本帖最後由 goodcat1111 於 2009-4-5 08:36 編輯
作者：Caroline Cassels
出處：WebMD醫學新聞
March 5, 2009(加州聖地牙哥) — Framingham心臟研究的新發現顯示，中年時，無症狀性腦梗塞(silent cerebral infarcts，SCI)是有症狀中風的五倍，且是造成此類人口心血管疾病的主要原因。
美國中風協會2009國際中風研討會中的研究顯示，在65歲以下者中，SCI的發生率是4.7%，有症狀的中風則是0.9%。
研究者、波士頓大學的Jose Romero醫師向Medscape Neurology & Neurosurgery表示，無症狀的梗塞遠比臨床中風常見；即使是65歲以下者，發生率也超出五倍；我們在整體樣本中著眼於此，發現即使是50歲以下者，SCI也比有症狀的中風常見。
在較年長的成人中，SCI與認知缺損有關，且增加有症狀之中風與失智的風險，發生率約為12%至18%；不過，Romero醫師表示，較年輕者的發生率還未曾被報告過。
Romero醫師表示，雖然有一些研究著眼於SCI盛行率，但只有兩篇族群基礎研究探討發生率，本研究是首度探究年輕族群發生率的研究。
他指出，對SCI有更多的瞭解，對於臨床運用有重要影響。
雖然SCI被視為沉默的、無症狀，但是就臨床觀點來看，與認知缺損、失智、大中風風險較高有關，它們實則並不沉默！
Romero醫師表示，我們發現，較年輕者的SCI會讓這群人增加對風險因素的警覺—特別是有關有效處理高血壓的重要性；這也表示，除了醫師提供的訊息之外，年輕病患需自己對風險因素有更積極的監控與處置。
【一點也不沉默】
該研究包括1,485名Framingham Original and Offspring研究的參與者，在兩種不同狀況下接受腦部核磁共振造影(MRI)。
全部都未曾有過臨床中風、暫時性腦缺血(TIA)、或者其他已知會改變腦部MRI的神經症狀；這些研究對象平均被追蹤偶發臨床中風與SCI達5.4年。參與者於研究開始時的平均年紀為63歲，54%是女性。
整體來說，在平均五年追蹤期間，SCI的發生率是8.7%、臨床中風則是1.7%；此外，大部份(83%)是單一的SCI病灶。
不過，當以年紀分析時，小於65歲者的SCI發生率是4.8%，有症狀中風則是0.9%。
作者報告指出，SCI和臨床中風都隨年紀而增加，但是在75歲以上者，這兩種的差異只有兩倍—SCI為17.4%、臨床中風為9.1%。50歲以下者未發現有臨床中風，但有SCI者為2.4%。
Romero醫師表示，再次強調，本研究的重點是，應增加腦部缺血性疾病的警覺，強調這是不只有年長者才有的常見現象的事實。
國家健康研究中心支持本研究。
美國中風協會2009國際中風研討會：摘要 P129。發表於2009年2月18日。
ISC 2009: Silent Cerebral Infarcts Far Outnumber Symptomatic Strokes in Midlife
By Caroline Cassels
Medscape Medical News
March 5, 2009 (San Diego, California) — New findings from the Framingham Heart Study show that in middle age, silent cerebral infarcts (SCI) are 5 times more common than symptomatic stroke and represent a major, unmeasured portion of the burden of cerebrovascular disease in this population.
Presented here at the American Stroke Association International Stroke Conference 2009, the study showed that, among individuals younger than 65 years, the incidence of SCI was 4.7%, vs 0.9% for symptomatic stroke.
"Silent infarcts are much more common than clinical strokes. Even in those younger than age 65, the incidence was about 5 times more common. We looked at this in the overall sample as well as by sex and age and found that even in individuals younger than age 50, SCIs were more common than symptomatic strokes," study investigator Jose Romero, MD, Boston University, Massachusetts, told Medscape Neurology & Neurosurgery.
In older adults, SCIs have been associated with cognitive impairment and an increased risk for symptomatic stroke and dementia, with a reported incidence of 12% to 18%. However, said Dr. Romero, the incidence in younger populations has not previously been reported.
"While there are a number of studies looking at the prevalence of SCI, there are only 2 other population-based studies looking at incidence, and this is the first to look at incidence in a younger cohort," said Dr. Romero.
He added that gaining a better understanding of SCI has potentially important clinical implications.
"Even though [SCIs] have been labeled as 'silent,' they are linked to a higher risk of cognitive impairment, dementia, and major stroke, so from a clinical perspective. they are not really 'silent' at all.
"Our finding that [SCIs] occur in younger people makes a strong case for increasing awareness of the risk factors in this group — particularly regarding the importance of effectively managing high blood pressure. This also means getting the message out to physicians that they need to be more aggressive in their surveillance and management of risk factors among younger patients," said Dr. Romero.
Not "Silent" At All
The study included 1485 participants from the Framingham Original and Offspring study who underwent brain magnetic resonance imaging (MRI) on 2 separate occasions.
All subjects were free of prevalent clinical stroke, transient ischemic attack (TIA), or other neurological conditions known to alter brain MRI. Subjects were followed for a mean period of 5.4 years for incident clinical stroke and SCI. Participants' average age was 63 years at study outset, and 54% were women.
Overall, the incidence of SCI was 8.7%, vs 1.7% for clinical stroke, over a mean follow-up period of 5 years. In addition, the majority of SCI lesions (83%) were single.
However, when analyzed by age, the incidence of SCI was 4.8% vs 0.9% for symptomatic stroke in those younger than 65 years.
Both SCI and clinical stroke increased with age, but the difference was only twice as great in those older than 75 years — 17.4% and 9.1% for SCI and clinical stroke, respectively. No clinical strokes were observed in individuals younger than age 50 years, but 2.4% had SCI, the authors report.
"Again, the main point is that this study should increase awareness of ischemic vascular disease in the brain and reinforce the fact that it is a common phenomenon that is not exclusive to the elderly," said Dr. Romero.
The study was supported by the National Institutes of Health.
American Stroke Association International Stroke Conference 2009: Abstract P129. Presented February 18, 2009. |
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