Ischemic Stroke, AcuteBoss-StrokeNCT05600374
Brain-Oscillation-Synchronized Stimulation to Enhance Motor Recovery in Early Subacute Stroke
A study testing Bossdevice in people with Ischemic Stroke, Acute, run by University Hospital Tuebingen at 4 sites in Germany.
Trial summary
We will investigate the therapeutic efficacy of EEG-synchronized noninvasive repetitive transcranial magnetic stimulation (rTMS) in the early subacute phase after ischemic stroke to improve upper limb motor rehabilitation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ischemic Stroke, Acute
- What is being tested?
- Bossdevice
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 144 participants
- Where
- 4 sitesGermany
- Study dates
- 6 Feb 2023to 28 Feb 2028
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Subjects meeting all of the following criteria will be considered for admission to the trial:
- Age ≥ 18 years at the time of signing the informed consent.
- Cerebral ischemia identified by brain imaging (cerebral MRI or CT) occurred 1-14 days ago.
- Subject understands and voluntarily signs an informed consent document prior to any study related assessments/procedures.
- Stroke has resulted in a new arm-/hand motor deficit with ≤ 50 points in the FMA-UE.
- Presence of motor evoked potentials (MEPs) in the paretic hand. MEPs has to be obtained in the resting muscle
Show all 9Show fewer
- o If no MEPs can be obtained, MEP search procedure can be repeated later up to 14 days after stroke onset.
- ● μ-oscillation (8-12 Hz) is recordable by EEG in the ipsilesional sensorimotor cortex with a sufficient signal-to-noise ratio of at least 3 dB
- ● Subject is able to adhere to the study visit schedule and other protocol requirements.
Who cannot join
- Subjects presenting with any of the following criteria will not be included in the trial:
- Hemorrhagic stroke (this refers to primary intracerebral hemorrhage only; hemorrhagic transformation of ischemic infarcts is not an exclusion criterion)
- Estimated life expectancy < 12 months
- Presence of intracranial ferromagnetic metal (extracranial stents ≥10 cm away from the TMS coil are acceptable) in accordance with current safety guidelines [18]
- Intraocular metal, cochlear implants
- If TMS might interact with sensors of active implants (e.g., intra-cardiac defibrillators).
Show all 15Show fewer
- If a cranial bone gap affects currents induced by TMS (such as after craniotomy).
- History of seizures or epilepsy.
- Treatment intervention can't be started within 14 days after onset of stroke.
- Women during pregnancy and lactation.
- Participation in other studies if they are MDR or AMG studies or there is otherwise a high risk of insurance law issues intervening between two studies. In case of uncertainty, competing insurances must be contacted prior to participation
- persistent addiction disorder (except for nicotine dependence)
- CNS malignoma
- If there is any concern by the investigator regarding the safe participation of the subject in the study or for any other reason the investigator considers the subject inappropriate for participation in the study.
- The ability to consent for patients who are unable to speak will be assessed on the basis of the NIHS-Score by an independent physician (details see chapter 21 and appendix).
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Sven Poli, Dr. contact
Germany4 sites, 4 recruiting
- Recruiting
Uniklinik Köln, Klinik und Poliklinik für Neurologie
Cologne, 50937
Lukas Volz, Prof.Dr.
- Recruiting
Universitätsklinikum Frankfurt, Zentrum der Neurologie und Neurochirurgie
Frankfurt a.M., Frankfurt a.M., 60528
Christian Grefkes-Hermann, Prof. Dr.
- Recruiting
Universitätsklinikum Münster, Klinik für Allgemeine Neurologie
Münster, 48149
Sonja Suntrup-Krueger, PD Dr.
- Recruiting
Universitätsklinikum Tübingen, Klinik für Neurologie
Tübingen, 72076
Ulf Ziemann, Prof. Dr
About this study
We will investigate the therapeutic efficacy of EEG-synchronized noninvasive repetitive transcranial magnetic stimulation (rTMS) in the early subacute phase after ischemic stroke to improve upper limb motor rehabilitation. We hypothesize that synchronization of rTMS with the phase of the ongoing sensorimotor oscillation indicating high corticospinal excitability leads to significantly stronger improvement of paretic upper limb motor function than the same rTMS protocol non-synchronized to the ongoing sensorimotor oscillation or sham stimulation.
Read the detailed description
High-frequency rTMS will be applied to the ipsilesional motor cortex in 400 bursts of 100 Hz triplets with a mean inter-burst interval of 3 s (20 min treatment duration, 1,200 pulses per day) for 5 consecutive workdays (6,000 pulses total) at a stimulus intensity of 80% of resting motor threshold, in one of three conditions/arms, followed by 40 min task-specific hand/arm-physiotherapy.
- Conditions
- Ischemic Stroke, Acute
- Being tested
- Bossdevice
- Keywords
- Oscillation, motor recovery, Transcranial magnetic stimulation, EEG-synchronized
- Medical subject headings
- Ischemic Stroke
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BossdeviceDevice
The bossdevice is a real-time digital signal processor consisting of hardware and software algorithms. It is designed to read-in a real-time raw data stream from a bio-signal amplifier (electroencephalography, EEG), to continuously analyze this data and to detect patterns based on oscillations in different frequencies. When such a specific bio-signal pattern is detected, the device indicates this through a standard output port. This enables a connected device to know with millisecond accuracy when a specific biosignal pattern occurs.
| Study group | Role | What they receive |
|---|---|---|
| Personalized stimulation | Experimental | Each 100 Hz triplet is triggered when a real-time analyzed EEG-defined state of high corticospinal excitability is detected (i.e., the negative peak of the ongoing sensorimotor ~10 Hz μ-oscillation). Receives: Device: Bossdevice |
| Non-personalized stimulation | No intervention | The identical rTMS protocol as in Arm 1, but 100 Hz triplets are not synchronized to the ongoing sensorimotor μ-oscillation. |
| Sham stimulation | No intervention | The same protocol as in arm 1 synchronized to the EEG-defined high excitability state, but with ineffective rTMS, using the sham side of an active/placebo TMS coil designed for double-blind clinical trials. Conditions/arm 2 and 3 are control conditions. Arm 2 controls for the specific effect of Condition/arm 1 to synchronize stimulation to the ongoing μ-oscillation. Arm 3 tests if auditory or somatosensory inputs (which are identical in the real and sham stimulation conditions) synchronized with the ongoing μ-oscillation are relevant for the effects of Arm 1. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Motor performance after the intervention
Primary efficacy endpoint is the motor performance after the intervention, as assessed by the Fugl-Meyer assessment (FMA-UE, range 0-66, 0 = no motor function, 66 = normal motor function) of the upper extremity (FMA-UE). The upper-extremity (UE) portion of the Fugl-Meyer assessment is the most frequently used scale to quantify post-stroke motor recovery of the upper extremity. The FMA-UE was used as an endpoint in most of the recent high-frequency rTMS trials in early subacute stroke patients.
Measured: After the last treatment session (5 days after first treatment)
Secondary outcomes (6)
Motor performance after 3 months
Motor performance 3 months after the intervention, as assessed by the FMA-UE
Measured: 3 months after the intervention
grip strength
Relative grip strength measured with a vigorimeter (measured in kg).
Measured: At screening and after 3 months after treatment
Assessment to measure quality of life
Stroke-Specific Quality-of-Life Scale (SS-QOL)
Measured: At screening and after 3 months after treatment
modified Rankin Scale Score
Rankin Scale Score (range 0-6, 0 = no disability, 6 =death)
Measured: At screening and after 3 months after treatment
Barthel Index
Barthel Index (ordinary scale ordinal scale 0-100, 0 = fully dependent, 100 =independent in feeding, walking and grooming)
Measured: At screening and after 3 months after treatment
inpatient/npatient rehabilitation
- Number of days as an inpatient (in days)
- Number of days in inpatient rehabilitation (in days)
Measured: At screening and after 3 months after treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Oct 2022
- Study start6 Feb 2023
- Primary completion31 Oct 2027 (estimated)
- Study completion28 Feb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Ischemic Stroke, AcuteStudies of the same condition, open and under way.
- More trials run by University Hospital TuebingenThe 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
- Model description
- Multicenter randomized controlled double-blind three-arm parallel-group exploratory clinical trial Medical Device Regulation (MDR) clinical trail
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 144 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital Tuebingen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05600374
- Sponsor's protocol ID
- BOSS-STROKE
- Other IDs
- CIV-22-01-038788, 01KG2125
- Acronym
- Boss-Stroke
- Status last verified
- Apr 2026
- First submitted
- 21 Oct 2022
- Last updated
- 15 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Lieb A, Zrenner B, Zrenner C, Kozak G, Martus P, Grefkes C, Ziemann U. Brain-oscillation-synchronized stimulation to enhance motor recovery in early subacute stroke: a randomized controlled double-blind three- arm parallel-group exploratory trial comparing personalized, non- personalized and sham repetitive transcranial magnetic stimulation (Acronym: BOSS-STROKE). BMC Neurol. 2023 May 25;23(1):204. doi: 10.1186/s12883-023-03235-1.
PubMed 37231390
Study at a glance
From the registry record, last updated by the sponsor on 15 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Brain-Oscillation-Synchronized Stimulation to Enhance Motor Recovery in Early Subacute Stroke
- ClinicalTrials.gov ID
- NCT05600374
- Acronym / sponsor ID
- Boss-Stroke / BOSS-STROKE
- Conditions
- Ischemic Stroke, Acute
- Keywords
- Oscillation, motor recovery, Transcranial magnetic stimulation, EEG-synchronized
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 144 participants (estimated)
- Lead sponsor
- University Hospital TuebingenUniversity, hospital or other
- Study start
- 6 Feb 2023 (actual)
- Primary completion
- 31 Oct 2027 (estimated)
- Study completion
- 28 Feb 2028 (estimated)
- First posted
- 31 Oct 2022 (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.
We will investigate the therapeutic efficacy of EEG-synchronized noninvasive repetitive transcranial magnetic stimulation (rTMS) in the early subacute phase after ischemic stroke to improve upper limb motor rehabilitation. We hypothesize that synchronization of rTMS with the phase of the ongoing sensorimotor oscillation indicating high corticospinal excitability leads to significantly stronger improvement of paretic upper limb motor function than the same rTMS protocol non-synchronized to the ongoing sensorimotor oscillation or sham stimulation.
Detailed description
High-frequency rTMS will be applied to the ipsilesional motor cortex in 400 bursts of 100 Hz triplets with a mean inter-burst interval of 3 s (20 min treatment duration, 1,200 pulses per day) for 5 consecutive workdays (6,000 pulses total) at a stimulus intensity of 80% of resting motor threshold, in one of three conditions/arms, followed by 40 min task-specific hand/arm-physiotherapy.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
- Model description
- Multicenter randomized controlled double-blind three-arm parallel-group exploratory clinical trial Medical Device Regulation (MDR) clinical trail
| Arm | Type | Receives |
|---|---|---|
| Personalized stimulation | Experimental | Device: BossdeviceEach 100 Hz triplet is triggered when a real-time analyzed EEG-defined state of high corticospinal excitability is detected (i.e., the negative peak of the ongoing sensorimotor ~10 Hz μ-oscillation). |
| Non-personalized stimulation | No intervention | –The identical rTMS protocol as in Arm 1, but 100 Hz triplets are not synchronized to the ongoing sensorimotor μ-oscillation. |
| Sham stimulation | No intervention | –The same protocol as in arm 1 synchronized to the EEG-defined high excitability state, but with ineffective rTMS, using the sham side of an active/placebo TMS coil designed for double-blind clinical trials. Conditions/arm 2 and 3 are control conditions. Arm 2 controls for the specific effect of Condition/arm 1 to synchronize stimulation to the ongoing μ-oscillation. Arm 3 tests if auditory or somatosensory inputs (which are identical in the real and sham stimulation conditions) synchronized with the ongoing μ-oscillation are relevant for the effects of Arm 1. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Subjects meeting all of the following criteria will be considered for admission to the trial:
- Age ≥ 18 years at the time of signing the informed consent.
- Cerebral ischemia identified by brain imaging (cerebral MRI or CT) occurred 1-14 days ago.
- Subject understands and voluntarily signs an informed consent document prior to any study related assessments/procedures.
- Stroke has resulted in a new arm-/hand motor deficit with ≤ 50 points in the FMA-UE.
Key exclusion criteria (15 listed)
- Hemorrhagic stroke (this refers to primary intracerebral hemorrhage only; hemorrhagic transformation of ischemic infarcts is not an exclusion criterion)
- Estimated life expectancy < 12 months
- Presence of intracranial ferromagnetic metal (extracranial stents ≥10 cm away from the TMS coil are acceptable) in accordance with current safety guidelines [18]
- Intraocular metal, cochlear implants
- If TMS might interact with sensors of active implants (e.g., intra-cardiac defibrillators).
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 |
|---|---|---|
| BossdeviceThe bossdevice is a real-time digital signal processor consisting of hardware and software algorithms. It is designed to read-in a real-time raw data stream from a bio-signal amplifier (electroencephalography, EEG), to continuously analyze this data and to detect patterns based on oscillations in different frequencies. When such a specific bio-signal pattern is detected, the device indicates this through a standard output port. This enables a connected device to know with millisecond accuracy when a specific biosignal pattern occurs. | Device | Personalized stimulation |
Primary outcome
Motor performance after the intervention
Time frame: After the last treatment session (5 days after first treatment)
Primary efficacy endpoint is the motor performance after the intervention, as assessed by the Fugl-Meyer assessment (FMA-UE, range 0-66, 0 = no motor function, 66 = normal motor function) of the upper extremity (FMA-UE). The upper-extremity (UE) portion of the Fugl-Meyer assessment is the most frequently used scale to quantify post-stroke motor recovery of the upper extremity. The FMA-UE was used as an endpoint in most of the recent high-frequency rTMS trials in early subacute stroke patients.
6 secondary outcomes
Motor performance after 3 months
Time frame: 3 months after the intervention
grip strength
Time frame: At screening and after 3 months after treatment
Assessment to measure quality of life
Time frame: At screening and after 3 months after treatment
modified Rankin Scale Score
Time frame: At screening and after 3 months after treatment
Barthel Index
Time frame: At screening and after 3 months after treatment
inpatient/npatient rehabilitation
Time frame: At screening and after 3 months after treatment
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 15 May 2026.
- Derived from this study: PubMed 37231390Lieb A, Zrenner B, Zrenner C, Kozak G, Martus P, Grefkes C, Ziemann U. Brain-oscillation-synchronized stimulation to enhance motor recovery in early subacute stroke: a randomized controlled double-blind three- arm parallel-group exploratory trial comparing personalized, non- personalized and sham repetitive transcranial magnetic stimulation (Acronym: BOSS-STROKE). BMC Neurol. 2023 May 25;23(1):204. doi: 10.1186/s12883-023-03235-1.
Related trials for Ischemic Stroke, Acute
Not yet recruiting
Temporal Interference Stimulation for Upper-Limb Motor Recovery in Early Subacute Stroke
Acute Ischemic Stroke
RecruitingObservational study
ELATE Study: Evaluating Large-vessel Acute Thrombectomy in Extended Time Window
Acute Ichemic Stroke
Not yet recruiting
Selective Intra-Arterial Hypothermia After Endovascular Treatment for Acute Basilar Artery Occlusion
Acute Ischemic Stroke, Basilar Artery Occlusion
RecruitingObservational study
Continuous Dual Aspiration Technique With Zoom System for Stroke
Ischemic Stroke, Acute Stroke
Not yet recruitingPhase 2/3
A Multicenter, Open-label, Randomized, Non-inferiority Clinical Trial With Blinded Endpoint Assessment of Early Tirofiban After Intravenous Thrombolysis in Acute Ischemic Stroke
Acute Ischemic Stroke
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.
Sven Poli, Dr. contact
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Bossdevice in people with Ischemic Stroke, Acute, run by University Hospital Tuebingen at 4 sites in Germany.
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 15 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 15 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Germany. 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. 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 Ulf Ziemann, Prof. Dr. (+49 7071 29 ext. 82049, Ulf.Ziemann@med.uni-tuebingen.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Motor performance after the intervention (time frame: After the last treatment session (5 days after first treatment)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05600374, which also lists 1 linked publication.
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 15 May 2026.