Naro Antonino, Chillura Antonino, Portaro Simona, Bramanti Alessia, De Luca Rosaria, Bramanti Placido, Calabrò Rocco Salvatore
IRCCS centro Neurolesi Bonino-Pulejo, Messina, Italy.
Front Neurol. 2018 Feb 5;9:47. doi: 10.3389/fneur.2018.00047. eCollection 2018.
The assessment of behavioral responsiveness in patients suffering from chronic disorders of consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. Even if a patient is unresponsive, he/she may be covertly aware in reason of a cognitive-motor dissociation, i.e., a preservation of cognitive functions despite a solely reflexive behavioral responsiveness. The approach of an external stimulus to the peripersonal space (PPS) modifies some biological measures (e.g., hand-blink reflex amplitude) to the purpose of defensive responses from threats. Such modulation depends on a top-down control of subcortical neural circuits, which can be explored through changes in cerebral blood flow velocity (CBFV), using functional transcranial Doppler (fTCD) and, thus, gaining useful, indirect information on brain connectivity. These data may be used for the DoC differential diagnosis. We evaluated the changes in CBFV by measuring the pulsatility index (PI) in 21 patients with DoC (10 patients with MCS and 11 with UWS) and 25 healthy controls (HC) during a passive movement and motor imagery (MI) task in which the hand of the subject approached and, then, moved away from the subject's face. In the passive movement task, the PI increased progressively in the HCs when the hand was moved toward the face and, then, it decreased when the hand was removed from the face. The PI increased when the hand was moved toward the face in patients with DoC, but then, it remained high when the hand was removed from the face and up to 30 s after the end of the movement in the patients with MCS (both MCS+ and MCS-) and 1 min in those with UWS, thus differentiating between patients with MCS and UWS. In the MI task, all the HCs, three out of four patients with MCS+, and one out of six patients with MCS- showed an increase-decrease PI change, whereas the remaining patients with MCS and all the patients with UWS showed no PI changes. Even though there is the possibility that our findings will not be replicated in all patients with DoC, we propose fTCD as a rapid and very easy tool to differentiate between patients with MCS and UWS, by identifying residual top-down modulation processes from higher-order cortical areas to sensory-motor integration networks related to the PPS, when using passive movement tasks.
对患有慢性意识障碍（DoC）的患者进行行为反应性评估具有挑战性，这些患者包括无反应觉醒综合征（UWS）和最低意识状态（MCS）。即使患者无反应，由于认知 - 运动解离，即尽管行为反应仅为反射性，但认知功能仍得以保留，他/她可能仍存在隐蔽意识。向个人周边空间（PPS）施加外部刺激会改变一些生物学指标（如手眨眼反射幅度），以引发对威胁的防御反应。这种调节依赖于皮质下神经回路的自上而下控制，可通过使用功能经颅多普勒（fTCD）测量脑血流速度（CBFV）的变化来探究，从而获取有关脑连接性的有用间接信息。这些数据可用于DoC的鉴别诊断。我们通过测量21例DoC患者（10例MCS患者和11例UWS患者）以及25名健康对照者（HC）在被动运动和运动想象（MI）任务期间的搏动指数（PI）来评估CBFV的变化，在该任务中，受试者的手靠近然后移开其面部。在被动运动任务中，当手移向面部时，HC组的PI逐渐增加，然后当手从面部移开时，PI降低。DoC患者在手动移向面部时PI增加，但在MCS患者（MCS +和MCS -）中，当手从面部移开后直至运动结束后30秒，PI仍保持较高水平，而在UWS患者中则持续1分钟，从而区分MCS和UWS患者。在MI任务中，所有HC、四分之三的MCS +患者和六分之一的MCS -患者显示PI出现先增加后降低的变化，而其余MCS患者和所有UWS患者均未出现PI变化。尽管我们的研究结果有可能无法在所有DoC患者中得到重复验证，但我们建议将fTCD作为一种快速且非常简便的工具，通过在使用被动运动任务时识别从高级皮质区域到与PPS相关的感觉运动整合网络的残余自上而下调节过程，来区分MCS和UWS患者。
