快樂小藥師 Im pharmacist nichts glücklich

Menstrual cramps may actually change the structure of women's brains, according to new research in the journal Pain.

Aug. 11, 2010 -- Menstrual cramps may actually change the structure of women's brains, according to new research in the journal Pain.

Primary dysmenorrhea (PDM) -- menstrual pain in otherwise healthy women -- affects between 20% to 90% of adolescent girls, researchers say. It is marked by cramps in the lower abdomen that start with menstruation and can last up to 72 hours.

Researchers led byJen-Chuen Hsieh, MD, PhD, of the Institute of Brain Science at the National Yang-Ming University in Taipei, Taiwan, used magnetic resonance imaging scans to look at the brains of 32 women with a history of menstrual pain and 32 women with no history of menstrual pain. Scans were conducted when the women were pain-free, and the researchers used these images to help create maps of the gray matter of the brain. The brain's gray matter comprises the bulk of nerve cells or neurons within the brain.

There were changes in the volume of the brain's gray matter among women who experience painful menstrual cramps. Specifically, there were decreases of gray matter in areas of the brain involved in pain transmission and mood regulation and increases in areas of the brain that are involved in pain sensations and in regulating certain hormones, the study showed.

“Our results demonstrated that abnormal gray matter changes were present in PDM patients even in absence of pain," the study authors write. "This shows that not only sustained pain, but also cyclic occurring menstrual pain can result in longer-lasting central changes." The researchers cite previous studies that have found brain changes in people with chronic, persistent pain conditions.

Menstrual Pain and the Brain

Although the consequences of these changes are not known, "these results indicate that the adolescent brain is vulnerable to menstrual pain." The next step would be to conduct studies to see what role hormones play in these changes, and to determine whether or not the gray matter changes are reversible,” the researchers write.

"There are certain brain structural changes that occur with menstrual cramps," says Duke Han, PhD, assistant professor of neuropsychology at Rush University Medical Center in Chicago. "These changes could be related to pain, but there could be other contributing factors in addition to pain that are causing these structural changes." Hormonal changes and stress may play a role.

But if these results are validated, "targeting treatments toward the brain axis where there are changes may help better focus therapies for menstrual pain," he says.

"Hormonal changes sensitize the neurons to pain so you are apt to feel more pain given a stimulus such as cramps," says Edna Ma, MD, an anesthesiologist at St. John’s Health Center in Santa Monica, Calif.

"If these brain changes are related to the pain, and we can find a receptor, it would make sense to target it and minimize the menstrual pain, but if it is hormone-related then those changes may be unrelated to the pain," she says.

Put another way: "Yes, it is true that there is pain and yes, it is true that there are brain changes, but this may not be cause and effect," she tells WebMD

WebMD Health News 
by Denise Mann 
Reviewed By Louise Chang

Last Modified: 2010/8/11 下午 03:40:44

c 2010 WebMD, LLC. All rights reserved.

研究中，疼痛的女性有大腦異常變化。

　　【24drs.com】Aug. 11, 2010 -- 根據一項發表於疼痛期刊的新研究，經痛可能確實會改變女性腦部的結構。
　　
　　研究者們表示，原發性痛經（Primary dysmenorrhea，PDM）一種發生在健康女性的經痛，影響大約20%到90%的少女；通常是以下腹部絞痛表現，發生在經期開始時，可以維持超過72小時。
　　
　　台灣台北國立陽明大學腦科學研究所的謝仁俊教授，使用核磁共振掃描針對32位有經痛病史女性以及32位沒有經痛病史的女性進行分析；研究者在這些女性沒有疼痛時進行掃描，同時使用這些影響協助創造腦部灰質圖；大腦的灰質由腦部大量的神經細胞與神經元構成。
　　
　　研究顯示，有經痛問題的女性，腦部灰質的體積發生變化；具體來說，牽涉到痛覺傳遞以及情緒調控的腦部區域灰質減少，而牽涉到痛覺感受以及調控特定荷爾蒙的腦部區域增加。
　　
　　研究作者們寫到，其研究結果顯示，PDM患者的腦部灰質異常變化發生在即使沒有疼痛的時候，顯示這不僅僅是持續疼痛，週期性發生的經痛也會造成較長持續性的中樞變化。研究團隊引用過去的已經發現慢性、持續性疼痛患者腦部變化的研究結果。
　　
　　【經痛與大腦】
　　雖然這些變化的後果仍然未知，但這些結果代表青少年的腦部容易受到經痛影響。研究者們寫到，下一步將是進行一項針對荷爾蒙在這些變化中所扮演角色的研究，以及確認灰質變化是否是可逆的。
　　
　　芝加哥Rush大學醫學中心的神經精神學助理教授Duke Han表示，經痛時確實發生特定的腦部變化。這些變化與疼痛有關，但是除了疼痛之外，可能還有其他因子會造成這些結構上的變化。荷爾蒙改變與壓力可能扮演一個角色。
　　
　　但是如果這些結果經過確認，針對有變化之腦部的標的治療，可能協助發展針對經痛的治療。
　　
　　美國加州聖摩尼卡聖約翰健康中心的麻醉科醫師Enda Ma表示，荷爾蒙的變化敏感化了疼痛神經元，所以你會有對例如絞痛的刺激感受到更多的疼痛。
　　
　　她指出，如果這些腦部變化與疼痛有關，而我們可以找到受體，將可以針對這個受體且減緩經痛；但如果這個是與荷爾蒙相關的，那些變化可能與疼痛無關。
　　
　　她向WebMD表示，換句話說，是的，確實有疼痛且確實有腦部變化，但是這可能並不是原因與後果。