Introduction

Dementia is a syndrome which involves progressive disturbance of multiple cognitive functions, emotional control and social behaviour in clear consciousness (International Classification of Diseases, ICD-10).1 Alzheimer’s disease (AD) accounts for more than 50% of all dementias and hence is the most widely studied. Although Alzheimer’s first description of the condition included noncognitive features like hallucinations, delusions and screaming,2 most research has focused on the cognitive features, i.e. memory loss, perceptuo-motor skills and language disturbance.