Tecchio Franca, Zappasodi Filippo, Tombini Mario, Oliviero Antonio, Pasqualetti Patrizio, Vernieri Fabrizio, Ercolani Matilde, Pizzella Vittorio, Rossini Paolo Maria
Department of Neuroscience, MEG Unit, Istituto di Scienze e Tecnologie della Cognizione (ISTC)-CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy.
Neuroimage. 2006 Sep;32(3):1326-34. doi: 10.1016/j.neuroimage.2006.05.004. Epub 2006 Jun 27.
The aim of this paper was to deepen understanding about the role played by brain plasticity in obtaining clinical recovery. Eighteen patients, who had recovered partially or totally from dysfunctions due to a monohemispheric infarction within the middle cerebral artery territory, underwent magnetoencephalographic (MEG) recordings of rolandic areas cerebral activity both in rest state (spectral power properties) and in response to the electrical stimulation of the contralateral median nerve (M20 and M30 cortical sources). MEG evaluation was performed in acute (T0: mean 5 days from ischemic attach) and post-acute phase (T1: median 6 months). At T1, all the inter-hemispheric asymmetries were reduced for both spontaneous and evoked activity parameters with respect to T0. In post-acute phase, lower cortical excitability, higher delta and theta power and lower spectral entropy were associated to a worse clinical state. An unusual recruitment-as revealed by an excessive inter-hemispheric asymmetry of M20 cortical source position-correlated with higher level of clinical amelioration in the patients who showed a partial recovery. In addition to confirmative evidence that "normalization" of neural activity in both the affected and unaffected hemispheres subtends best clinical recovery, present data provide support to the positive role of cerebral plasticity phenomena--i.e. unusual neural recruitments--to regain lost functions in those patients unable to achieve total recovery.
本文的目的是加深对大脑可塑性在临床恢复中所起作用的理解。18名因大脑中动脉区域单半球梗死导致功能障碍而部分或完全恢复的患者，接受了静息状态（频谱功率特性）和对侧正中神经电刺激（M20和M30皮质源）时罗兰区大脑活动的脑磁图（MEG）记录。MEG评估在急性期（T0：缺血发作后平均5天）和急性后期（T1：中位数为6个月）进行。在T1时，与T0相比，自发和诱发活动参数的所有半球间不对称性均降低。在急性后期，较低的皮质兴奋性、较高的δ波和θ波功率以及较低的频谱熵与较差的临床状态相关。在部分恢复的患者中，一种不寻常的募集现象——如M20皮质源位置的半球间不对称过度所显示——与更高水平的临床改善相关。除了确凿证据表明受影响和未受影响半球的神经活动“正常化”是最佳临床恢复的基础外，目前的数据还支持大脑可塑性现象——即不寻常的神经募集——在那些无法实现完全恢复的患者中恢复丧失功能的积极作用。
