Stajcic 1990.

Methods	A randomised, double‐blind, prospective, parallel group study
Participants	Intervention: peripheral streptomycin + lidocaine Diagnostic criteria of patients included in the trial   Internation Headache Society criteria, excluded those with pain relief for over 24 hours after test doses of lidocaine No remissions for at least 1 year To locate correct nerve at first visit gave lidocaine block 9 had had previous local surgery           Age range 49 to 85 Severity Not available Duration of condition range years 1.2 to 29 years Number       9      Control: peripheral lidocaine Diagnostic criteria of patients included in the trial     International Headache Society criteria, excluded those with pain relief for over 24 hours after test doses of lidocaine No remissions for at least 1 year To locate correct nerve at first visit gave lidocaine block 9 had had previous local surgery      Age range  49 to 85 years          Severity Not available Duration of condition mean (range) years 1.2 to 29 years Number          8
Interventions	Intervention: peripheral streptomycin + lidocaine Type of intervention       1 g streptomycin + 3 ml 2% lidocaine into trigger area weekly for 5 weeks Usual medication not changed  Length of follow‐up (mean in months) Shortest 6 months Control: peripheral lidocaine Type of intervention    3 ml lidocaine into trigger area weekly for 5 weeks Usual medication not changed    Length of follow‐up (mean in months) Shortest 6 months
Outcomes	Primary outcome Pain relief measured at 1 week and 30 months following intervention Adverse events Nil reported
Notes	Randomised double‐blind trial in 18 patients with TN of varying duration. There are insufficient details to determine whether there is bias, whether the groups were comparable, no details of how outcomes measured, no details of follow up time on all patients. Initially the results suggested some improvement in those having streptomycin but longer follow‐up showed that this was not maintained. However, no details provided as to overall versus triggered branch relief or whether medication was stopped or reduced
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly selected
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding (performance bias and detection bias) All outcomes	Low risk	Fitted sleeve over injection barrel to decrease recognition  independent person prepared injections in identical syringes
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	May have been 1 dropout , shortest follow‐up time was 6 months not clear how many had final assessment at 30 months
Selective reporting (reporting bias)	Unclear risk	Table 3 provides outcome on all patients but no time frame
Other bias	Unclear risk	No power calculation, no details as to what classified as good outcome. No mention of whether pain relief gained was total or only for the treated branch