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Department of Neurology, University of California at San Francisco, San Francisco, CA 94143-1207, USA.
Neurology (Impact Factor: 8.29). 05/2005; 64(8):1384-90. DOI: 10.1212/01.WNL.0000158425.46019.5C
Source: PubMed


The temporal variant of frontotemporal dementia (tvFTD) features asymmetric anterior temporal/amygdala degeneration as well as ventromedial frontal, insular, and inferoposterior temporal involvement. Left temporal atrophy has been linked to loss of semantic knowledge, whereas behavioral symptoms dominate the right temporal variant.
To investigate the first symptoms and the timing of subsequent symptoms in patients with left versus right tvFTD.
Twenty-six patients with tvFTD were identified. Six had right > left temporal atrophy (right temporal lobe variant [RTLV]) and were matched with six having comparable left > right temporal atrophy (left temporal lobe variant [LTLV]). Clinical records were reviewed to generate individualized symptom chronologies.
In all patients, first symptoms involved semantics (4/6 LTLV, 1/6 RTLV), behavior (4/6 RTLV, 1/6 LTLV), or both (1 LTLV, 1 RTLV). Semantic loss began with anomia, word-finding difficulties, and repetitive speech, whereas the early behavioral syndrome was characterized by emotional distance, irritability, and disruption of physiologic drives (sleep, appetite, libido). After an average of 3 years, patients developed whichever of the two initial syndromes--semantic or behavioral--that they lacked at onset. A third stage, 5 to 7 years from onset, saw the emergence of disinhibition, compulsions, impaired face recognition, altered food preference, and weight gain. Compulsions in LTLV were directed toward visual, nonverbal stimuli, whereas patients with RTLV were drawn to games with words and symbols.
The temporal variant of frontotemporal dementia follows a characteristic cognitive and behavioral progression that suggests early spread from one anterior temporal lobe to the other. Later symptoms implicate ventromedial frontal, insular, and inferoposterior temporal regions, but their precise anatomic correlates await confirmation.

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    • "and impulsivity, lack of insight, and emotional blunting, callousness , and a loss of empathy (Gustafson, 1987; Neary et al., 2005). Notably, patients with semantic dementia with right temporal lobe atrophy also tend to demonstrate similar behavioural symptoms early in the course of illness (Bozeat et al., 2000; Seeley et al., 2005; Snowden et al., 2001), and all three subtypes can include these behavioural abnormalities (Neary et al., 1998; Rosen et al., 2006). One of the core diagnostic features of bvFTD is a loss of empathy , exhibited by decreased social interest, diminished responsiveness to the feelings of others, and increased coldheartedness (Perry and Miller, 2001; Rascovsky et al., 2011). "
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    ABSTRACT: Objectives: Behavioural variant frontotemporal dementia (bvFTD) is a debilitating neurodegenerative disorder characterized by frontal and temporal lobe atrophy primarily affecting social cognition and emotion, including loss of empathy. Many consider empathy to be a multidimensional construct, including cognitive empathy (the ability to adopt and understand another's perspective) and emotional empathy (the capacity to share another's emotional experience). Cognitive and emotional empathy deficits have been associated with bvFTD; however, little is known regarding the performance of patients with bvFTD on behavioural measures of emotional empathy, and whether empathic responses differ for negative versus positive stimuli. Methods: 24 patients with bvFTD and 24 healthy controls completed the Multifaceted Empathy Test (MET; Dziobek et al., 2008), a performance-based task that taps both cognitive and emotional facets of empathy, and allows for the discrimination of responses to negative versus positive realistic images. MET scores were also compared with caregiver ratings of patient behaviour on the Interpersonal Reactivity Index, which assesses patients' everyday demonstrations of perspective taking and empathic concern. Results: Patients with bvFTD were less accurate than controls at inferring mental states for negative and positive stimuli. They also demonstrated lower levels of shared emotional experience, more positive emotional reactions, and diminished arousal to negative social stimuli relative to controls. Patients showed reduced emotional reactions to negative non-social stimuli as well. Lastly, the MET and IRI measures of emotional empathy were found to be significantly correlated within the bvFTD group. Conclusions: The results suggest that patients with bvFTD show a global deficit in cognitive empathy, and deficient emotional empathy for negative, but not positive, experiences. Further, a generalized emotional processing impairment for negative stimuli was observed, which could contribute to the emotional empathy deficit. This work highlights potential treatment targets and a means to assess the impact of novel therapies on socioemotional impairment in bvFTD.
    Neuropsychologia 11/2014; 67. DOI:10.1016/j.neuropsychologia.2014.11.022 · 3.30 Impact Factor
    • "One of the most representative examples is the comparison between Alzheimer's disease (AD) and semantic dementia (SD), two clinically distinct syndromes. Semantic dementia (Neary et al., 1998), also referred to as the semantic variant of primary progressive aphasia (Gorno-Tempini et al., 2011) or temporal variant of frontotemporal lobar degeneration (Seeley et al., 2005), is characterized by a gradual and modality-independent loss of semantic knowledge, resulting in specific language disturbances with impaired naming and word comprehension but a fluent and grammatically correct speech. Neuroimaging studies showed that, in both diseases, the medial temporal lobe undergoes atrophy (Chan et al., 2001; Galton et al., 2001; Nestor et al., 2006; Schroeter and Neumann, 2011; Duval et al., 2012; La Joie et al., 2012) and hypometabolism (Desgranges et al., 2007; Rabinovici et al., 2008; Mosconi et al., 2005; Nestor et al., 2006; Duval et al., 2012; La Joie et al., 2012). "
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    • "Indeed, our voxel-based morphometry analyses revealed that although the left hemisphere was overwhelmingly affected in our semantic dementia group, bilateral insult to the amygdalae, anterior temporal cortices, and temporal poles was also present. It is likely therefore, that the extent to which social cognitive processes are disrupted in semantic dementia depends upon the integrity of right anterior temporal structures , with ToM impairments and behavioural egocentrism becoming more prominent with disease evolution (Thompson et al., 2003; Seeley et al., 2005). We have demonstrated here that cases with left predominant semantic dementia, in which atrophy has progressed to the contralateral hemisphere, present with marked disturbances in ToM processing, which in turn are corroborated by caregiver ratings of severe alterations in cognitive and emotional aspects of everyday interpersonal functioning on the Interpersonal Reactivity Index. "
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    ABSTRACT: Semantic dementia is a progressive neurodegenerative disorder characterized by the amodal and profound loss of semantic knowledge attributable to the degeneration of the left anterior temporal lobe. Although traditionally conceptualized as a language disorder, patients with semantic dementia display significant alterations in behaviour and socioemotional functioning. Recent evidence points to an impaired capacity for theory of mind in predominantly left-lateralized cases of semantic dementia; however, it remains unclear to what extent semantic impairments contribute to these deficits. Further the neuroanatomical signature of such disturbance remains unknown. Here, we sought to determine the neural correlates of theory of mind performance in patients with left predominant semantic dementia (n = 11), in contrast with disease-matched cases with behavioural-variant frontotemporal dementia (n = 10) and Alzheimer's disease (n = 10), and healthy older individuals (n = 14) as control participants. Participants completed a simple cartoons task, in which they were required to describe physical and theory of mind scenarios. Irrespective of subscale, patients with semantic dementia exhibited marked impairments relative to control subjects; however, only theory of mind deficits persisted when we covaried for semantic comprehension. Voxel-based morphometry analyses revealed that atrophy in right anterior temporal lobe structures, including the right temporal fusiform cortex, right inferior temporal gyrus, bilateral temporal poles and amygdalae, correlated significantly with theory of mind impairments in the semantic dementia group. Our results point to the marked disruption of cognitive functions beyond the language domain in semantic dementia, not exclusively attributable to semantic processing impairments. The significant involvement of right anterior temporal structures suggests that with disease evolution, the encroachment of pathology into the contralateral hemisphere heralds the onset of social cognitive deficits in this syndrome.
    Brain 02/2014; 137(Pt 4)(4). DOI:10.1093/brain/awu003 · 9.20 Impact Factor
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