In patients with neurodegenerative diseases such as Alzheimer’s disease (AD) and behavioral variant frontotemporal dementia (bvFTD), impaired
awareness is common, though it differs in modality and degree (Ecklund-Johnson and Torres 2005; Rankin et al. 2005; Hornberger et al. 2012). Many AD patients are highly aware of their cognitive Inhibitors,research,lifescience,medical deficits early in the disease, but all patients show increasingly inaccurate self-evaluation as the disease progresses (Ecklund-Johnson and Torres 2005). In contrast, early loss of self-awareness is a central feature of bvFTD (Neary et al. 1998). Typically, bvFTD patients describe their personality traits less accurately and are less aware of their specific behavior deficits than AD patients (Eslinger et al. 2005; Rankin et al. 2005; Salmon et al. 2008; Hornberger et al. 2012). bvFTD patients may also be less aware of their cognitive
deficits than AD patients, even when they are less cognitively impaired (Williamson et al. 2010). In fact, bvFTD patients can display substantial deficits in self-awareness Inhibitors,research,lifescience,medical before showing measureable cognitive impairments (Lee et al. 2012), suggesting that self-awareness involves factors beyond the domains tested in a standard neuropsychological battery. This also suggests that the focal anatomy affected early in bvFTD may be more directly involved in self-awareness than the anatomy affected early in AD. Results of functional Inhibitors,research,lifescience,medical and structural neuroimaging studies of self-awareness deficits in neurodegenerative
disease generally confirm these hypotheses (Zamboni and Wilcock 2011). Results, however, Inhibitors,research,lifescience,medical are divergent across studies, likely due to methodological and conceptual differences such as the modality of self-awareness studied, the assessment methods used, or the sample’s characteristics (Markova et al. 2005; Zamboni and Wilcock 2011). While some studies found correlations between self-awareness deficits and right frontal dysfunction (Starkstein et al. 1995; Mendez and Shapira 2005; McMurtray et al. 2006) Inhibitors,research,lifescience,medical and right ventro-medial GDC-0994 chemical structure atrophy (Rosen et al. 2010), others found correlations with lateral temporo-parietal Rebamipide (Salmon et al. 2006; Ruby et al. 2009) or anterior temporal dysfunction (Ruby et al. 2007), and right posterior temporal atrophy (Zamboni et al. 2010). These divergent results may indicate that self-awareness involves a large-scale supramodal neural network (Schmitz and Johnson 2007; Legrand and Ruby 2009), as reported in functional neuroimaging studies investigating the self in healthy individuals, that comprises the medial prefrontal cortex, precuneus/posterior cingulate gyrus, temporo-parietal junction, and temporal poles (Legrand and Ruby 2009). Most previous neuroimaging studies of self-awareness in neurodegenerative disease have focused on whether patients were able to accurately estimate their level of cognitive functioning (Zamboni and Wilcock 2011).