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作者：Daniel M. Keller, PhD  
出處：WebMD醫學新聞

　　September 23, 2009 (賓州費城) —可逆性腦部血管收縮症候群(RCVS)是雷擊頭痛(thunderclap headache)的一個原因，在這些急性發作頭痛的不同診斷中應將其納入考量。
　　
　　為了清楚定義與RCVS有關的誘發原因、症狀以及診斷發現，華盛頓大學醫學院神經科助理教授Todd Schwedt醫師等人回顧了文獻中的RCVS案例，發表於第14屆國際頭痛研討會中。
　　
　　研究者報告指出，RCVS主要影響婦女，且大約三分之一的案例與暫時性神經缺損有關，但有10%的案例是持續性缺損。症狀一般發生在產後，或者由某些藥物引起。病患有顱內出血、缺血性中風、腦水腫等風險。血管收縮通常在12週內恢復。
　　
　　德州Baylor醫學院神經科臨床教授Medscape Neurology科學諮詢委員會委員、未參與本研究的Randolph Evans醫師表示，RCVS是一種罕見狀況，有許多神經科專家未曾聽過此病。1988年，有作者在Stroke期刊中描述此病，之後，該病也被稱為「Call-Fleming syndrome」。
　　
　　Evans醫師向Medscape Neurology表示，不過，因為症狀依舊未被確認，可能不如我們所認為的這麼罕見。
　　
　　他建議，我們的當務之急在於確認它，特別是有雷擊頭痛者發生突發的嚴重頭痛時。
　　
　　【RCVS的系統性回顧】
　　發表的這個系統性回顧中，納入新發生的頭痛或多處顱內動脈血管收縮案例，或者血管收縮在發生12週內緩解的案例，或者沒有動脈瘤蛛網膜下出血的案例。
　　
　　80篇發表的文獻中，有250名RCVS病患符合此一準則。女性和男性的比率為6比1。病患年紀在13至70歲之間(平均43歲)。發生的狀況包括產後(18%的案例)或有偏頭痛病史(27%)，其他活動包括洗澡、費力活動/ Valsalva氏現象，以及血管創傷。RCVS病患有44%使用各種藥物或非法藥物。幾乎所有(92%)RCVS病患都出現雷擊頭痛。腦脊液參數為正常或接近正常，有27% RCVS病患的蛋白質略為升高，且19% RCVS病患白血球計數大於5 cells/mm3。
　　
　　29%的RCVS病患發生暫時性神經缺損，10%是持續性缺損。RCVS病患皮質蛛網膜下出血、腦內出血、缺血性中風、腦水腫的發生比率分別是17%、9%、24%以及22%。
　　
　　研究者在摘要中寫道，血管收縮在前循環中最常見，特別是中腦動脈。他們發現，在他們搜尋的文獻中，91%的RCVS病患有中腦動脈血管收縮，60%有前腦動脈收縮、56%為後腦動脈收縮，19%發生在基底動脈，10%發生在內頸動脈。
　　
　　【罕見狀況】
　　Evans醫師表示，神經科專家對於懷孕末期病患、產後、或高血壓病患應提高懷疑。引起RCVS的藥物，例如古柯鹼或迷幻藥或一些處方藥，如選擇性血清素再吸收抑制劑，或者完全沒有誘發原因。
　　
　　Evans醫師指出，這通常是有偏頭痛病史的年輕婦女會發生的疾病。他表示，影像檢查可以發現發生收縮的動脈，但是，他也指出，沒有可以確認診斷的單一種檢測方式。其他疾病也可能會引起血管收縮，例如血管炎，必須加以排除。
　　
　　需要就治療方面進行更多研究，但是有些醫師曾經使用nimodipine用於預防和急性治療，其他鈣通道阻斷劑如verapamil也有用。
　　
　　除了Schwedt醫師等人提出的誘發狀況之外，Evans醫師指出，性行為、排便、突發的情緒、排尿、咳嗽、打噴嚏或彎腰也會。約有20%的人在休息時、沒有前述行為時發生雷擊頭痛。
　　
　　Evans醫師表示，病患可能有出血1週且接著發生缺血性事件。動脈X光正常、顯示沒有血管收縮，並無法排除RCVS。再者，有些病患後來完全恢復。
　　
　　許多RCVS病患一開始會前往急診，但是如果他們還有雷擊頭痛，或許會找神經科醫師就醫。Evans醫師對神經科醫師的建議是，將RCVS視為反覆雷擊頭痛的不同診斷的一部份。
　　
　　Schwedt醫師宣告接受GlaxoSmithKline、AGA以及Allergan的臨床研究費用、獎金與研究資金，以及擔任VersusMed之顧問或諮詢委員的酬勞。Evans醫師宣告擔任Merck、Ortho-McNeil、Pfizer、GlaxoSmithKline、Lilly、Teva以及UCB等之建言者或顧問、接受臨床研究支持、接受獎助金。他也是Medscape Neurology的無給職諮詢委員。
　　
　　第14屆國際頭痛研討會：壁報PO373。展示於2009年9月11-12日。

Reversible Cerebral Vasoconstriction Syndromes Another Cause of Thunderclap Headache

By Daniel M. Keller, PhD
Medscape Medical News

September 23, 2009 (Philadelphia, Pennsylvania) — Reversible cerebral vasoconstriction syndromes (RCVS) are a cause of thunderclap headache and should be considered in the differential diagnosis of these acute-onset headaches.

To better define the triggers, symptoms, and diagnostic findings associated with RCVS, Todd Schwedt, MD, assistant professor of neurology, and colleagues at Washington University School of Medicine in St. Louis, Missouri, reviewed RCVS cases in the literature and presented their findings here at the 14th International Headache Congress.

The researchers report that RCVS primarily affects women and is associated with transient neurological deficits in about one third of cases, but that these deficits may persist in 10% of cases. The syndromes commonly occur in the postpartum period or may be brought on by certain drugs. Patients are at risk for intracranial bleeds, ischemic stroke, and cerebral edema. Vasoconstriction usually reverses within 12 weeks of onset.

Randolph Evans, MD, clinical professor of neurology at Baylor College of Medicine in Houston, Texas, and a member of the Medscape Neurology scientific advisory board, who was not involved in the study, said RCVS is a rare condition and that many neurologists have never heard of it. It has been referred to as Call-Fleming syndrome after the authors who described it in Stroke in 1988. As the syndrome is still underrecognized, however, "it may not be as rare as we think," Dr. Evans told Medscape Neurology.

"The first thing is for us to start recognizing it, particularly when people have thunderclap headaches — when they have sudden, severe headaches," he advised.

Systematic Review on RCVS

In the systematic review presented here, cases were included if they had new-onset headache or multifocal intracranial artery vasoconstriction, if the vasoconstriction resolved within 12 weeks of onset and if there was no aneurysmal subarachnoid hemorrhage.

Eighty publications containing 250 patients who had RCVS met these criteria. Women outnumbered men by 6 to1. Patients ranged in age from 13 to 70 years (mean, 43 years). Predisposing conditions included being postpartum (18% of cases) or having a history of migraine (27%), and activities included bathing, physical exertion/Valsalva, and vascular trauma. Exposure to various medications or illicit drugs occurred in 44% of patients with RCVS. Almost all patients with RCVS (92%) presented with a thunderclap headache. Cerebrospinal fluid parameters were normal or nearly so, with mildly elevated protein in 27% of patients with RCVS and white blood cell count greater than 5 cells/mm3 in 19% of patients with RCVS.

Transient neurologic deficits occurred in 29% of patients with RCVS, and 10% experienced persistent deficits. Cortical subarachnoid hemorrhage, intraparenchymal hemorrhage, ischemic stroke, and cerebral edema occurred in 17%, 9%, 24%, and 22% of patients with RCVS, respectively.

The researchers write in their abstract that "vasoconstriction is most commonly identified in the anterior circulation, specifically the middle cerebral artery." They found in their literature search vasoconstriction of the middle cerebral artery in 91% of patients with RCVS, anterior cerebral artery in 60%, posterior cerebral artery in 56%, basilar artery in 19%, and internal carotid in 10%.

A Rare Condition

Dr. Evans said that neurologists' suspicions should be raised for patients in late pregnancy, during postpartum, or with hypertension. RCVS can be triggered by drugs such as cocaine or ecstasy or some prescription drugs such as selective serotonin reuptake inhibitors, or there may be no trigger at all.

"It's usually a disease of young women who may have a history of migraine," Dr. Evans noted. He said imaging may reveal constriction of affected arteries, but added that "there is no single test to confirm the diagnosis." Other diseases that can also cause vasoconstriction, such as vasculitis, need to be ruled out.

More research into treatments is needed, but some clinicians have been using nimodipine for prevention and acute treatment, and other calcium channel blockers such as verapamil may also work.

In addition to the triggers mentioned by Dr. Schwedt and colleagues, Dr. Evans added sexual intercourse, bowel movement, sudden emotion, urination, coughing, sneezing, or bending over. About 20% of people have a thunderclap headache at rest with no predisposing activities.

Dr. Evans said that patients may have a hemorrhage 1 week and go on to have an ischemic event the next. A normal arteriogram showing no vasoconstriction cannot rule out RCVS. Furthermore, some patients go on to recover completely.

Many RCVS patients will be seen initially in the emergency department, but if they have additional thunderclap headaches, they will probably see a neurologist. Dr. Evans' advice is for neurologists to consider RCVS as part of the differential diagnosis of recurrent thunderclap headaches.

Dr. Schwedt has disclosed receiving payments for conducting clinical research, honoraria, research grants (from GlaxoSmithKline, AGA, and Allergan), and compensation as a consultant or advisory board member for VersusMed. Dr. Evans has disclosed that he has served as an advisor or consultant to, received clinical research support from, or received honoraria from Merck, Ortho-McNeil, Pfizer, GlaxoSmithKline, Lilly, Teva, and UCB. He is also an uncompensated advisory board member for Medscape Neurology.

14th International Headache Congress: Poster PO373. Displayed September 11 and 12, 2009.