Shaking hand & Feet movements. Of ideas?

My niece was a playful young girl who was smart and liked to dance, Recently after she got chicken pox and jaundice which got cured and now She is behaving abnormalities like shaking of hand legs and crying on any and gets irritated she is not being able to walk or have any energy to do any.(she was never like dis before) None of her parents or anyone in family had any such abnormal conditions. Recently her blood urine liver test was done which was normal but slight less hemoglobin. The condition isn't getting better even after medication and she is turning into an abnormal acting child day by day. What should we do? Who should we consult? We are out of ideas? Recently we went to AMC where the Dr. checked her and sent her back saying everything is ok with her health wise and suggest MRI & ECG..