Because my mom has sleep apnea, the quality of her sleep is very poor. This leads to excessive sleepiness all day long. She is 96 yrs old. Is it worth having a sleep study, and perhaps purchase an apnea device? The possibility exists that she will just try to take it off during the night anyway. Please lend advice.
I’d really discuss this with a doctor who understands dementia. Most people with dementia can’t tolerate anything that overloads their senses.
No way on Earth you'll get your mother to keep that mask on her face all night, so why bother going through the nightmare? That's my opinion. Your only goal here is to keep your mother as comfortable as possible, which may mean getting hospice involved for comfort care at this point. Severe dementia warrants a hospice evaluation; see what her PCP has to say on the subject and if he'll write the order.
Best of luck!