• Transverse Myelitis (TM) is the development of grey and white matter inflammation of the spinal cord, which can result in demyelination.
• Hallmark characteristics of this condition include: (1) isolated spinal cord (not brain) dysfunction, and (2) the lack of associated cord compression.
• TM can be acute or subacute, such that it progresses over the course of hours to several days.  Nearly half of cases will reach its maximal deficit within 1 to 10 days of onset.
• The diagnosis of TM is primarily based on the history and physical examination findings.  MRI of the spinal cord and myelography are often used as diagnostic adjuncts.
• This condition typically presents with paresthesias, back pain, and ascending leg weakness.
• Febrile illnesses often serve as a precursor; one series found this to be the case in 37% of complete TM cases.
• While steroids are sometimes administered over the first several days of illness to decrease inflammation, there is no cure for TM and treatment is largely supportive in nature. 

References

• Knebusch M, Strassburg HM, Reiners K. "Acute Transverse Myelitis in Childhood:  Nine Cases and Review of the Literature ."  Dev Med Child Neurol. 1998;40(9):631-9.