Hughes Laura E, Ghosh Boyd C P, Rowe James B
Department of Clinical Neurosciences, University of Cambridge, CB2 2QQ, UK ; Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK.
Neuroimage Clin. 2013;2:459-468. doi: 10.1016/j.nicl.2013.03.009.
The disruption of large-scale brain networks is increasingly recognised as a consequence of neurodegenerative dementias. We assessed adults with behavioural variant frontotemporal dementia and progressive supranuclear palsy using magnetoencephalography during an auditory oddball paradigm. Network connectivity among bilateral temporal, frontal and parietal sources was examined using dynamic causal modelling. We found evidence for a systematic change in effective connectivity in both diseases. Compared with healthy subjects, who had focal modulation of intrahemispheric frontal-temporal connections, the patient groups showed abnormally extensive and inefficient networks. The changes in connectivity were accompanied by impaired responses of the auditory cortex to unexpected deviant tones (MMNm), despite normal responses to standard stimuli. Together, these results suggest that neurodegeneration in two distinct clinical syndromes with overlapping profiles of prefrontal atrophy, causes a similar pattern of reorganisation of large-scale networks. We discuss this network reorganisation in the context of other focal brain disorders and the specific vulnerability of functional brain networks to neurodegenerative disease.
大规模脑网络的破坏日益被认为是神经退行性痴呆的一个后果。我们在听觉oddball范式期间使用脑磁图对患有行为变异型额颞叶痴呆和进行性核上性麻痹的成年人进行了评估。使用动态因果模型检查双侧颞叶、额叶和顶叶源之间的网络连通性。我们发现两种疾病中有效连通性都有系统性变化的证据。与健康受试者相比，健康受试者半球内额颞连接有局灶性调制，而患者组显示出异常广泛且低效的网络。连通性的变化伴随着听觉皮层对意外偏差音调（MMNm）的反应受损，尽管对标准刺激的反应正常。总之，这些结果表明，在两种具有重叠前额叶萎缩特征的不同临床综合征中，神经退行性变会导致类似的大规模网络重组模式。我们在其他局灶性脑疾病的背景下以及功能性脑网络对神经退行性疾病的特定易损性方面讨论这种网络重组。
