Lewy body dementia, the second most common type of progressive dementia after Alzheimer’s disease, causes a progressive decline in mental abilities. It may also cause visual hallucinations, which may take the form of seeing shapes, colors, people or animals that aren’t there or, more complexly, having conversations with deceased loved ones.
Another indicator of Lewy body dementia may be significant fluctuations in alertness and attention, which may include daytime drowsiness or periods of staring into space. And, like Parkinson’s disease, Lewy body dementia can result in rigid muscles, slowed movement and tremors.
In Lewy body dementia, abnormal round structures — called Lewy bodies — develop in regions of your brain involved in thinking and movement.
Lewy body dementia symptoms and signs may include:
- Visual hallucinations. Seeing colors, shapes, animals or people that aren’t there may be one of the first symptoms of Lewy body dementia.
- Movement disorders. Parkinson’s-like signs may include slowed movement, rigid muscles, tremors or a shuffling walk.
- Delusions. These may consist of false ideas about another person or situation.
- Cognitive problems. Alzheimer’s-like problems may include confusion, memory loss and a reduced attention span.
- Sleep difficulties. A sleep disorder can cause you to physically act out your dreams while you’re asleep.
- Fluctuating attention. This may include frequent episodes of drowsiness, long periods of staring into space, lethargy or disorganized speech.