Parkinson DiseaseNCT07323121
40 Hz Flickering for Insomnia in Parkinson's Disease
A study testing 40 Hz flicker light device and 100 Hz flicker light device in people with Parkinson Disease and Insomnia, run by Jiangsu Province Nanjing Brain Hospital at 1 site in China.
Trial summary
This randomized, single-blind, controlled clinical trial aims to evaluate the efficacy and safety of 40 Hz flicker light stimulation for insomnia in patients with Parkinson's disease (PD). Read more about this study
- Who is it for?
- Ages 50 to 75 years
- Conditions the study is for
- Parkinson Disease, Insomnia
- What is being tested?
- 40 Hz flicker light device and 100 Hz flicker light device
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteChina
- Study dates
- 1 Jan 2026to 31 Dec 2026
- 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 50 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of Parkinson's disease according to established clinical criteria (e.g., Movement Disorder Society criteria).
- Age between 50 and 75 years.
- Disease duration ≤ 10 years and Hoehn and Yahr stage ≤ 3 in the "on" state.
- Clinically significant insomnia, defined as Parkinson's Disease Sleep Scale-2 (PDSS-2) total score ≥ 18 points and/or meeting diagnostic criteria for insomnia.
- Stable antiparkinsonian medication regimen for at least 4 weeks prior to enrollment.
- Able and willing to comply with study procedures and provide written informed consent.
Who cannot join
- Secondary insomnia primarily due to severe systemic diseases or major psychiatric disorders (e.g., psychosis, severe depression or anxiety) or substance abuse.
- History of epilepsy, photosensitive seizures, photosensitive dermatitis, or other conditions in which flicker light stimulation is contraindicated.
- Severe visual impairment or eye diseases that would interfere with light stimulation or safety assessment.
- Unstable or severe medical conditions (e.g., uncontrolled cardiovascular, hepatic, renal, or endocrine disease) that, in the investigator's opinion, make participation unsafe.
- Participation in another interventional clinical trial within the past 3 months.
- Inability to complete study procedures or follow-up due to cognitive, physical, or social reasons.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road
Nanjing, Jiangsu, 210029
Haochen Sun, MD, +86-025-82296261, 735690822@qq.com
About this study
Official title: Randomized, Single-blind, Controlled Study of 40 Hz Flickering Stimulation for Insomnia and Other Non-motor Symptoms in Patients With Parkinson's Disease
This randomized, single-blind, controlled clinical trial aims to evaluate the efficacy and safety of 40 Hz flicker light stimulation for insomnia in patients with Parkinson's disease (PD). Patients with PD and clinically significant insomnia will be randomly assigned in a 1:1 ratio to receive either 40 Hz flicker light or control light for 30 minutes every night at bedtime for 7 consecutive days, in addition to standard antiparkinsonian treatment.
The primary objective is to determine whether 40 Hz flicker light stimulation improves PD-related insomnia as measured by Parkinson's Disease Sleep Scale-2 (PDSS-2). Secondary objectives include evaluating changes in polysomnography-derived sleep parameters, subjective sleep quality, and other non-motor symptoms, as well as assessing the safety and tolerability of the intervention.
This registration specifically covers the Parkinson's disease insomnia cohort of a larger, previously approved multi-cohort protocol that also includes healthy volunteers and primary insomnia patients.
Read the detailed description
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by both motor and non-motor symptoms. Insomnia and other sleep disturbances are highly prevalent in PD and significantly impair quality of life, yet current pharmacological therapies are often insufficient and may produce adverse effects. There is a clear need for novel, non-pharmacological approaches to improve sleep in PD.
Gamma-band (around 40 Hz) neural oscillations are associated with cortical network activity and may influence sleep regulation, brain adenosine levels, and glymphatic clearance. Flicker light stimulation at 40 Hz has been shown in preclinical and early clinical studies to modulate gamma oscillations and related neurophysiological processes. Based on these findings, 40 Hz visual flicker stimulation may represent a promising, non-invasive strategy for improving insomnia and other non-motor symptoms in PD.
In this single-center, randomized, single-blind, controlled trial, approximately 30 patients with PD and clinically significant insomnia will be enrolled. Eligible participants will be randomly assigned to receive either 40 Hz flicker light stimulation or control light. Participants in the 40 Hz group will receive visual flicker stimulation at 40 Hz for 30 minutes every night at bedtime for 7 consecutive days, using a dedicated light device, in addition to their stable antiparkinsonian medication. Participants in the control group will receive non-40 Hz light of similar intensity and duration under otherwise identical conditions.
Clinical assessments will include PD-specific sleep scales, particularly the Parkinson's Disease Sleep Scale-2 (PDSS-2), general sleep questionnaires such as the Pittsburgh Sleep Quality Index (PSQI), and sleep diaries. Objective sleep parameters, including total sleep time, sleep efficiency, sleep latency, wake after sleep onset, and number of nocturnal awakenings, will be obtained from polysomnography where applicable. Other non-motor symptoms may also be evaluated using standardized scales. Safety assessments will include monitoring of adverse events, vital signs, and visual or ophthalmic discomfort during and after stimulation.
The parent protocol, initially approved in 2022, included healthy volunteers and primary insomnia patients. The present registration focuses exclusively on the Parkinson's disease insomnia cohort introduced by later protocol amendments and does not include the non-PD cohorts.
- Conditions
- Parkinson Disease, Insomnia
- Being tested
- 40 Hz flicker light device, 100 Hz flicker light device
- Keywords
- Parkinson's disease, insomnia, sleep disorders, 40 Hz flickering, gamma oscillation
- Medical subject headings
- Parkinson Disease, Sleep Initiation and Maintenance Disorders, Sleep Wake Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
40 Hz flicker light deviceDevice
A visual stimulation device delivering flicker light at 40 Hz. Participants assigned to this intervention receive 30 minutes of 40 Hz flicker light stimulation every night at bedtime for 7 consecutive days, in addition to their stable antiparkinsonian medication. Device parameters, including light intensity and distance, are adjusted according to the protocol to ensure safety and comfort.
100 Hz flicker light deviceDevice
A visual stimulation device delivering 100 Hz light (e.g., steady or low-frequency light) with similar appearance and intensity as the 40 Hz device. Participants assigned to this intervention receive 30 minutes of control light exposure every night at bedtime for 7 consecutive days, in addition to their stable antiparkinsonian medication.
| Study group | Role | What they receive |
|---|---|---|
| 40 Hz flicker light stimulation | Experimental | Parkinson's disease patients with insomnia receiving 40 Hz flicker light stimulation plus standard PD care. Receives: Device: 40 Hz flicker light device |
| 100 Hz flicker light stimulation | Sham comparator | Parkinson's disease patients with insomnia receiving 100 Hz flicker light stimulation plus standard PD care. Receives: Device: 100 Hz flicker light device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Parkinson's Disease Sleep Scale-2 (PDSS-2) total score (0-60 points; higher scores indicate worse sleep disturbance).
The Parkinson's Disease Sleep Scale-2 (PDSS-2) is a 15-item questionnaire assessing nocturnal symptoms in Parkinson's disease. Each item is scored from 0 to 4, yielding a total score from 0 to 60 points. Higher scores indicate more severe sleep disturbance. The outcome measure is the change in PDSS-2 total score from baseline to Day 7 after the intervention, and the between-group difference (40 Hz vs control) in mean change will be compared.
Measured: Baseline and Day 7
Secondary outcomes (2)
Change in Parkinson's Disease Sleep Scale-2 (PDSS-2) total score at follow-up (0-60 points; higher scores indicate worse sleep disturbance).
The Parkinson's Disease Sleep Scale-2 (PDSS-2) total score ranges from 0 to 60 points, with higher scores indicating more severe sleep disturbance. The outcome measure is the change in PDSS-2 total score from baseline to Day 7 and to Day 28, and the between-group differences (40 Hz vs control) in these changes will be analyzed.
Measured: Baseline, Day 7, and Day 28
Change in Non-Motor Symptoms Scale (NMSS) total score (0-360 points; higher scores indicate more severe non-motor symptoms).
The Non-Motor Symptoms Scale (NMSS) is a clinician-rated instrument assessing the severity and frequency of non-motor symptoms in Parkinson's disease. The total score ranges from 0 to 360 points, with higher scores indicating more severe non-motor symptom burden. The outcome measure is the change in NMSS total score from baseline to Day 7 between the two groups.
Measured: Baseline and Day 7
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jan 2026
- Study start1 Jan 2026
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (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.
- 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
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jiangsu Province Nanjing Brain Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- The Eye Hospital of Wenzhou Medical University
- Responsible party
- Sponsor
- Investigators
- Haochen Sun, Principal investigator, Jiangsu Province Nanjing Brain Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07323121
- Sponsor's protocol ID
- 2022-130-K-99-01
- Other IDs
- 82430045
- Status last verified
- Jul 2026
- First submitted
- 11 Dec 2025
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Individual participant data that underlie the results of this trial (after de-identification) may be shared upon reasonable request to the principal investigator after publication of the main results, subject to ethics committee approval and institutional regulations.
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized, Single-blind, Controlled Study of 40 Hz Flickering Stimulation for Insomnia and Other Non-motor Symptoms in Patients With Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07323121
- Acronym / sponsor ID
- 2022-130-K-99-01
- Conditions
- Parkinson Disease, Insomnia
- Keywords
- Parkinson's disease, insomnia, sleep disorders, 40 Hz flickering, gamma oscillation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Jiangsu Province Nanjing Brain HospitalUniversity, hospital or other
- Collaborators
- The Eye Hospital of Wenzhou Medical University
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 7 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 randomized, single-blind, controlled clinical trial aims to evaluate the efficacy and safety of 40 Hz flicker light stimulation for insomnia in patients with Parkinson's disease (PD). Patients with PD and clinically significant insomnia will be randomly assigned in a 1:1 ratio to receive either 40 Hz flicker light or control light for 30 minutes every night at bedtime for 7 consecutive days, in addition to standard antiparkinsonian treatment.
The primary objective is to determine whether 40 Hz flicker light stimulation improves PD-related insomnia as measured by Parkinson's Disease Sleep Scale-2 (PDSS-2). Secondary objectives include evaluating changes in polysomnography-derived sleep parameters, subjective sleep quality, and other non-motor symptoms, as well as assessing the safety and tolerability of the intervention.
This registration specifically covers the Parkinson's disease insomnia cohort of a larger, previously approved multi-cohort protocol that also includes healthy volunteers and primary insomnia patients.
Detailed description
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by both motor and non-motor symptoms. Insomnia and other sleep disturbances are highly prevalent in PD and significantly impair quality of life, yet current pharmacological therapies are often insufficient and may produce adverse effects. There is a clear need for novel, non-pharmacological approaches to improve sleep in PD.
Gamma-band (around 40 Hz) neural oscillations are associated with cortical network activity and may influence sleep regulation, brain adenosine levels, and glymphatic clearance. Flicker light stimulation at 40 Hz has been shown in preclinical and early clinical studies to modulate gamma oscillations and related neurophysiological processes. Based on these findings, 40 Hz visual flicker stimulation may represent a promising, non-invasive strategy for improving insomnia and other non-motor symptoms in PD.
In this single-center, randomized, single-blind, controlled trial, approximately 30 patients with PD and clinically significant insomnia will be enrolled. Eligible participants will be randomly assigned to receive either 40 Hz flicker light stimulation or control light. Participants in the 40 Hz group will receive visual flicker stimulation at 40 Hz for 30 minutes every night at bedtime for 7 consecutive days, using a dedicated light device, in addition to their stable antiparkinsonian medication. Participants in the control group will receive non-40 Hz light of similar intensity and duration under otherwise identical conditions.
Clinical assessments will include PD-specific sleep scales, particularly the Parkinson's Disease Sleep Scale-2 (PDSS-2), general sleep questionnaires such as the Pittsburgh Sleep Quality Index (PSQI), and sleep diaries. Objective sleep parameters, including total sleep time, sleep efficiency, sleep latency, wake after sleep onset, and number of nocturnal awakenings, will be obtained from polysomnography where applicable. Other non-motor symptoms may also be evaluated using standardized scales. Safety assessments will include monitoring of adverse events, vital signs, and visual or ophthalmic discomfort during and after stimulation.
The parent protocol, initially approved in 2022, included healthy volunteers and primary insomnia patients. The present registration focuses exclusively on the Parkinson's disease insomnia cohort introduced by later protocol amendments and does not include the non-PD cohorts.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 40 Hz flicker light stimulation | Experimental | Device: 40 Hz flicker light deviceParkinson's disease patients with insomnia receiving 40 Hz flicker light stimulation plus standard PD care. |
| 100 Hz flicker light stimulation | Sham comparator | Device: 100 Hz flicker light deviceParkinson's disease patients with insomnia receiving 100 Hz flicker light stimulation plus standard PD care. |
Who may qualify
- Ages
- 50 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Diagnosis of Parkinson's disease according to established clinical criteria (e.g., Movement Disorder Society criteria).
- Age between 50 and 75 years.
- Disease duration ≤ 10 years and Hoehn and Yahr stage ≤ 3 in the "on" state.
- Clinically significant insomnia, defined as Parkinson's Disease Sleep Scale-2 (PDSS-2) total score ≥ 18 points and/or meeting diagnostic criteria for insomnia.
- Stable antiparkinsonian medication regimen for at least 4 weeks prior to enrollment.
Key exclusion criteria (6 listed)
- Secondary insomnia primarily due to severe systemic diseases or major psychiatric disorders (e.g., psychosis, severe depression or anxiety) or substance abuse.
- History of epilepsy, photosensitive seizures, photosensitive dermatitis, or other conditions in which flicker light stimulation is contraindicated.
- Severe visual impairment or eye diseases that would interfere with light stimulation or safety assessment.
- Unstable or severe medical conditions (e.g., uncontrolled cardiovascular, hepatic, renal, or endocrine disease) that, in the investigator's opinion, make participation unsafe.
- Participation in another interventional clinical trial within the past 3 months.
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 |
|---|---|---|
| 40 Hz flicker light deviceA visual stimulation device delivering flicker light at 40 Hz. Participants assigned to this intervention receive 30 minutes of 40 Hz flicker light stimulation every night at bedtime for 7 consecutive days, in addition to their stable antiparkinsonian medication. Device parameters, including light intensity and distance, are adjusted according to the protocol to ensure safety and comfort. | Device | 40 Hz flicker light stimulation |
| 100 Hz flicker light deviceA visual stimulation device delivering 100 Hz light (e.g., steady or low-frequency light) with similar appearance and intensity as the 40 Hz device. Participants assigned to this intervention receive 30 minutes of control light exposure every night at bedtime for 7 consecutive days, in addition to their stable antiparkinsonian medication. | Device | 100 Hz flicker light stimulation |
Primary outcome
Change in Parkinson's Disease Sleep Scale-2 (PDSS-2) total score (0-60 points; higher scores indicate worse sleep disturbance).
Time frame: Baseline and Day 7
The Parkinson's Disease Sleep Scale-2 (PDSS-2) is a 15-item questionnaire assessing nocturnal symptoms in Parkinson's disease. Each item is scored from 0 to 4, yielding a total score from 0 to 60 points. Higher scores indicate more severe sleep disturbance. The outcome measure is the change in PDSS-2 total score from baseline to Day 7 after the intervention, and the between-group difference (40 Hz vs control) in mean change will be compared.
2 secondary outcomes
Change in Parkinson's Disease Sleep Scale-2 (PDSS-2) total score at follow-up (0-60 points; higher scores indicate worse sleep disturbance).
Time frame: Baseline, Day 7, and Day 28
Change in Non-Motor Symptoms Scale (NMSS) total score (0-360 points; higher scores indicate more severe non-motor symptoms).
Time frame: Baseline and Day 7
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 28 Jul 2026.
- Individual participant dataSharing planned: Undecided. Individual participant data that underlie the results of this trial (after de-identification) may be shared upon reasonable request to the principal investigator after publication of the main results, subject to ethics committee approval and institutional regulations.
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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.
Haochen Sun principal investigator
Jiangsu Province Nanjing Brain Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 40 Hz flicker light device and 100 Hz flicker light device in people with Parkinson Disease and Insomnia, run by Jiangsu Province Nanjing Brain Hospital at 1 site in China.
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 6 inclusion and 6 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 28 Jul 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 China. 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 Haochen Sun, MD (+86-025-82296261, 735690822@qq.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Parkinson's Disease Sleep Scale-2 (PDSS-2) total score (0-60 points; higher scores indicate worse sleep disturbance). (time frame: Baseline and Day 7). 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 28 Jul 2026.