Clinical Aspects Diagnosis
The physician will often be notified by family carers or professional carers concerning acute onset of aggression, agitation, irritability, or hyperactivity. If the patient already has a diagnosis of Alzheimer’s disease (AD), or another dementia disorder, the symptoms may be interpreted as part of dementia but should always elicit a stepwise management program, as described below (Sect. 9.4 “Management of Agitation, Aggression, Irritability, and Hyperactivity”). Note, however, that the onset of such symptoms in a person with a specific dementia diagnosis may in some cases lead to a reconsideration of the classification of dementia (e.g., appearance of vivid hallucinations specifically at nighttime indicates that the patient is suffering from dementia with Lewy bodies (DLB)). An alternative diagnosis, such as autoimmune encephalopathies or cerebral malignancies, should be considered in particular in patients who develop the symptoms in relation to an unexpectedly rapid decline.
Sometimes aggression, agitation, irritability, or hyperactivity may arise in individuals not diagnosed with any specific brain disorder (e.g., not known to be suffering from dementia, brain tumor, stroke, depression, psychotic disorder), in which case an appropriate diagnostic work-up should be completed prior to or simultaneously with initiation of the management plan (Sect. 9.4 “Management of Agitation, Aggression, Irritability, and Hyperactivity”) described below. Finally, before diagnosing the symptoms as a reflection of acute or subacute manifestations of a chronic brain disorder, the possibility of delirium (see Chap. 5) should also be considered.
When identifying and mapping symptoms, a thorough interview with the patient and their carers is important. It is essential that the carer, whether a family member or a professional, is given the opportunity to talk about the symptoms in the absence of the patient. The physician should be aware that aggression, agitation, irritability, and hyperactivity may reflect underlying psychotic symptoms (e.g., delusions and hallucinations), fluctuations in consciousness, and physical symptoms, which is why the physician should enquire specifically about these symptoms.