Alzheimer's patient Louise Billings's monotonous, ``Little do you know, little do you know,'' seems an apt complaint, for as this small collection of sketchy anecdotes shows, doctors know too little about Alzheimer's to be able to offer anything resembling hope. Geriatric psychiatrist Mathiasen has gathered most of his stories from the inpatient psychiatric unit at Northwestern Hospital in Seattle, Wash. Alzheimer's runs in Mathiasen's own family, and his early memories of visits with his father to a stricken aunt, and the fears these visits aroused, helped to shape his desire to understand this mysterious illness. Alzheimer's disease, says Mathiasen, touches on fears that may be even stronger than the fear of death: the fear of losing our minds, of becoming something not quite human. The patients he describes are still very human--singing bits of opera, dancing an Irish jig, railing at a painting by a hated artist. In one story about a mother and her alienated sons--appropriately titled ``My Babies,'' for that is how she sees them--he shows us its power to tear families apart and also to bring them together. In another, ``The Cuban Baseball Team,'' he contrasts the happiness of the patient, who is reliving the best days of his life as a young ballplayer, with the anguish of his family, who are watching his disintegration. Tucked into the stories are some facts about how Alzheimer's is diagnosed and some information about other conditions, such as clinical depression and post-traumatic stress syndrome, that are sometimes confused with it. But readers hoping to have the enigma of Alzheimer's demystified will be dissatisfied; answers simply don't exist yet. Those hoping for comforting insights will be similarly let down. Mathiasen seems to be curiously removed from his patients and their families, to be almost more a voyeur than a caregiver. Altogether a disappointment.