What Causes Severe Headache,stiffness In Neck And Numbness In Hands?

my wife suffers from severe headaches stiffness and pain in neck along with numbness in one of her hands as of late...she went to the e.r. and they couldnt diagnose the cause..she neglected to tell them that she has for many years also suffered from severe thorcic scoliosis and i was wondering if it could be the cause of her current condition and if so will it continue to get worse and what should she do