皮質ニューロン。 クレジット: 国立高度トランスレーショナル科学センター、NIH。
交互性片麻痺は、ATP1A3 遺伝子の変異に起因する衰弱性の神経発達障害です。 この状態は幼い頃の子供に影響を与え、生活の質に大きな影響を与えます。 数分から数日にわたる麻痺のエピソードの間、体の片側または交互の側が麻痺することがあります. さらに、患者はジストニアとして知られる反復的な筋肉収縮を経験する可能性があり、これは何時間も続き、重大な痛みを引き起こす可能性があります.
現在、睡眠中に症状が治まる傾向があるため、状態の管理は鎮静剤の使用に重点を置いています。 ストレスや運動などの引き金を避けることは、片麻痺やジストニアのエピソードの頻度を減らすのに役立つかもしれません.
「私たちはこれらの患者を助ける方法を知りません。 したがって、私たちは、それらを緩和する可能性のある予期しない要因に特に注意を払っています」と、神経科医で異常な動きの専門家であるエマニュエル・フラマン・ロゼは説明します. 「最近、25 歳の男性が、ジストニアのエピソード中に笑気ガスを投与された後、症状が数分で治まったと私たちに話しました。 このガスが -[{” attribute=””>nitrous oxide – is usually administered with 50% oxygen. As it is impossible to give nitrous oxide in daily treatment, we wanted to test whether oxygen was responsible for stopping the attack.”
The researchers then installed an oxygen therapy device in the patient’s home. “We observed that dystonic attacks stopped 15 minutes after the oxygen was administered,” says the researcher. This is a significant benefit, as this young man could experience up to 8 episodes a day, some of which could last several hours. His quality of life was improved. Oxygen therapy is a safe, highly accessible treatment that can significantly reduce the use of potent sedatives, such as midazolam, which the patient was taking at a rate of 40 doses per month.”
Team member Quentin Welniarz proposed a hypothesis to explain the effect of oxygen. According to him, a phenomenon called cortical spreading depression (CSD), which corresponds to a wave of electrical disturbance in the brain, plays an essential role in triggering the symptoms of alternating hemiplegia. This wave consists of a rapid phase of neuronal hyperactivity and a slower phase of electrical silence in the cortex cells. It’s also associated with hypoxia – i.e., reduced oxygen availability. Rapid administration of oxygen at the time of attacks could therefore interrupt or mitigate this phenomenon.
To ensure that the association between oxygen delivery and mitigation of dystonia attacks is not coincidental, researchers must ensure that the same effect occurs in other patients under comparable conditions. Similarly, it remains to be clarified how to optimize the use of oxygen therapy, especially at home, so that it is as little restrictive as possible.
Reference: “Oxygen Therapy: An Acute Treatment for Paroxysmal Dystonia in Alternating Hemiplegia of Childhood?” by Quentin Welniarz, Ph.D., Domitille Gras, MD, Agathe Roubertie, MD, Ph.D., Maria T. Papadopoulou, MD, Eleni Panagiotakaki, MD, Ph.D. and Emmanuel Roze, MD, Ph.D., 16 February 2023, Movement Disorders.
DOI: 10.1002/mds.29357