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Study on Oxygen and Nitrous Oxide for Treating Dystonic and Plegic Attacks in Children with Alternating Hemiplegia

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a rare neurological disorder called Alternating Hemiplegia of Childhood (AHC). AHC is a condition that causes sudden episodes of paralysis or muscle stiffness, known as dystonic or plegic attacks. The study aims to evaluate the effectiveness of a treatment using high-flow oxygen therapy to manage these acute attacks. The treatment involves inhaling a mixture of nitrous oxide and oxygen, commonly known as laughing gas, through a facial mask. This therapy will be compared to a placebo to determine its impact on stopping motor attacks.

Participants in the study will receive the treatment over a period of five weeks. During this time, the main focus will be on observing whether the high-flow oxygen therapy can stop the motor attacks within 30 minutes of their onset. The study does not involve any long-term treatment changes, ensuring that participants' existing treatments remain stable throughout the trial.

The goal of this research is to provide a better understanding of how high-flow oxygen therapy can be used as an immediate treatment for the sudden and distressing symptoms of AHC. By comparing the effects of the therapy against a placebo, researchers hope to gather valuable information that could lead to improved management of this challenging condition.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on specific criteria such as age, ability to use a high-flow oxygen mask, and diagnosis of alternating hemiplegia of childhood (AHC) with frequent attacks.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to establish a baseline for the frequency and duration of dystonic or plegic attacks. This involves documenting the patient's medical history and current condition.

  3. Step 3

    Treatment phase

    During the treatment phase, high-flow oxygen is administered through a non-rebreathing facial mask. This is done at the onset of a dystonic or plegic attack.

    The treatment aims to assess the effect of oxygen as an acute intervention. The primary goal is to stop motor attacks within 30 minutes of symptom onset.

  4. Step 4

    Monitoring and documentation

    Throughout the trial, the frequency and duration of attacks are monitored. The effectiveness of the oxygen treatment is documented, focusing on the proportion of attacks stopped within the specified timeframe.

  5. Step 5

    Conclusion of trial participation

    The trial concludes after a period of 5 weeks. A final assessment is conducted to evaluate the overall impact of the treatment on the patient's condition.

Who can join the trial?

7 criteria

  • Must be older than 1 year.
  • Must be able to use a high-flow oxygen mask, either by themselves or with help. A high-flow oxygen mask is a special mask that helps deliver a large amount of oxygen to the person wearing it.
  • Must have a diagnosis of Alternating Hemiplegia of Childhood (AHC) caused by ATP1A3 mutations. AHC is a rare condition that causes temporary paralysis on one side of the body. ATP1A3 mutations are changes in a specific gene that can cause AHC.
  • Must experience at least one dystonic or plegic attack per week lasting more than 30 minutes. A dystonic attack involves muscle spasms or abnormal movements, while a plegic attack involves temporary paralysis.
  • Must not be on long-term treatment, or if on long-term treatment, it must be stable for the last month and during the trial. Long-term treatment refers to ongoing medication or therapy for a condition.
  • Must be able to provide written informed consent. This means agreeing to participate in the study after understanding all the details and risks involved.
  • Must have social insurance. Social insurance is a system where people pay into a fund that helps cover medical costs.

Who cannot join the trial?

4 criteria

  • Individuals who do not have Alternating Hemiplegia of Childhood cannot participate. This is a rare condition that causes temporary paralysis on one side of the body.
  • Participants must be within certain age ranges, specifically from 2 to 4 years old.
  • Both males and females are eligible, so gender is not a reason for exclusion.
  • Participants must not belong to a vulnerable population that is not selected for this study. A vulnerable population might include groups like children, pregnant women, or those with certain disabilities.
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Investigated drugs

Oxygen Therapy is being studied as a treatment for sudden muscle spasms or paralysis attacks in children with alternating hemiplegia. The trial aims to see if giving high-flow oxygen can help reduce these attacks.

What is already known about the treatment

Oxygen Therapy – This treatment is administered through inhalation, typically using a mask or nasal cannula to deliver high-flow oxygen. It is currently being studied in clinical trials for its potential benefits in treating acute dystonic or plegic attacks in children with Alternating Hemiplegia of Childhood. Oxygen therapy is widely recognized in medical literature for its role in various respiratory and emergency conditions. The main therapeutic indication in this trial is to alleviate sudden muscle spasms or paralysis episodes. At the molecular level, oxygen therapy works by increasing the oxygen supply to tissues, which may help reduce symptoms by improving cellular function and energy production. It is classified as a respiratory therapy.

Investigated diseases

Alternating Hemiplegia of Childhood – This is a rare neurological disorder that typically begins in infancy or early childhood. It is characterized by recurrent episodes of temporary paralysis affecting one side of the body, which can switch sides. These episodes can last from minutes to days and may be accompanied by other symptoms such as abnormal eye movements, muscle stiffness, and developmental delays. The frequency and severity of episodes can vary widely among individuals. Over time, some children may experience persistent neurological issues, including movement difficulties and cognitive challenges. The exact cause of the condition is often linked to genetic mutations.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508413-16-00Protocol codeAPHP230673Estimated enrolment24 patientsSponsorAssistance Publique Hopitaux De Paris

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