Transcranial Magnetic Stimulation for Children With Tourette's Syndrome: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transcranial Magnetic Stimulation for Children With Tourette's Syndrome (NCT02356003), a na na study. The primary outcome is Yale Global Tic Severity Scale.

2. Clinical Question

The study rationale describes tics as a core symptom of Tourette syndrome and proposes targeting the supplementary motor area, a brain region identified in the record as involved in tics. The intervention is intended to inhibit activity in that region. The stated primary measure is the Yale Global Tic Severity Scale, with a four-week timeframe. A higher score on the scale indicates greater tic severity.

The registry also describes secondary interests in glutamate concentration and functional connectivity. The study aims refer to changes in GABA and glutamate and to connectivity between the supplementary motor area and primary motor cortex. The record does not provide the detailed results or analysis methods for these secondary measures. Because there is no comparison group, the primary question represented by the design is a within-group question about change, not a randomized comparison of treatment against a control condition.

3. Trial Design

This is a completed, single-group study of low-frequency repetitive transcranial magnetic stimulation for children with Tourette syndrome. The registry lists the start as 2015-05 and primary completion as 2018-12. Enrollment is recorded as 10. The study description and arm description refer to a plan for 11 children aged 7-12 years, while the primary-outcome record says recruitment stopped at 10 because the study ran out of money. These are different details in the record and should not be treated as interchangeable.

The intervention is described as stimulation targeting the supplementary motor area, delivered five times a week for three weeks. The primary outcome is the Yale Global Tic Severity Scale, with a four-week timeframe. Glutamate concentration and functional connectivity are listed as secondary outcomes. The registry identifies one intervention, low-frequency repetitive transcranial magnetic stimulation, and one group, Low Frequency rTMS.

The design is listed as single-group; allocation is NA and masking is none. No concurrent control group is described, so changes over time cannot be separated from other changes that may occur during the study period using a randomized between-group contrast. The study phase is listed as NA. The record does not report a detailed statistical analysis plan, the timing of any outcome assessments beyond the primary timeframe, or how the listed secondary outcomes were analyzed.

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

Analysis population for the primary outcome, as defined in the registry: We stopped recruitment at 10 as the study ran out of money.

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 Yale Global Tic Severity Scale, measured over Four weeks.

The primary endpoint is the Yale Global Tic Severity Scale, a measure of tic severity. The registry describes the Global Severity Score as having a range of 0- 100 and states that higher scores on the scales indicate greater tic severity. It identifies the measure as the standard measure for studies of Tourette syndrome.

The endpoint is continuous: it is recorded as a mean with standard deviation. In general, a continuous score can describe both the typical level of severity in a group and the spread of scores among participants. A change in the group mean can describe how the group’s average score differs across assessment times, while the standard deviation gives information about variation among individual scores. These are general interpretations of the measurement type, not findings from this study.

The registry gives a four-week timeframe for the primary outcome. It does not report the observed mean, standard deviation, change from baseline, or uncertainty interval for the outcome. The record therefore identifies what was intended to be measured, but does not give the numerical results needed to characterize the observed change in tic severity or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a continuous primary outcome, analyzed in terms of a mean and standard deviation. These summaries answer different questions. The mean describes the group’s average score, while the standard deviation describes how dispersed individual scores are around that average. Neither summary alone indicates how precisely the group mean or a change in the mean has been estimated. The primary results needed to apply these concepts are not reported in the registry record.

What does a confidence interval communicate?

General explanation: a confidence interval is a range of values compatible with the data and the assumptions of the analysis. It conveys uncertainty around an estimate. A narrow interval indicates greater precision than a wide interval, all else being equal. An interval around a change in a continuous score would help readers assess both the plausible size and direction of the change. The registry record does not report a confidence interval for the primary outcome, so no conclusion about the estimate’s precision can be drawn from the posted record.

Why does the single-group design matter?

General explanation: in a single-group study, measurements may be compared across time within the same group. Such a comparison describes change, but does not provide the same causal contrast as a randomized comparison against a concurrent control group. Without a control condition, it is difficult to determine how much observed change reflects the intervention rather than natural fluctuation, changes in reporting or measurement, or other influences. Here, the record identifies a single-group model and does not describe a comparison arm.

What does the mean-and-standard-deviation format leave unanswered?

A mean and standard deviation can describe the level and spread of scores at an assessment, but interpretation of a treatment-related change also depends on the analysis and the available observations. For example, a change estimate needs a defined comparison, such as a change over time, and uncertainty around that estimate. The registry does not give the primary endpoint values, the method for comparing assessments, or an estimate of uncertainty. It also does not report the number contributing data at each assessment.

How should planning illustrations be understood?

General explanation: sample-size planning calculations describe the amount of information a hypothetical study might need under specified assumptions. They are not observed outcomes and do not show whether a study has demonstrated an effect. The registry describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also says the effect to detect is a stated fraction of the observed effect. Those planning assumptions do not describe this study’s single-group design, and numerical planning results are not reported in the registry record. They should not be mistaken for the study’s design rationale or for an analysis of the enrolled participants.

What is not available for evaluating the analysis?

The record does not report the statistical test or model for the primary outcome, how repeated measurements were handled, how missing measurements were treated, or whether any adjustment was made for baseline values or other variables. It lists 0 analyses. The analysis population and any departures from the planned enrollment are not described beyond the statement that recruitment stopped at 10 because the study ran out of money. Since there is no reported primary estimate, recalculation from posted summary statistics is not possible. These gaps limit the statistical interpretation independently of the intervention’s biological rationale.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome, the Yale Global Tic Severity Scale, and two secondary outcome topics: glutamate concentration and functional connectivity. The study aims also refer to GABA and to functional connectivity between the supplementary motor area and primary motor cortex. The record does not provide the detailed outcome definitions or numerical results for those measures.

When a study examines multiple outcomes or multiple analyses, general statistical practice recognizes that the chance of at least one apparently notable result can increase if each is assessed separately without an appropriate plan. A prespecified hierarchy, adjustment, or clear distinction between primary and exploratory analyses can help readers understand how to interpret a set of findings. The registry record does not report a multiplicity strategy, a detailed statistical analysis plan, or results for the listed outcomes. No conclusion about whether multiplicity was addressed can be drawn.

The record lists 0 analyses and does not report the number of participants with outcome data at each assessment. Missing-data methods, reasons for missing measurements, analysis populations, and handling of participants who did not complete the planned intervention are not reported in the registry record. Enrollment is 10, while the intervention descriptions refer to 11 children; the registry does not explain the difference beyond stating that recruitment stopped at 10 because the study ran out of money.

These omissions matter because outcome availability and analysis choices can affect the estimate and its uncertainty. Without information about missingness and the analyzed population, readers cannot determine whether the reported enrollment corresponds to the participants included in an outcome analysis. Since primary outcome results are also absent, the record does not allow an assessment of how these issues affected the findings.

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 adverse-event record lists the Low Frequency rTMS group with 10 at risk for serious adverse events and 0 affected. It also lists 10 at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse-event terms are listed.

These figures describe what is entered in the registry for this group. They should not be expanded into a claim that no adverse events of any kind occurred: the record distinguishes serious adverse events from other adverse events, and the number affected is shown as 0 in both categories. The record does not provide event narratives, monitoring details, follow-up completeness, or a description of how adverse events were collected. Nor does it provide comparative safety data from a control group.

General explanation: an observed count of zero does not establish that an event is impossible or that the intervention has no risk. The precision of a safety estimate depends on factors including the amount of observation and the completeness of event ascertainment. The registry’s at-risk counts and event counts can be reported as recorded, but the information available does not support a broader estimate of safety or a comparison with another treatment.

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

The record shows that the study was registered as a completed, single-group investigation of low-frequency repetitive transcranial magnetic stimulation in children with Tourette syndrome. It describes stimulation of the supplementary motor area and identifies the Yale Global Tic Severity Scale as the primary measure of tic severity. The planned intervention is described as five sessions a week for three weeks, and the primary outcome timeframe is four weeks.

The registry does not report the primary outcome values or analysis results. It therefore does not show the observed direction or size of change in tic severity, or the precision of an estimate. The planned question should not be confused with a reported finding: the study objectives state hypotheses, but hypotheses are not results.

The design also limits what a within-group change could establish. With no comparator described, a change in scores would not alone distinguish an intervention effect from other influences over time. The record’s secondary-outcome listings indicate additional biological and connectivity interests, but it does not report their results or analysis details.

The serious adverse-event record lists 0 affected among 10 at risk, and the other adverse-event record likewise lists 0 affected among 10 at risk; deaths are recorded as 0. These are registry entries for the group, not a controlled safety comparison and not proof that risk is absent.

In short, the record provides useful information about the study question, intervention, design, intended measurement, enrollment, and recorded adverse-event counts. It does not provide outcome evidence with which to quantify change or draw a conclusion about the intervention’s effect.

13. Why This Trial Matters Statistically

Statistically, this study illustrates why a registered research question and a reported result are different kinds of information. The record describes a focused continuous outcome, the Yale Global Tic Severity Scale, and a single-group intervention schedule. Yet it does not report the outcome values or analyses needed to estimate change. Without those estimates, readers cannot judge either the observed magnitude or the uncertainty of the primary result.

The single-group structure is also important. A within-group pattern can describe what happened among participants observed over time, but does not supply a randomized counterfactual for what would have happened without the intervention. This distinction is central when interpreting any apparent change in a clinical measure. The record labels the design as single-group and does not describe a comparator.

The enrollment discrepancy is another reporting detail relevant to interpretation: the registry lists enrollment as 10 and says recruitment stopped at 10 because the study ran out of money, while the intervention descriptions refer to 11 children. The record does not explain the discrepancy further. This makes it especially important not to infer an analyzed sample from the planned description.

The record also demonstrates the limits of safety counts in isolation. Zero recorded events in the listed categories is informative as a registry entry, but does not provide a comparative safety estimate or establish absence of risk. In combination, these issues show why design, outcome availability, and analysis reporting are necessary alongside a study’s rationale and planned objectives.

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.

Several limitations of interpretation follow directly from the registry record. The study is single-group, with no comparator described, allocation listed as NA, and masking listed as none. This means the record does not describe a randomized, masked comparison that could separate intervention-associated change from other changes over time.

The central limitation is that the primary outcome results are not reported in the registry record. The mean and standard deviation, a change estimate, an uncertainty interval, and a statistical test result are absent. Although the primary outcome has a four-week timeframe, the record does not provide enough detail to establish the assessment schedule or the timing of measurements relative to the intervention beyond the listed timeframe.

Enrollment is 10, and the record says recruitment stopped at 10 because the study ran out of money. The intervention descriptions refer to 11 children. The registry does not explain this difference or state how many participants contributed data to the primary endpoint. It also does not report missing-data handling, analysis populations, or reasons for any missing outcome data.

The record lists glutamate concentration and functional connectivity as secondary outcomes, but detailed definitions, analyses, and results are not reported. It does not report a multiplicity plan or a detailed statistical analysis plan. The serious and other adverse-event counts are listed, but event-collection methods, follow-up details, and comparative safety information are not reported. These limitations constrain what can be concluded from the registry record; they do not establish what results might have been observed but are not reported.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Transcranial Magnetic Stimulation for Children With Tourette's Syndrome — NCT02356003.
• Registry record last updated 2020-10-29; status last verified 2020-10.
• Results first posted 2020-04-13.
• 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 describes a completed single-group study of low-frequency repetitive transcranial magnetic stimulation targeting the supplementary motor area in children with Tourette syndrome. Enrollment is 10; the primary-outcome text says recruitment stopped at 10 because the study ran out of money, while the intervention descriptions refer to 11 children aged 7-12 years. The primary measure is the Yale Global Tic Severity Scale, with a four-week timeframe. Glutamate concentration and functional connectivity are listed as secondary outcomes.

The registry lists the study as completed, with a start of 2015-05 and primary completion of 2018-12. It does not report primary or secondary outcome results, a detailed analysis plan, or missing-data methods. Serious adverse events and other adverse events are each recorded as 0 affected among 10 at risk, with 0 deaths. These entries do not provide a controlled comparison.