Improving Motor Function After Spinal Cord Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Improving Motor Function After Spinal Cord Injury (NCT01915095), a randomized na study. The primary outcome is Physiology Measurements Before and After rTMS/Sham rTMS Protocol- Changes in Amplitude of Motor Evoked Potential (MEP) From TMS.

2. Clinical Question

The study aimed to examine nervous-system pathways involved in movement and to investigate movement recovery through non-invasive brain stimulation and motor training. Its registered primary outcome is a physiological measure: change in MEP amplitude, recorded in millivolts. The descriptions distinguish wrist flexion from wrist extension, study visits or stimulation conditions, and participants with spinal cord injury from controls. Separate descriptions cover training combined with rTMS or sham rTMS.

This is therefore a set of related physiology questions rather than one simple comparison between two groups. The registry identifies a randomized, single-masked crossover design, but does not report the exact sequence of conditions, the identity of the masked party, or a complete analysis plan. The clinical question should be read in that context: the record describes what was measured, but does not give numerical estimates that would establish the magnitude or precision of any change.

3. Trial Design

The study, registered as NCT01915095, is titled “Improving Motor Function After Spinal Cord Injury”; its official title is “Enhancement of Hand Motor Function After Cervical Spinal Cord Injury.” It is listed as completed, with enrollment of 42. The recorded start date is 2017-09-01 and the primary completion date is 2019-09-01. The phase is listed as NA, and the sponsor is the VA Office of Research and Development.

The registry describes the study as randomized, single-masked, and crossover. In a crossover study, participants can take part in more than one condition, so measurements may be made within the same participant under different conditions. The record specifically states that participants with spinal cord injury and controls participated in both rTMS and sham rTMS sessions for the described wrist-movement protocols. It also describes visits for rTMS, sham rTMS, and sham rTMS over a control brain area. The exact order of conditions, masking target, and any washout procedure are not reported in the registry record.

Study activities included precision-grip tasks paired with wrist flexion or extension, stimulation during movement, and motor training involving precision grips or foot movement. The registry separately describes training with rTMS and training with sham rTMS. These descriptions indicate several task and visit contexts; they should not be collapsed into one uniform treatment comparison.

The registry says the number of participants differs because the study visits differ across groups. The safety record also lists different numbers at risk for its distinct groups. Those group counts do not establish the number contributing to each primary-outcome measurement. Detailed eligibility criteria, participant characteristics, allocation sequence, and the protocol’s rationale for the enrollment target are not reported in the registry record.

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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The number differs due to different study visits in each arm

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 8 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Physiology Measurements Before and After rTMS/Sham rTMS Protocol- Changes in Amplitude of Motor Evoked Potential (MEP) From TMS, measured over Post rTMS, Sham rTMS, and Sham rTMS over control brain for all sessions at minute 0, 10, 30, and 60.

The primary endpoint concerns changes in the amplitude of motor-evoked potentials, or MEPs, measured in millivolts. An MEP is a recorded muscle response following transcranial magnetic stimulation. In this study, the registry describes MEP measurement in the context of wrist flexion or extension with precision grip, as well as stimulation visits and training conditions.

The registry identifies the outcome summary as a mean with standard deviation. Measurements are described before and after rTMS or sham rTMS at minute 0, 10, 30, and 60. For the training conditions, the record describes measurements at baseline, after 5 training sessions, and after all training sessions. These timing and task distinctions matter because a physiological response can vary with the movement being performed, the study visit, and when measurement occurs.

MEP amplitude is used to assess a physiological response associated with motor pathways. It is not itself a direct measure of everyday hand function. The registry lists the Jebsen Taylor Hand Function Test as a secondary outcome, but reports no numerical primary-outcome results or secondary-outcome results in the record described. The endpoint’s intended measurement is clear; its observed magnitude, variability, and precision are not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the endpoint summarize?

The registry describes a continuous outcome: MEP amplitude in millivolts, summarized as a mean with standard deviation. A continuous measure can take a range of values rather than belonging to a set of categories. The mean gives a central summary, and the standard deviation describes dispersion among measurements. These summaries answer different questions: a similar average can accompany either tightly clustered or widely dispersed observations.

The record refers to changes measured before and after stimulation, but does not report the numerical change summaries. It also does not give confidence intervals or hypothesis-test results. In general, a confidence interval expresses uncertainty around an estimate; it is not a guarantee that the true value lies within the interval. Without an estimate and its interval, the magnitude and precision of the endpoint cannot be evaluated from the registry record.

Why do the measurement contexts matter?

Measurements are described separately for wrist flexion and wrist extension with precision grip. The record also distinguishes rTMS and sham sessions, participants with spinal cord injury and controls, and measurements at minute 0, 10, 30, and 60. A separate description covers measurements at baseline, after 5 training sessions, and after all training sessions. These are not interchangeable settings. In general, reporting condition-specific results helps readers understand which task, visit, and measurement time an estimate represents.

Repeated measurements from the same participant are related. In general, an analysis that accounts for that within-participant relationship can differ from one that treats each measurement as independent. The registry identifies a crossover design, but does not report the model used to analyze repeated observations, whether baseline values were adjusted for, or how study period was handled.

What does crossover imply for interpretation?

In general, crossover designs compare conditions experienced by the same participant, which can reduce the effect of stable differences between participants. They also require attention to the order of conditions, changes over time, and the possibility that an earlier condition could affect a later one. The record says that participants took part in both rTMS and sham rTMS sessions for specified protocols. It does not report the order of those sessions, a washout interval, or how possible carryover was assessed. Those omissions prevent a fuller assessment of the crossover analysis.

Randomization is recorded, but the registry does not describe the allocation sequence or explain how randomization applied across all the different activities. Single masking is also recorded; the identity of the masked party is not reported in the registry record. These design labels describe features of the study, but they do not establish how successfully masking was maintained or how the allocation was implemented.

How should multiple measurements be considered?

The primary-outcome description spans multiple movements, conditions, participant characteristics, and time points. In general, examining many outcomes or time points creates a multiplicity issue: the more comparisons considered, the greater the chance of a chance finding if each is interpreted separately. A prespecified primary comparison and an explicit multiplicity strategy can help clarify interpretation. The registry does not report a multiplicity adjustment or identify a single contrast among these contexts as the sole primary comparison.

Different scientific questions may justify distinct comparisons, but results should then be interpreted in light of that plan. The registry record does not report a statistical analysis plan, planned contrasts, or whether any interim analyses were conducted. Those details should not be inferred from the number of measurement occasions or from the study’s completed status.

What can be concluded from the analysis record?

No analysis results are listed for the primary endpoint. The registry gives no numerical means, standard deviations, sample sizes for individual comparisons, effect estimates, confidence intervals, or p-values. Consequently, statistical significance, precision, and the direction or magnitude of the measured changes cannot be assessed from the registry record. The listed enrollment of 42 is a study-level figure, not a substitute for condition-specific analysis counts.

In general, a well-interpreted result needs both an estimate and information about its uncertainty, alongside a clear account of who was analyzed and how repeated measures were handled. Those elements are not reported in the registry record. The measurement descriptions remain useful for understanding the planned physiological questions, but they do not support a quantitative conclusion about the endpoint.

10. Multiplicity, Missing Data and Analysis Populations

The primary-outcome description includes several movements, stimulation conditions, participant characteristics, and measurement times. The training protocols add a distinct schedule of baseline, post-training, and post-all-training measurements. When multiple comparisons are examined, chance findings can arise even when each test uses a conventional significance threshold. In general, investigators may address this through prespecified primary contrasts, multiplicity adjustments, or a clear distinction between confirmatory and exploratory analyses. The registry does not report which approach, if any, was used.

The record does not provide an analysis plan, identify a single contrast that represents the complete primary question, or report interim analyses. These matters are not reported in the registry record; their absence from the record does not establish what was or was not done outside it.

Missing-data methods and analysis populations are also not reported in the registry record. The record notes that participant numbers differ across study visits and groups, but does not give endpoint-specific counts, reasons for missing measurements, or the population included in each analysis. It is therefore not possible to determine whether all randomized participants contributed to each comparison or how incomplete observations were handled.

For a crossover study, the number contributing data may also depend on completion of the relevant conditions. In general, exclusions or incomplete periods can affect which within-participant comparisons are available. The registry does not report completion by condition or a method for handling incomplete crossover data. Numerical estimates and their interpretation would require those analysis details as well as the endpoint results.

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.

The safety record lists five distinct groups. For “Wrist Flexion and Precision Grip + rTMS and Sham rTMS,” 10 participants were at risk; for “Wrist Extension and Precision Grip + rTMS and Sham rTMS,” 10 were at risk. For “rTMS/Sham rTMS/Sham rTMS Over Control Brain Area,” 5 were at risk. For “Training + rTMS,” 4 were at risk, and for “Training + Sham rTMS,” 3 were at risk.

For each listed group, the registry records 0 participants affected by serious adverse events, 0 affected by other adverse events, and 0 deaths. No serious adverse-event terms are listed. The counts should be read within their respective groups; the group sizes differ, and the registry does not describe a single safety population covering all activities.

These are reported counts, not proof that no adverse events occurred outside the registry’s recorded categories, periods, or groups. The record does not give event-level narratives, exposure duration, or a method for comparing safety between conditions. The figures therefore describe what the registry reports, without establishing comparative safety or allowing broader conclusions about risk.

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

The registry record establishes that this was a completed randomized, single-masked crossover study with a planned focus on MEP amplitude and motor tasks. It identifies stimulation and training conditions, describes measurement timing, and lists a secondary hand-function outcome. This information helps define the scientific question and the kinds of data the study sought to collect.

It does not establish the size, direction, or precision of any primary-outcome change. Numerical results for MEP amplitude, variability, between-condition estimates, and uncertainty are not reported in the registry record. Therefore, the record cannot show whether one condition had a larger measured response than another or how consistent any response was among participants.

The endpoint is physiological, not a direct report of hand function in daily life. The registry lists the Jebsen Taylor Hand Function Test as a secondary outcome, but provides no result for it in the information recorded. It would not be appropriate to infer functional consequences from a physiological measure without relevant outcome results.

The listed enrollment of 42 does not tell readers how many participants contributed to each task, condition, or time point. Nor does the record specify how repeated measurements, incomplete data, or multiple comparisons were analyzed. Those details affect how estimates should be interpreted, but are not reported in the registry record.

Finally, zero recorded adverse events in the listed groups is a description of the registry’s safety counts, not a general assurance about safety. The most supportable reading is that the record documents the study design and measurement framework while leaving the primary quantitative findings and important analysis details unavailable.

13. Why This Trial Matters Statistically

This study illustrates a statistical challenge common in physiology research: the primary measure is collected repeatedly across tasks, conditions, and time points. That structure can capture how responses vary by context, but it also means that a concise interpretation depends on clearly identifying the comparison being estimated. A single overall statement may obscure differences among wrist movements, visits, or training stages.

The crossover design makes within-participant comparisons relevant. In general, such designs can distinguish condition differences from stable participant-to-participant variation, while also requiring attention to sequence, period, and carryover. The registry identifies the design but does not report the analysis used to address those features. This makes the distinction between a study’s design label and its reported statistical evidence particularly important.

The record also demonstrates why outcome definitions alone are not enough for evaluating evidence. It names MEP amplitude as the primary measure and specifies a mean and standard deviation, yet reports no numerical summaries or inferential results. Without estimates and uncertainty, readers cannot assess effect magnitude, variability, or precision. A completed study status does not fill that gap.

Finally, the differences in participant counts across visits underline the need for analysis-specific denominators and transparent reporting of missing observations. The registry notes that the number differs across study visits, but does not report endpoint-specific analysis counts or missing-data methods. Those details are necessary to connect the design to the evidence and to judge how broadly any result applies.

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 most important limitation for statistical interpretation is that the registry does not report numerical primary-outcome results. Means, standard deviations, effect estimates, confidence intervals, and p-values are not available in the record. As a result, neither the size nor the precision of MEP changes can be evaluated.

The primary outcome is described across multiple movements, stimulation conditions, participant characteristics, and time points, while training has a separate schedule. The record does not identify the exact primary contrast among these measurements or report how multiplicity was handled. It also does not describe the statistical model for repeated observations or how the crossover design’s period and possible carryover effects were addressed.

Participant counts vary across study visits, but endpoint-specific analysis populations, completion counts, and reasons for missing data are not reported in the registry record. The allocation sequence, masking target, and session order are also not described. These omissions limit assessment of the analysis and the potential for bias; they do not establish that the procedures were inadequate.

The record lists the Jebsen Taylor Hand Function Test as a secondary outcome but does not report its results. It also does not provide participant characteristics or detailed eligibility information in the registry record recorded. Consequently, the record supports description of the study structure, but not a full assessment of the observed physiological or functional findings or of the population represented by those findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Improving Motor Function After Spinal Cord Injury — NCT01915095.
• Registry record last updated 2021-06-11; status last verified 2021-05.
• Results first posted 2020-11-04.
• 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

NCT01915095 is a completed, randomized, single-masked crossover study titled “Improving Motor Function After Spinal Cord Injury.” The registry lists enrollment of 42, a start date of 2017-09-01, a primary completion date of 2019-09-01, and the VA Office of Research and Development as sponsor. The phase is listed as NA.

The primary outcome is change in MEP amplitude, measured in millivolts and summarized as a mean with standard deviation. The registry describes wrist-movement and precision-grip protocols, rTMS and sham conditions, and training conditions. The Jebsen Taylor Hand Function Test is listed as a secondary outcome.

Numerical primary and secondary outcome results, analysis estimates, and key analysis details are not reported in the registry record. The listed safety groups each record 0 serious adverse events, 0 other adverse events, and 0 deaths.