Did her doctor put her on Zyprexa? The problem with dementia or Alzheimer's is that sometimes certain medications don't work right. Zyprexa is used to treat Schizophrenia, bipolar or other psychotic disorders. The chemical make up (in the brain) of a person with AD changes. For instance, sleeping medications can cause aggression and or restlessness in a person with AD. There are other medications that can be tried to help control her outbursts. Also too, if she is taking Zyprexa with certain medications, there can be interactions.
http://health.yahoo.net/goldcontent/olanzapine?brand=Zyprexa