Correlation of clinical course with magnetic resonance imaging in tuberculous myelopathy

Sixty cases of spinal tuberculosis with neurological deficit treated with 'middle path regimen' were analysed and therapeutic response was correlated with the magnetic resonance imaging (MRI) observations. Tuberculous lesions were found to be more extensive than seen on plain X-ray in 60% of the cases. MRI showed the involvement of one or both pedicles in nearly 90% of the cases, in addition to the vertebral body lesion as seen in the X-rays. The patients showing predominantly extradural collection of fluid with relatively preserved cord size, and MRI evidence of myelitis/oedema, improved neurologically with treatment. The myelomalacia of cord was found to be a poor prognostic sign for neural recovery. The magnitude of thinning of cord did not always correlate with severity of neural deficit, however, thinning of cord in association with myelomalacia carried a bad prognosis. The complete neural recovery is not expected in patients with syrinx formation proximal or distal to the diseased spine, either with antitubercular drugs or after mechanical decompression. MRI changes in dura-subarachnoid complex suggesting arachnoiditis generally correlated with poor neural recovery. MRI provided a reliable guide to the level and extent of surgical decompression, and prognostication of the outcome of therapeutic measures.