Symptoms of transverse myelitis usually evolve over hours or sometimes over a week or 2, but rarely will develop within minutes or stutter over a month (Lipton and Teasdall 1973; Ropper and Poskanzer 1978; Dunne et al 1986; Group TMCW 2002). Before the onset of neurologic dysfunction, there can be nonspecific complaints such as fever or muscle aches. Although the clinical signs are bilateral (ie, from "transverse" or horizontal cord lesions), there is usually also longitudinal expansion of cord pathology. Ascending symptoms are presumably from a lesion expanding both rostrally and caudally. In theory, lesions spreading centripetally from the meninges inward through somatotopic layers of the long tracts could cause ascending symptoms, but peripheral cord tracts are preserved compared to deeper fibers, making this unlikely.
Complete transverse myelitis (the main subject of this article) and partial transverse myelitis differ. The spinal cord damage in acute complete transverse myelitis generally affects all cord functions, and the symptoms are typically more severe than in typical cord lesions of multiple sclerosis. When inflammatory cord lesions are not transverse, the partial cord lesion causes a Brown-Sequard syndrome. Acute partial cord lesions cause unilateral or markedly asymmetric bilateral sensory and motor dysfunction (Scott et al 2005; Scott 2007). This asymmetric picture is more often associated with multiple sclerosis (Miller et al 1989; Ford et al 1992).
The first symptoms in transverse myelitis are ascending paresthesias or back pain at the level of the myelitis, plus leg weakness and sphincter dysfunction (Altrocchi 1963; Ropper and Poskanzer 1978; Dunne et al 1986). Tingling or paresthesias in the feet soon progress to loss of pain, temperature, and vibration sensation, and then halt at a sensory level, usually thoracic (approximately 80%). There is an encircling band of hyperesthesia at the dermatome right above the sensory loss in one third of cases. Cervical levels are less commonly involved. There may be a dermatomal band of hyperesthesia 2 or 3 segments more rostrally, and pain is often interscapular. Weakness is usually flaccid at onset ("spinal shock"). In two thirds of cases, weakness is severe, with inability to walk, and often evolves to total leg paralysis and spasticity. The arms are weak in one fourth of cases and are occasionally involved before the legs. Later, deep tendon reflexes become brisk. Five percent of patients have respiratory weakness. Tonic spasms and Brown-Sequard symptoms can occur. Damage to autonomic pathways can cause a sweat level, adynamic ileus, paroxysms of hypertension and sweating or poikilothermia, autonomic dysreflexia with paroxysms of sympathetic output due to renal denervation, myocardial ischemia, and orthostatic hypotension--especially with higher level lesions. Association with acute motor axonal neuropathy has appeared several times. Bladder and bowel function is frequently lost and is often heralded by urinary retention. Acute lumbosacral myelitis causes bladder symptoms and anogenital sensory loss.
Symptoms typically begin to resolve in 2 to 17 days (Dunne et al 1986). The rate of resolution is most marked in the first few weeks after the symptoms have crested. Improvement is maximal in the first 3 to 6 months after disease onset but may continue for several years. Recovery can be complete, but many of the motor, sensory, and autonomic symptoms persist.
In children, acute transverse myelitis follows a similar clinical course. However, paresthesias are less common, and recovery is more frequent (Paine and Byers 1953; Dunne et al 1986). Fifty-eight percent report pain, 28% motor symptoms, and 11% numbness; 61% had T2 MRI brain lesions (Thomas et al 2012). In 27 children with non-Devic acute transverse myelitis, lesions were in the center of the cord, with a median length of 5 segments (Alper et al 2011). Forty-three percent had swelling. Recurrences were only 6% over 5 years (Alper et al 2011). Cognition is normal.
Recurrent transverse myelitis, without evidence of multiple sclerosis and with negative MRI and CSF studies, is unlikely to progress to multiple sclerosis but is sometimes part of the NMO/Devic disease spectrum (Tippett et al 1991; Ungurean et al 1996; Garcia-Merino and Blasco 2000; Kim 2003; Jacob et al 2004; Chan et al 2006). Recurrent myelitis is associated with brucellosis and hepatitis C infection (Grewal et al 2004). Recurrent idiopathic myelitis is usually considered to be rare. However, in 30 patients with partial transverse myelitis, 14 (47%) had cord relapses over 5 years in Pennsylvania (Scott et al 2005). Relapses recurred in 31% of 13 transverse myelitis cases in Pavia, Italy (Ravaglia et al 2009); it was recurrent in 61% of 41 cases from Rio de Janeiro, Brazil (Alvarenga et al 2010), and in 69% of 29 cases from Guangzhou, China (Li et al 2011).
Three patients selected from all spinal cord syndromes at Graz Medical University in Austria had relapsing acute transverse myelitis. All 3 had necrotizing inflammation and severe disability (Seifert et al 2005), and in retrospect they may have had Devic disease. Four of 17 tested in the Brazilians were positive for NMO-IgG, and 3 of these were recurrent, again suggesting significant mixing of transverse myelitis with Devic disease in a second series (Alvarenga et al 2010), and likely many other reported cases of recurrent myelitis. Neuromyelitis optica and CNS Sjögren disease are discussed in the differential diagnosis section.