Information regarding non-cognitive symptoms in patients with senile dementia of Lewy body type (SDLT) was abstracted from a number of sources including postmortem, clinical and prospective studies. Psychotic symptoms occur in more than 80% of patients with SDLT. Visual hallucinations are especially common. Visual hallucinations, auditory hallucinations and delusional misidentification occur significantly more often in SDLT than Alzheimer's disease. Major depression occurs in 15% of patients with SDLT and Alzheimer's disease. Falls are common in SDLT occurring in 50% or more of patients, but not all studies find them to be significantly more common in SDLT than Alzheimer's disease. Little is known about the association of psychotic symptoms, depression or falls in SDLT and no effective treatment strategies are established.
Other important symptoms such as anxiety, aggression, wandering and inappropriate sexual activity have not been systematically studied.
It is necessary to set the scene by considering the prevalence rates and the importance of noncognitive features in patients with Alzheimer's disease as there is only rudimentary information available concerning these symptoms in Lewy body dementia (LBD). Fifteen to 30% of patients with Alzheimer's disease in contact with clinical services suffer from concurrent depression and the prevalence rate of psychotic symptoms in clinical samples exceeds 60%. Psychotic symptoms cause distress to carers and to the patients themselves. They reduce the likelihood of people continuing to live in their own homes (Steele et al., 1990), are associated with increased family discord and there is accumulating evidence to suggest that the presence of psychotic symptoms predicts a more rapid rate of cognitive decline (Rosen & Zubenko, 1991).