根據一項最新研究發現：使用超聲波合并應用組織-纖維蛋白溶酶原激活劑(tissue-plasminogen activator, t-PA)，能夠改善缺血性腦卒中的預后。該研究比較了聯合應用超聲波和t-PA與單獨使用t-PA的作用與安全性，研究涉及了126例患者。

研究人員評估了使用穿透頭顱的多普勒超聲波(transcranial Doppler ultrasound, TCD)合并使用t-PA的治療效果。較早期的研究已經證實在缺血性腦卒中發作后3小時內應用t-PA，能夠極大地增加患者完全恢復的幾率。但是這個藥物不能用于出血性腦卒中的治療。

一個國際研究小組研究了126例缺血性腦卒中患者；所有患者在卒中發作后3小時內應用了t-PA。其中對照組63例患者僅僅使用t-PA；而其它63例患者使用t-PA，并且在患者使用t-PA之前開始持續使用TCD監測。將一個小設備貼附在患者頭顱上用來發送超聲波。研究結果發表于2004年11月18日第2204期的《新英格蘭醫學期刊》(the New England Journal of Medicine)。

結果證實：在持續接受超聲波和t-PA的患者中，有49％在治療后的2小時內，臨床情況發生明顯改善，很少或者沒有血流阻斷；而單獨使用t-PA的只有30％。值得指出的使，在接受持續TCD和t-PA的患者中，有38％患者被證實2小時內沒有發生血流阻斷，而單獨使用t-PA的只有13％。所有73％接受聯合治療的患者出現完全或者部分的血栓清除，而對照組只有50％。兩個治療組都有4.8％患者發生腦組織出血。腦組織早期血流改善產生了這樣的趨勢：超過13.5％的接受持續TCD和t-PA治療的患者在腦卒中發作后3月內完全恢復。

這些科學家還發現：在治療后2小時內完全清除血凝塊的患者，其語言、機體力量、以及其它受到腦卒中影響的功能獲得恢復的幾率最大。研究人員將該研究稱為 "聯合穿越頭顱超聲波以及系統使用t-PA治療所產生的缺血性腦卒中的血栓裂解"(Combined Lysis of Thrombus in Brian Ischemia Using Transcranial Ultrasound and Systemic t-PA, CLOTBUST)

“在過去30年中，世界范圍內的科學家已經證實超聲波是一項快速、溫和以及有效的裂解血凝塊的方法。我們是首次在患者中證實了其療效。這種方法增加了流向腦組織的血流，改善了臨床預后，并且有利于患者的護理者，”該項研究的負責人Andrei Alexdrov醫學博士說。他是德克薩斯-休斯頓大學醫學院神經病學副教授。

美國國立神經系統疾病與腦卒中研究院(NINDS; Bethesda, MD., USA)主任Story C. Landis博士評論說：“腦卒中對患者以及他們的護理者而言都是后果嚴重的。這些初步結果提示：在缺血性腦卒中發作之后患者接受聯合治療能夠給醫院更多機會。這是一項鼓舞人心的進步，將改進目前的治療方法并促使疾病向好的方向發展。”該研究獲得了NINDS的部分資助。

超聲波能夠使血栓組織內的分子產生振動，從而可以為t-PA創造更多的結合位點，促使血凝塊崩解。研究人員相信：與單獨應用t-PA相比較，這種分子振動促使藥物運輸至血凝塊內以及周圍，從幫助開放更多的阻斷血管。

Ultrasound Plus t-PA Improves Stroke Outcome
 
Utilizing ultrasound combined with the drug tissue-plasminogen activator (t-PA) can improve the outcome of an ischemic stroke, according to a new study. The study compared the efficacy and safety of ultrasound with t-PA vs t-PA only in a trial involving 126 patients.

The investigators evaluated the effectiveness of using transcranial Doppler ultrasound (TCD) in combination with t-PA. Earlier studies have demonstrated that t-PA, when administered within three hours of onset of ischemic stroke, can greatly improve a patient’s likelihood of a full recovery. This agent, however, cannot be used to treat a typical hemorrhagic stroke.

An international group of investigators examined 126 patients who suffered an ischemic stroke; all patients received t-PA within three hours after stroke onset. The 63 patients in the control group received t-PA alone, while the other 63 patients received the agent in combination with continuous TCD monitoring that began right before the patients received t-PA. A small device attached to a head frame was used to deliver the ultrasound waves. The study was published in the November 18, 2204, issue of the New England Journal of Medicine.

Results demonstrated that 49% of patients who received continuous ultrasound and t-PA showed drastic clinical improvement and little or no blockage within two hours after therapy began compared to 30% of patients who received t-PA alone.

Remarkably, 38% of the patients who received continuous TCD and t-PA demonstrated no blockage within two hours, compared to 13% who received t-PA alone. All 73% of patients who received the combined therapy demonstrated total or partial clearance of the thrombus, compared to 50% in the control group. Bleeding into the brain was seen in 4.8% of patients in both groups. This early improvement of blood flow to the brain resulted in a trend by which 13.5% more patients who received continuous TCD and t-PA had recovered completely by three months after stroke.

The group of scientists also discovered that patients who had complete clearance of their clot within two hours following treatment had the greatest probability of regaining speech, body strength, and other functions affected by stroke. The nvestigators called the trial CLOTBUST (Combined Lysis of Thrombus in Brian Ischemia Using Transcranial Ultrasound and Systemic t-PA).

“In the past 30 years, scientists around the world have shown that ultrasound is fast, gentle, and effective in helping t-PA to break up clots. For the first time, we have demonstrated this benefit in patients. This approach enhances flow to the brain and augments clinical recovery and their caregivers,