Sphenopalatine Ganglion Nerve Block vs. Elavil for Treatment of Transformed Migraines: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Sphenopalatine Ganglion Nerve Block vs. Elavil for Treatment of Transformed Migraines (NCT02090998), a randomized phase 4 study. The primary outcome is Number of Daily Headaches.

2. Clinical Question

The registry describes a randomized comparison intended to assess safety and efficacy, and the brief summary states that the researchers expected a difference in outcomes. That stated expectation is a rationale for the comparison, not evidence that a difference was demonstrated. The record does not provide a posted estimate of the between-arm effect or its uncertainty.

The registry lists an enrollment of 10. The posted primary-outcome summaries include 2 participants in the Amitriptyline / Elavil arm and 8 in the SPG nerve block arm. Those arm counts are important context for reading the results, especially because the comparison has no reported inferential analysis. The registry record does not explain the allocation imbalance or report a target enrollment.

3. Trial Design

This was a Phase 4, randomized, open-label, parallel-group study sponsored by Rutgers, The State University of New Jersey. The registry lists the start as 2014-05, primary completion as 2020-03-16, and overall status as terminated. Enrollment is listed as 10. The reason for termination and any planned enrollment target are not reported in the registry record.

Participants were assigned to one of two treatment groups. The SPG procedure arm used 5% lidocaine gel, with the arm description specifying weekly administration for 4 weeks. The comparator was Amitriptyline / Elavil, described as 10 mg once a day for one week followed by 20 mg once a day for three weeks. The record describes the interventions as intended to address headaches over the period investigated.

Masking is listed as none. Participants and study personnel therefore were not described as masked to the assigned treatment. The registry does not report whether outcome assessment used any separate masking process. With a self-reported or assessed symptom measure, awareness of the assigned approach can matter to how outcomes are recorded, although the record does not describe the measurement procedures in enough detail to assess that issue.

The primary outcome was the number of daily headaches, measured from Study Day 1 through Study Day 30. The results are reported as means with standard deviations. The posted outcome counts are 2 for Amitriptyline / Elavil and 8 for SPG nerve block. The record does not explain whether these are all randomized participants, all participants with available endpoint data, or another analysis population.

Although the study is randomized, the posted record does not include a statistical analysis comparing the arms. It lists 2 outcome measures and no posted secondary outcome results. Details such as sequence generation, allocation concealment, analysis population definitions, and handling of missing outcome values 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

Analysis population for the primary outcome, as defined in the registry: participants from 18-82 who had failed conventional headache therapies

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 Number of Daily Headaches, measured over Study Day 1 through Study Day 30.

The primary endpoint is the number of daily headaches, described as the number of times per day that symptoms occur. Its timeframe is Study Day 1 through Study Day 30. It is a continuous measure summarized as a mean and standard deviation for each treatment arm.

Headache frequency is a direct count of how often the symptom occurs during the stated observation period. As an endpoint, it can summarize the frequency dimension of the condition being studied; it does not, by itself, describe headache intensity, duration, functional impact, or patient satisfaction. Those outcomes are not reported as posted secondary results.

The registry identifies the population for the primary outcome as participants from 18-82 who had failed conventional headache therapies. The posted summaries show a mean of 20.5 with a standard deviation of 0.5 for Amitriptyline / Elavil, based on 2 participants. For the SPG nerve block with lidocaine 5% gel arm, the mean is 13.4 with a standard deviation of 10.4, based on 8 participants.

These are arm-specific summaries, not an adjusted or inferential comparison. The registry does not state whether the measure represents a daily count on a particular day, an average across days, or another summary of the observations within the timeframe. That measurement detail is not reported in the registry record, so the endpoint should be interpreted according to its stated label and timeframe rather than an assumed calculation.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized and parallel-group. In a randomized study, assignment is intended to reduce systematic differences between groups at the outset. A parallel-group design assigns each participant to one approach rather than having the same participant receive both approaches in sequence. These design labels describe the intended structure; they do not tell us how assignment was generated or concealed. Those details are not reported in the registry record.

What do the reported summaries describe?

The primary outcome is continuous and is summarized using a mean and standard deviation. The mean is a measure of the center of the observed values. The standard deviation describes how spread out those values are around the mean. Neither summary shows the full set of participant-level observations. In this record, the mean and standard deviation are reported separately for each arm, together with the arm-specific number of participants represented in the summary.

The arm-level summaries are not equivalent to a direct estimate of the treatment contrast. A comparison would ordinarily report an estimated difference or another specified contrast, together with a measure of uncertainty such as a confidence interval, and possibly a test result. Those comparative results are not posted. The registry lists 0 analyses, and the outcome-comparison information indicates that a two-arm comparison for this continuous measure could not be estimated. No confidence interval or p-value is reported.

How should uncertainty be understood?

In general, a confidence interval is a range of values compatible with the data and the assumptions of a particular analysis. It conveys precision: a narrow interval indicates more precision than a wide interval, while an interval spanning a broad range of possible effects leaves more uncertainty. A confidence interval for this trial's between-arm effect is not reported in the registry record, so the precision of that contrast cannot be assessed from the posted results.

In general, a p-value evaluates how compatible the observed data are with a specified null hypothesis under the assumptions of a statistical model. It is not a measure of the probability that a treatment works, and it does not describe the size or clinical importance of an effect. No comparative p-value is posted for this outcome. It would be inappropriate to infer one from the arm summaries.

Why do the group sizes and spread matter?

The outcome summaries are based on 2 participants in the Amitriptyline / Elavil arm and 8 in the SPG nerve block arm. Small groups leave limited information for estimating both the center and variability of an outcome. Unequal group sizes can also affect the precision of a comparison. The reported standard deviations are 0.5 and 10.4, respectively; the difference in spread suggests that a simple model assuming similar variability should not be taken for granted. The registry does not report a model or diagnostic checks to evaluate distributional assumptions.

In general, over-dispersion means that observed variation is greater than a model expects. When present, it can make standard errors and inferential results from an insufficiently flexible model unreliable. Here, the posted summaries alone do not establish whether over-dispersion is present or whether any particular model was used. The registry does not provide participant-level data, a model specification, or an inferential analysis that would permit that assessment.

What do the planning illustrations represent?

The accompanying sample-size section is described as a planning illustration based on the observed effect, not the trial's own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation. The table's quantities are planning illustrations for participants per arm, not observed power and not the actual number of participants enrolled in each arm.

In general, a sample-size calculation asks how many participants a future study might need under specified assumptions about the effect to detect, variability, significance level, and allocation. Such an illustration depends on those assumptions and is not evidence that the present study had a particular probability of detecting an effect. The registry does not report that these assumptions were used to plan the trial. A protocol-based sample-size justification is not reported in the registry record.

The illustration's equal-allocation assumption differs from the posted arm counts, which are 2 and 8. This distinction is relevant when reading the planning display: it is a hypothetical design calculation, not a restatement of the trial's allocation or a test of its results. No calculated planning values are repeated; the sample-size section should be read as planning context rather than as an analysis of what happened in the trial.

What is not available for reanalysis?

The posted material contains arm-level means and standard deviations, but no participant-level observations, adjusted estimates, analysis model, confidence intervals, or comparative p-values. Details about the exact endpoint aggregation, covariate adjustment, and handling of missing observations are also not reported in the registry record. Without those elements, an independent reconstruction of the intended treatment comparison is not possible from the posted summaries alone.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Amitriptyline / Elavil", "SPG Nerve Block With Lidocaine 5% Gel")
n   <- c(2, 8)
m   <- c(20.5, 13.4)
sp  <- c(0.5, 10.4)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Amitriptyline / Elavil  2  20.500  0.500  16.008  24.992
CARM  SPG Nerve Block With Lidocaine 5% Gel  8  13.400  10.400  4.705  22.095

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures, but no secondary outcome results are posted. The primary endpoint is the number of daily headaches. The existence of more than one listed outcome makes it relevant to ask whether the analyses were prespecified and how the possibility of multiple comparisons was handled. A multiplicity plan, including any hierarchy or adjustment, is not reported in the registry record.

The registry lists 0 analyses, and there is no posted inferential comparison for the primary outcome. Consequently, there is no set of reported outcome tests from which to assess how multiplicity might have affected statistical conclusions. The record also does not report interim analyses or stopping rules; their presence or absence should not be inferred from the overall terminated status.

Missing-data handling is not reported in the registry record. The record does not say whether every randomized participant contributed primary-outcome data, how incomplete daily observations were treated, or whether any imputation or sensitivity analysis was used. The posted arm counts describe the participants represented in the outcome summaries, but the registry does not define those counts as an intention-to-treat population or another analysis population.

Likewise, the analysis population is not reported in the registry record. Without a clear account of who was included and how missingness was handled, the scope of the posted means cannot be fully established. These omissions limit interpretation independently of the small arm counts and the absence of a comparative analysis.

12. 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 registry reports serious adverse events for 0 of 2 participants at risk in the Amitriptyline / Elavil arm and 0 of 8 participants at risk in the SPG nerve block with lidocaine 5% gel arm. It also reports 0 other adverse events among 2 at risk in the comparator arm and 0 among 8 at risk in the procedure arm. Deaths are reported as 0 in each arm. No serious adverse event terms are listed.

These are the safety counts posted for the participants at risk in the registry record. They indicate that no events were recorded in the listed categories for these groups. They do not establish that an event is impossible, nor do they provide a precise estimate of the frequency of uncommon harms. The numbers of participants at risk are limited, and the record does not describe the duration or completeness of adverse-event surveillance.

The safety counts should be read separately from the primary headache-frequency summaries. They do not provide evidence about comparative efficacy, and the registry does not post a statistical safety comparison. Definitions, event-collection procedures, severity grading beyond the serious/other categories, and attribution methods are not reported in the registry record.

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

The posted results provide a descriptive snapshot of daily headache frequency over Study Day 1 through Study Day 30. The mean is 20.5 with a standard deviation of 0.5 among 2 participants assigned to Amitriptyline / Elavil. The mean is 13.4 with a standard deviation of 10.4 among 8 participants assigned to SPG nerve block with lidocaine 5% gel. The accompanying tables and plots can display these summaries, but the values remain arm-level descriptions.

What the record does not provide is a formal estimate of the contrast between those arms, its confidence interval, or a comparative p-value. The registry lists 0 analyses, and the two-arm comparison for this continuous outcome is not available. The displayed means therefore do not establish that one approach caused a greater reduction in headaches. The record also does not report baseline values or a change-from-baseline analysis, so the word “reduction” in the study description should not be treated as a result demonstrated by the posted endpoint summaries.

The small number of participants represented, especially in the comparator arm, limits how much can be learned about the wider population from these summaries. The large standard deviation in the SPG arm indicates spread in the observed values, while the comparator-arm standard deviation is based on a very small group. Neither the individual observations nor their distribution are available in the registry record.

The safety section records no serious adverse events, other adverse events, or deaths in the listed groups. Those counts are useful descriptions of what was reported, but they cannot rule out events that were not observed in a small study. Information about monitoring and completeness is not reported.

In general, a randomized design can support a treatment comparison when its conduct, outcomes, and analysis are sufficiently documented. Here, randomization is reported, but the posted outcome information does not include a comparative analysis, and several details needed to evaluate the analysis are absent. The appropriate reading is therefore limited: the registry provides arm-specific outcome and safety summaries, not a definitive answer to the trial's comparative question.

14. Why This Trial Matters Statistically

This record is a useful example of the distinction between describing groups and estimating a treatment effect. A randomized study can be designed to compare approaches, but arm-specific means alone do not communicate the uncertainty around a between-arm contrast. Readers need the comparative estimate and its precision, or a clearly reported analysis, to evaluate what the trial results support.

The trial also illustrates why sample size and allocation need to be read alongside the outcome summaries. The registry lists an enrollment of 10, while the primary-outcome summaries represent 2 participants in one arm and 8 in the other. The imprecision that can accompany such small groups is important context, especially when one arm's reported standard deviation is much larger than the other's. The record does not report why the counts differ or what enrollment was planned.

It is also statistically important to distinguish a planning calculation from evidence generated by the trial. The sample-size section is explicitly a planning illustration based on the observed effect and specified assumptions. Such illustrations are not observed power and do not substitute for a reported analysis. The registry does not state that those assumptions formed the original design justification.

Finally, the status is terminated, but the reason is not reported in the registry record. The status alone should not be used to infer why the study ended or whether the outcome summaries reflect a planned endpoint analysis. Clear reporting of the analysis population, missing-data approach, endpoint definition, and comparative results would help readers assess the evidence. Their absence leaves important statistical questions unresolved.

15. 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 posted primary outcome is labelled as the number of daily headaches over Study Day 1 through Study Day 30, but the registry does not explain exactly how the observations across that period were summarized. It is not reported whether the mean represents a specific day, an average over days, or another participant-level summary. That ambiguity makes it difficult to connect the numerical summaries to a precise estimand.

The outcome summaries include 2 participants in the Amitriptyline / Elavil arm and 8 in the SPG nerve block arm. The registry does not explain the difference between those counts, whether they reflect all randomized participants, or whether anyone lacked endpoint data. A target enrollment, recruitment account, and reason for termination are not reported in the registry record.

The record does not provide baseline headache frequency, change from baseline, individual observations, or an adjusted comparison. As a result, the reported means cannot be interpreted as changes attributable to treatment. The registry also does not report endpoint collection procedures, adherence, protocol deviations, allocation concealment, or a statistical analysis plan.

The study is listed as unmasked, and no separate masking process for outcome assessment is described. The record does not explain how this feature was addressed in measurement or analysis. It also does not report a multiplicity strategy, missing-data method, analysis population, interim analyses, or stopping rules. These omissions are distinct from the small sample and further limit assessment of the reported findings.

The safety data list no events in the reported categories, but details of surveillance, event definitions, and completeness are not reported. Overall, the registry gives limited descriptive outcome information without the design and analysis details needed to evaluate the robustness of a comparative conclusion.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Sphenopalatine Ganglion Nerve Block vs. Elavil for Treatment of Transformed Migraines — NCT02090998.
• Registry record last updated 2026-06-23; status last verified 2023-05.
• Results first posted 2021-12-29.
• 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.

19. Record Summary

NCT02090998 is a Phase 4 randomized, open-label, parallel-group study sponsored by Rutgers, The State University of New Jersey. The registry lists the start as 2014-05, primary completion as 2020-03-16, status as terminated, and enrollment as 10. The reason for termination is not reported in the registry record.

The comparison was SPG nerve block with lidocaine 5% gel versus Amitriptyline / Elavil. The primary endpoint was the number of daily headaches from Study Day 1 through Study Day 30. Posted arm summaries are based on 2 participants for Amitriptyline / Elavil and 8 for the SPG nerve block. No comparative analysis is posted. The safety record reports no serious adverse events, other adverse events, or deaths in either group.