Jan 04 2008

Global Warming Is Causing More Migraines

OK, not directly. This is more of a manifestation of the law of unintended consequences. Here is the chain of events:

Concerns over man-made global warming have increased awareness of the need for energy conservation. This in turn has led to the popularity of compact fluorescent bulbs (CFB’s) as replacement for the old incandescent bulbs. (CFB’s use 75% less energy for the same light output, as they generate less waste heat). Governments, wanting to seem proactive in tackling the high-profile problem of global warming, are beginning to pass laws requiring the phasing out of incandescent bulbs in favor of the new fangled CFB’s. This will save money, energy, and atmospheric carbon. So far so good.

However, 38.1% of migraine headache suffers are sensitive to bright or fluorescent lights, which can trigger migraine attacks. Fluoresecent bulbs have a subtle flicker – which is too fast for most people to perceive, but it’s there. (BTW – computer screens also flicker too fast for most people to see, but some people can perceive the flicker of computer screens and this can cause headaches and eye strain.) For some migraine sufferers, any bright light can trigger a migraine, but for most light-sensitive migraineurs a flickering light is much more of a hazard. For example, the light dappling through the trees while driving along a country road creates a flicker effect that can trigger a migraine.

So those migraine sufferers who are light sensitive now face a world illuminated by flickering fluorescent bulbs all thanks to Al Gore and global warming. This has led some migraine advocacy groups to lobby their respective governments not to ban incandescent bulbs outright. Perhaps a special exception can be made for those with migraines. Before long I may be writing a prescription for a migraine patient to obtain otherwise-banned incandescent bulbs for their home. (disp: 12 70w incandescent bulbs, use as needed for domestic illumination, refills: 5)

The question of how migraine attacks are triggered by bright or flickering lights is an interesting one. The current thinking is that migraines are very similar, neurophysiologically, to seizures. Both are the result of excessive or out-of-control neuronal firing in the brain. Seizures can be triggered by many of the things that trigger migraines, including flickering lights (remember the Japanese video game that induced seizures? – although this sparked a flurry of anxiety attacks that were not true seizures also). Many of the same medications that are used to treat seizures are also effective as a preventive treatment for migraines. All of this speaks to a similar underlying mechanism.

The current working model of migraines is that they begin with activation of the trigeminovascular reflex – the trigeminal nucleus is that part of the brainstem that receives sensory information from the face. This sensory information is connected to the cranial vasculature. Hyperactivity in the trigeminovascular system results in a phenomenon known as central sensitization, where the trigeminal nucleus becomes over responsive to sensory input. It also causes the cranial vasculature to go through a process of vasoconstriction (shrinking of the blood vessels) followed by vasodilation (expansion of the blood vessels).

All of this relates well to the symptoms of migraines. They typically begin with an aura, which is commonly visual involving a bright zig-zagging distortion in the vision which moves across the visual field, followed by a trail of darkening of vision. Other auras are possible also, including numbness, tingling, weakness, or nausea. This is followed by a pounding headache (caused by the vasodilation), which is classically one-sided but can occur in any distribution. There are also symptoms of hypersensitivity to sensory input – including intolerance of light and loud noise and sometimes increased sensitivity to even soft touch over part of the face.  These symptoms then slowly subside. A typical migraine will run through its course over several hours.

Migraines can be very debilitating and significantly impair quality of life, so having an increased frequency of migraine due to widespread use of CFB’s is no joke. One of the primary preventive treatments for migraines is avoidance of triggers.

And therein lies the dilemma. I am all for energy conservation, especially through implementing new technologies that are more efficient and cost effective. That’s a win-win. It is just unfortunate that there is this unintended consequence of potentially making life more difficult for those who already have the burden of suffering from migraines. At the very least governments need to take this into consideration and perhaps not be so heavy-handed in banning incandescent bulbs.

But fear not – technological advancement has already provided the ultimate solution to this dilemma: the LED lightbulb. These are already available and are cost effective. LED bulbs are 30 times as energy efficient as incandescent light bulbs and last 60 times as long. They do not contain mercury as do CFB’s, and they produce a more natural white light without any migraine inducing flicker. The only downside is the upfront cost is much higher, even though the long term savings are huge. And LED lights will only get better over time.

Ironically, just as there is a big push for CFB’s they are already obsolete. In fact, the technology should be entirely bypassed in favor of even more efficient, environmentally friendly, and non-migraine inducing LED’s.

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