Cognitive symptoms arise from the location of brain dysfunction and are not linked directly to any particular pathology. In the early stages of disease, symptoms may be non-specific, and while certain symptom clusters are commonly seen in particular disorders, atypical presentations are not infrequent. For example, in Alzheimer’s disease, patients may present with a focal language syndrome instead of the more commonly appreciated autobiographical memory disturbance despite identical pathology. In our approach to the cognitive assessment, we maintain a symptom oriented approach. This facilitates the localisation of pathology and subsequent clinical diagnosis, which may then be supplemented by associated neurological signs, imaging or other investigations.