After witnessing how Alzheimer's stripper her patients of dignity and life, a former British Columbia nurse drafted and signed a "living will" more than 20 years ago, detailing how she wanted to be cared for if she ever fell ill in the same way.

Margot Bentley -- who spent most of her career caring for patients with Alzheimer's and was intimately aware of the consequences of the illness -- asked in the 1991 document that care workers not keep her artificially alive if she ever had no chance of recovery. That included "no nourishments or liquids."

Now the family of Bentley is preparing to challenge the home caring for the woman because it won't stop forcibly feeding her despite the fact that she is suffering from advanced-stage Alzheimer's and is unable to speak or move.

The case, which will be heard before the B.C. court sometime this fall, opens up many questions, including what are the limitations of a living will.

Shael Eisen, a Toronto-based lawyer explains what the document is.

What is a living will?

Living wills have different names depending on where a person lives in Canada. In Ontario, for example, living wills are referred to as powers of attorney for personal care. This document gives someone else the right to act on a person's behalf with regards to personal decisions such as housing and hospital treatment.

"You can set out various things as to your medical care, who’s to cloth you and who’s to feed you," Eisen told CTV's Canada AM on Wednesday, adding that one can be very specific in the document with respect to end-of-life care.

"You can ask for no emergency measures, no heroic measures," he said.

The only limitation according to Eisen is when it comes to assisted suicide. "You really can't ask for assistance from someone else to push a button or to give you a pill."

Will the wishes expressed on a living will be respected?

According to Eisen, living wills are legal documents that should be respected by both health care professionals and family members. "You should be able to have your wishes fulfilled as long as you're not asking for someone to help you with assisted suicide," he said.

But despite the legal ramifications of the document, Eisen said living wills are fairly recent additions to the legal system in some parts of Canada – in Ontario, for example, they've only been around for the past 20 years – meaning there may be institutions or individuals who are afraid to carry them out.

Eisen said that might be the situation behind the Bentley case. He said the home caring for her may be afraid of facing charges from family members who don't agree with the living will.

"(The home caring for Bentley) is looking for a judge or a court to order them to do this so that they don't have any problems with the police for failing to provide necessities of someone that is in their care."