Chapter 6 - Behavioral variant of frontotemporal dementia

Abstract

Decrease of social contacts, emotional impoverishment, early decrease of criticism, and lack of insight are cardinal symptoms of the behavioral variant of frontal temporal dementia (FTD). On a behavioral level, conspicuous behavior, disinhibition in social interaction, loss of interest (e.g., in self-care) and risky decision making characterize the disease. Neuropsychological testing should encompass prefrontal lobe functions sensitive tests [e.g., working memory and flexibility of the Testbatterie zur Aufmerksamkeitsprüfung (TAP)], the reading the mind in the eyes test, picture arrangement of the Wechsler Intelligenztest für Erwachsene, Wechsler Adult Intelligence scale (WIE), and the neuropsychiatric inventory (NPI) answered by close friends or relatives. Tests for affective empathy and object alternation task are especially sensitive in the early stages of behavioral FTD (bvFTD). Standard neuropsychological tests, for example, the Consortium to Establish a Registry for Alzheimer’s Disease, Neuropsychological Assessment Battery (CERAD-NAB) and the DemTect, are not effective for a differential diagnosis of bvFTD. If there is any indication for bvFTD, the NPI should be answered by a relative of the patient. Changes in eating behavior and in irritability, disinhibition, and distraction are of major interest. Moreover the clinical observation should look for signs of prehension behavior and the anamnesis and increasing tension in the relationship not only related to increase irritability but also to a loss of affective empathy. Up to now, there is no specific treatment for bvFTD neither on a functional nor on a pharmacological level. Serotonergic modulation might have the potential for symptom modulation (reducing disinhibition in the patients), but there is no large-scale randomized controlled trial to show that on a high level of evidence. The German guidelines for dementia argue for risperidone to reduce the behavioral impairments in bvFTD. In any case relatives of bvFTD should be offered professional education on how to deal with their affected family members because their behavior leads to severe losses of quality of live and often poses the question how to respond correctly.