Repetition is usually a sign that your loved one feels fearful or insecure; he may be looking for something comfortable and familiar -- something he has some degree of control over -- when he engages in repetition.
To address repetition, look for a specific antecedent or reason for the repetition as well as for the emotion behind the behavior. This will reduce your chances of responding impatiently with your loved one. If the repetition takes the form of an action, try turning it into an activity that makes him feel useful. For instance, if your relative is constantly fidgeting with his hands, try giving him some laundry to sort or some napkins to fold.
Sources:
Behaviors: What causes dementia-related behavior like aggression, and how to respond. Alzheimer's Association. 2005. http://www.alz.org/national/documents/brochure_behaviors.pdf
Mace, N. L., & Rabins, P. V. (2006). The 36-hour day: A family guide to caring for people with Alzheimer's disease, other dementias, and memory loss in later life (4th ed.). Baltimore, MD: Johns Hopkins University Press.
