Barts-MS rose-tinted-odometer: ★★
How do you distinguish transverse myelitis that is not MS-related from spinal cord involvement in MS?
Yesterday after reporting the possible and likely link between the Oxford-AstraZenca vaccine and transverse myelitis (TM) and possibly MS you asked how do neurologists differentiate TM from CIS or MS.
Idiopathic or post-infectious/vaccine-related TM tends to be more extensive, i.e. involve multiple segments of the spinal cord compared to CIS/MS. This is often referred to as longitudinally-extensive TM. In addition, typical non-MS TM tends to involve the whole cord and not particular areas of the spinal cord. In comparison, CIS/MS tends to have discrete lesions that may involve the back or a segment of the spinal cord and extend over one or two segments.
CIS/MS myelitis tends to fit the demographic profile of MS, i.e. more common in females, youngish age of onset (20-40 years) and is more common in regions of the world with a high MS prevalence. In addition, there are often other lesions in the brain and/or spinal cord that look like MS and CSF analysis usually shows oligoclonal IgG band and the cell counts in the spinal fluid are lower.
Non-MS related TM can occur in any age group, occurs in both sexes and its quite common in Asian, African, Afro-Caribbean and African-American populations. Brain imaging is usually normal; the exception being some patients with NMO. CSF analysis is OCB negative and the cell count is often raised. Interestingly, it is not uncommon in acute TM to find some neutrophils and occasionally eosinophils in the spinal fluid that does not happen in MS-related myelitis.
An important clue is that non-MS related TM may have obvious precipitating factors of a recent viral or bacterial infection or vaccination.
Saying all this it is sometimes very hard to differentiate the two and then time becomes the best diagnostician, i.e. you have to wait to see if someone goes onto to develop recurrent events. This is why medicine and neurology remain as much an art as a science.
Worryingly the number of TM cases post-COVID-19 in the literature is quite high considering we are only 6-9 months into this pandemic. This would indicate that SARS-CoV-2 and its proteins may be the triggering factor for TM and/or MS and this will make this adverse event from this vaccine a real problem and we are likely to see more cases emerge. This does not mean the vaccine won’t be effective it simply means that some people with have to suffer harm to protect the many or the herd. This is the basic premise that population health is based on.