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【Science编译】 消灭帕金森
【背景介绍】帕金森病又称震颤麻痹，是发生于中年以上成人黑质和黑质纹状体通路变性疾病。原发性震颤麻痹的病因尚未明了，可能与脑组织中多巴胺含量减少，乙酰胆碱功能相对亢进有关，故应补充多巴胺含量和降低胆碱能功能10%左右的病人有家族史；部分患者可因脑炎、脑动脉硬化、脑外伤、甲状旁腺功能减退，一氧化碳、锰、汞、氰化物、利血平、酚噻嗪类药物中毒及抗忧郁剂（甲胺氧化酶抑制剂等）作用等都可引起类似帕金森病的表现，称为帕金森综合征。本病起病缓慢，呈进行性加重，表现有：姿势与步态 面容呆板，形若假面具； 震颤 多见于头部和四肢，以手部最明显，手指表现为粗大的节律性震颤（呈搓丸样运动）；肌肉僵硬 ；运动障碍；易激动，偶有阵发性冲动行为等症状。
【内容编译】一种新技术能快速减轻帕金森病的一些难治性症状。科学家希望通过在狒狒脑部成功的运用这一新技术，能够帮助改进复杂的外科治疗手段。而目前来说，外科手术是治疗严重帕金森病的唯一手段。
而尽管目前大部分病人能通过药物来增加脑内多巴胺的水平，而其他病人则需要一种复杂的深部脑刺激来进行治疗，这一过程需要通过外科植入类似起博器样的装置，它能传输电脉冲信号。尽管它的应用受到了电极植入深部的大脑区域的准确性的影响，但确是非常有效的。
在12月2日的 Neuron刊物中介绍了一种新的手段，可能能成为一种有效的选择。神经专家Stéphane Palfi和他的同伴们在狒狒身上发现，通过在大脑和颅骨间，直接在motor cortex上方植入一种扁平的电极能够有效地提高狒狒帕金森病模型的活动能力，而所需的电压也仅仅是一节AA的强度，而狒狒受刺激后，对其并无任何负面影响。
另外，据Palfi说，临床 I 试验正在法国进行，大约有10名患者接受上述治疗，从而判断这一方案在人体是否安全。
【原文】A new technique could soon help alleviate some of the most debilitating symptoms of Parkinson's disease. Scientists hope the process, in which gentle shocks were applied to the surface of the brain in baboons, could be a dramatic improvement over the more extreme and complex surgical treatments that are currently the only recourse for patients with the worst symptoms.
In Parkinson's patients, a depletion of the neurotransmitter dopamine causes neurons in the basal ganglia to fire abnormally. This decreases the activity of neurons in the motor cortex and leads to a host of problems including slowness of movement, rigidity, and tremors.
Although most patients benefit from drugs that increase the levels of dopamine in the brain, others require a complex treatment known as deep brain stimulation, in which surgeons implant a pacemaker-like device that delivers pulses of electricity to the basal ganglia. The procedure can be highly effective, although its use is limited by the difficulties in placing electrodes properly in such tiny regions located deep within the brain.
A new procedure, described in the 2 December issue of Neuron, may prove to be a powerful alternative. Stéphane Palfi, a neuroscientist and neurosurgeon at Henri Mondor Hospital and the Centre National de la Recherche Scientifique in Paris and colleagues focused on the more accessible motor cortex. Using baboons afflicted with a form of Parkinson's disease, the researchers placed a flat electrode between the brain and the skull directly over the motor cortex. Low-voltage electrical stimulation (about the strength of a AA battery) delivered through the electrodes dramatically improved the baboons' ability to walk and climb. The baboons didn't appear to have any significant side effects from the stimulation.
Additional experiments suggested that the treatment had prompted neurons in the basal ganglia to resume a normal pattern of activity and had restored some activity in the baboons' previously sluggish motor cortex. Palfi says phase I clinical trials are currently under way in France on about 10 patients to determine whether the procedure is safe to try in humans.
This study could "suddenly open up surgical therapy for Parkinson's patients everywhere," says Gary Heit, a neurosurgeon at the Permanente Medical Group in Redwood City, California. "If the clinical trial works, this will be a very big deal."
http://sciencenow.sciencemag.org/cgi/content/full/2004/1201/1
screen.width-333)this.width=screen.width-333" width=438 height=119 title="Click to view full 2004120111.jpg (438 X 119)" border=0 align=absmiddle> 上述方法与目前正在临床上运用的DBS电极植入术是一个意思。 [标签:content1][标签:content2]
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作者:admin@医学,生命科学 2011-08-29 17:14
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