パーキンソン病歴３０年の男性、脊髄電気刺激で歩行回復　スイス研究

【ローザンヌＡＦＰ＝時事】パーキンソン病歴約３０年の男性患者の体内に電極を埋め込み、脊髄に電気刺激を与えることでほぼ普通に歩けるようになったとするスイスの研究成果が６日、学術誌ネイチャー・メディシンで発表された。（写真は歩行が回復したパーキンソン病歴約３０年のマルクさん〈左〉。スイス・ローザンヌで）
　外科医のジョスリーヌ・ブロック氏と神経科学者のグレゴワール・クルティーヌ氏が率いるチームは、数年前に同様の方法で下半身がまひしていた患者の歩行を回復させている。
　フランス在住の患者マルクさん（６２）は約３０年にわたり、パーキンソン病に苦しんできた。病状が進行した患者の９０％にみられる歩行障害の中でも、特に「すくみ足がひどい」とＡＦＰに語った。「障害物があったり、誰かが不意に目の前を横切ったりすると、足がすくんで転んでしまう」
　マルクさんはスイスで手術を受ける機会が訪れた際に飛び付いたという。「今はもう、ある位置から次の位置までどうやって行くか、心配せずに歩くことができる。散歩でも買い物でも、どこでも好きなところへ自分で行ける」
　■ブラジル旅行も計画
　研究チームはマルクさんの脊髄に沿って、複数の要所に「神経プロテーゼ」の複雑な電極システムを埋め込んだ。そして歩行を促すために電気刺激を送るだけでなく、患者の望む動きになるよう刺激のタイミングを適正化した。
　スイス連邦工科大学ローザンヌ校に所属するクルティーヌ氏は「脚に装着した小型センサーで、残存する動き、つまりさらなる歩行の意思の測定を試みた。これによって患者が歩きたいのか、停止したいのかを知り、それに応じて刺激を調整することができる」とＡＦＰに語った。
　マルクさんはすでに２年近くにわたって、この神経プロテーゼを１日約８時間使用してきた。今ではだいぶ楽に歩けるようになり、ブラジル旅行を計画しているほどだと語った。ただし、特に階段を上る際など、集中力は依然必要だという。
　研究チームは対象をさらに６人のパーキンソン病患者に拡大して研究を続けている。ブロック、クルティーヌ両氏は、将来的な商品化を視野に「オンワード」というベンチャー企業を立ち上げている。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2023/11/09-17:47）

A man with advanced Parkinson's disease is now able to walk almost normally again thanks to electrodes implanted in his spinal cord, researchers said on Monday.
The medical first was achieved by Swiss researchers who had previously pioneered similar breakthroughs to help paraplegic people walk again.
This could be a game-changing technology to help restore movement in people with advanced Parkinson's, said David Dexter, research director at Parkinson's UK, emphasising that the procedure is invasive and more research was needed.
Marc, the 62-year-old patient who lives in France, has suffered from the debilitating brain disorder for about 30 years.
Like more than 90 percent of people with advanced Parkinson's, Marc has had great difficulty walking.
What are known as freezing episodes -- during which patients are temporarily unable to move, putting them at risk of falling -- are particularly awful, Marc told AFP.
If you have an obstacle or if someone passes in front of you unexpectedly, you start to 'freeze' and you fall, said Marc, who asked not to reveal his last name.
Much remains unknown about Parkinson's disease, making treatment difficult. But the symptoms can seriously affect the lives of patients, sometimes confining them to bed or a wheelchair.
When the opportunity arose to undergo surgery in Switzerland, Marc leapt at the chance.
- 'I can go do whatever I want' -
Now I can walk from one point to another without worrying about how I'm going to get there, he said.
I can go for a walk, go out shopping by myself -- I can go do whatever I want.
The Swiss team, led by surgeon Jocelyne Bloch and neuroscientist Gregoire Courtine, implanted a complex system of electrodes called a neuroprosthesis at crucial points along Marc's spinal cord.
The pair had previously introduced the use of spinal cord implants to enable paraplegic patients to walk again.
The latest research, published in the journal Nature Medicine, works roughly along the same principle.
For Marc and other Parkinson's patients, communication between the brain and the spinal cord has been impaired by the progressive disappearance of neurons which generate the neurotransmitter dopamine.
Therefore, the neuroprosthesis has to not only send electrical stimulation to prompt walking, but also assume the role of the brain by properly timing the stimulation, so the resulting movements correspond to the patient's wishes.
The idea is that we are going to measure residual movements -- so, the intention to walk -- with small sensors which are located in the legs, Courtine told AFP.
Thanks to this, we know if the person wants to oscillate or stop, and we can adjust the stimulation accordingly, said Courtine, a researcher at the Swiss Federal Institute of Technology Lausanne.
- 'Major potential advance' -
The neuroprosthesis was first tested on primates, then implanted in Marc, who has used it for roughly eight hours a day over nearly two years.
Marc said he can now walk much more easily -- he is even planning a trip to Brazil -- but emphasised that it still requires concentration, particularly when climbing up stairs.
The Swiss team has expanded their experiment to a group of six Parkinson's patients, aiming to know how it could help others, given the disease affects people in different ways.
Treatment using the invasive implant could be quite expensive, potentially limiting how many patients would have access.
Bloch and Courtine have launched a startup called Onward looking at future marketing.
But even reaching this point represents a major potential advance, Dexter said.