The Brain: The Greatest Mystery of All?

The Brain: The Greatest Mystery of All?

I still remember the day I fell in love with the alluring, impenetrable mystery of the brain. I was sixteen, during a humid July in summer school. (I had actually chosen to go to summer school, obviously prone to such nerdy infatuations.) Flipping through my Psychobiology text, I came upon this beauty: alien hand syndrome.Even the name is delightful.Let’s explore the syndrome a bit. As you may know, the brain is divided into left and right sides. This dissociation has, in fact, spawned an entire industry, with strategies claiming to bulk up your analytical left side or creative right side, depending on your lack. In my humble neurological opinion, this is nonsense. We are all bi-brained, allowing us to remember, speak, feel, and, in essence, be human.

You may wonder how these hemispheres communicate. The answer is: the corpus callosum—a wondrous, fibrous, connective band running right on top of the brain. Back in the day, when neurosurgeons were still slicing through the corpus callosum to cure seizures (still done, though sparingly, for severe epilepsy), a little problem emerged.

The left hand got ornery.

It seems once the hemispheres stopped talking to each other, the left side took umbrage with the right. As a mild symptom, for instance, the left hand would get tired of reading and slam the book shut. Sometimes the left hand got downright furious, shoving food into its owner’s mouth, or even grabbing its neck in a choke hold. You may recall the Hollywood version, the mad scientist from Dr. Strangelove whose rambunctious left hand keeps trying to perform a Nazi salute, while the right hand shoves it down.

This disorder not only arises from “iatrogenic” (meaning, the doctors did it) causes. It can also result from a stroke or a neurodegenerative disease called cortico-basilar degeneration. In other words, sometimes the brain simply disconnects itself. The brain is a complex tapestry, woven from a complex array of neuronal connections. Taking out one thread can unravel the whole work of art.

We see this in the stroke ward all the time. I still remember a consult for “personality change” in a patient after coronary bypass surgery. The problem sounded more psychiatric than neurological, but I entered the room with an open mind. Indeed, the neurological exam was completely normal. No numbness, no weakness, no language problems. He was a tad slow to answer questions and didn’t smile a whole lot, but that was about it. When our team explained the findings to his wife, she didn’t want to hear it. “Something is wrong,” she insisted. “This is not the man I married.”

It turns out she was right.

The physical exam may have been negative, but the MRI didn’t lie. The patient had had a small but definite stroke in his caudate region. Now, the caudate isn’t a flashy piece of brain. The “head” of the caudate (which suffered the stroke) is the size and shape of a bean, mainly involved in motor functions. But in this case, an infarct in this unassuming little tissue had caused abulia, or total lack of motivation or expression. The patient could think, move, and speak, but he could not emote. One little string pulled out, and the patient was left a shell of himself.

Such syndromes are fascinating, albeit tragic, examples of neuroanatomy gone awry. But over the years, I’ve come to see this neuronal disconnection as emblematic of something larger, a metaphor for an even greater disconnection—the clash between the mind and the brain.

The human body is essentially a long, bony extension of the brain. Sure, the liver is important, as is the heart. But what are we really without our brains? Which is why it is so startling and traumatic when the brain turns against us. When a hyperintelligent, college-bound teenager starts hearing taunting voices. When a sixty-five-year-old grandmother on the verge of retirement gets lost on the way home from work. When a middle-aged man becomes so paralyzed with fearful thoughts that he can no longer leave his house. When a man goes in for heart surgery and wakes up as a different person, completely devoid of personality.

In my psychological thriller, Little Black Lies, Zoe Goldman is a psychiatry resident with ADHD. She’s been working and fighting with her brain for her whole life. But her greatest struggle has been with hidden memories. Her birth mother died in a fire when Zoe was four, and she has only fragmented memories of that time. She tries to fill in the holes of her past but her adoptive mother’s memory is failing from dementia so she cannot help her. The more Dr. Goldman strives to remember, through therapy and hypnosis, the more her brain shuts her out. In the name of self-preservation, her cortex seems to understand that sometimes the brain is smarter than the mind, and some secrets are best left buried.

It’s been almost thirty years since that fateful summer. And to this day, as a neurologist and a mystery writer, my love affair with the ever-mysterious brain goes on.

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