hallucinations and disrupted sleep patterns

Do you have any idea what may be wrong with the following individual ...

This is an older gentleman (approximately 70 years old) who has not slept through the night in years. He will sleep extensively during the day, however, driving his wife nuts. He was diagnosed years ago with depression and has been taking medication since then. He was also diagnosed with early stage Parkinsons last summer.

He now suffers hallucinations which started a couple of months ago. He is on some medication that has reduced the number of imaginary people he sees in the house. The hallucinations are almost entirely visual as he has mentioned frustration when he speaks to these people and they don't respond.

He rambles around his home aimlessly literally all night and seems to have no idea what he is doing. He has  been caught trying to leave the house in his pyjamas in the middle of the night to "take these guys home" (although there seems to
be less of that now). He appears to be completely out of it. He will remove his clothes and be very agitated and then simply stand still for quite a long time, doing nothing. Then, as soon as the sun comes up he seems to be right back to his old self. This is strange. It appears as though a switch went on in his head as soon as it was daylight.

A few weeks ago he had a CAT scan done that revealed he had had
two mini strokes. A second scan done by another neurologist revealed absolutely nothing.

Any thoughts or suggestions as to what could be wrong would be greatly appreciated.

[Roger Gould, M.D.]

There are many possibilities, but they all point to a brain disorder that is probably something like alzheimers or senile dementia. All of this is probably exacerbated at night because of sleep cycle disturbance and added disorientation. The neurologist is the best person to manage this because some medications are necessary but others make it worse.