My mother has mild vascular dementia, and normally does well. Her cognitive level was tested and is the same as one year ago. However we had two bad weeks of what we thought was agitation and hallucinations. The neurologist said he believes she has REM sleep disorder, with a non determined cause at this time. He mentioned stress, dementia and sleep apnea as possible causes. His decision was to wait and see. No meds, no treatment, no tests at this time. I don't think he understands what we have been thru these past two weeks. Things are better, but wait and see? I'm a little terrified to face those problems again.