RT Journal Article
SR Electronic
T1 Differentiating between right-lateralised semantic dementia and behavioural-variant frontotemporal dementia: an examination of clinical characteristics and emotion processing
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 1082
OP 1088
DO 10.1136/jnnp-2014-309120
VO 86
IS 10
A1 Jody Kamminga
A1 Fiona Kumfor
A1 James R Burrell
A1 Olivier Piguet
A1 John R Hodges
A1 Muireann Irish
YR 2015
UL http://jnnp.bmj.com/content/86/10/1082.abstract
AB Background and purpose Right-lateralised semantic dementia (right SD) and behavioural-variant frontotemporal dementia (bvFTD) appear clinically similar, despite different patterns of underlying brain changes. This study aimed to elucidate distinguishing clinical and cognitive features in right SD versus bvFTD, emphasising emotion processing and its associated neural correlates.Methods 12 patients with right SD and 19 patients with bvFTD were recruited. Clinical features were documented. All patients were assessed on standardised neuropsychological tests and a facial emotion processing battery. Performance was compared to 20 age-matched and education-matched controls. Grey matter intensity was related to emotion processing performance using whole-brain voxel-based morphometry analysis.Results Patients with right SD exhibited disproportionate language dysfunction, prosopagnosia and a suggestion of increased obsessive personality/behavioural changes versus patients with bvFTD. In contrast, patients with bvFTD demonstrated pronounced deficits in attention/working memory, increased apathy and greater executive dysfunction, compared to patients with right SD. Decreased empathy, disinhibition and diet changes were common to both dementia subtypes. Emotion processing deficits were present in both FTD syndromes but were associated with divergent patterns of brain atrophy. In right SD, emotion processing dysfunction was associated with predominantly right medial and lateral temporal integrity, compared to mainly left temporal, inferior frontal and orbitofrontal and right frontal gyrus integrity in bvFTD.Conclusions This study demonstrates comparable deficits in facial emotion processing in right SD and bvFTD, in keeping with their similar clinical profiles. These deficits are attributable to divergent neural substrates in each patient group, namely, right lateralised regions in right SD, versus predominantly left lateralised regions in bvFTD.