I have a 64 yr old friend who complains of being extremely tired, sleeps a lot, has low energy, experiences shortness of breath upon limited exercise, and lately has chills that come and go. He has also begun to shuffle when he walks. His symptoms seemed to develop slowly over time, but are getting progressively more severe. His doctors suggested he has encephalitis, and he also has had a mass in his brain partially removed. This does NOT sound like encephalitis to me. Does it to you? What other possibilities do you suggest the doctors might consider?