What Causes Leg Pain While Suffering From Spinal Abscess?

i have been diagnosed with spinal abscess-t3-t6..on tb medication..though the blood test or biopsy has not shown tb,but doctor said scan shows tb and tb medication will cure the abscess and tb.had back pain for the last 6 months which has reduced to as great extend after resting for a month and tb medication,but my legs feel weak and pain,,sometimes feel leg pain and pain in hands as well..did mri scan after 5 weeks of taking tb medication...abscess is still there...i just want to know what is causing the leg pain and how long can it take to cure the abscess??