This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Investigating Motor Cortex Processing for Pain Modulation (NCT01404039), a randomized phase 1 study. The primary outcome is Change in Motor Cortex Excitability MEP Amplitude.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01404039 |
| Phase | Phase 1 |
| Condition | Motor Activity |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 115 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Spaulding Rehabilitation Hospital |
| Results posted | Yes |
2. Clinical Question
Population
The study is described as an exploratory investigation in healthy male subjects. The registry record does not report a fuller eligibility description or detailed participant characteristics. The overall enrollment is 115.
Intervention
The interventions include motor learning, somatosensory learning, an observational task, mental imagery, and transcranial direct current stimulation. The study description frames these as different ways to examine pain perception and motor-cortex excitability.
Comparator
Comparator activities vary by intervention: examples include simple hand movements, no somatosensory input, observation of geometric shapes, simple mental calculation, and sham stimulation. The registry describes both crossover and parallel arrangements, rather than one common comparator for the entire study.
Primary question
The primary outcome concerns change in motor-cortex excitability, measured as the change in motor-evoked-potential amplitude before and after an intervention. The registry also mentions pain perception as an area of interest, but a separate pain-perception outcome is not reported in the registry record.
The clinical question is therefore exploratory and covers several distinct intervention comparisons, rather than a single treatment-versus-control contrast. For motor learning, the described comparison involves visual feedback, no visual feedback, and a control task, with measurements repeated within participants across sessions. For somatosensory learning, observational tasks, and mental imagery, the descriptions instead identify groups receiving different tasks or controls. The tDCS intervention is also listed, with real and sham sessions in counterbalanced randomized order.
These differences matter when interpreting the question. A change in MEP amplitude is a physiological measure of motor-cortex excitability; it is not itself a direct measure of pain perception. Although the study summary names both pain perception and excitability, the registry lists only one outcome measure, the MEP-amplitude change. Whether pain perception was measured as a separate endpoint, and how it was assessed, is not reported in the registry record. The record also does not give a single prespecified comparison that combines all intervention types into one question.
3. Trial Design
The study is identified as phase 1, randomized, double-masked, and parallel in its overall design description. Enrollment is recorded as 115, and the study status is terminated. The study began in 2010-09, with primary completion recorded in 2014-04. The sponsor is Spaulding Rehabilitation Hospital.
The overall design label does not fully describe every intervention group. Motor learning is explicitly described as a crossover design: participants experience motor-learning sessions with visual feedback, without visual feedback, and a control task. The primary-outcome description records 15 participants enrolled in the motor-learning groupings and says one participant dropped out after the first intervention, leaving 14 participants with available data. The somatosensory-learning groups are described as parallel, with sighted, blind, activation, and control groups. The observational-task and mental-imagery comparisons are also described as parallel. The tDCS description specifies real and sham sessions in counterbalanced randomized order.
Thus, the study contains several related experiments or intervention comparisons within one registry record. Some descriptions anticipate 15 participants per arm, while the somatosensory-learning descriptions anticipate 10 participants per arm. These are arm-level descriptions, not outcome results. They should not be read as a complete account of actual enrollment in every group: detailed final group counts, apart from the motor-learning information, are not reported in the registry record.
The registry does not explain why the study was terminated, whether all planned intervention groups were completed, or how the overall enrollment relates to each component. The exact masking procedures, randomization implementation, allocation concealment, and protocol-specific analysis plan are not reported in the registry record. The broad design labels therefore establish the general framework, but they do not resolve all design details relevant to interpreting individual comparisons.
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.
Only the first 6 of 13 groups are shown.
Overall Study
| Stage | Motor Learning - MLsighted/MLblind/MLcontrol | Motor Learning (ML) MLblind/MLcontrol/MLsighted | Motor Learning (ML) MLcontrol Group/MLsighted/MLblind | Somatosensory Learning (SL Sighted) | Somatosensory Learning (SL Blind) | Somatosensory Activation (S Activation) |
|---|---|---|---|---|---|---|
| STARTED | 5 | 5 | 5 | 10 | 10 | 10 |
| COMPLETED | 4 | 5 | 5 | 10 | 10 | 10 |
| NOT COMPLETED | 1 | 0 | 0 | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: ML: crossover design - ML sighted/MLblind/ML control. 15 patients were enrolled, but one participant dropped-out after the first intervention - participants with available data: 14. SL: parallel design - SL sighted/SLblind/Sactivation/SLcontrol. OT: parallel design - OT real and OT control. MI: parallel design - MI real and MI control.
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.
Only the first 6 of 10 groups are shown.
| Characteristic | Unit | Motor Learning (ML) | Somatosensory Learning (SL Sighted) | Somatosensory Learning (SL Blind) | Somatosensory Activation (S Activation) | Somatosensory Learning (SL) Control Group | Observational Task (OT) - Real |
|---|---|---|---|---|---|---|---|
| Participants analysed | 15 | 10 | 10 | 10 | 10 | 15 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 15 | 10 | 10 | 10 | 10 | 15 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 15 | 10 | 10 | 10 | 10 | 15 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Motor Cortex Excitability MEP Amplitude, measured over after each intervention.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | microV |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in motor-cortex excitability, measured by the change in motor-evoked-potential amplitude. The unit is microV, the summary parameter is the mean, and the stated dispersion measure is the standard deviation. The assessment is described as occurring after each intervention, with MEP measurements taken before and after the intervention session or sessions.
MEP amplitude is used in this study as a physiological indicator of motor-cortex excitability. In general, a before-and-after measure can describe how the recorded signal changes across an intervention session. This outcome is distinct from a direct report of pain: the registry summary mentions pain perception as an area of interest, but the listed primary endpoint is the MEP-amplitude change. A separately defined pain measure is not reported in the registry record.
The measurement schedule differs by intervention. Motor learning is described as repeated measurement within the same participant across crossover sessions. Somatosensory learning, observational tasks, and mental imagery are described as parallel-group interventions with one session per group. Those distinctions affect what a comparison means: within-participant changes and between-group differences depend on different sources of information and different assumptions.
The endpoint description does not include a numerical effect estimate, a measure of uncertainty, or a statistical test result. Those results are not reported in the registry record. The registry also does not report further details about MEP acquisition, processing, aggregation across measurements, or the precise statistical definition of change.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes the purpose and design of an exploratory study, but it does not report analyzed primary-outcome results. There is no posted mean change in MEP amplitude, standard deviation by intervention group, comparison estimate, confidence interval, or p-value. Consequently, the registry record does not establish the direction or magnitude of any observed change, or how precisely such a change was estimated.
This absence of outcome estimates limits what can be concluded statistically. A study objective is not evidence that an effect was observed. Likewise, listing interventions and planned comparisons does not establish that every intervention was completed or that each comparison was analyzed. The record lists one outcome measure and zero analyses. The reason analyses are not listed is not reported in the registry record.
The total enrollment of 115 describes the overall study enrollment, not the number contributing data to every particular comparison. The motor-learning outcome description states that 15 participants were enrolled and one dropped out after the first intervention, with 14 participants having available data. Complete final sample counts for the other intervention groups are not reported in the registry record. The anticipated arm sizes in the intervention descriptions should not be treated as observed analysis counts.
The record's overall label of randomized, double-masked, and parallel should be read alongside its more specific design descriptions. Motor learning and tDCS involve repeated sessions within participants, whereas other listed components are described as parallel groups. The registry does not report enough detail to determine how randomization and masking were implemented for each component, or whether the overall labels apply uniformly across them.
No inference about pain perception can be drawn from the listed primary outcome alone. The study summary names pain perception, but no separate pain outcome or corresponding results are reported in the registry record. Similarly, a physiological measure of excitability should not be treated as a direct measure of a participant's pain experience.
The terminated status is a registry status, not an explanation of why the study ended or an indication of the results. The reason for termination and whether it affected completion of planned analyses are not reported in the registry record. Overall, the available record supports a description of the study's exploratory aims, intervention structure, and stated outcome, but not an estimate of intervention effects.
9. Statistical Methods Explained
For a continuous endpoint such as MEP-amplitude change, a mean describes the average recorded value in a group or condition, while a standard deviation describes how dispersed individual values are around that average. These are general statistical concepts. The registry identifies the mean and standard deviation as the endpoint's summary measures, but does not post the corresponding outcome values.
A comparison estimate would quantify the contrast between intervention conditions or groups. A confidence interval, if reported, would express the range of values reasonably compatible with the observed data under the analysis assumptions. A narrower interval generally indicates greater precision, while a wider interval indicates more uncertainty. No comparison estimate or confidence interval is reported in the registry record, so the precision of any intervention contrast cannot be assessed from this record.
The study includes both crossover and parallel-group arrangements. In general, a crossover design measures the same participant under multiple conditions. This can help account for stable differences between participants because each person contributes observations under more than one condition. It also requires attention to session order, possible carryover, and the dependence among repeated observations. The motor-learning description identifies a crossover design, and the tDCS description gives real and sham sessions in counterbalanced randomized order. The registry does not report the statistical methods used to account for repeated observations, period effects, or carryover.
In a parallel-group design, different participants receive different conditions. A comparison then depends on the groups being comparable in relevant ways, including through the randomization process. The somatosensory-learning, observational-task, and mental-imagery descriptions identify parallel arrangements. The registry does not report the method used to generate allocation sequences or conceal assignments. It also does not report a detailed analysis plan specifying adjustment for baseline measurements or other covariates.
The primary outcome uses a before-and-after measurement. In general, an analysis might compare individual changes, compare post-intervention values while accounting for baseline, or model all repeated measurements. These approaches can answer related but non-identical questions, and their assumptions differ. The registry states that MEP is measured before and after intervention, but the exact analysis of those measurements is not reported in the registry record.
Multiplicity is a general concern when a study examines several interventions, conditions, or outcomes. Testing many contrasts can increase the chance that at least one result appears unusual by chance if no adjustment or hierarchy is specified. Here, multiple intervention types and several arm comparisons are described. The registry does not report a planned hierarchy of comparisons, a multiplicity adjustment, or whether particular comparisons were designated as primary beyond the single listed outcome measure.
For continuous outcomes, statistical uncertainty depends on factors including the observed variability, the number of participants contributing data, and the analysis structure. The overall enrollment alone is not enough to determine precision for each contrast. In this record, only the motor-learning description gives a count of participants with available data, and group-specific analyzed counts for the other components are not reported in the registry record.
The registry includes planning assumptions for a sample-size illustration: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These are assumptions for planning illustrations, not evidence of the trial's original design justification or statistical plan. Sample-size illustrations are planning scenarios; they are not observed power. Because no observed effect estimates are posted, the record does not allow readers to judge the basis or practical relevance of such illustrations. The trial's own sample-size justification is not reported in the registry record.
Over-dispersion is a general issue when observed variation exceeds what a chosen statistical model expects. For a continuous endpoint, unexplained variability can make estimates less precise than a model anticipates; for other outcome types, it can also invalidate standard errors if not addressed. The registry does not report an analysis model or diagnostics, so there is no basis to assess whether over-dispersion was relevant or how it was handled in this study.
Randomization can reduce systematic differences between groups on average, but it does not guarantee balance in a study of any particular size, and it does not address missing outcomes after allocation. Double masking can reduce some forms of bias when participants or assessors are unaware of assignments, but the record does not specify who was masked or how masking was maintained across behavioral tasks and stimulation conditions. These are general considerations; implementation details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The study describes multiple intervention families and several distinct contrasts, while listing one primary outcome measure. A single listed endpoint does not by itself explain how multiple comparisons were prioritized. The registry does not report a testing hierarchy, a multiplicity adjustment, or a prespecified strategy for interpreting results across the intervention arms. It also lists zero analyses, so there are no posted analysis results from which to assess how many comparisons were actually performed.
Missing-data information is limited. The motor-learning outcome description states that 15 participants were enrolled and one dropped out after the first intervention; 14 participants had available data. The reason for that dropout and the handling of the participant's partial observations are not reported in the registry record. Complete outcome-specific missingness information for the other intervention groups is also not reported in the registry record.
The record does not state whether analyses followed an intention-to-treat principle, used only participants with complete measurements, or used another analysis population. The specific population included in each analysis is not reported in the registry record. The overall enrollment should therefore not be treated as the denominator for every outcome comparison.
In general, missing outcomes can affect both the amount of information available and the interpretation of results, particularly if the reasons data are missing are related to intervention or outcome. The record does not provide enough detail to evaluate those possibilities. It also does not report imputation methods, sensitivity analyses, or rules for handling incomplete crossover sessions. Without these details and without posted outcome analyses, the impact of missing data and multiplicity cannot be assessed.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Motor Learning (ML) Sighted | 0 | 15 | 0.0% |
| Motor Learning (ML) Blind | 0 | 15 | 0.0% |
| Motor Learning (ML) Control | 0 | 15 | 0.0% |
| Somatosensory Learning (SL) Sighted | 0 | 10 | 0.0% |
| Somatosensory Learning (SL) Blind | 0 | 10 | 0.0% |
| Somatosensory Activation (SA) | 0 | 10 | 0.0% |
| Somatosensory Learning (SL) Control | 0 | 10 | 0.0% |
| Observational Task (OT) - Real | 0 | 15 | 0.0% |
| Observational Task (OT) - Control | 0 | 15 | 0.0% |
| Mental Imagery (MI) - Real | 0 | 15 | 0.0% |
| Mental Imagery (MI) - Control | 0 | 15 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Motor Learning (ML) Sighted | 0 of 15 |
| Motor Learning (ML) Blind | 0 of 15 |
| Motor Learning (ML) Control | 0 of 15 |
| Somatosensory Learning (SL) Sighted | 0 of 10 |
| Somatosensory Learning (SL) Blind | 0 of 10 |
| Somatosensory Activation (SA) | 0 of 10 |
The registry lists serious adverse events and other adverse events for the intervention groups shown. For every listed group, the reported number affected is 0 for serious adverse events and 0 for other adverse events. The listed numbers at risk vary by group, as recorded in the safety information. These counts describe what the registry reports; they do not supply additional information about event definitions, collection methods, or the observation period.
Deaths are recorded as null rather than as a numerical zero. A null entry should not be interpreted as confirmation that no deaths occurred; the death count is not reported in the registry record. The registry also lists no top serious adverse-event terms.
In general, an absence of reported events is not the same as proof that an intervention has no risk. The meaning of zero counts depends on how events were solicited, how long participants were followed, what events qualified for reporting, and how complete reporting was. Those details are not reported in the registry record. The record's terminated status does not explain whether safety follow-up was completed. These safety counts should therefore be read narrowly as the posted adverse-event figures, not as a comprehensive assessment of safety.
12. What the Result Does, and Does Not, Mean
The record establishes that investigators planned an exploratory study of several interventions in healthy male subjects, with a primary physiological endpoint based on change in MEP amplitude. It also documents a mix of crossover and parallel components, an overall enrollment of 115, and a terminated status. The motor-learning description reports 14 participants with available data after one dropout from 15 enrolled.
The registry does not post the primary outcome estimates or analyses. It therefore does not show how MEP amplitude changed, whether groups or conditions differed, or the uncertainty around any estimated contrast. No conclusion about the size, direction, statistical evidence, or precision of an intervention effect can be drawn from the outcome information in this record.
The study summary refers to pain perception, but the listed primary endpoint is motor-cortex excitability. A change in MEP amplitude would be a physiological finding, not by itself proof of a change in pain perception. A separate pain outcome and its results are not reported in the registry record.
The record also does not establish why the trial was terminated, whether every planned group completed its intervention, or whether all intended data were analyzed. The listed adverse-event counts are limited to the registry entries and do not substitute for detailed safety reporting. Overall, the record documents an exploratory research question and broad methods, but lacks the results needed to evaluate what the study found.
13. Why This Trial Matters Statistically
This study is statistically notable for combining several intervention types and design structures under one registry record. Motor learning is described as a crossover comparison, while somatosensory learning, observational tasks, and mental imagery are described as parallel-group comparisons. The tDCS description also involves real and sham sessions within participants. Those structures require different approaches to analysis and interpretation; a single overall design label does not capture all of them.
The endpoint also highlights the distinction between a physiological measure and a patient-relevant experience. MEP-amplitude change is the listed primary measure of motor-cortex excitability, while the study summary also mentions pain perception. Keeping those constructs separate is important: evidence about one measure cannot automatically be interpreted as evidence about the other.
The record is also a useful example of why enrollment totals and arm descriptions should not be mistaken for analysis results. Overall enrollment is recorded, and the motor-learning description includes a dropout and an available-data count, but group-specific analyzed counts and endpoint estimates are not posted. Without those, readers cannot assess precision or compare interventions.
Finally, the absence of listed analyses and outcome estimates places a clear boundary on interpretation. Study aims, design labels, and safety counts can describe what was planned or recorded, but cannot establish the direction or strength of an intervention effect. The registry record makes those distinctions especially important for an exploratory study with multiple comparisons and incomplete reporting of analysis details.
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 principal limitation for interpretation is that the registry record contains no analyzed primary-outcome estimates. The mean changes, standard deviations, between-condition contrasts, confidence intervals, and statistical test results are not reported in the registry record. The record lists zero analyses, leaving no results with which to assess the size or precision of the measured effects.
The outcome description names motor-cortex excitability but the study summary also refers to pain perception. A separate pain outcome, its measurement method, and any results for it are not reported in the registry record. The relationship between the stated exploratory aims and the single listed outcome is therefore not fully specified.
Several design details remain unclear. The record gives an overall randomized, double-masked, parallel description while also describing crossover components and multiple parallel comparisons. It does not report how masking was implemented for each intervention, how randomization was performed, or how repeated measures and crossover sessions were analyzed. The registry does not report the planned comparison hierarchy or a method for addressing multiplicity.
Information about participants and outcome availability is also incomplete. The motor-learning description records one dropout and 14 participants with available data, but the reason for the dropout and handling of incomplete observations are not stated. Final analysis counts for other groups, detailed eligibility criteria, and the analysis population are not reported in the registry record. The overall enrollment cannot resolve those gaps.
The registry marks the study terminated but does not report the reason or whether all planned components and follow-up were completed. Safety counts are posted, but event definitions and observation periods are not reported in the registry record. These omissions limit both effectiveness and safety interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Investigating Motor Cortex Processing for Pain Modulation — NCT01404039.
- Registry record last updated 2020-04-24; status last verified 2020-04.
- Results first posted 2017-03-16.
- 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.
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18. Record Summary
This is a phase 1 randomized study with an overall double-masked, parallel designation and enrollment of 115. It is described as an exploratory investigation of motor learning, somatosensory learning, observational tasks, mental imagery, and tDCS in healthy male subjects. The record identifies both crossover and parallel components and lists change in MEP amplitude as the primary outcome.
The study status is terminated. The motor-learning description reports 15 enrolled, one dropout after the first intervention, and 14 participants with available data. The registry lists zero serious and other adverse events in each displayed group; deaths are not reported as a numerical count.
No primary-outcome estimates or analyses are reported in the registry record. The reason for termination, detailed analysis methods, and results for pain perception are also not reported in the registry record. The available information describes the study's aims and broad structure but does not support conclusions about intervention effects.