People with dementia with Lewy bodies not only experience problems with memory and judgement, like those with Alzheimer's disease, but are also likely to have difficulties with concentration and visual perception (recognising objects and making judgements about where they are in space). They may experience: slowed movement, stiff limbs, and tremors recurrent visual hallucinations (seeing things that aren't there) sleep disturbances, including sleepiness during the day fainting, unsteadiness, and falls People with the condition tend to swing from a state of alertness to drowsiness or staring into space. These extreme changes may be unpredictable and happen from hour to hour or day to day.