Research Review By Dr. Ceara Higgins©

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Date Posted:

July 2019

Study Title:

The effect of aerobic exercise on the number of migraine days, duration and pain intensity in migraine: a systematic literature review and meta-analysis

Authors:

Lemmens J, De Pauw J, Van Soom T, et al.

Author's Affiliations:

University of Antwerp, Belgium; Antwerp University Hospital, Edegem, Belgium; Universitair Ziekenhuis Brussel, Belgium; Amsterdam Public Health research institute, Amsterdam, the Netherlands; Healthcare Center Haarlemmermeer, Hoofddorp, The Netherlands.

Publication Information:

The Journal of Headache and Pain 2019; 20: 16–24.

Background Information:

Worldwide, migraine is the main cause of years lived with disability in people between the ages of 15 and 49 (4). This is a significant impact on individuals during their prime working years (4) and places significant financial burden on society, with the average migraine patient missing 18 days of work or household activities per year. The average annual cost of migraine is over €1200 per-person (~$1800 CDN, ~$1350 USD at the time of publication for this Review) (1). Prophylactic treatments are commonly advised for patients with headache more than 8 days per month, where disability is present despite acute medication, or when headache where acute medication is not effective is present more than 3 days per month (3). However, as prophylactic drugs are not always tolerated well, nor desired by patients, non-pharmacological treatments are often sought.

Exercise has been shown to play a role in modulating pain processing, producing both short-term and long-term analgesic effects, at both a central and peripheral level (2). As a result of this and the updated version of the International Classification of Headache Disorders (ICHD-III) specifically indicating the need for a systematic overview of the effects of aerobic exercise in migraine, these authors aimed to summarize the available literature and assess the effect of aerobic exercise on the number of migraine days, duration and pain intensity in patients with migraine.

Pertinent Results:

Six studies (5 RCTs and 1 controlled clinical trial) were included in this analysis, including a total of 357 patients with migraine. The average age of included patients was 38 years and 88% were women. At baseline, the average headache frequency was 9.4 days per month and the average disease duration was 19 years. A moderate risk of bias was found in all included studies, primarily due to high dropout rates and a lack of blinding of outcome assessors.

One article utilized a walking program that included 40-45 min of fast walking, with intensity modulated by heartrate and the Rate of Perceived Exertion scale (RPE). Patients also received 25mg amitriptyline each day. Two articles used jogging protocols including either alternating jogging and walking or a continuous moderate intensity run for 30-45 minutes. Heart rate or RPE was measured during the warm up, exercise, and cool down. One article used indoor cycling, including a 15-minute warm up, 20 minutes of moderate intensity exercise, and a 5-minute cool down, all measured using percentage of VO2peak and the Borg-scale or RPE. One article used a combined protocol of cross-training, brisk walking, running, or indoor cycling, including a 10-minute warm up, 30 minutes of exercise, and a 5-minute cool down, measured by RPE to ensure aerobic training. Finally, one article used a behavioural weight loss program which was designed to lead to a ≥ 7% weight loss over 16 weeks. Participants performed a gradually progressive exercise protocol up to 250 minutes per week (5 x 50 minutes of home-based exercises), followed a standard calorie- and fat-restricted diet and received instructions on behavioural modification strategies.

In all but one study, participants trained at least 3 times per week. Patients were asked to keep dairies reporting on the number of migraine days, attack duration, pain intensity, and their use of analgesic medication. As well, patients were assessed before, during, and after the aerobic exercise treatment with follow-up periods ranging from 8 weeks to 12 months. One study had no follow-up period. Six studies used randomized control groups for comparison. Only one control group was age- and gender-matched. Control groups received no intervention, treatment based on medication (amitriptyline or topiramate), education, advice to maintain a habitual daily activity profile, or relaxation therapy.

When compared to topiramate, both aerobic exercise and relaxation therapy were equally effective in reducing attack frequency and number of migraine days, while topiramate was more effective in reducing pain intensity. The combination of amitriptyline and aerobic exercise significantly reduced the number of migraine days, pain intensity, and attack duration when compared to amitriptyline alone. Migraine education and self-management were equally effective in reducing pain intensity and attack duration compared to a behavioural weight loss program.

Meta-analysis of data from four studies was conducted, showing that aerobic exercise significantly reduced the number of migraine days at 10-12 weeks with an average reduction of 0.6 ± 0.3 migraine days per month. Data from three studies showed a reduction of 20-54% in pain intensity and 20-27% in attack duration after aerobic exercise. No significant reduction in acute medication use was seen with aerobic exercise. However, the topiramate group (in one of the studies) showed a 71% decrease in the use of analgesic medications.

Clinical Application & Conclusions:

Overall, there is moderate quality evidence indicating that aerobic exercise therapy decreases the number of migraine days and low-quality evidence that it can decrease pain intensity, duration of migraine attacks, or analgesic medication use. Meta-analysis showed a decrease of 0.6 migraine days per month, which is of low clinical relevance, but may be more significant if added to current usual care (Reviewer’s note: As a migraine sufferer, I can state that a reduction of 0.6 migraine days per month would seem VERY relevant to me!). Larger exercise volumes (high-intensity training or higher exercise duration) seem to be related to increased reductions in number of migraine days. Therefore, further research utilizing larger exercise volumes is warranted.

Topiramate and tricyclic antidepressants were found to have similar results to aerobic exercise in reducing the number of migraine days per month. Given the possible side effects of pharmacological treatment, aerobic exercise would seem to be a valuable alternative, especially as no negative side effects were reported in any of the included trials. There is low quality evidence showing greater treatment effects where aerobic exercise was combined with amitriptyline. This requires further study. Duration of migraine attacks were found to decrease by 20-27% after aerobic exercise training and pain intensity was decreased by 20-54%.

When active controls (topiramate, relaxation, migraine education, and maintaining habitual function with standard physical activity recommendations) are compared to aerobic exercise, no significant differences are seen. However, when aerobic exercise is compared to no treatment or maintaining habitual function, significant treatment effects were revealed.

EDITOR’S COMMENT: we need more work in this area to approach a definitive answer, but there certainly seems to be mounting evidence that aerobic exercise can benefit those with migraine headaches. This mirrors exercise research for…well, every condition! Exercise helps just about everything and with all the secondary benefits, recommending exercise to our migraine patients should be an easy fit as part of a comprehensive management strategy.

Study Methods:

A systematic review was performed based on the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) and the PICO format for search strategies. PubMed, the Cochrane library for trials, and Web of Science were searched from January 1, 2004 to February 21, 2018. Two authors independently screened titles and abstracts and two other authors independently screened the selected full texts. In cases of author disagreement, a third author was consulted to facilitate consensus. Data from articles with identical diagnosis based on the ICHD and units of outcome measurement were pooled for meta-analysis.

All articles were searched for information regarding sample size characteristics (migraine diagnosis), experimental intervention characteristics, exercise intensity, control group characteristics and intervention, follow-up period, results of outcome measures (the number of migraine days, duration of attacks, and pain intensity), and confounding factors. The Cochrane risk of bias tool for randomized controlled trials was used to perform the risk of bias assessment.

Inclusion criteria were as follows:
  • Subjects with migraine with or without aura, as classified by the ICHD-III
  • Interventions including physical endurance, physical fitness, aerobic exercise, and/or exercise therapy performed for at least 6 weeks
  • Outcome measures including number of migraine days, attack frequency, pain intensity, or duration of migraine attacks
  • Randomized clinical trials, randomized controlled trials, or clinical trials
Exclusion criteria were as follows:
  • Studies with non-human subjects, other types of headaches, or pregnant women
  • Studies including manual therapy or medication as stand-alone treatment or no intervention (ex. diagnosing or performing tests on patients)
  • Studies not available in English, Dutch, or French
  • Studies published before Jan 1st, 2004
  • Cohort studies, case control studies, case reports, reviews, or meta-analyses

Study Strengths / Weaknesses:

Strengths:
  • The use of the ICHD-III diagnostic criteria for migraine with and without aura ensured a homogeneous group (to the degree migraineurs can be considered homogenous) and allowed for pooling of data.
Weaknesses:
  • No additional search of the reference lists of accepted articles was performed. As a result, pertinent studies may have been missed.
  • There is an inherent risk of performance and detection bias in the included studies due to a lack of blinding of participants, personnel and outcome assessors.
  • Meta-analysis and comparison was complicated by the wide variety of controls used in the different studies.

Additional References:

  1. Edmeads J, Mackell JA. The economic impact of migraine: an analysis of direct and indirect costs. Headache 2002; 42(6): 501-509.
  2. Naugle KM, Fillingim RB, Riley JL. A meta-analytic review of the hypoalgesic effects of exercise. J Pain 2012; 13(12): 1139-1150.
  3. Pringsheim T, Davenport WJ, Mackie G, et al. Canadian Headache Society Guideline for Migraine Prophylaxis: Supplement 2. Can J Neurol Sci 2012; 39(S2): 63 Available from: http://www.journals.cambridge.org/abstract_S0317167100015109
  4. Steiner TJ, Stovner LJ, Vos T, et al. Migraine is first cause of disability in under 50s: will health politicians now take notice? J Headache Pain 2018; 19(1): 17-20.