The syndrome of acute or subacute and usually complete spinal cord dysfunction may be due to a non-infectious inflammatory process, whence it is known as transverse myelitis. Most cases are preceded by an infectious illness 1–3 weeks earlier, and are considered likely to have an immunopathogenic basis. In a few instances, transverse myelitis follows vaccination, while a sizeable number of cases have no antecedent event (idiopathic).
A small number of cases occur in association with:
- collagen vascular disorders,
- systemic lupus erythematosus and the
- primary antiphospholipid syndrome
In these instances, the pathological basis may be inflammatory or vasculitic, but may also relate to a non-inflammatory vasculopathy.
In the majority of instances, transverse myelitis is a monophasic disorder, but occasional cases are described in whom there were multiple, recurrent episodes.
In the most common setting, post-infectious transverse myelitis, the preceding infection may be identifiable from either the clinical or serological features (e.g. varicella, Epstein–Barr virus, mycoplasma, and, rarely, Campylobacter sp.), or it may have been a non-specific upper respiratory or gastrointestinal tract infection.
All ages can be affected, and presentation is common in childhood as well as in adults.
The neurological onset may be accompanied by pain in the spine, but this is usually not prominent. Weakness and paraesthesia develop in the lower limbs and early urinary retention or incontinence is common.
Symptoms rapidly evolve and typically reach their peak within hours to days. Either the cervical or thoracic cord may be affected and the upper level of the symptoms and signs will vary accordingly. Sometimes, after a complete transverse lesion has emerged clinically, evidence of ongoing activity of the disorder is manifested by a progressively ascending level of motor and sensory loss.
Spinal MRI reveals swelling and signal change (high signal on T2-weighted images) which is typically extensive, involves several cord segments and the whole antero-posterior diameter on sagittal images. In the acute phase there is patchy gadolinium enhancement. Brain MRI occasionally reveals disseminated white matter lesions, suggesting a more diffuse, albeit asymptomatic, inflammatory/demyelinating process; more often, brain imaging is normal.
CSF examination usually exhibits a moderate mononuclear pleocytosis, although occasionally it is acellular. The protein is moderately elevated but the glucose is normal. Oligoclonal bands are sometimes, but not always, present, and with follow-up may disappear. Pathologically, the affected cord will reveal perivascular inflammation, sometimes with demyelination; more severe cases exhibit more intense and widespread inflammation and necrotic changes. Other investigation should include microbiological work-up to exclude infectious causes of myelitis, and serological investigations for collagen vascular disease.
Therapy for post-infectious transverse myelitis in the acute stage normally includes a short course of high-dose corticosteriods, e.g. intravenous meythylprednisolone, 1 gm/day for 3 days with or without an oral taper.
In the acute transverse myelopathy associated with systemic lupus erythematosus, vigorous immunosuppression with high-dose steroids and pulse cyclophosphamide is often employed, but if the neurological deficit is already established, recovery may not occur. In cases of systemic lupus or primary antiphospholipid syndrome where coagulopathy is thought to be contributing to spinal cord disorder, anticoagulation first with heparin and then warfarin may be recommended.
The prognosis is variable—some cases make an excellent recovery in spite of a complete paraplegia during the acute stage; others are left with severe residual deficits.