Leocani Letizia, Colombo Bruno, Comi Giancarlo
Institute of Experimental Neurology Dept. of Neurology, Clinical Neurophysiology, Neurorehabilitation, Univ. Vita-Salute and Scientific Institute San Raffaele, Via Olgettina 60, 20132, Milan, Italy.
Neurol Sci. 2008 Sep;29 Suppl 2:S241-3. doi: 10.1007/s10072-008-0950-1.
Fatigue is an overwhelming sense of tiredness or lack of energy, affecting both mental and physical domains. Fatigue is reported by about 50% of patients with multiple sclerosis (MS), and may be independent from depressed mood or weakness. Recently, the importance of distinguishing between subjective complaint and objective signs of fatigue has been emphasized, since the self-reported increase of subjective cognitive fatigue may not be related to a decline of cognitive performances. There is a general consensus that fatigue in MS is a central phenomenon, related to several factors. Neurophysiological studies revealed an impairment of volitional drive to the descending motor pathways and functional imaging studies indicated a selective involvement of frontal cortex and basal ganglia. Thus, the physiopathology of fatigue may rely on dysfunction of circuits involving thalamus, basal ganglia, and frontal cortex, which, affected by the MS lesions or disturbed in their function by the products of inflammation, could be the substrate of fatigue. The abnormal subjective fatigue observed in MS and perhaps in other neurological disorders could be due to a higher brain working load required to perform a given mental or physical activity, or to an internal overestimation of such load.
疲劳是一种极度的疲倦感或缺乏精力的状态，会影响精神和身体两个方面。约50%的多发性硬化症（MS）患者报告有疲劳症状，且疲劳可能与情绪低落或虚弱无关。最近，区分疲劳的主观主诉和客观体征的重要性得到了强调，因为自我报告的主观认知疲劳增加可能与认知能力下降无关。人们普遍认为，MS中的疲劳是一种中枢现象，与多种因素有关。神经生理学研究揭示了下行运动通路的意志驱动受损，功能成像研究表明额叶皮质和基底神经节有选择性受累。因此，疲劳的病理生理学可能依赖于涉及丘脑、基底神经节和额叶皮质的神经回路功能障碍，这些神经回路受MS病变影响或其功能被炎症产物干扰，可能是疲劳的基础。在MS以及可能在其他神经系统疾病中观察到的异常主观疲劳，可能是由于进行特定精神或体力活动所需的大脑工作负荷增加，或者是对此类负荷的内部高估。
