Neuhauser 2003.

Study characteristics
Methods	Randomised, double‐blind, placebo‐controlled, cross‐over (after one attack) trial Total duration of treatment and follow‐up not reported
Participants	Setting:  Specialist dizziness neurology clinic, hospital outpatient management in Germany (single‐centre). Study dates not reported.  Sample size: Number randomised: 19 participants Number completed: 16 participants (although only 10 participants experienced attacks) Participant baseline characteristics Only reported for those who completed the trial  Age:  Zolmitriptan group: range 29 to 57 years Placebo group: range 29 to 57 years Gender:  Zolmitriptan group: 7 females: 1 male Placebo group: 7 females: 2 males Probable/definite vestibular migraine:  Not reported (study was published before the IHS criteria were defined) Attack frequency at baseline:  At least 2 attacks in the preceding 12 months; no other information provided  Duration of disease: Not reported  Inclusion criteria: A diagnosis of vestibular migraine. At least 2 episodes of migrainous vertigo lasting longer than 2 hours within 12 months before enrollment. Aged between 18 and 65 years.  Exclusion criteria: Vestibular disorders other than vestibular migraine. Non‐vertiginous dizziness (e.g. orthostatic or due to panic disorder) unless it could be clearly differentiated from attacks of VM by the patient. History of basilar, ophthalmoplegic or hemiplegic migraine. Severe impairment of hepatic or renal function. Symptoms suggestive of ischaemic heart disease. History of stroke or transitory ischaemic attacks. Alcohol or drug abuse. Diastolic blood pressure more than 95 mmHg or systolic more than 160 mmHg. No contraception for women of childbearing age. Hypersensitivity to the study medication. In addition, patients should not use a triptan or ergot derivative within 24 hours before and after taking study medication; change or start any prophylactic migraine treatment 3 months before taking study medication; and take any other anti‐vertiginous drugs or pain medication within 6 hours before taking study medication. Diagnosis of vestibular migraine: Criteria were: 1) episodic vestibular symptoms of at least moderate severity (rotational vertigo, other illusory self‐ or object‐motion, positional vertigo or head motion intolerance, i.e. sensation of imbalance or illusory motion provoked by head movements). Vestibular symptoms were “moderate” if they interfered with but did not prohibit daily activities, “severe” if patients could not continue daily activities; 2) current or previous history of migraine according to the 1988 criteria of the International Headache Society; 3) one of the following migrainous symptoms during at least 2 vertiginous attacks: migrainous headache, photophobia, phonophobia, visual or other auras; and 4) other causes ruled out by appropriate investigations.
Interventions	Intervention (n = 11 randomised, number completed not reported) Zolmitriptan 2.5 mg to be taken orally when symptoms of vestibular migraine were moderate or severe  Comparator (n = 8 randomised, number completed not reported) A placebo of identical appearance and taste was to be taken when symptoms of vestibular migraine were moderate or severe Background interventions administered to all participants A second dose of study medication (either triptan or placebo, accordingly) or a rescue medication (dimenhydrinate 150 mg for vertigo and paracetamol 500 mg for headache) could be taken after 2 hours
Outcomes	Primary outcomes relevant to this review: Improvement in vertigo Vertigo was measured as mild, moderate, severe or no vertigo. Improvement was counted as vertigo severity changing from moderate or severe to mild or no vertigo. Patients reported symptoms in a structured diary. Change in vertigo Not reported  Serious adverse events Not reported  Secondary outcomes relevant to this review: Disease‐specific health‐related quality of life Not reported  Improvement in headache Assessed using the same score as vertigo. Improvement was counted as headache changing from moderate or severe to mild or no headache. Patients reported symptoms in a structured diary. Improvement in other migrainous symptoms  Not reported  Other adverse effects Not reported  Other outcomes reported in the study: No further outcomes were reported
Notes	Research integrity checklist: No retractions/expressions of concern were identified  Trial registration was not required, as this article was published before 2010  Plausible loss to follow‐up was reported  No implausible results were noted The numbers allocated to each group do not suggest any issues with randomisation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: no information given on randomisation sequence generation.
Allocation concealment (selection bias)	Unclear risk	Comment: no information given on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: stated to be "double‐blind" and placebo was used. No other information given on blinding of study personnel.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "placebo of identical appearance and taste"  Comment: primary outcome measures were self‐reported symptoms by blinded participants.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: 3 withdrawals from the study (only 19 participants in total). In addition, 6 participants who did not suffer an attack during the study period (which is undefined) were also excluded from analysis, therefore further reduction in sample size.
Selective reporting (reporting bias)	High risk	Comment: data are not reported in a way that accounts for the cross‐over design of this trial, therefore it is impossible to appropriately assess correlation in outcomes for an individual participant.
Other bias	Low risk	Comment: no other concerns identified.

ICHD: International Classification of Headache Disorders; IHS: International Headache Society; RCT: randomised controlled trial; VM: vestibular migraine