Aurora Sheena K
Swedish Pain and Headache Center, 1101 Madison Street, Suite 200, Seattle, WA 98104, USA.
Neurology. 2009 Feb 3;72(5 Suppl):S8-13. doi: 10.1212/WNL.0b013e31819749fd.
Chronic migraine (CM) typically evolves from episodic migraine (EM) over months to years in susceptible individuals. Headaches increase in frequency over time, becoming less intense but more disabling and less responsive to treatment. The results of electrophysiologic and functional imaging studies indicate that CM is associated with abnormalities in the periaqueductal gray matter that may be progressive. In addition, CM is associated with a greater degree of impairment in cortical processing of sensory stimuli than EM, perhaps because of more pervasive or persistent cortical hyperexcitability. These findings fit with the model of migraine as a spectrum disorder, in which the clinical and pathophysiologic features of migraine may progress over time. This progression is postulated to result from changes in nociceptive thresholds and ensuing central sensitization caused by recurrent migraine in susceptible individuals, for whom risk factors have been described. Also, progression may lead to changes in baseline neurologic function between episodes of headache, evident in electrophysiologic and functional imaging studies and as an increase in depression, anxiety, nonhead pain, fatigue, gastrointestinal disorders, and other somatic complaints that may occur after years of EM. From the available research and migraine models, a concept of CM is emerging that identifies relatively permanent and pervasive central changes warranting novel, tolerable treatments. This model also implies that prevention of CM is an important goal in the management of EM, particularly for individuals who exhibit risk factors for chronic transformation.
慢性偏头痛（CM）通常在易感个体中由发作性偏头痛（EM）在数月至数年的时间里演变而来。随着时间的推移，头痛频率增加，强度减轻但致残性增强，对治疗的反应性降低。电生理和功能影像学研究结果表明，CM与导水管周围灰质异常有关，这种异常可能是进行性的。此外，与EM相比，CM在感觉刺激的皮层处理方面存在更大程度的损害，这可能是由于更广泛或持续的皮层兴奋性过高所致。这些发现符合偏头痛作为一种谱系障碍的模型，其中偏头痛的临床和病理生理特征可能随时间进展。这种进展被认为是由易感个体反复偏头痛导致的伤害性感受阈值变化及随之而来的中枢敏化引起的，针对这些个体已经描述了风险因素。此外，进展可能导致头痛发作间期基线神经功能的变化，这在电生理和功能影像学研究中很明显，并且表现为抑郁、焦虑、非头痛性疼痛、疲劳、胃肠道疾病以及其他躯体不适的增加，这些情况可能在多年的EM后出现。从现有的研究和偏头痛模型中，一个关于CM的概念正在形成，该概念确定了相对持久和广泛的中枢变化，需要新的、可耐受的治疗方法。这个模型还意味着预防CM是EM管理中的一个重要目标，特别是对于那些表现出慢性转化风险因素的个体。
