Neuroanatomy of the self - Evidence from patients with frontotemporal dementia

Objective: To evaluate the frequency and types of change in "self" seen in frontotemporal dementia (FTD) and to determine the relative involvement of the nondominant and dominant frontal and temporal brain regions in FTD pati ents with or without changes in a sense of self using neuropsychology tests and neuroimaging. Background: The self has been defined as "the total, ess ential, or particular being of a person" involving "the essential qualities distinguishing one person from another." Some suggest that the frontal lob es play a dominant role in maintaining the self FTD affects anterior fronta l and temporal areas and can be associated with a loss of self. Methods: Se venty-two consecutive FTD patients were evaluated with neuropsychiatric, ne uropsychologic, and behavioral measures. Patients were imaged with MRI and SPECT. Charts were reviewed by a social psychologist to determine patients who exhibited a dramatic change in their self as defined by changes in poli tical, social, or religious values. The brain areas with the most severe at rophy or hypoperfusion on neuroimaging were noted. Results: Seven of 72 pat ients exhibited a dramatic change in self. In six of the seven, the selecti ve dysfunction involved the nondominant frontal region. In contrast, only o ne of the other 65 patients without selective nondominant frontal dysfuncti on showed a change in self. Conclusions: FTD patients with asymmetric loss of function in the nondominant frontal lobe often exhibit a diminished main tenance of previously learned self-concepts despite intact memory and langu age. Normal nondominant frontal function is important for the maintenance o f the self.