A reader writes:

As an emergency physician, if I were taking care of a 72-year-old man with a history of melanoma who was having episodes of confusion I would be extremely concerned. High on my priority list would be to get a brain MRI to look for metastatic melanoma. When melanoma metastasizes it commonly goes to the brain. I do not think the American people should decide whether or not to vote for Senator McCain until he has had a brain MRI and we know the results.

Here’s a quote from emedicine.com on melanoma:

“Melanoma has an increased incidence among other systemic cancers in terms of metastasizing to the brain. About 40-60% of patients with melanoma will have brain metastasis. Melanoma commonly metastasizes to the brain. Melanoma cells are closely related to CNS cells due to their embryonic origin and neural crest cells, and they share common antigens such as MAG-1 and MAG-2. After melanoma is detected in the brain, median survival is 3 months. These metastases are poorly responsive to all treatments.”