Stolen Mind : THE SLOW DISAPPEARANCE OF RAY DOERNBERG by Myrna Doernberg (Algonquin: $14.95; 223 pp.) : THE LOSS OF SELF: A FAMILY RESOURCE FOR THE CARE OF ALZHEIMER’S DISEASE AND RELATED DISORDERS by Donna Cohen, Ph.D., and Carl Eisdorfer, Ph.D., MD (Norton: $18.95; 381 pp.)

In “Adieux,” her farewell to Jean-Paul Sartre, Simon de Beauvoir wrote of her gratitude and grief--gratitude because death came while Sartre was still very recognizably himself, and grief because his absence is so absolute: “His death does separate us. My death will not bring us together again. That is how things are.” The two books reviewed here were written by and for those denied De Beauvoir’s certitude. Victims of dementia die gradually. Those who love them spend anywhere from 10 to 300 months saying goodby, never certain whether they have seen the last recognizable glimpse of the victim, never knowing how things are.

In “Stolen Mind,” Myrna Doernberg recounts her experience of her husband’s slow death, which seemed to her more like a series of small abductions. Ray Doernberg, an architect, died in his 40s of Binswanger’s disease, a rare form of dementia which mimics Alzheimer’s disease. He became inefficient at work, apathetic at home, forgetful, and easily disoriented. Myrna suspected a mid-life crisis until she was terrified to realize, one weekend when he was stymied by a simple illustration assignment, that he had actually forgotten how to structure perspective drawings, a former specialty of his.

Ray’s physicians did not identify his disease until shortly before he died. His family knew he was dying as they watched, but they could not name the cause or exact time of his death. How much of him had already died the night Myrna found him watching the static on the television? Or the moment she decided that the despair she felt after making love outweighed any comfort Ray felt, which he seemed to forget immediately?

Myrna noted occasional echoes of the Ray she remembered and found them unsettling consolations. Ray had prided himself on his vocabulary. Checking his rate of decline, Myrna asked him to define “epistemology”: “He said, ‘It means how you know the things you know. It’s used specifically in referring to knowledge and knowledge systems.’ A few minutes later, however, he told me his sandwich was stuck to the table and he couldn’t move it.”

Myrna is a teacher of learning-disabled children. This is her first book, and she seems to intend it to be both a vindication of her husband and an accusation of his former employer, who never contacted the Doernbergs again after angrily forcing Ray to take a leave of absence. As Ray became more seriously impaired, Myrna became his champion, unable to fight his illness, but defending him against all other adversaries, from the insurance bureaucracy to his apparently unfeeling and ineffective physicians.

Binswanger’s disease, like Alzheimer’s, has resisted all treatments to date, but many other dementias can be partially reversed or at least slowed if diagnosed and treated early. Unfortunately, some diagnoses, including Alzheimer’s, can be confirmed only by autopsy. Clinicians therefore diagnose Alzheimer’s by exclusion--that is, by ruling out all the more definitely identifiable dementias. This trial-and-error exclusion process drains the emotional reserves of both the patient and the quickly haggard family members charting the patient’s response to various treatments.

Causes of treatable dementia include high blood pressure, depression, vitamin deficiencies (sometimes the result of absorption problems, rather than poor diet), drug interactions (sometimes involving over-the-counter purchases as well as prescription drugs), hormonal imbalances, and unwitnessed head injuries. Ray was treated for several of these problems; Myrna experienced renewed hope with each new treatment, and a bleaker depression as Ray continued to deteriorate.

I wish “The Loss of Self” had been available to the Doernberg family three years ago, and that all the physicians involved in Ray’s treatment had read it. This invaluable book reminds physicians how many questions patients and families are too bewildered, frightened or embarrassed to ask. It suggests some answers for those physicians who have never considered the questions, and brings others up to date on state and national helping agencies and other resources.

For the patients and families lucky enough to find this book, Donna Cohen and Carl Eisdorfer offer an excellent summary and translation of the medical literature on dementia, and mention some very recent research not covered in currently standard medical texts. They suggest general criteria for deciding when eccentricities have become symptoms, and for choosing a qualified physician. They emphasize the importance of early diagnosis for those 30-35% of Alzheimer’s-like dementias that can be successfully treated.

The Medicare and Medicaid systems are not designed to help chronically ill middle-class patients, and even a sketchy list of the absurd impasses faced by elderly patients is disheartening. The authors urge patients to obtain legal counsel as soon as possible after diagnosis.

One section advises the family shopping for nursing homes. Another demystifies mortuary and life insurance procedures. One does not want to read these things; neither does one want to have to learn it all at once later. Every family should have this information on hand.

Even in their closing discussion on organ donation, the authors offer encouragement and informed compassion. They speak plainly and movingly, with wisdom drawn from years of close involvement with their patients. They make firm recommendations for the care of care-givers who are giving too much. They broach difficult topics with graceful candor, and quote patients and families who have come through dreaded readjustments with more genuine kinds of dignity and deeper kinds of love. Anyone who expects someday to be living with an elderly person should read this book.