- Presence of other significant neurological or psychiatric disorders including (but not limited to) Alzheimer's disease; dementia with Lewy bodies; prion disease; Parkinson's disease (which has not subsequently been revised to PSP); any psychotic disorder; severe bipolar or unipolar depression; seizure disorder; tumor or other space-occupying lesion; or history of stroke or head injury with loss of consciousness for at least 15 minutes within the past 20 years.