While you may never know the reason behind your mother's refusal to shower, it is important to understand that rationalizing with her may be ineffective, especially if her judgment is impaired. Even though Alzheimer's disease affects everyone differently, many individuals with this disease have difficulty expressing their thoughts clearly. As a result they will often reply, "No!" to any requests that cause them to feel uncomfortable, anxious or unsafe. Therefore, instead of asking your mother "Would you like to shower?", you should try to direct and guide her into the shower.
One recommendation to begin is to go with what you know about your mother's past routine. Did she take showers in the morning, afternoon or evening? Was it right after waking up, her morning coffee or watching the nightly news? Taking into consideration her shower routine prior to her illness can help set things in motion. Also of importance is to prepare the bathroom beforehand. Preparation can include running the water to make sure the temperature is to her liking, as well as bringing in items like her bathrobe, change of clothes, hairbrush, and any other things you need for her. Having such items handy is important to ensure you will not have to leave your mother alone to run out for something you may have forgotten.
Once you have your mother in the bathroom, talking to her and walking her through the routine is also important as she will know what to expect. Doing so can prevent her from becoming afraid of something she is unprepared for. For example, if you are going to assist your mother with getting undressed, you may want to say, "Okay mom, I'm going to help you unbutton your shirt. Here's a towel for you to cover yourself so you won't feel cold." Take into account that the act of showering or bathing is when people are most vulnerable. Having to disrobe and exposing your body to a cool room are discomforting things. In addition, some people have to do it in front of someone else, which can be a very scary and frightening experience, even if it is a relative.