Motor and Neurophysiological Changes After Ischemic Conditioning in Individuals With Stroke: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Motor and Neurophysiological Changes After Ischemic Conditioning in Individuals With Stroke (NCT05906602), a randomized na study. The primary outcome is Change in Corticomotor Excitability.

2. Clinical Question

3. Trial Design

This is a randomized, single-masked, crossover trial. Its registry enrollment is 20, and its status is completed. The record lists University of Illinois Chicago as the sponsor and Stroke as the condition. The phase is recorded as NA. The study start is 2024-05-20, and primary completion is recorded as 2025-12-31.

In a crossover design, each participant receives more than one study condition, so a participant can contribute observations under both the intervention and comparator. Here, the two conditions are real ischemic conditioning and sham ischemic conditioning. Randomized order is described through two sequences: ischemic conditioning then sham ischemic conditioning, and sham ischemic conditioning then ischemic conditioning. The record does not say which party was masked.

The real-conditioning description places a rapid inflation cuff around the paretic thigh while the participant is seated. Pressure is increased for 5 minutes and then removed for 5 minutes, repeated 5 times, for a total of 50 min. The sham description also identifies a cuff and a sequence of pressure and no pressure, but its registry text is truncated before the full procedure is stated. The exact sham pressure and the complete sham procedure are not reported in the registry record.

Brain-activity and motor-behavior measures were scheduled before and after both sessions. The primary outcome description specifies baseline (Pre), immediate-post (Post), and 30-minutes-post (Post-30) assessments for corticomotor excitability. The registry record does not report the interval between sessions, a washout procedure, or how period and carryover effects were addressed. Those details matter in crossover studies because an effect of an earlier condition could persist into a later session.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: 22 individuals with stroke were screened for eligibility. Of these, 2 were excluded prior to study procedures due to contraindications to IC. Of the 20 eligible participants, 1 withdrew for health reasons unrelated to study procedures (GI tract discomfort). Thus, 19 participants completed the study and experienced one session of IC and one session of sham-IC. All eligibility assessments and consent were conducted in person before randomization/ IC and sham-IC.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants (n=19) who completed one session of real IC and one session of sham IC were analyzed. Participants (n=1) who withdrew from the study or did not complete the interventions were not included in the analyses.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Change in Corticomotor Excitability, measured over Changes in corticomotor excitability will be calculated within and between sessions at baseline (Pre), immediate-post (Post), and 30-minutes-post (Post-30) one session of sham IC and real IC..

The primary endpoint is change in corticomotor excitability, measured in millivolts (mV) and summarized using the mean and standard deviation. The registry describes assessment of the primary lower-limb motor cortex using single pulse transcranial magnetic stimulation (TMS). Motor evoked potentials (MEPs) are recorded from the tibialis anterior muscle of the paretic leg. The registry states that higher values indicate more corticomotor excitability.

This measure is used to assess whether the intervention is associated with a change in motor-cortex response. It is a neurophysiological measure rather than a direct measure of walking ability or daily function. The trial’s stated rationale links brain-activity changes with motor behavior, but the primary endpoint itself is the excitability measure.

Assessments are described at baseline, immediately after a session, and 30-minutes-post, within and between the real and sham sessions. Comparing measurements across time can characterize whether excitability changes after a condition; comparing conditions can help distinguish changes associated with real conditioning from changes observed after sham conditioning. The registry record does not report the numerical means, standard deviations, changes, or a direct real-versus-sham estimate. It therefore does not establish the direction or magnitude of any observed endpoint change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary measure is continuous: corticomotor excitability is recorded in millivolts, and the registry identifies the mean and standard deviation as its summary statistics. A mean describes the central level of a set of measurements. A standard deviation describes how spread out individual measurements are around that mean. These summaries can be useful for describing an outcome, but they do not, by themselves, show the uncertainty in a comparison between conditions.

A comparison would ordinarily need an effect estimate, such as a difference in change between real and sham conditioning, together with an uncertainty measure. A confidence interval is a range of values compatible with the observed data under the statistical model and its assumptions. It indicates precision: a narrower interval represents more precision than a wider one. A p-value, when reported, summarizes how surprising the data would be under a specified null model; it does not measure the size or clinical importance of an effect. No confidence interval, p-value, or estimated real-versus-sham effect is reported in the registry record.

The crossover structure affects how measurements should be interpreted. Because each participant experiences both conditions, analyses can compare a participant with themself, accounting for stable characteristics that might otherwise differ between separate groups. The paired nature of the observations also means that the relationship between a participant’s measurements under the two conditions matters. Separate group means alone would not reveal that within-participant relationship. The registry record does not report the analysis model, the paired comparison, or whether period and carryover effects were considered.

How do the assessment times matter?

The primary outcome is measured at baseline (Pre), immediate-post (Post), and 30-minutes-post (Post-30). A change from baseline describes movement in the outcome after a session. A comparison of changes between conditions asks whether the observed movement differs between real and sham conditioning. These are not interchangeable questions: a change within one condition does not by itself show that the change differs from the comparator. Repeated measurements can also be analyzed jointly, but the choice of method should reflect the within-participant structure and the repeated observations. The specific method used is not reported in the registry record.

For a crossover comparison, treatment sequence and time period can matter. An order effect occurs when the order of conditions is associated with the outcome. A carryover effect occurs when an earlier condition continues to influence a later measurement. Randomizing the sequence can help balance order, but it does not establish that carryover is absent. The registry record describes randomized sequences but does not report a washout interval, a carryover assessment, or an adjustment for sequence or period.

What does the planning information mean?

The registry includes general sample-size planning assumptions: a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect stated as a fraction of the observed effect. The registry describes these as planning illustrations based on the observed effect, not as the trial’s own design. It also notes that such illustrations report participants per arm for 80% power for non-time-to-event outcomes. These assumptions do not constitute an observed result or observed power. No calculated planning values are reported in the record, and the planning assumptions should not be treated as evidence that the trial was designed to detect a particular effect.

Observed power is not a substitute for reporting the effect estimate and its confidence interval. Once results are available, the estimate and interval communicate the magnitude and precision more directly. Since numerical primary-outcome results are not reported, a planning illustration cannot fill that gap or indicate whether the observed comparison supports a particular conclusion.

Why does variability matter?

Continuous outcomes vary across participants. If measurements are more variable, an estimate of a mean difference is generally less precise when other aspects of the design are unchanged. The standard deviation describes variability in the measurements, while the standard error and confidence interval describe uncertainty in an estimated mean or contrast. These quantities answer different questions and should not be conflated. In a crossover study, the variability of within-participant differences may be especially relevant; marginal standard deviations alone do not reveal it.

There is no reported evidence about over-dispersion, and the endpoint is described as a continuous measure. In general, over-dispersion refers to variability greater than expected under a model. If a model fails to account for excess variability, its standard errors and intervals may be too small, leading to overstated precision. This is a general statistical consideration, not a reported feature of this trial.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint is assessed at baseline, immediate-post, and 30-minutes-post, and the trial also describes within-session and between-session comparisons. Considering multiple time points, conditions, and outcomes creates a multiplicity question: the more comparisons examined, the greater the chance of finding an apparently notable result by chance if no adjustment or prespecified hierarchy is used. A prespecified primary contrast or multiplicity strategy can clarify which result is confirmatory and how other comparisons should be interpreted.

The registry record does not report a statistical analysis plan, a multiplicity adjustment, a hierarchy among time-point comparisons, or whether analyses were prespecified. It identifies NRS for Pain as a secondary outcome and says there are 5 outcome measures, but numerical results for those outcomes are not reported in the information described. The record also does not specify how the additional motor-behavior measures were analyzed.

For the primary outcome, the record states that n=19 participants who completed both sessions were analyzed and that n=1 participant who withdrew or did not complete the interventions was not included. It does not report the reason for withdrawal or noncompletion, the timing of missing measurements, or whether any endpoint observations were missing among analyzed participants. The missing-data method, if any, is not reported in the registry record.

Excluding participants without completed interventions can affect interpretation if completion is related to outcome or tolerability. In general, complete-case results describe those with the required observed data and may not represent everyone enrolled when missingness is informative. The record does not report an intention-to-treat analysis or sensitivity analyses addressing missing data. These omissions limit assessment of how robust the reported analysis would be, and numerical outcome results are not available in the registry record to assess in any case.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The posted adverse-event figures list 0 serious adverse events for Ischemic Conditioning and 0 for Sham Ischemic Conditioning. They list other adverse events for 8 in the Ischemic Conditioning group and 0 in the Sham Ischemic Conditioning group. The record lists 19 at risk for each condition. Because this is a crossover study, the condition-specific records refer to exposures under each condition; the figures should not be added to infer a number of distinct participants.

The serious-event figures describe what is recorded, not a guarantee that no risk exists. The registry lists no serious adverse-event terms. It does not provide descriptions, severity, timing, duration, or attribution for the other adverse events, so their clinical character and relationship to conditioning cannot be judged from these counts. Nor do these figures establish whether surveillance was identical across conditions.

Adverse-event counts are descriptive safety information. They do not by themselves show that one condition caused an event or that the conditions have equivalent safety profiles. Interpretation depends on how events were defined, collected, and attributed, details not reported in the registry record. The record also identifies NRS for Pain as a secondary outcome, but numerical pain results are not reported in the information.

12. What the Result Does, and Does Not, Mean

This trial addresses a focused neurophysiological question: whether real ischemic conditioning is associated with changes in lower-limb corticomotor excitability compared with sham conditioning in individuals with stroke. Its randomized crossover design means that the planned comparison uses both conditions within participants, and the primary endpoint is measured at several time points around each session. These features make the design relevant to studying short-term responses under the two conditions.

The available registry information does not include numerical primary-outcome results. It therefore cannot establish the direction or magnitude of the observed change, whether the change differed between real and sham conditioning, or how precisely any difference was estimated. The study’s completion status and description of its objectives do not answer those questions. A missing posted result is not proof of no effect and is not proof of benefit.

The endpoint is a measure of motor-cortex excitability, not a direct measure of gait, daily activity, or long-term recovery. Even if a neurophysiological difference were reported, its interpretation would depend on the size and precision of the difference and on how it relates to motor behavior. The registry record’s stated interest in strength, motor control, and gait does not itself show that those outcomes changed.

The adverse-event figures are also limited: they describe recorded serious and other events by condition, but do not provide event descriptions or attribution. They cannot establish that a condition is free of risk or that one condition is safer. Likewise, sample-size planning assumptions are not observed treatment effects and should not be read as observed power.

The defensible conclusion is therefore about what the record documents: a completed randomized crossover study, its primary neurophysiological endpoint, its analysis population statement, and descriptive adverse-event counts. Numerical efficacy results and important analysis details are not reported in the registry record, so conclusions about treatment effects, precision, and clinical relevance remain unavailable.

13. Why This Trial Matters Statistically

This design is statistically interesting because a crossover trial can make within-participant comparisons. Each participant serves as a reference for their own response under the other condition, which can reduce the influence of stable differences between participants. That advantage depends on appropriate handling of paired measurements and on considering whether condition order or carryover affects the outcome.

The outcome also has a time dimension. Measurements at baseline, immediately after a session, and 30-minutes-post can distinguish an immediate response from a later measurement. But multiple time points raise questions about which contrast is primary and how comparisons are handled. Without a reported analysis plan, readers cannot tell how the repeated measurements and potential multiplicity were addressed.

The trial’s stated scientific aim connects a physiological measure with motor behavior after stroke. Keeping those outcomes distinct is important: a change in corticomotor excitability is not automatically a change in strength, motor control, or gait. Statistical evidence for one endpoint cannot be transferred to another without corresponding results.

Finally, the record illustrates why design descriptions and outcome data serve different purposes. The registry describes a randomized sequence and identifies an analysis population, but it does not report the primary numerical findings. Without an effect estimate and its uncertainty, the study’s central statistical comparison cannot be evaluated. Reporting those results, alongside the analysis approach and missing-data handling, would allow readers to assess magnitude, precision, and robustness rather than relying on the study rationale or completion status.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpretation is that numerical results for the primary endpoint are not reported in the registry record. Means, standard deviations, changes, between-condition estimates, confidence intervals, and p-values are not available in the information described. As a result, neither effect magnitude nor precision can be assessed.

The registry describes several assessment times and within-session and between-session comparisons, but does not report the statistical model or identify a single primary contrast across those measurements. The approach to multiple comparisons is not reported. The record also does not state whether period, sequence, or carryover effects were assessed in the crossover design, or give the interval between sessions or a washout procedure.

Masking is recorded as single, but the masked party is not reported in the registry record. The description of sham conditioning is incomplete in the registry text, which ends before the full procedure is stated. Consequently, the precise sham pressure and the degree to which the sham matched the real condition cannot be evaluated from this record.

The primary analysis population excludes the participant recorded as withdrawn or not completing interventions. The reason and timing are not reported, and no missing-data method or sensitivity analysis is described. The record does not report numerical results for the stated motor-behavior aims or for NRS for Pain. Safety information lists event counts but not event details or attribution. These reporting limitations constrain assessment of efficacy, robustness, and safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Motor and Neurophysiological Changes After Ischemic Conditioning in Individuals With Stroke — NCT05906602.
• Registry record last updated 2026-05-19; status last verified 2026-04.
• Results first posted 2026-02-23.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes NCT05906602, a completed randomized, single-masked crossover trial sponsored by University of Illinois Chicago. It lists enrollment of 20 and compares real with sham ischemic conditioning in individuals with stroke. Participants were assigned to one of two condition sequences and were intended to experience both sessions.

The primary endpoint is change in corticomotor excitability, measured in millivolts through TMS-elicited MEPs recorded from the tibialis anterior muscle of the paretic leg. Assessments are described at baseline, immediate-post, and 30-minutes-post. The primary analysis population is stated as n=19; n=1 who withdrew or did not complete interventions was not included.

The record lists 5 outcome measures and NRS for Pain as a secondary outcome. It reports adverse-event counts by condition but does not provide event descriptions. Numerical primary-outcome results and the statistical analysis details are not reported in the registry record.