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Parkinson DiseaseSloW-iRBDNCT07355842

Role of Slow Waves in the Progression of Neurodegeneration in Isolated REM Sleep Behavior Disorder

A study testing Tosoo Axora in people with Parkinson Disease and REM Sleep Behavior Disorder (iRBD), run by University of Zurich at 1 site in Switzerland.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This study tests whether enhancing deep sleep with gentle sounds at night can slow progression in people with iRBD or early Parkinson's disease. Participants wear a sensor headband and headphones for 18 months. Read more about this study

Who is it for?
Any age
What is being tested?
Tosoo Axora
Type of treatment
Medical device
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
80 participants
Where
1 siteSwitzerland
Study dates
15 Jan 2026to 30 Jun 2029
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • Signed informed consent
  • Diagnosis of polysomnography-confirmed isolated REM Sleep Behavior Disorder (iRBD) based on international criteria (ICSD-3), combined with EITHER
  • UPDRS III without action tremor ≥ 4 AND abnormal olfaction, OR
  • diagnosis of PD along international criteria for less than 2 years
  • Further inclusion criteria are:
  • no dopaminergic treatment and no foreseen start of such treatment during duration of the study
Show all 9Show fewer
  • ability to apply the intervention, alone or with help of a co-habitant, stable living situation
  • sufficient language skills in German, French or Italian
  • negative pregnancy test for women of child-bearing potential

Who cannot join

  • Suspected or known non-compliance to other therapies
  • current or recent participation in another clinical trial
  • extended absences
  • hearing impairment that prevents hearing the tones for auditory stimulation
  • non-responder to auditory stimulation during screening
  • clinically significant concomitant disease or unstable condition
Show all 18Show fewer
  • Apnea-Hypopnea-Index (AHI) > 15/h or under Continuous Positive Airway Pressure (CPAP) treatment
  • Restless Legs Syndrome
  • meeting criteria for diagnosis of atypical Parkinson syndrome
  • diagnosis of Dementia or Montreal Cognitive Assessment (MoCA) < 24
  • severe Depression or other psychiatric disorder
  • regular use of benzodiazepines and other central nervous system depressant substances
  • current or recent history within the last year of substance abuse disorders or chronic alcohol consumption
  • recent or planned major surgery
  • history of allergies and hypersensitivity relevant for electrode application or medication allergies
  • additional exclusion criteria for PET imaging
  • any criterion that may pose the participant at risk
  • breastfeeding, intention to become pregnant, or unwillingness to use medically reliable contraception for women of child-bearing potential

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Jana Bünzli, MSc contact

+41 44 255 10 43

jana.buenzli@usz.ch

Marta Menéndez, Dr. phil. contact

+41 43 253 69 54

marta.menendezgranda@usz.ch

Switzerland1 site, 1 recruiting
  • University Hospital Zurich, Neurology Department

    Zurich, Canton of Zurich, 8091

    Angelina Maric, Dr. phil., +41 255 86 15, angelina.maric@usz.ch

    Jana Bünzli, MSc, +41 44 255 10 43, jana.buenzli@usz.ch

    Recruiting

Other trials in Switzerland

About this study

This study tests whether enhancing deep sleep with gentle sounds at night can slow progression in people with iRBD or early Parkinson's disease. Participants wear a sensor headband and headphones for 18 months. Four assessments including mobility, memory, imaging (PET/MRI), lumbar puncture, and blood tests are assessed.

Read the detailed description

Many people with REM sleep behavior disorder (iRBD) develop Parkinson's disease or similar conditions over the years. To date, there is no effective method to prevent this transition. Animal experiments and observational studies in patients and older adults indicate that deeper sleep is associated with a slower progression of brain changes. In this study, we are now investigating whether enhancement of deep sleep using sounds during sleep can influence the progressive brain changes in iRBD or early Parkinson's disease.

Participants wear a headband with sensors and headphones for 18 months, which plays gentle sounds during sleep to enhance deep sleep. In addition, four examinations are carried out, including tests of mobility, memory, imaging (PET/MRI), a lumbar puncture, and blood sampling. Two of the examinations will take place at the University Hospital of Zurich, and two more can also be carried out at home if desired.

The aim is to investigate whether enhancement of deep sleep can help slow the progression of iRBD or early-stage Parkinson's disease. The study is double-blind and controlled, which means that neither the participants nor the researchers know who is receiving the active treatment.

Being tested
Tosoo Axora
Keywords
Parkinson, Parkinson disease, Sleep, Neurodegeneration, Auditory stimulation, iRBD, REM sleep behavior disorder
Medical subject headings
Parkinson Disease, REM Sleep Behavior Disorder, Nerve Degeneration

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Tosoo AxoraDevice

    Also called PTAS Intervention (Verum)

    Phase Targeted Auditory Stimulation (PTAS) will be applied through integrated headphones with a portable EEG device when non-rapid-eye-movement (NREM) sleep is detected during the night.

  • Tosoo AxoraDevice

    Also called PTAS Intervention (Sham)

    Auditory stimuli will be delivered during the night through integrated headphones with a portable EEG device in a non-PTAS manner.

Study groups in NCT07355842
Study groupRoleWhat they receive
Verum armExperimentalNightly enhancement of slow waves through Phase Targeted Auditory Stimulation (PTAS) over 18 months.
Receives: Device: Tosoo Axora
Sham armSham comparatorNightly application of tones that will be applied in a non-PTAS manner, resulting in no enhancement of slow waves over 18 months.
Receives: Device: Tosoo Axora

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Presynaptic Dopaminergic Integrity

    Striatal dopaminergic function as measured by high-resolution 18F-Fluorodopa (18F-DOPA)-PET imaging.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

Secondary outcomes (19)
  1. MDS-UPDRS Part III Score

    Motor symptom severity assessed by the Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), a clinician-rated examination of motor signs.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  2. Purdue Pegboard Test Score

    Manual dexterity and fine motor coordination assessed by total score on the Purdue Pegboard Test.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  3. Alternate Finger Tapping Test

    Motor speed and coordination assessed by performance on the Alternate Finger Tapping Test.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  4. UPDRS I.1 (subjective cognition)

    Patient-reported cognitive experiences of daily living assessed by MDS-UPDRS Part I, Item 1.1.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  5. Montreal Cognitive Assessment (MoCA) Score

    Global cognitive function assessed by MoCA total score.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout)

  6. Trail Making Test Part A

    Processing speed and attention assessed by time to completion on Trail Making Test Part A.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  7. Trail Making Test Part B

    Executive function assessed by time to completion on Trail Making Test Part B.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  8. Digit Span Forward

    Attention assessed by Digit Span Forward from the Wechsler Adult Intelligence Scale.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  9. Digit Span backward

    Working memory assessed by Digit Span Backward from the Wechsler Adult Intelligence Scale

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  10. Stroop Test

    Executive function and inhibitory control assessed by Stroop Color-Word Test.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  11. Verbal Fluency - Semantic

    Semantic verbal fluency assessed by category fluency task.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  12. Benton Judgment of Line Orientation (BJLO)

    Visuospatial function assessed by Benton Judgment of Line Orientation test.

    Measured: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))

  13. LPS-4 Logical Reasoning

    Logical reasoning assessed by Leistungsprüfsystem subtest 4.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  14. Rey-Taylor Complex Figure Test - Copy

    Visuoconstruction assessed by copy trial of the Rey-Taylor Complex Figure Test.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  15. Rey-Taylor Complex Figure Test - Recall

    Visual memory assessed by delayed recall of the Rey-Taylor Complex Figure Test.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  16. California Verbal Learning Test (CVLT)

    Verbal learning and memory assessed by California Verbal Learning Test.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  17. Verbal Fluency - Phonemic

    Phonemic verbal fluency assessed by letter fluency task.

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  18. Boston Naming Test (BNT)

    Naming and language function assessed by Boston Naming Test

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

  19. WAIS Similarities

    Verbal abstract reasoning assessed by similarities subtest from the Wechsler Adult Intelligence Scale

    Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Jan 2026
  2. Study start15 Jan 2026
  3. Primary completion30 Jun 2029 (estimated)
  4. Study completion30 Jun 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Care provider, Outcomes assessor
Enrolment
80 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07355842
Sponsor's protocol ID
SloW-iRBD
Other IDs
2025-D0069
Acronym
SloW-iRBD
Status last verified
Feb 2026
First submitted
22 Dec 2025
Last updated
17 Feb 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Tosoo Axora in people with Parkinson Disease and REM Sleep Behavior Disorder (iRBD), run by University of Zurich at 1 site in Switzerland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 17 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Jana Bünzli, MSc (+41 44 255 10 43, jana.buenzli@usz.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Presynaptic Dopaminergic Integrity (time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Feb 2026; AzTrials last refreshed its copy on 8 Nov 2026.

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