拳击手研究揭示慢性创伤性脑病机制

新奥尔良(EGMN)——美国神经病学会(AAN)年会上公布的一项对各种拳手的纵向研究的初步结果显示，持续击打头部的累积效应可能需要数年才会转化为明显的认知功能改变，但解剖改变出现的时间比认知改变出现的时间提前一半。

这项研究由克利夫兰医院Lou Ruvo脑健康中心的Charles Bernick博士及其同事进行。研究者对受试者进行MRI脑体积测定和计算机认知功能检查。此外，还检查情绪障碍、冲动性和言语能力。研究者从自我报告和已发表的记录中收集有关搏斗史的信息，包括搏斗年数和每年的搏斗次数。研究者还检查了一些可能是损伤标志物的指标，包括生物标志物、遗传标志物和血清蛋白。

在初步分析中，研究者根据搏斗的中位年数将109名拳手分成3组(6年以下、6~12年和12年以上)，并通过相关分析来分析暴露变量、脑体积与认知结果之间的关系。

结果显示，32名搏斗年数≥6年的拳手的海马和丘脑体积小于其他拳手。但认知改变(记忆测验评分较低和处理速度评分较低)仅见于39名搏斗年数超过12年的拳手。在校正年龄效应后，仍观察到这些关联。

Bernick博士表示，上述研究结果表明，如果等到出现症状才进行诊治的话，那么疾病可能已经进展到一定阶段。临床医生应尽早评估拳手的潜在损伤情况。休息一段时间或甚至停止搏斗生涯可能有助于阻止神经退行性改变，但这还有待于进一步证实。该研究将继续对已经入组的受试者进行跟踪，并在今后4年陆续招募达600人。

这项进行中的研究由Lincy基金会资助。Bernick博士声明无经济利益冲突。

BY ALICIA AULT
Elsevier Global Medical News
Breaking News

NEW ORLEANS (EGMN) – How long does it take before the cumulative effect of repeated blows to the head result in significant cognitive changes? Preliminary results from a longitudinal study of boxers and mixed martial arts fighters suggest that it takes maybe a dozen years – but that anatomical changes begin showing up in half that time.

The results so far in 109 fighters suggest that “if you wait for people to get symptomatic, the disease has possibly progressed a fair amount,” said Dr. Charles Bernick, lead investigator of the study and associate medical director of the Cleveland Clinic’s Lou Ruvo Center for Brain Health in Las Vegas.

Clinicians may need to be assessing fighters sooner for potential damage, he said at the annual meeting of the American Academy of Neurology. Although it is not yet known, perhaps rest periods or even stopping fighting altogether might halt the neurodegenerative process.

Dr. Bernick and his colleagues at the center aim to enroll 600 people in the Professional Fighters Brain Health Study by the time funding runs out 4 years from now. Because it is longitudinal, it has a running enrollment. Those already enrolled will be continually followed.

“The real payoff will be following these guys over time and looking at the trajectories,” Dr. Bernick said in an interview. The investigators are conducting volumetric brain MRI and computerized cognitive testing. Participants also are tested for mood disorders and impulsivity, and they also undergo speech analysis as well, said Dr. Bernick.

The researchers obtain fighting history, including years of fighting and fights per year, from self-reports and published records. The study will also examine biomarkers, genetic profiles, and serum proteins that might be markers of damage, he said.

In the preliminary analysis, the investigators divided the fighters into three groups based on median years of fighting: less than 6 years, 6-12 years, and greater than 12 years. The relationship between exposure variables, brain volumetrics, and cognitive results were examined by correlational analysis.

The 32 fighters who fought 6 years or more had lower hippocampal and thalamic volumes. But cognitive changes – measured in lower scores on memory tests and processing speed – were found only in the 39 fighters who had fought more than 12 years. The relationships remained even after adjusting for the effect of age.

The ongoing study is funded by the Lincy Foundation. Dr. Bernick reported having no financial disclosures.