Boisgontier Matthieu P, Cheval Boris, van Ruitenbeek Peter, Levin Oron, Renaud Olivier, Chanal Julien, Swinnen Stephan P
Movement Control and Neuroplasticity Research Group, Department of Kinesiology, Biomedical Sciences Group, KU Leuven, Leuven, Belgium.
Methodology and Data Analysis Research Group, Faculty of Psychology and Educational Sciences (FAPSE), Geneva University, Geneva, Switzerland.
Gait Posture. 2016 Mar;45:143-50. doi: 10.1016/j.gaitpost.2016.01.019. Epub 2016 Jan 29.
Functional and structural imaging studies have demonstrated the involvement of the brain in balance control. Nevertheless, how decisive grey matter density and white matter microstructural organisation are in predicting balance stability, and especially when linked to the effects of ageing, remains unclear. Standing balance was tested on a platform moving at different frequencies and amplitudes in 30 young and 30 older adults, with eyes open and with eyes closed. Centre of pressure variance was used as an indicator of balance instability. The mean density of grey matter and mean white matter microstructural organisation were measured using voxel-based morphometry and diffusion tensor imaging, respectively. Mixed-effects models were built to analyse the extent to which age, grey matter density, and white matter microstructural organisation predicted balance instability. Results showed that both grey matter density and age independently predicted balance instability. These predictions were reinforced when the level of difficulty of the conditions increased. Furthermore, grey matter predicted balance instability beyond age and at least as consistently as age across conditions. In other words, for balance stability, the level of whole-brain grey matter density is at least as decisive as being young or old. Finally, brain grey matter appeared to be protective against falls in older adults as age increased the probability of losing balance in older adults with low, but not moderate or high grey matter density. No such results were observed for white matter microstructural organisation, thereby reinforcing the specificity of our grey matter findings.
功能和结构成像研究已经证明大脑参与平衡控制。然而，灰质密度和白质微观结构组织在预测平衡稳定性方面的决定性作用，尤其是与衰老效应相关时，仍不清楚。对30名年轻人和30名老年人在不同频率和振幅移动的平台上进行睁眼和闭眼站立平衡测试。压力中心方差用作平衡不稳定的指标。分别使用基于体素的形态计量学和扩散张量成像测量灰质的平均密度和白质微观结构组织。建立混合效应模型以分析年龄、灰质密度和白质微观结构组织对平衡不稳定的预测程度。结果表明，灰质密度和年龄均独立预测平衡不稳定。当条件难度增加时，这些预测得到加强。此外，灰质在不同条件下预测平衡不稳定的能力超过年龄，且至少与年龄一样稳定。换句话说，对于平衡稳定性，全脑灰质密度水平至少与年轻或年老一样具有决定性。最后，随着年龄增加，灰质似乎对老年人跌倒具有保护作用，因为在灰质密度低但不是中等或高的老年人中，年龄增加了失去平衡的可能性。白质微观结构组织未观察到此类结果，从而加强了我们关于灰质研究结果的特异性。
