Yes, that is a symptom of dementia.

thanks i should have worded my question differenty does insomnia that someone has had through all their life cause this disease

Yes, sleeping troubles are associated with dementia. There is also a term I am not sure if you are aware of called 'sundowning'. This is confusion in the later day (late afternoon, early evening) which could cause a individual to become tired and name throughout the day, and then have a more active mind throughout the night!