15 years old female nigerian was well 10 years back when she developed fever with headache 5 years back and subsequently devloped right hemiperesis with facial palsy and contracture of right hand.mri shows gliosis and encephalomalacia of periventricular and basal ganglia and pons region .doppler of lower limb is normal .2d echo shows mild mvp with mild mr.she has a Hb of 9.3 gm.and serum sodium of 130.she is aphasic but of normal intelligence.weakness is present in both upper and lower limbs.and there is autoamputation of both lower limb fingers which started after the incidence of fever. Guide me about the probable diagnosis and line of investigations.birth history is normal.