INTRODUCTIONSemantic dementia (SD) is a clinical syndrome characterized by a progressive loss of conceptual knowledge. Patients typically present in the presenium with difficulty in recalling and understanding words, and later show impairment in recognizing objects (Lambon Ralph et al., 1998Hodges et al., 1992). Surface dyslexia is also part of the SD clinical picture, as patients have greater difficulty reading words with irregular pronunciations (such as "yacht") compared to regularly spelled words (such as "context"). Within the language domain, speech, phonological and syntactic processing are usually spared. Spatial abilities, non-verbal reasoning and day-to-day episodic memory also remain relatively intact, while episodic memory is often impaired on formal testing (see Hodges and Miller, 2001). Current clinical research criteria list SD as one of the possible clinical presentations of frontotemporal lobar degeneration (FTLD) (Neary et al., 1998). Neuroimaging findings in SD indicate that the anterior temporal lobe is the site of most prominent atrophy and/or hypometabolism, providing a powerful model for studying this brain region rarely hit by other neurological diseases (Mummery et al., 2000;Galton et al., 2001;Chan et al., 2001;Rosen et al., 2002a). Voxel-based Morphometry studies (VBM) and region of interest analysis on MRI scans have shown that the hippocampal/amygdala structures and the infero-lateral temporal neocortex are both significantly atrophied in SD (Chan et al., 2001;Rosen et al., 2002aRosen et al., , 2002b. It has also been shown that the ventro-medial frontal lobe and the insula are involved (Rosen et al., 2002a). The finding that orbitofrontal cortex and amygdala are damaged in SD is consistent with reports that personality changes, disturbances in social behavior, and abnormalities in emotional processing can be part of the clinical syndrome.Most reported cases of semantic dementia have shown mainly left anterior temporal lobe atrophy. Thus, the classic clinical picture of SD with prominent semantic memory deficits has also been labeled as the "left temporal lobe variant"(LTLV) of FTLD (Edwards-Lee et al., 1997). Less evidence is available regarding the clinical presentation of cases with "right-temporal lobe variant" (RTLV) of FTLD. Only a few reports of RTLV cases have concentrated on describing early difficulties in processing information regarding familiar people, either as progressive disturbance in recognizing familiar faces, or as a more generalized semantic deficit for person-specific information (Gainotti et al., 2003;Barbarotto et al., 1995;Gentileschi et al., 1999;Tyrrell et al., 1990;Evans et al., 1995). In these cases, the presence of behavioral changes was sometimes mentioned, but its significance and the time of first manifestation was not reported (Gainotti et al., 2003 ABSTRACT Semantic dementia (SD) is a clinical variant of frontotemporal lobar degeneration (FTLD) characterized by progressive deterioration of semantic memory with relative sparing of other cognitive fun...