Related:

Signs and Symptoms of Dementia with Lewy Bodies

Fluctuations in attention and alertness. - These fluctuations may last for hours or days. Signs of these fluctuations include staring into space, lethargy, frequent drowsiness, and disorganized speech. These fluctuations have been referred to as "pseudodelirium," because they are similar to delirium.

Why do people with dementia keep their mouth open?

A symptom of dementia is the patient's mouth hanging open. This results from memory loss and the brain's failure to tell the body to keep the mouth closed.

Movement symptoms consistent with PD. These movement symptoms include: slow movement, rigidity, and falls.

Source: https://www.lbda.org/wp-content/uploads/2017/09/2017_diagnostic_checklist_-_updated_criteria_v2_1.pdf