My kind and loving mother was diagnosed with Alzheimer's when it became obvious that her memory was impaired. She was put on drugs to treat Alzheimer's, which did nothing to improve her memory or stop the progression of the disease.
The first symptoms were spontaneous hallucinations. These hallucinations were oddly pleasing to Mom. A smile would cross her face and she would extend her hand toward an invisible person.
She would tell the hallucination, "come here honey, you don't have to stand against that wall."
Mom loved babies and children (she had five kids and endless patience for her "tribe"). I later learned that LBD hallucinations are generally not confusing or frightening but are often pleasing. The only disappointing thing about her hallucinations that no one else could see them.
Aside from seeing things, Mom's personality was pretty much the same.