4.499. PMID: 12236201.