Bimanual non-congruent actions in motor neglect syndrome: a combined behavioral/fMRI study.
Bimanual non-congruent actions in motor neglect syndrome: a combined behavioral/fMRI study.
复制标题
DOI：
10.3389/fnhum.2015.00541
复制
发表时间：
2015
影响因子：
2.9
通讯作者：
Fadiga L
中科院分区：
文献类型：
--
作者：
Garbarini F;Turella L;Rabuffetti M;Cantagallo A;Piedimonte A;Fainardi E;Berti A;Fadiga L
在运动忽略综合征(MN)中，描述了一种不一致的双手运动的特殊损害。在目前的病例对照研究中，我们调查了这种行为缺陷的神经功能相关性。2例右脑损害患者，1例有(MN+)和1例无(MN−)MN，采用双手环-线(CL)范式进行功能磁共振成像。患者被要求进行右手动作(划线)，同时进行一致(划线)或不一致(画圆圈)左手动作。在行为任务中，MN−患者表现出双手耦合效应，而MN+患者则没有。功能磁共振成像研究表明，在MN−中，额顶网络，主要涉及补充前运动区和后顶叶皮质，在不一致的情况下比在一致的情况下明显活跃，正如先前在健康受试者中所显示的那样。相反，MN+患者在SMA前和PPC中均表现出相反的激活模式。在这个额顶网络中，前SMA被认为对同种肌肉的默认连接施加了抑制影响，从而允许执行不一致的运动。在MN综合征中，所描述的SMA前异常活动支持这样的假设，即未能抑制自发性运动程序可能确定不一致运动的特定损害。
In Motor Neglect (MN) syndrome, a specific impairment in non-congruent bimanual movements has been described. In the present case-control study, we investigated the neuro-functional correlates of this behavioral deficit. Two right-brain-damaged (RBD) patients, one with (MN+) and one without (MN−) MN, were evaluated by means of functional Magnetic Resonance Imaging (fMRI) in a bimanual Circles-Lines (CL) paradigm. Patients were requested to perform right-hand movements (lines-drawing) and, simultaneously, congruent (lines-drawing) or non-congruent (circles-drawing) left-hand movements. In the behavioral task, MN− patient showed a bimanual-coupling-effect, while MN+ patient did not. The fMRI study showed that in MN−, a fronto-parietal network, mainly involving the pre-supplementary motor area (pre-SMA) and the posterior parietal cortex (PPC), was significantly more active in non-congruent than in congruent conditions, as previously shown in healthy subjects. On the contrary, MN+ patient showed an opposite pattern of activation both in pre-SMA and in PPC. Within this fronto-parietal network, the pre-SMA is supposed to exert an inhibitory influence on the default coupling of homologous muscles, thus allowing the execution of non-congruent movements. In MN syndrome, the described abnormal pre-SMA activity supports the hypothesis that a failure to inhibit ipsilesional motor programs might determine a specific impairment of non-congruent movements.