慢性疼痛是指持续一个月以上（以前为三个月或半年）的疼痛，也有人把慢性疼痛比喻为一种不死的癌症。目前，中国至少有一亿以上的慢性疼痛患者。
一般而言，急性疼痛是一种症状，慢性疼痛则是一种疾病，也是预示人体其他部位可能出现健康危机的“警报器”。由于它的频繁“发威”会使人出现睡眠紊乱、食欲缺乏、精神崩溃甚至人格扭曲和家居不宁等后果，致使不少病人因无法忍受长期的疼痛折磨而选择自杀。
Riitta Haria等研究人员最新通过对慢性疼痛患者的fMRI 研究发现，和急性疼痛不同，慢性疼痛可能让大脑的和自主神经系统有关的区域在功能上重新配线。
推荐原文出处：
PNAS doi: 10.1073/pnas.1001504107
Aberrant temporal and spatial brain activity during rest in patients with chronic pain
Sanna Malinena,b,1, Nuutti Vartiainena,b, Yevhen Hlushchuka,b, Miika Koskinena,b, Pavan Ramkumara, Nina Forssa,c, Eija Kalsod, and Riitta Haria,b,e,1
In the absence of external stimuli, human hemodynamic brain activity displays slow intrinsic variations. To find out whether such fluctuations would be altered by persistent pain, we asked 10 patients with unrelenting chronic pain of different etiologies and 10 sex- and age-matched control subjects to rest with eyes open during 3-T functional MRI. Independent component analysis was used to identify functionally coupled brain networks. Time courses of an independent component comprising the insular cortices of both hemispheres showed stronger spectral power at 0.12 to 0.25 Hz in patients than in control subjects, with the largest difference at 0.16 Hz. A similar but weaker effect was seen in the anterior cingulate cortex, whereas activity of the precuneus and early visual cortex, used as a control site, did not differ between the groups. In the patient group, seed point-based correlation analysis revealed altered spatial connectivity between insulae and anterior cingulate cortex. The results imply both temporally and spatially aberrant activity of the affective pain-processing areas in patients suffering from chronic pain. The accentuated 0.12- to 0.25-Hz fluctuations in the patient group might be related to altered activity of the autonomic nervous system.
