AGAINST THE ARROW | Kenneth Iserson
They set the valve at three. Then it drifts to four. Then, inexplicably, to six. Each number is a different country, with its own customs of thought, its own laws of motion. At three I am almost myself. I walk steadily. I remember your name. Words come when I call for them. At six, everything becomes provisional. My legs wobble. Friends become familiar strangers whose names hover just beyond reach. The simplest sentence requires an excavation.
The game—if you can call it that—is to guess what the valve has decided to do this week.
Five days. That’s how long it lasted this time. Five days between the neurosurgeon’s magnet and the return of fog.
***
Last Tuesday I was in the grocery store and could not remember the word for the thing I was holding. I knew its color, its weight, its smell. I knew I needed three of them for the recipe I’d looked up that morning—a recipe I could no longer recall either. I stood in the produce aisle turning it over in my hands, this ordinary object suddenly nameless, while other shoppers reached around me with easy certainty. Eventually I put it in the cart anyway. It was an onion. I know that now. I did not know it then.
Three days later, after the adjustment, I made the recipe from memory. Chopped the onions without thinking. Spoke their name to no one.
This is what it means to oscillate. Not a steady decline—that would be easier, in its way. A linear loss you could grieve and accommodate. Instead: clarity, then fog, then clarity again. A week’s cycle governed by a valve the width of an AA battery buried beneath my skin. You hold simultaneously the knowledge of who you can be and the reality of who you are right now. You remember being better, which makes being worse unbearable.
***
Eddington’s arrow: entropy increases, time flows forward, systems move from order to disorder.
We age. We do not reassemble into younger versions of ourselves.
Except, apparently, I do.
Every time the valve returns to its proper setting, dementia retreats. Confusion lifts. My gait steadies. I become, briefly, a violation of thermodynamics. The fog clears and the person I was emerges from the person I became. For a few days I defy the arrow. I walk it backward. I am the improbable thing: a human being getting better in the direction the universe says is wrong.
Then the valve drifts, and entropy collects its debt.
***
I was a physician for forty years. I understood cerebrospinal fluid as a clinical abstraction—pressure gradients, drainage pathways, ventricle size on imaging. I taught residents to recognize the triad: gait disturbance, cognitive decline, urinary incontinence. I could diagnose it in others without hesitation.
I never imagined the diagnosis as a mirror.
What I did not understand, could not have understood, was the phenomenology of it. The way your selfhood becomes a question of hydraulics. The way walking and thinking—the two most fundamental human activities—become contingent. Negotiable. Subject to the whims of a mechanical valve and the mysterious physics of fluid finding its level inside your skull. The way you start checking yourself constantly: Am I foggy today, or is this just Tuesday? Is my gait off, or did I sleep badly? Am I losing words, or am I just tired? The brutal arithmetic of self-surveillance, performed hourly, with no reliable instrument except your own compromised brain.
The brain trying to evaluate itself. The ruler measuring its own length while someone keeps changing the units.
***
Another surgery ahead. I am not looking forward to it. No one would. But the alternative is to let the valve win—to let six become the permanent setting, the fog becomes the climate, the names of friends become permanently foreign.
People say things. You’re so brave. You have such a great attitude. They mean well. But bravery implies a choice. What I have is a programmable valve and a neurosurgeon with a magnet and an insurance company that will, for now, approve the procedure. What I have is the stubborn machinery of modern medicine holding the arrow at bay—not reversing it, not defeating it, just arguing with its direction for as long as the shunt holds and the surgeon’s hands stay steady.
I used to be those hands.
Now I am the skull beneath them.
***
At three, I wrote this essay. At six, I will not remember writing it. Somewhere between those numbers is the person I call myself—provisional, mechanical, dependent on a setting someone else chose. But here. Still here. Arguing with the arrow, one adjustment at a time, until the adjustments run out or the argument does.
Kenneth Iserson is a professor emeritus of emergency medicine at the University of Arizona College of Medicine. A pioneer in emergency medicine ethics, wilderness medicine and disaster response, he has authored over 300 peer-reviewed publications and 15 books including Ethics in Emergency Medicine and Death to Dust: What Happens to Dead Bodies? Iserson served 30 years as medical director of a Level I trauma center and has practiced medicine on all seven continents. As a ventriculoperitoneal shunt patient, he writes from dual physician-patient perspectives about medical ethics, epistemic injustice and device dependence.