Non-compressive myelopathy: clinical and radiological study.

Fifty seven patients (42 males and 15 females) with non-compressive myelopathy were studied from 1997 to 1999. Acute transverse myelitis (ATM) was the commonest (31) followed by Vit B12 deficiency myelopathy (8), primary progressive multiple sclerosis (5), hereditary spastic paraplegia (3), tropical spastic paraplegia (2), subacute necrotising myelitis (1), radiation myelitis (1), syphilitic myelitis (1) and herpes zoster myelitis (1). 4 cases remained unclassified. In the ATM group, mean age was 30.35 years, antecedent event was observed in 41.9% case, 25 cases had symmetrical involvement and most of the cases had severe deficit at onset. CSF study carried out in 23 patients of ATM revealed rise in proteins (mean 147.95mg%, range 20-1200 mg/dL) and pleocytosis (mean 20.78/cumm, range 0-200 mm3). Oligoclonal band (OCB) was present in 28% of cases of ATM. The most common abnormality detected was a multisegment hyperintense lesion on T2W images, that occupied the central area on cross section. In 6 patients hyperintense signal was eccentric in location. MRI was normal in 4 cases of ATM. Thus ATM is the leading cause of non-compressive myelopathy. Clinical features combined with MRI findings are helpful in defining the cause of ATM.