(綜合報導)一項最新研究的初步結果顯示，相當一部分多發性硬化症(multiple sclerosis，MS)病人頸部靜脈狹窄，這可能是這一神經疾病的風險因素之一。意大利血管疾病專家桑伯尼醫生(Dr. Paulo Zamboni)假設，慢性腦脊髓靜脈機能不全(CCSVI)是多發性硬化症的原因。血流限制可以損壞大腦組織，可能是多發性硬化症的原因之一。在實驗性 手術中，他採用血管再造技術為65名病人清除了靜脈阻塞。醫學界長期認為，多發性硬化症屬於自身免疫性疾病，免疫細胞攻擊圍繞在神經細胞周圍的髓鞘。本研 究負責人，水牛城大學的澤瓦迪諾醫生(Dr. Robert Zivadinov)表示，對研究的初步結果謹慎樂觀，並感到興奮。其研究採用多普勒超聲波影像技術，觀測了500人的情況，科學家發現，被診斷為多發性 硬化症的病人中，大約55%顯示顱外靜脈狹窄，相比之下，健康對照組中僅22%出現這類情況。若研究員將情況屬於邊緣性質的10%排除之外，多發性硬化症 病人中靜脈異常的比例升至62.5%，而健康對照組中僅26%靜脈異常。桑伯尼周三在水牛城接受採訪時表示：「在這兩組人中，存在重大的統計學上差異，前者靜脈異常的比例高近3倍。」水牛城全科醫院神經影像分析中心負責人桑伯尼表示，將進一步展開研究，探討是否隨著多發性硬化症病情的進展，靜脈機能不足情況更加嚴重。他說，將在4月份於多倫多舉行的美國神經學會年會上提交本次研究。
First Blinded Study of Venous Insufficiency Prevalence in Multiple Sclerosis Shows Promising ResultsScienceDaily (Feb. 14, 2010) — More than 55 percent of multiple sclerosis patients participating in the initial phase of the first randomized clinical study to determine if persons with MS exhibit narrowing of the extracranial veins, causing restriction of normal outflow of blood from the brain, were found to have the abnormality.
The results were reported February 10 by neurology researchers at the University at Buffalo.
When the 10.2% of subjects in which results were border line were excluded, the percentage of affected MS patients rose to 62.5%, preliminary results show, compared to 25.9% of healthy controls.
These preliminary results are based on the first 500 participants in the Combined Transcranial and Extracranial Venous Doppler Evaluation (CTEVD) study, which began at UB in April 2009. Investigators are planning to examine 500 additional subjects, who will be assessed in the second phase of the study with more advanced diagnostic tools. Complete data on the first 500 will be presented at the American Academy of Neurology meeting in April.
Robert Zivadinov, MD, PhD, UB associate professor of neurology and principal investigator on the study, says he is "cautiously optimistic and excited" about the preliminary data. Zivadinov directs the Buffalo Neuroimaging Analysis Center (BNAC), located in Kaleida Health's Buffalo General Hospital, where the study is being conducted.
"The data encourage us to continue on the same course," he says. "They show that narrowing of the extracranial veins, at the very least, is an important association in multiple sclerosis. We will know more when the MRI and other data collected in the CTEVD study are available." The analyses are being conducted by an independent statistician.
The investigation is the first step in determining if a condition called chronic cerebrospinal venous insufficiency (CCSVI) is a major risk factor for MS. CCSVI is a complex vascular condition discovered and described by Paolo Zamboni, MD, from Italy's University of Ferrara. Zamboni's original investigation in a group of 65 patients and 235 controls showed CCSVI to be associated strongly with MS, increasing the risk of having MS by 43 fold.
Zamboni and Zivadinov hypothesize that this narrowing restricts the normal outflow of blood from the brain, resulting in alterations in the blood flow patterns within the brain that eventually cause injury to brain tissue and degeneration of neurons.
The first 500 patients, both adults and children, were grouped based on their diagnosis: MS, clinically isolated syndrome (CIS) and "other neurologic diseases" (OND), in addition to healthy controls.
All participants in the first phase underwent ultrasound (Doppler) scans of the head and neck in different body postures to view the direction of venous blood flow. MS subjects also underwent MRI scans of the brain to measure iron deposits in lesions and surrounding areas of the brain, using a method called susceptibility-weighted imaging. Iron findings on these images will be related to subjects' disability and neuropsychological symptoms.
Of the total participants, 97.2 % were adults, with the 280 MS patients comprising the largest disease cohort examined in the study to date. The majority of MS subjects were diagnosed with the relapsing-remitting form of MS. There were 161 healthy controls. Doppler scan results were reported on five specific criteria that affect venous blood flow. Patients who met at least two of the criteria were considered to have CCSVI. More detailed analysis of specific Doppler criteria and their association to disease status is underway.
When the 10.2 % borderline subjects were included in the "normal" category (no venous insufficiency), the CCSVI prevalence was 56.4% in MS subjects and 22.4% in healthy controls.
In this large MS cohort, the presence of CCSVI did suggest an association with disease progression, a finding that was not shown in Zamboni's smaller cohort, Zivadinov notes.
The finding that 22.4% of healthy controls also met two CCSVI criteria requires continuing investigation, he says.