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.
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
- Conditions the study is for
- Parkinson Disease, REM Sleep Behavior Disorder (iRBD)
- 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.
Switzerland1 site, 1 recruiting
- 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
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 group | Role | What they receive |
|---|---|---|
| Verum arm | Experimental | Nightly enhancement of slow waves through Phase Targeted Auditory Stimulation (PTAS) over 18 months. Receives: Device: Tosoo Axora |
| Sham arm | Sham comparator | Nightly 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.
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)
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))
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))
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))
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))
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)
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))
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))
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))
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))
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))
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))
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))
LPS-4 Logical Reasoning
Logical reasoning assessed by Leistungsprüfsystem subtest 4.
Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)
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)
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)
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)
Verbal Fluency - Phonemic
Phonemic verbal fluency assessed by letter fluency task.
Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)
Boston Naming Test (BNT)
Naming and language function assessed by Boston Naming Test
Measured: assessed at Baseline Visit and Closeout Visit (after 18 months)
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.
- First posted21 Jan 2026
- Study start15 Jan 2026
- Primary completion30 Jun 2029 (estimated)
- Study completion30 Jun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies of the same condition, open and under way.
- More trials run by University of ZurichThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital, Zürich
- Responsible party
- Sponsor
- Investigators
- Andreas Luft, Prof. Dr. med., Principal investigator, University of Zurich
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
Study at a glance
From the registry record, last updated by the sponsor on 17 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Role of Slow Waves in the Progression of Neurodegeneration in Isolated REM Sleep Behavior Disorder
- ClinicalTrials.gov ID
- NCT07355842
- Acronym / sponsor ID
- SloW-iRBD / SloW-iRBD
- Keywords
- Parkinson, Parkinson disease, Sleep, Neurodegeneration, Auditory stimulation, iRBD, REM sleep behavior disorder
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Collaborators
- University Hospital, Zürich
- Study start
- 15 Jan 2026 (actual)
- Primary completion
- 30 Jun 2029 (estimated)
- Study completion
- 30 Jun 2029 (estimated)
- First posted
- 21 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Verum arm | Experimental | Device: Tosoo AxoraNightly enhancement of slow waves through Phase Targeted Auditory Stimulation (PTAS) over 18 months. |
| Sham arm | Sham comparator | Device: Tosoo AxoraNightly application of tones that will be applied in a non-PTAS manner, resulting in no enhancement of slow waves over 18 months. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (9 listed)
- 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
- no dopaminergic treatment and no foreseen start of such treatment during duration of the study
Key exclusion criteria (18 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Tosoo AxoraAlso: 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. | Device | Verum arm |
| Tosoo AxoraAlso: PTAS Intervention (Sham)Auditory stimuli will be delivered during the night through integrated headphones with a portable EEG device in a non-PTAS manner. | Device | Sham arm |
Primary outcome
Presynaptic Dopaminergic Integrity
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Striatal dopaminergic function as measured by high-resolution 18F-Fluorodopa (18F-DOPA)-PET imaging.
19 secondary outcomes
MDS-UPDRS Part III Score
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Purdue Pegboard Test Score
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Alternate Finger Tapping Test
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
UPDRS I.1 (subjective cognition)
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Montreal Cognitive Assessment (MoCA) Score
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout)
Trail Making Test Part A
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Trail Making Test Part B
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Digit Span Forward
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Digit Span backward
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Stroop Test
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Verbal Fluency - Semantic
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
Benton Judgment of Line Orientation (BJLO)
Time frame: assessed at each visit (Baseline, after 6 months, after 12 months, after 18 months (Closeout))
LPS-4 Logical Reasoning
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Rey-Taylor Complex Figure Test - Copy
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Rey-Taylor Complex Figure Test - Recall
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
California Verbal Learning Test (CVLT)
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Verbal Fluency - Phonemic
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Boston Naming Test (BNT)
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
WAIS Similarities
Time frame: assessed at Baseline Visit and Closeout Visit (after 18 months)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Andreas Luft, Prof. Dr. med. principal investigator
University of Zurich
1 site in 1 country: see every site and its status.
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.