Our guest on ST Medical Monday is Dr. Daniel Gibbs, who's one of the 50 million or so people worldwide who've been diagnosed with Alzheimer's disease. But unlike most Alzheimer's patients, Dr. Gibbs worked as a neurologist for 25 years, caring for those with the very disease now affecting himself. He joins us to discuss his candid and engaging new memoir, "A Tattoo on My Brain: A Neurologist's Personal Battle against Alzheimer's Disease." In this work, Dr. Gibbs describes how he actually started to suspect he had Alzheimer's several years before an official diagnosis could be rendered. Based on genetic testing, he learned that he carried certain genes that greatly increased the risk of developing the disease -- and he moreover noticed symptoms of mild cognitive impairment long before any tests would have alerted him. As was noted by a critic writing for The Bookbag: "Profoundly moving.... [This] memoir is a symbol of resistance."