Migraines: window to the brain

migraines

It was while lying in the MRI scanner, slightly impressed at my lack of claustrophobia and seriously reconsidering my chances as an astronaut that I had time to reflect on how I landed there. I never would have imagined it would be due to something as mundane as a migraine.

Like most people, when I thought of the classic migraine it conjured up images of crippling headaches or an airtight sick-day excuse. It wasn’t until I experienced the disorder’s complex neurological effects for myself that I truly appreciated both the condition and the relationship between mind and body it highlights.

What is important to note at this point is that a headache is not the sole arbiter of a migraine attack. The disorder is better thought of as a continuum of physical, physiological and psychological symptoms. The symptoms which led me to the click-clacking MRI were not obvious or straightforward. My first migraine experience came in the form of an ‘aura’; a curious and, I admit, frightening collection of neurological phenomena. These can range from the sensory to disruptions of higher thought processes such as speech, ideation, perception and memory.

This first encounter was during an extremely busy morning at my old IT job. Dying for some semblance of energy, a triple espresso seemed like a perfectly sane idea. It was to be this act of caffeinated self-destruction coupled with the stress of the morning that triggered what was to follow. Slaving away behind a hot spreadsheet I began to notice something in the middle of my screen. What had started as a tiny spot had, in the space of about a minute, grown to block out the centre of my vision. In a matter of seconds I was completely blinded. As if that wasn’t terrifying enough, this was followed by numbness down the entire right-hand side of my body.

“Brilliant”, I thought. “I’m dying at work. Great start to the week this is.”

Thankfully within a few minutes all was well. Except, of course, for my complete panic and existential dread. It’s hard to keep working on soul-destroying spreadsheets after what you think is a stroke. In fact, all of these symptoms were part of what is known as the ‘excitation’ phase of a migraine attack; the first of five such stages. It’s common for these stages to last anywhere from four to seventy two hours with the sufferer mentally and physically incapacitated until their resolution. The blindness in my attack is referred to in the literature as a ‘negative scotoma’. What still stands out for me is how my mind simply couldn’t process whatever visual information it was receiving. I could mechanically ‘see’ what was in front of me, yet my mind was unable to process it. It was absent from my visual reality.

This is where the true strangeness of the aura lies, in its ability to open a window onto the complexities of the mind-body problem.

As great an insight as this may have given me in retrospect, at the time I was more than a little freaked out. Making my excuses, I headed off to my GP. “It’s probably nothing too serious”, she said. “Most likely a migraine.” Thankyousweetjebus.

“Or it might have been a TIA.”

“What’s that?”

“A mini stroke.”

What followed was a month of panicked WebMD queries. People complain about the NHS – they should see the Irish medical system and count their blessings. In that time I did learn another interesting fact at the expense of my blood pressure and sanity; whichever hand you write with, your speech centre is located in the opposite hemisphere of your brain. How did I find this out? More aura shenanigans.

My second attack in as many weeks started with pins and needles down the left-hand side of my body. I was preparing myself for blindness when instead I experienced a much less frightening visual disturbance. A zig-zag pattern in blinding white etched its way in front of me. A little research by way of Oliver Sacks’ imaginatively titled tome on the subject, Migraine, explained that this too was a common feature of classical migraines. Unlike the ‘negative scotoma’ of the first attack, this was ‘scintillating’; an accurate description of its blinding clarity and associated movement.

What followed after this light-show was even more interesting. While describing my attack over the phone, I found it difficult to speak. Common phrases and words escaped me as I battled my fatigued mind. It was at my neurologist’s that I learnt of the connection between handedness and the location of the speech centre. It turns out that for us righties it’s in the left hemisphere. The numbness and hence the attack itself had occurred in the left hemisphere, and therefore it was normal for my conversational ability to take a hit.

With my diagnosis of migraine with aura in hand I decided to continue my investigations. For a neurological disorder as widespread as migraine, it is surprising that the root cause is still unknown. For aura sufferers, the chief mechanism is what’s known as a ‘cortical spreading depression’, in which neurons burst into activity only to fall silent. This can be thought of as a wave starting in the occipital lobe at the back of the brain and spreading forwards. The areas of the cerebral cortex affected then experience less blood for two to six hours. The pain-causing mechanism is unknown.

While my migraines are at their worst a mild inconvenience, there are many sufferers whose quality of life is drastically reduced.  This more severe form of the condition is known as hemiplegic migraine. What makes this different from that previously discussed is the prolonged aura phase. Instead of lasting minutes as in my case, the hallucinations, numbness and confusion can last for days or even weeks. Some severe attacks can even result in coma. Cognitive impairment is also an issue – many people have difficulty in concentration and problem-solving during an attack. If a sufferer gets trapped into a cycle of migraines it can leave them feeling drained and distracted for weeks and adversely affect their performance at work or at school. It’s at these times one can see peoples’ prejudices at play. Even from my own life, I know how calling in sick with a migraine can raise an eyebrow or two.

From what was initially a rather frightening experience, I now see my migraines as more than mere annoyances. They are windows into the workings of my mind; glitches in reality that tease the fundamental mechanisms of the brain. For that I am grateful.

 

IMAGE: tudedude, flickr

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