She’s got the pedal to the metal, which is okay because somehow, in the middle of the day, there is not one other car on the highway. And the sky is all fake colours, a kind of bruised green roiling over Melrose-cheese orange. My wife is saying something: stop apologising. But she doesn’t mean “No need to apologise.” She is very, very tense. She wants me to shut the hell up.

In the flash, I am aware that my thoughts, the part of me that feels like me, can’t claw to the surface. It is scary – like being buried alive.

This is not, it turns out, a dream.

This is a story about what happened to me on the day that Hurricane Irene – the one that lulled Americans into a false sense of security before Sandy – bore down on New York City. It’s a challenging story to write, because the events of that day remain a blank to me even now: nearly 24 hours of my life went missing, skipped away on long leave. It was like one of those old amnesia movies where the hero wakes up with a headful of mirror-shard visions: Wha…Where am I? Except that I hadn’t been conked in the head. And in this story I’m no kind of hero.

My mind snapped back into place in a ward bed at New York-Presbyterian Hospital in the predawn hours of the following morning, rain spattering the window beside me. About four metres away, our beds arranged toe-to-toe, I faced a sweating man handcuffed to his bed rail. The cop seated beside him nodded to me; then they both turned back to a sitcom on the overhead TV.

A neurology researcher would later tell me, “I know of only one place where this sort of thing is actually common, and that’s on soap operas.” That sounds about right, until your life starts imitating daytime TV. As it turns out, this plot twist isn’t receiving its due. I had been ambushed by a particular form of amnesia that day – 
doctors call it “transient global amnesia”, or TGA – and it might be more common than most people, maybe even many doctors, realise.

In one Swiss study, titled “Transient Global Amnesia – Not So Rare After All”, researchers determined that the condition strikes about seven in 100 000 people every year, and that 30% of the cases reviewed were initially misdiagnosed. So not run-of-the-mill, but not exactly hitting the mental Mega Millions either. And that’s for the whole population. Research shows that the number of occurrences actually jumps in the over-50 age group, with accounts ranging from 24 to 32 cases out of 100 000 people annually. That would put me, at age 54, in the TGA sweet spot.

In seeking possible causes of my own attack, I read vivid personal accounts of TGA victims who snapped out of it miles from home, lost, or 
who came around bruised and scraped, perhaps from fights they 
didn’t remember getting into.

In my own case, I just floated out of the fog and found myself in a strange bed with EKG terminals taped under my shirt, a bandage holding a pulse monitor in place, and an IV dripping magnesium. (Apparently I was slightly low. “That was all they could find,” a nurse would explain, almost apologetically.) Big wads of gauze were taped to the back of each hand. I saw that I’d cut and bruised my ankle somewhere along the line. It was still bleeding a little, but it didn’t hold my interest. My full attention focused on my so-called brain.

There was a clipboard next to me, with a note in my wife Claire’s familiar handwriting:
– This is not a STROKE.
– Claire brought you to New York–Presbyterian Hospital in the car. She is OK!!!!
– You are having memory loss. Don’t have a reason.
– This is TEMPORARY.

Claire had spelled it out in huge letters. Possibly, I thought at the time, because they were written in haste or anxiety. I now realise it was something else: a subconscious shout, an attempt to make something register with me and stick. TGA, I later learned, has the quality of being both retrograde, meaning that the amnesia blots out older memories, and anterograde, meaning that you can’t hold on to new information after the amnesia’s onset. I had about a one-minute window of recall. Then: reset to zero.

I also now understand that the note’s bullet points (there were many more) were direct answers to questions I couldn’t let go of – How did I get here? Are you all right? I’d asked them over and over.

The bizarre, relentless repetition of questions is a common theme in TGA reports. In one study’s description, it’s as if “a fragment of a sound-track is being repeatedly rerun.” It would be almost comical if it didn’t fray the nerves of everyone around the victim, who of course can’t remember a thing about it. (I spoke to one man who’d reached the point of exasperation when his longtime life partner kept saying, “Remind me how we met?”)

In the days after my attack subsided, I still had a few new relentless questions: was I sick? What caused this? Will I blank out again? What the hell just happened to me?

In search of my balking brain, 
I read up on the surprisingly rich (if murky) literature on TGA, spoke to neurologists and fellow patients, and tried to affix that evidence to my own case. There hasn’t been enough to convict. That in itself is a scary detail.
The last thing I actually remember doing on that pre-hurricane morning was fitting a patio-furniture cover over the basement 
coal grate in our Brooklyn backyard. Through my earphones, Van 
Morrison sang, “Say goodbye 
to Madame George.”

About noon, I was later told, I showered and dressed and then wandered down to find my wife, small children, and dog glued to the TV weather report. I hovered in the background for a beat or two. “There’s a storm?” I asked. My family is accustomed to my annoying jokes, but a chill gradually crept over them. “You were taking care of everything all morning,” my wife would later say. “Suddenly it was like a stranger had taken your place.” (As usual, there is a country song that covers this situation.)

The scene evolves.

Me, stalking out to the backyard and back inside: “I want to know who stacked up all our outdoor furniture!”

Family: “You did. For the storm.” Me: “What storm?”

Repeat four times.

I had stepped out of the shower and fallen off a cliff. But why?

Based on the medical literature, the list of moods and events thought to precipitate a TGA episode pretty much reads like everything anybody ever did before amnesia struck. Potential TGA triggers apparently include anxiety or depression, exercise, extremely tiring situations, headaches, money worries, “a general context of psychological pressure,” and “sudden immersion in hot or cold water.” In one widely publicised case, a woman arrived at the emergency room after having an orgasm during intercourse with her husband left her unable to remember the preceding 24 hours. (ABC News’s Web headline: “Mind-Blowing Sex Causes Amnesia in 54-Year-Old Woman.”)

Dr Thorsten Bartsch, who has personally seen about 100 TGA patients at the University Hospital Schleswig-Holstein’s Memory Disorders Group in Kiel, Germany, notes that most of the triggers fall into three broad categories: emotional or psychological stress, physical exertion, and temperature change. (This last category is apparently not as far-out as it sounds. “The old English doctors used to talk about ‘amnesia by the seaside,’ ” Bartsch says, “because it happened to people who jumped into the cold North Sea.”) By this measure I had hit a TGA trifecta – pre-hurricane stress, pre-hurricane exertion from the 
garden work… and that shower.

According to some researchers, I may actually have managed to score a superfecta. Dr Beatrice Golomb of UC San Diego, told me that she and her colleagues have found a link between statin use and TGA. (A spokesperson for Merck, which makes Zocor, the statin I take for high cholesterol, categorically denied any such link with cognitive impairment.)

The mechanism, if it exists, works something like this: your brain cells are energy hogs, and statins can short-circuit the power supply. Next step, maybe you miss out on an entire hurricane hitting your hometown. Take your medicine, maybe lose your mind. Temporarily.

Golomb has advice for statin users who have dealt with any kind of cognitive misfire: talk to your doctor about taking a statin holiday. “Give it two months to see if your memory shows signs of improvement,” she says. Fortunately, the impairment does not seem to be permanent. In her study, 90% of people with brain complaints improved – sometimes within days – after they’d stopped taking statins.

What about the other three potential causes? In one hypothesis studied by Bartsch and others, the unifying element in all three classes of non-statin TGA triggers – those stresses, strains and temperature changes – may be the fact that they raise the pressure of the venous system in the hippocampus, the area of the brain’s medial temporal lobe associated 
with memory formation. (To gauge your own risk factors for brain decline, take the quiz on this page.) This may in turn touch off a kind of short-
circuit in a subregion of the hippocampus called the CA1 – thought to be crucial to our capacity for memory and “mental time travel”. In other words, it governs our ability to remember, look ahead, and place ourselves in the moment. Perhaps tellingly, the CA1 is also configured into the stress circuits of the brain, a potentially dangerous combination when that 
circuitry goes awry.

“The CA1 is very sensitive to metabolic stress,” explains Bartsch, “so any acute change of the metabolic situation in the brain may cause a disturbance in that region.” In turn, this disturbance may cause a dysfunction of the memory nerve cells that can actually be captured on film. Using supersensitive diffusion-weighted magnetic resonance imaging, Bartsch and other researchers have observed tiny lesions appearing and then 
disappearing in the hippocampuses of some TGA victims.

This dysfunction is sometimes likened to a kind of mini-stroke, in which case TGA is a godsend of a near-miss. “The difference is that TGA almost never progresses to a stroke, even though it’s sometimes associated with the kind of imaging change that is linked with the early phases of a stroke that causes permanent brain damage,” says Dr Dana Leifer, the neurologist and specialist in vascular neurology and imaging who headed the team that treated me at New York–Presbyterian.

My trip to the ER began with my wife anxiously ringing doorbells. She found our neighbours at home with their newborn, battening down for the hurricane. Could they possibly add to their mix our two children, ages three and eight, and our jolly, slobbery dog? They could.

Hurricane Irene would ultimately spare the city its worst; it was downgraded to a tropical storm by the time it blew garbage around on the streets. But that fact wasn’t at all clear in the eerie, ominous sky as Claire raced up the rainswept FDR Drive with her changeling husband. She knew nothing about a condition called transient global amnesia, of course. She was 
gunning the car in the clear belief that I was suffering a stroke.

I met her anxiety with a beatific, wistful cheeriness. And the questions!

“Where are we going?”
“Why aren’t the children with us?”
Then: “I’m sorry!… I’m sorry!… I’m so sorry!”
“You were very sweet,” she said later, “but annoying.”

Once we had passed through the double doors of New York–Presbyterian’s emergency entrance, we encountered another obstacle: the fact that absolutely nothing was visibly wrong with me. The ER itself, however, had an unsettled, improvisational feel. With the approaching storm, the city’s transit system had been shut down, so the hospital was being staffed by a 
skeleton crew. My wife began buttonholing security guards and triage nurses and whispering, “He’s having a stroke… he’s having a stroke.”

“A set of beepers went off,” Leifer later explained to me. A wide range of technicians prepared for a guy with blocked brain blood vessels..

Medical testing is unpleasant enough anytime, but the difference that day was that all the CAT scanning, MRI-ing, puncturing, blood-pressure cuffing, questioning, poking, tongue depressing, eyeball inspecting, and interminable waiting was taking place for me in a disturbing one-minute-reset mental vacuum: Where am I? Who are you people? Why am I freezing naked under a flimsy gown? Then I confronted my personal nightmare.

At some point during my half century on the planet, I managed to develop a clawing claustrophobia and fear of suffocation that rarely, if ever, manifests itself. Except in MRI machines. Before that day at New York–Presbyterian, I had sworn I would never be fed into another MRI tube without taking a tranquiliser, preferably the kind they dart-shoot into rogue elephants. Now I found myself repeatedly swimming up to consciousness every few minutes during a 40-minute MRI series, completely unaware of where I was, finding myself flat on my back, my head restrained in a helmet, and my body jammed inside a narrow plastic cylinder the size of a sewer pipe.

I was, I am reliably informed, freaking out.

The instinct for self-preservation is a near-automatic, reptile-brain reaction when you’re trapped in such a situation. A subtler kind of self-preservation was an itchy idea that kicked in only in the predawn hours, as my medial temporal lobe began to flicker back online: completely without warning or explanation, what I thought of as my essential “self” had slipped through a hairline fissure I hadn’t known was there.

During the ordinary course of things, you might think of your “self” as all parts of you. Stub your toe – yep, that’s you all right. But here the connectedness had been severed. At some point during the day, a nurse apparently came upon me doing jumping jacks and slapping myself on the cheeks, trying to bring the mind back to the meat. But no amount of slapping would wake it up.

As TGA and other illnesses that affect the hippocampus point out, what puts the “I” in “mind” is the ability to remember. “Some people say we are our memories,” says Dr Geoffrey Kerchner, director of research at the Stanford Center for Memory Disorders. “That’s our consciousness, and the hippocampus is very important in that. We all have a filmstrip of our lives that is continuously updating from moment to moment. We can rewind it and think about what we were doing yesterday and construct a sequence of events. When you don’t know how you came to be in this moment, right now, that is very dislodging.”

As my consciousness returned in the early dawn of the next day, it disobligingly began to press fragments of a poem into my thoughts. The poem was by Robert Lowell, a teacher of mine in varsity whom I greatly admired and whose own mental torments I had naively romanticised at the time. That night, as the familiar phrases from “Skunk Hour” floated through my head – the ones ending with “My mind’s not right” – I felt for the first time the close-on, sharkskin grain of his words, harsh enough to flay the skin off you.

But how wrong, really, was my mind? Apparently, not as wrong as it felt at the time. As far as is known, these odd episodes aren’t predictive of future medical issues, including stroke. (Indeed, notes Bartsch, TGA victims tend to be among the healthiest of neurology patients.) I could take comfort in the fact that while a disturbance in the CA1 area of my brain could be seen as a kind of appetiser version of Alzheimer’s disease (it is the region where Alzheimer’s first manifests itself), the main course is no more likely to arrive for me than for the rest of the population.

Then there is the issue of repeat attacks. It is reassuring to be told, by my doctors and the mainstream medical literature generally, that transient global amnesia rarely strikes twice. But as with a lot of information about this confusing illness, this counsel seems to be shaky. One patient of Leifer’s I spoke to, a woman who has experienced three episodes in just over two and a half years, now takes the precaution of wearing a TGA medical alert bracelet.

She is far from alone. TGA-related websites are peppered with reader comments from people who report having had two, three, five recurrences. And the research numbers are funky. The website of the National Institutes of Health Office of Rare Diseases Research offers the helpful information that “the condition reoccurs in about five to 25% of people”, which can be read as a statistical mea culpa signifying, “We have no idea.”

I have not, as far as I can remember, experienced a repeat episode, but I still carry the thought around. I have a vague recollection – though it’s also possible I constructed this after the fact – that just before I blanked out that autumn morning, I felt a kind of fizziness in my head similar to the symptom declaring the onset of a migraine. If I feel it again, I hope I have the clarity of mind to jump into bed and pull the covers over my head.

Though there is no consensus on what actually causes TGA attacks, there is no doubt that, as Kerchner puts it, “with aging, brains are more 
vulnerable to a wide, wide variety of things going wrong.”

File it all under the heading of “More Glimpses of Your Fragility,” in the Growing Old Is Not for Wimps folder. It is another of the chilly, apparently hidden realities of aging, hidden in the sense that no matter how often you are bombarded with certain information – like advertisements for haemorrhoid cream – it will never seem to apply to you, until 
it urgently does.

But while no talismans can ward off a TGA attack, you can do plenty to improve the health of your aging memory centre. Start with the best 
news: the hippocampus, unlike the brain generally, has the ability to generate new nerve cells in adult life. It is highly plastic and responsive, but 
it needs stimulation. The best 
safeguard against the array of challenges your brain may endure is to be aggressive in establishing a social life and ongoing, challenging mental activity. (So: more poker, crosswords, and John le Carré novels, and less laugh-track TV.) That and exercise. “The most powerful thing a person can do,” Kerchner says, “is aerobic exercise.

It is incredibly effective at delaying the onset of, or even preventing the symptoms of age-associated memory loss. We don’t know how it works; if we could put it into a pill, we would.” (Between interval workouts, add in mind-boosting exercises, like the 27 online games at gamesforthebrain.com.)

For one night during Hurricane Irene, I was a resident of Hospital World, that walled-off, parallel reality that operates on a 24-hour clock of monitors beeping, temperature taking, and overhead lights being switched on as flocks of white-coated doctors alight at the bedside.

Shadowy vignettes drifted through my mind, of being awakened to squeeze people’s fingers and push their downturned palms upwards. Around first light, a spectral doctor appeared, asking me to name the president of the US. My first reaction was indignation; my second, surprise: I had to pause and chase the answer.

I was given a three-word set to repeat, and the way he suggested that I take my time responding gave me the sinking feeling that I’d blown quite a few of these in previous attempts. (My wife confirmed this when I finally reached her in the early hours of the morning. My partner in crime, she tipped me off: “It’s usually an animal, a sport and a colour.”)

When my doctor with his good, honest, Bert Lahr face, heaved into view with his team during morning rounds, it was like Hunk, Hickory, and Zeke appearing at Dorothy’s post-Oz bedside in Kansas. I felt that I’d seen these people recently, but in some hazy, shifted context.

“I’d like you to try to remember three words,” Leifer said. I mustered a top-of-the-roller-coaster focus; to get sprung, I knew I’d have to nail this.

“Hummingbird-Baseball-Red” may pop into my mind on my deathbed.

By Richard Nalley