Behavioral Variant Frontotemporal Dementia

Frontotemporal dementia (FTD) is a sporadic or genetic neurodegenerative disease in which frontotemporal involvement is typically encountered. According to clinical features, three groups are distinguished as behavioral (bvFTD) and progressive aphasia variants; semantic dementia and progressive non-fluent aphasia. The most common type is bvFTD mimicking as disinhibition, apathy, loss of empathy, perseverative / compulsive behaviors, hyperorality, executive dysfunction and diagnosed with imaging, pathogenic mutation and histopathological evidence as well as clinical diagnosis. Brain magnetic resonance imaging (MRI) studies show atrophy especially in ventromedial frontal cortex, posterior orbital frontal regions, insula, anterior cingulate cortex and subcortical structures; the degeneration of these structures, known as the salience network, is held responsible for deterioration of the executive functions. In the early period, the presence of frontotemporal hypometabolism in positron emission tomography is more sensitive than MRI, parietal hypometabolism and amyloid deposition are not seen. Tau levels in cerebrospinal fluid may be low or high in FTD, but the tau / amyloid-beta ratio is found to be highly specific. More than 40% of bvFTD cases have family history and most autosomal dominant inheritance patterns are present. In FTD, cholinergic system is protected, cell loss in serotoninergic receptor and raphe nucleus is evident. Dopaminergic and cholinergic therapy has not been found to be useful and even worsening of behavioral symptoms with cholinesterase inhibitors has been reported. Selective serotonin reuptake inhibitors and trazodone are effective on behavioral symptoms and sleep problems. Pharmacological and non-pharmacological interventions, training and counseling services are important for the relatives of patients.