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Three Part Question

In [an adult patient presenting with migraine] does [intranasal lidocaine or a sphenopalatine ganglion (SPG) block] provide [symptomatic relief]?

Clinical Scenario

A 36 year old female presents to the emergency department (ED) with symptoms of acute migraine. She has a history of migraine. She is systemically well. You wonder whether this patient could get symptomatic relief from a sphenopalatine ganglion (SPG) block via administration of intranasal lidocaine.

Search Strategy

Medline 1950–17 February 2022 and Embase 1980–17 February 2022
Medline-"MIGRAINE DISORDERS"/dt ((acute OR attack OR attacks) ADJ migrain*).ti,ab (1 OR 2) (("sphenopalatine ganglion" OR SPG OR "pterygopalatine ganglion") ADJ2 block*).ti,ab "SPHENOPALATINE GANGLION BLOCK"/ ((intranasal* OR nasal* OR transnasal*) ADJ (lidocaine OR lignocaine)).ti,ab (4 OR 5 OR 6)
EMBASE-exp *MIGRAINE/ ((acute OR attack OR attacks) ADJ migrain*).ti,ab (9 OR 10) (("sphenopalatine ganglion" OR SPG OR "pterygopalatine ganglion") ADJ2 block*).ti,ab ((intranasal* OR nasal* OR transnasal*) ADJ (lidocaine OR lignocaine)).ti,ab "SPHENOPALATINE GANGLION BLOCK"/ LIDOCAINE/na (12 OR 13 OR 14 OR 15) (11 AND 16)

Search Outcome

46 papers of which 4 included data on patients relevant to the clinical question, 1 was not included (see discussion). All were in English.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Blanda1 2000 USA	Intranasal 4% lidocaine vs intranasal normal saline (n=49) in patients with migraine at an emergency department (two-campus community teaching adult hospital)	Randomised, double-blind, placebo-controlled clinical trial	Primary outcome-pain relief at 5 minutes defined as a 50% reduction in pain score or a score below 2.5 cm on the visual analogue scale (VAS) No secondary outcome measure	Primary outcome-pain scores prior to medication were 8.4 (95% CI = 7.8 to 9.0) in the lidocaine group and 8.6 (95% CI = 8.0 to 9.2) in the control group (p=0.75) The average pain score at 5 minutes was 6.9 (95% CI = 5.9 to 7.8) in the lidocaine group and 7.0 (95% CI = 5.8 to 8.2) in the control group (p=0.83). The decrease in pain intensity scores were similar for the two groups over 30 minutes The absolute difference between groups showed a 6.2% (95% CI = 11.2 to 23.6) advantage for normal saline	All patients also received prochlorperazine which is likely to be a confounding factor Short follow-up time (30 minutes) The authors felt the methodology had the potential to recruit other types of headache Difficulty blinding due to local irritation from the local anaesthetic The study was isolated to a single centre, with a small sample size limiting its generalisability and its power
Avcu et al2 2016 Turkey	Intranasal 10% lidocaine vs intranasal normal saline (n=162) in patients with acute migraine at an academic emergency department	Single-centre, double-blind, randomised, controlled trial	Primary outcome-absolute change in pain score at 0 to 15 minutes Main secondary outcome measures-relationship between pain onset time and treatment response, any adverse event, and the need for rescue analgesics	Primary outcome-the median reduction in numeric rating scale score at 15 minutes was 3 (IQR 2 to 5) for the lidocaine group and 2 (IQR 1 to 4) for the saline solution group [95% CI = 0.1 to 2.1]). The reduction in pain score at 30 minutes was 4 (IQR 3 to 7) for the lidocaine group and 5 (IQR 2 to 7) for the saline solution group (median difference [95% CI = 2.1 to 0.1]) Secondary outcomes-No significant difference was found between the groups in terms of the relationship between pain onset time and treatment response. No serious adverse events were reported in either group At 30 minutes rescue medication was needed in 12.3% of the lidocaine group and 17.3% in the saline group	Blinding of participants was difficult due to the irritation associated with lidocaine Both treatment groups received intravenous metoclopramide, a potential confounding factor Difficulty blinding due to local irritation from the local anaesthetic The study was isolated to a single centre, with a small sample size limiting its generalisability and power
Maizels et3 1996 USA	Intranasal 10% lidocaine vs intranasal normal saline (n=162) in patients with acute migraine at an academic emergency department Intranasal 4% lidocaine vs intranasal normal saline placebo (n = 81) in patients with acute migraine from an urgent care department	A randomised, double-blind, Controlled Trial	Primary outcome-at least 50% reduction of headache within 15 minutes after treatment Secondary outcomes-reduction in nausea and photophobia, use of rescue medication, relapse of headache, and change in headache disability scores	Primary outcome-using a pain score of 0-10. In the lidocaine group the mean pain score was 7.7 (7.3-8.1) and 8.0 (7.4-8.6) in the control group (p=0.25). At 15 minutes in the lidocaine group the mean pain score was 4.1 (3.3-4.9) and 6.3 (5.2-7.3) in the control group (p=0.004) Secondary outcomes-using a score of 0-10 to measure nausea. In the lidocaine group the mean score was 4.6 (3.8-5.4), and 4.9 (3.9-5.8) in the control group pre-treatment (p=0.65). At 15 minutes in the lidocaine group the mean score was 1.7 (1.1-2.4), and 3.4 (2.2-4.5) in the control group (p=0.03) Using a score of 0-10 to measure level of photophobia. In the lidocaine group the mean score was 6.5 (5.8-7.1), and 9.9 (5.9-7.8) in the control group (p=0.24). At 15 minutes in the lidocaine group the mean score was 2.6 (1.8-3.4), and 4.9 (3.9-5.9) in the control group (p=0.001) Rescue medication was required in 28% and 54% of the lidocaine group, and 71% and 67% of the control group, at the urgent care facility and then at home respectively (p=<0.001 for urgent care figures and p=0.67 for at home figures) Relapse of headache occurred in 42% of the lidocaine group and 83% of the control group (p=0.17) Disability score was measured 0-3. In the lidocaine group the mean score was 2.2 (2.0-2.4) and in the placebo group was 2.3 (2.0-2.6) pre-treatment (p=0.46). Post treatment scores were 1.6 (1.3-1.9) for the lidocaine group and 2.0 (1.7-2.3) for the control group (p=0.08)	The study did not control for premedication use The administration of the SPG block was not standardised The study included patients with mixed headache symptoms Difficulty blinding due to local irritation from the local anaesthetic The study was isolated to a single centre, with a small sample size limiting its generalisability and its power

Comment(s)

Sphenopalatine ganglion (SPG) block via administration of intranasal lidocaine has been proposed as a treatment modality in the treatment of acute migraine by desensitizing the intracranial nociceptors that contribute to the vasodilation of the cerebral vasculature4. There have been a number of clinical studies to date on its use. We looked at studies conducted in the emergency setting, isolated to migraine patients. The highest level of evidence to date by Chi et al4 is a systematic review of 6 small studies. The authors did not state a priori what they considered to be a clinically important and relevant outcome in terms of pain relief and a time at which this should be assessed. Amongst the studies there was a wide variation in the time at which pain scores were assessed and significant heterogeneity across the trials, with a number not conducted in the emergency setting. For this reason we elected not to include the systematic review but analysed the trials in the study relevant to the emergency setting. All studies were randomised-controlled trials with small numbers of study participants from single centres, therefore lacking power and generalisability. The studies by Blanda et al and Avcu et al failed to demonstrate that lidocaine provided symptomatic relief compared to normal saline. Maizels et al did demonstrate early symptomatic relief with lidocaine, however they demonstrated that this benefit was not sustained. Due to the lack of high quality evidence there is a need for a multi-centre powered double-blind controlled study with appropriate follow-up time to answer this question.

Clinical Bottom Line

To date there is not enough evidence that a sphenopalatine ganglion (SPG) block administered via intranasal lidocaine is likely to provide sustained symptomatic relief of acute migraine in the emergency setting. Further work is needed to establish if it can provide benefit for this patient group.

References

1. Blanda M et al Intranasal lidocaine for the treatment of migraine headache: a randomized, controlled trial Acad Emerg Med. 2001 Apr;8(4):337-42. doi: 10.1111/j.1553-2712.2001.tb02111.x. PMID: 11282668.
2. Avcu N et al Intranasal Lidocaine in Acute Treatment of Migraine: A Randomized Controlled Trial Ann Emerg Med. 2017 Jun;69(6):743-751. doi: 10.1016/j.annemergmed.2016.09.031. Epub 2016 Nov 23. PMI
3. Maizels M et al Intranasal lidocaine for treatment of migraine: a randomized, double-blind, controlled trial JAMA. 1996 Jul 24-31;276(4):319-21. PMID: 8656545.