It is one thing to believe that you are devoted to your spouse. It is another to live that devotion for months and years, as he becomes inexorably incapacitated until the day he dies. Such an effort is a fight against frustration, an exercise of inner strength — and a labor of love.

In "No Saints Around Here: A Caregiver's Days," Susan Allen Toth chronicles with unstinting honesty her own experience of caring for her husband, James, as Parkinson's disease with dementia robs him of control over his body and, ultimately, his mind. The title alludes to the mixed feelings that caregivers experience in the emotionally and physically daunting and exhausting effort.

Remarkably, given the demands on Toth at that time, the book is written during the last and most challenging 18 months of James' life not as a mere venting of her own feelings but ultimately as an outreach to other caregivers because, as Toth puts it, "Besieged by thoughts and feelings not always easy to express, a caregiver can often feel quite alone."

Toth had faced the challenges of single parenting while building a career as writer and academic before she found happiness with James, a "vibrant, lighthearted and lively" man 15 years her senior who approached his work as an architect and his life in general with humor and passion. Theirs was a life rich with intellectual pursuits, good humor and plenty of spontaneity.

After James' Parkinson's is diagnosed, Toth says, the couple are "lucky" to enjoy several years during which his decline is gradual. But inevitably, the pair's circle of activity is reduced, along with James' mobility. For instance, their long rambles of former years turn into labored navigation around a single room and then into no perambulations at all.

Toth is a master of selecting the telling detail, as when she describes how James can no longer get out of — or safely down the stairs from — his comfy yellow chair in the couple's reading nook. The practical and dangerous conundrum that Toth faces in this incident is married to the awful reality that something so simple and comforting as reading companionably in a pair of chairs is lost not just to James but the couple.

NO SAINTS AROUND HERE by Susan Allen Toth

The author is also talented at understatement, and at delivering, almost as a background theme, the unrelenting reality of the constant danger she must prevent as — when the disease has progressed — every time James endeavors to stand up she must be there in case he falls.

Toth writes that she hopes that "No Saints Around Here" will spark conversation. This is an important book, not just for lonely caregivers but also for us all. It ought to be required reading for anyone in a position to affect funding and social policy to benefit those who toil to care for others.

Rosemary Herbert is a longtime literary critic and author of "Front Page Teaser: A Liz Higgins Mystery."