Positive Health Online

Some migraine patients even find their attacks are actually triggered by light, especially flashing light. Yet a recent survey of migraine patients using light therapy found that it really does help many of them. About half of the patients surveyed experienced a substantial reduction in the frequency of their migraine attacks, making light a valuable preventive treatment.

The LightMask™

Light Therapy for Migraine

The treatment of migraine with light originated in the late 1980s with the work of Dr Duncan Anderson, a neurologist at the Royal Postgraduate Medical School at Hammersmith Hospital in London. He found that when red light, flickering on and off at up to 30 cycles per second, was shone into a migraine patient's eyes for 15 minutes a day, the patient experienced a significant reduction in the frequency of migraine attacks, sometimes obtaining almost complete remission. The same treatment, applied for up to 30 minutes when a headache did start, sometimes terminated the attack. After Anderson published his results,[1] a home treatment unit was developed and in 1997 this became available as an easy-to-use commercial unit (the LightMask™).

A natural preventive treatment for migraine is much needed. The available preventive drugs are not very effective, have undesirable side effects, and are somewhat costly.[2] A non-drug treatment is of particular interest to patients whose condition (e.g. pregnancy) precludes the use of preventive drugs, who cannot tolerate the side effects of these drugs, or who desire a more natural treatment.

The Survey

As the use of Dr Anderson's light therapy unit for migraine became more widespread, many anecdotal reports were received by the manufacturer regarding the varying effectiveness of the unit. While some users reported significant benefit, even virtual elimination of their migraine attacks in some cases, others experienced little or no effect from the treatment.

In 1999 it was decided to carry out a survey of migraine patients using the unit, to determine what proportion of users experienced beneficial results and what level of benefit was achieved. Since there was some anecdotal evidence that users who experienced 'aura' or other warning signs before their migraine attacks might be the most likely to benefit, the survey was also intended to investigate this possibility and determine whether this or any other migraine symptoms were correlated with successful treatment.

Purchasers of the light therapy unit between December 1998 and December 1999 were asked, at the time of purchase, whether they were buying the unit for treatment of migraine and, if so, whether they would participate in the survey. Of approximately 90 buyers who agreed to participate, 55 eventually completed the survey and subsequent follow-up; there were 48 women and 7 men, none under the age of 18.

The other 35 were eliminated for a variety of reasons: because their headaches were determined not to meet the medical criteria for migraine, because they had other conditions which overlapped and confused the migraine diagnosis (e.g. tumour), because they did not comply with the correct procedures for use of the unit, or because they dropped out of the survey at some point. At least three attempts were made to contact each non-responsive subject and those who stated that they had dropped out because the treatment was not effective were included in the results in the appropriate category.

The Treatment Protocol

Subjects were asked to use the light therapy unit for at least 15 minutes per day for at least 30 days. Since the unit shuts off automatically after 15 minutes, compliance with the time limit was easily obtained. Compliance with the 30-day duration was considered acceptable if subjects missed 'only an occasional day'. Since the subjects were paying customers, not volunteers or paid subjects, stricter enforcement of compliance was not possible.

When used at the factory settings, the light therapy unit flashes at 30 Hz, each cycle consisting of 1/60 second with the left eye illuminated and the right eye in darkness and 1/60 second with the left eye in darkness and the right eye illuminated. The light is monochromatic red light with a peak wavelength of 654 nm.

The unit is designed to be used with the eyes closed, with the light filtering through the eyelids. The brightness of the light is adjustable, but at the factory setting it is typically quite comfortable for most users. Although the unit always starts each session at the factory settings of brightness and frequency, the user can then adjust the frequency and brightness of the flickering light, using control buttons built into the unit. However, from responses to the survey it was determined that almost all subjects used the unit at the factory settings and that even those who experimented with other settings did not do so very often.

The Survey Questionnaire

The first part of the survey asked the subjects about the nature of their headaches. Usually it was completed at the time they ordered the light therapy unit (though some did not complete it until a week or two later, due to various delaying circumstances). Typical questions included:

* Are your headaches mostly on one side or all over?
* Is the pain throbbing or fairly constant?
* Does exercise make the pain worse?
* Are the headaches preceded by warning signs?
* Do you become very sensitive to light or sound during the migraine?
* Do you have nausea or vomiting?

And, for women:

* Are the headaches more frequent around the time of your period?

These are standard diagnostic questions for migraine. The survey questionnaire was developed with the assistance of Dr Anderson, the discoverer of the light therapy treatment.

The subjects were contacted again approximately six weeks after receiving the unit and were then asked to complete the second and third parts of the survey. The second part asked about their use of the light therapy unit, mainly to see if they had complied with the request to use it for 15 minutes every day (with at most occasional missed days). The third part asked about any changes in the frequency of their migraine attacks during the six weeks of treatment; the answer categories were 'Much Less', 'Somewhat Less', 'About the Same', 'Somewhat More' and 'Much More'.

Most of the answers were obtained in direct telephone conversations with the subjects, but in a few cases it was only possible to contact the subjects by e-mail or by post, in which case the data were obtained from their replies on a survey form, which they returned by e-mail or post.

Conservative Interpretation of Subjects' Responses

The question in the third part of the survey, regarding changes in the frequency of migraine attacks, allowed for only two levels of improvement: 'Somewhat Less' and 'Much Less'. When taking verbal reports from subjects, the subjects' comments were interpreted in a conservative manner. Reports that were in any way dubious or vague about improvement were assigned to the category 'About the Same'. Only reports of a definite and meaningful improvement were assigned to the categories 'Somewhat Less' or 'Much Less', as appropriate.

The purchasers of the light therapy unit were obviously aware that they were being surveyed by the manufacturer of the unit, rather than by an independent researcher. There was therefore some concern that politeness or shyness might make them unwilling to report negative results and or otherwise bias their answers. In order to minimize this effect, in all conversations and communications with the subjects emphasis was laid on the need to collect objective data. The subjects were repeatedly told that negative results were as valuable as positive results and that the aim was to gather valid data, not to collect endorsements or praise for the light therapy unit.

Results of the Survey

Change in Frequency of Migraine Attacks

Table 1A shows the changes in frequency of migraine attacks experienced by the subjects after light therapy treatment for at least 30 days. It shows that 44% of the subjects reported that the frequency of their migraine attacks was 'Somewhat Less' or 'Much Less' (under a conservative interpretation of those categories, as described above). This percentage held equally for female or male subjects – 21 out of 48 women, 3 out of 7 men.

Significance of Aura or Other Warning Signs

One of the goals of the survey was to discover which kinds of migraine, if any, were most benefited by the light treatment and which were least benefited. An analysis of the detailed results showed only one migraine symptom which appeared to make a detectable difference to the success of the treatment: the presence or absence of aura or other warning signs. In the survey this question was phrased as follows:

'Are your headaches preceded by visual disturbances, such as flashing lights, zig-zag lines, or blind spots, or other warning signs, such as a spreading numbness or tingling or difficulty in getting words out?'

Crudely, this question divides the subjects into those suffering from migraine with aura (also known as classical migraine) and those suffering from migraine without aura (also known as common migraine). However, the exact medical diagnosis into these two categories involves some additional criteria, which were not fully investigated, so the results of the survey are simply presented in terms of headaches with and without warning signs.

Table 1B shows results for the subjects who stated prior to treatment that their migraine attacks were typically preceded by warning signs. It shows that 53% reported that the frequency of their migraine attacks after treatment was 'Somewhat Less' or 'Much Less'. This compares with a figure of 44% for the subject population as a whole in Table 1A. This result suggests that migraineurs whose attacks are preceded by warning signs are somewhat more likely to experience improvement with the light therapy treatment than those whose attacks are not so preceded, although the difference is not very great.

Efficacy of the Unit as an Acute Migraine Treatment

As mentioned above, the light therapy unit can be used acutely as well as preventively, i.e. it can be used to treat a migraine headache when the headache actually occurs, in addition to regular daily use to reduce the frequency of attacks. Owing to various circumstantial problems the survey was not successful in gathering data on acute use of the light therapy unit, but anecdotal evidence, from discussions with the subjects, suggested that acute use was only effective with a smaller number of users, fewer than had success with preventive use.

Conclusions of the Survey

The results in Table 1 may be summarized as follows: 44% of migraine sufferers who used the light therapy treatment for 30 days reported that after treatment the frequency of their migraine attacks was 'Somewhat Less' or 'Much Less' (under a conservative interpretation of these categories); for those whose attacks were usually preceded by warning signs the success rate rose to 53%.

It should be noted that the survey fell short of scientific rigour in several important respects: the subjects were paying purchasers of the light therapy unit, not volunteers; they were not assessed by a medical professional as part of the survey (though most had been diagnosed as migraineurs by their doctor or other medical professional); the survey was neither blind nor placebo-controlled; and the number of subjects was relatively small. However, within its limited scope, the survey was carried out with care and the success rate remained remarkably steady throughout the one-year course of the survey, giving additional credibility to the results. A more complete and rigorous study is needed to confirm the results reported here and would appear to be justified by the level of successful treatment and the poverty of alternative treatments.

In view of the quite limited effectiveness and undesirable side effects of the available migraine preventive drugs, light therapy must be considered a valuable preventive treatment for migraine.

Further Information

Additional details of the survey and its results can be found in a published journal article,3 which is available online at www.lightmask.com

The LightMask™ is available from LightMask Ltd, PO Box 25632, London N10 3ZA, tel: 0870 516 8143, or at www.lightmask.com, where much other information on light therapy may be found

References

1. Anderson DJ. The Treatment of Migraine with Variable Frequency Photo-Stimulation. Headache. 29: 154-155. 1989.
2. Ramadan NM, Schultz LL and Gilkey SJ. Migraine prophylactic drugs: proof of efficacy, utilization and cost. Cephalalgia. 17: 73-80. 1997.
3. Noton D. Migraine and Photic Stimulation: Report on a Survey of Migraineurs using Flickering Light Therapy. Complementary Therapies in Nursing and Midwifery. 6(3): 138-142. 2000.