The doctor reviewed the MRI results and detected some abnormal brain activity - "electrical firings". He's going to take a sample of cerebral spinal fluid through his ommaya reservior (that bump you see on his head) tomorrow and test it to see if the leukemia has returned in his spine. When he was first diagnosed with leukemia May 2007, cancer cells were found in his blood and spinal fluid. He's been in remission for several months, going through daily or weekly preventive treatments - mainly chemotherapy, radiation, and the stem cell transplant.
He's very frustrated by the news.