By Ishpreet Singh, M.B.B.S. and Sat Bir Singh Khalsa, Ph.D.
Headache refers to any pain in the region of the head and/or neck. Headaches can be classified into two broad categories: primary, which include tension headache, migraine, and cluster headache, or secondary, which are symptoms due to the presence of another condition or disorder. According to the National Institutes of Health, the tension-type headache is the most common form of primary headache. Emotional stress at work or at school, physical tension, and neck or back strain due to poor posture are among some of the most common causes of tension-type headache. According to the published prevalence estimates of tension-type headache, the episodic form is affecting 38.3 percent of the U.S. population and the chronic form is affecting 2.2 to 3 percent of the U.S. population, while migraine affects 29.5 million Americans with higher prevalence among women (17 percent) compared to men (6 percent).
Migraine is characterized by severe pain intensity on one or both sides with a pulsating sensation and is often accompanied by nausea and sensitivity to light and/or sound. Migraines are classified as either “with aura” or “without aura.” It is strongly believed that changes in blood vessels, disruption in the endocrine system, and some aspects of metabolism can create a dysfunction in brain blood flow that is the cause of migraine or primary headaches. The most commonly used treatment for headaches continues to be pharmaceutical. The pharmaceuticals for tension-type headaches consist of analgesic, non-steroidal anti-inflammatory drugs (NSAIDs), and opiate medications. Medications for migraine sufferers are divided into two categories: drugs to treat acute attacks, and other daily drugs to reduce frequency and severity of attacks preventively in addition to botulinum toxin (Botox) type A injections which work as a potent inhibitor of muscle tone.
There is a good deal of existing knowledge regarding the causes of headache. For migraine, certain factors like depression/anxiety, medication overuse, poor sleep, and high stress are associated with worse outcomes. Stress is considered to be one of the most common triggers for migraine headache and a major factor in the progression of headaches from episodic to chronic. Chronic stress involves a hyperarousal of the autonomic nervous system and creates an imbalance between its two branches by increasing activity of the sympathetic nervous system, thus contributing to the interruption of the normal balanced state that is essential for health and well-being. As we know, stress and anxiety are modifiable risk factors and conventional psychological relaxation-related behavioral interventions targeting these factors in people living with chronic headache have been introduced.
As a well-known and efficacious strategy for stress management, yoga is obviously well-positioned as a promising candidate treatment. Yoga therapy for migraine generally focuses on the prevention of the episodes of occurrence, which includes not only addressing stress reduction but also avoidance of the various causes of the attacks. The physical movement with enhanced body awareness in yoga practice can reduce the habits of adopting problematic and maladaptive physical postures. Pain perception and regulation in general is also known to be modulated more effectively in yoga practitioners. There is also evidence of reduction in physiological markers of both inflammation and stress. Specifically relevant to benefits for addressing headache symptoms, yoga-based interventions have been associated with decreased blood pressure and heart rate. By decreasing both of these cardiovascular variables, yoga-based interventions potentially allow the heart to work more efficiently thus contributing to a more efficient blood supply to the brain and lowered sympathetic nervous system activity. Yoga may also contribute to some behavioral changes that positively affect headaches. These may include an increased social network or an increase in regular physical activity. Psychological changes, such as increased positive mental state, can also contribute to more effective coping mechanisms and increased pain acceptance/tolerance. Given the scientific rationale above, it is not too surprising that there have been a number of clinical trials reporting on the efficacy of yoga to treat headaches.
Perhaps the earliest yoga-related study in 1981 compared savasana (corpse pose) alone with a biofeedback intervention and found that the yoga posture was equivalent to the biofeedback intervention, consistent with prior research that found the similar practice of progressive relaxation to also be somewhat effective. This was followed a decade later by a Journal of Neurology India publication in 1991 of a well-conducted randomized controlled trial (RCT) in which 47 patients were assigned to yoga therapy and 38 to drug therapy for tension headache. The results of the study indicated that the yoga and drug treatment were both equally effective in significantly reducing the duration, intensity, and frequency of headaches. Depression and anxiety also showed a significant decline in both treatments. However, the magnitude of improvement was significantly more in the yoga group in comparison to the drug group. One year later, yoga researcher Dr. Latha in Chennai published a small RCT with 20 patients suffering from migraine and tension headache in which the yoga therapy group reported reductions in headache characteristics (e.g. intensity, duration, and frequency) and medication intake. In comparison, the control group reported an increase in symptoms. Both of these latter 2 studies were encouraging not only with respect to headache symptoms but also noted important factors related to mechanism and lifestyle relevant to yoga for headache.
Other notable and more recent studies include a large study of migraine sufferers published in 2007 in the journal Headache, in which 72 patients were randomly assigned to either yoga therapy, which included yoga postures, pranayama, and neti kriyas (nasal water cleansing) or a self-care group for three months. The yoga therapy group demonstrated lower headache frequency and lower pain rating compared to the self-care group. Furthermore, anxiety and depression scores were significantly lower in the yoga group. The journal Pain Management Nursing in 2014 published one of the very few U.S. yoga-for-headache studies. This was done in a pediatric population with 7 participants aged 11-18 using alignment-based yoga. It reported improved quality of life (parent-reported), daily functioning scores (self-/parent-reported), and decreased state anxiety scores (self-reported). In addition to providing positive support for the efficacy of yoga, a few studies have additionally evaluated potential mechanisms involved. For example, a 2007 controlled study at the prestigious All India Institute of Medical Sciences in Delhi conducted an efficacy trial demonstrating the involvement of muscle spasm in tension headache showing that the yoga intervention reduced both pain scores and muscle activity as measured by the electromyogram. Another Indian study demonstrated changes in both headache frequency and intensity with a yoga treatment, while also showing changes in vagal tone and sympathetic activity consistent with the downregulation of autonomic activation. A more recent study by an Iranian research team reported improvements in headache with yoga but did not observe hypothesized changes in nitric oxide levels. Overall these studies have all provided support and preliminary evidence for the potential use of yoga for headache and possible mechanisms involved in yoga’s benefit.
Limitations of the research literature in this field include the absence of control groups and provisions for reducing potential bias in the research design, relatively few RCTs, inadequate description of methods and yoga practice within the RCTs, and small sample sizes. The outcome measures were also mostly subjective patient evaluations. As with much of the preliminary research in yoga, there is also a lack of long-term follow-up data which would test the durability of the treatment effect. There is also a need for information about the duration of yoga participation, or ‘‘dose,’’ required for benefit. However, despite these limitations, the preliminary evidence that yoga therapy can be an effective treatment for migraine and tension type headache is encouraging.
Ishpreet Singh is a medical doctor and researcher from the Dayanand Medical College in India. He has worked extensively in India and USA with individuals with mental health and neurological disorders and is inclined towards integrating eastern yogic and meditation methods into mainstream medicine. He is an avid practitioner of Kundalini Yoga and meditation and brings this as a tool to help people heal, addressing deeper causes of illness and disease.
Sat Bir Singh Khalsa, Ph.D. is the KRI Director of Research, Research Director for the Kripalu Center for Yoga & Health, and Assistant Professor of Medicine at Harvard Medical School. He has practiced a Kundalini Yoga lifestyle since 1973 and is a KRI certified Kundalini Yoga instructor. He has conducted research on yoga for insomnia, stress, anxiety disorders, and yoga in public schools. He is editor in chief of the International Journal of Yoga Therapy and The Principles and Practice of Yoga in Health Care and author of the Harvard Medical School ebook Your Brain on Yoga.