Another Day in the Frontal Lobe (13 page)

The biggest mouthful, holoprosencephaly, is also known as arhinencephaly, which does not sound any better. It’s a developmental defect of the midline brain structures (along the central dividing line) also typically associated with midline facial abnormalities. It sets in within the first few weeks of the fetus’s life when structures of the face and brain are normally going through a cleavage or separation process. As with many other conditions, there is a broad range of affliction, from very mild with subtle defects to quite severe and lethal. Worst is the Cyclops form, with only one midline eye, and no separation between the two halves of the brain.

I will never forget one patient with this disorder, a longer-term survivor as she was seven or eight years old when I met her. Although her anatomical defects were relatively mild, she was still so severely mentally challenged that she was unable to communicate at all, and suffered from symptoms stemming from underdevelopment of the hypothalamus, an important structure that controls many of the “vegetative” functions of the human body. So, for instance, her body couldn’t regulate its own temperature very well. I might approach her bedside to find her drenched in sweat despite the fact that her chubby form remained nearly immobile. On top of that, her sleep-wake cycles were always off. And, to add insult to injury, her body was starting to go through precocious puberty, which was distressing to everyone except her, as she remained not only immobile, but also unaware.

This poor girl would be in and out of the hospital for various problems at random intervals. With each hospital admission, multiple teams of doctors (pediatrics, neurosurgery, neurology, endocrinology, infectious disease) would all do their part to address the concern of the moment (clogged feeding tube? pneumonia? pubic hair?) and get her back to her mother, an exotic dancer whom I never met because she was never around. She was the type of mother who dropped off and picked up—definitely not the sleep-in-the-reclinerby-the-bedside type of mom.

Despite this girl’s complex developmental anomalies, she was an “easy” patient, even described as “so pleasant!” by the parents of the child in the bed next to her. When I went in one morning to examine her, these parents, who had spent the night in the room with their own child, stopped me to say how impressed they were by their sweet roommate: “So quiet…never a peep…such an angel.” I smiled and had to agree. It was not my place to expose the tragedy of her congenital misfortune to strangers.

I had the privilege of working with stellar pediatric neurosurgeons whose reputations brought patients in from all over the neighboring states and beyond. We saw the most complex, most bizarre, and most tragic of cases. Because modern medicine has become so good at treating every symptom, I was continually amazed at the children who were able to survive so long with so little brain function, with mothers, fathers, and hired help attending to every need and hauling around what amounted to miniature ICUs in their minivans. I became comfortable with conflicting emotions, thinking both “How touching!” and “How strange!” at the same time.

I had to perform a spinal tap on a child who had been neurologically devastated at birth. While I had the needle in his back, his mother mentioned that it was a good thing that she had forgotten to bring his Passe-Muir valve (an insert for a tracheostomy that allows a patient to talk). She explained that, this way, he would remain quiet through the spinal tap. I expressed some surprise that he actually had a Passe-Muir valve. I knew that his brain was not capable of speech or even thought. “No, you’re right, he’s completely nonverbal,” she confirmed, very matter-of-fact and even smiling, “but he does make noises.” This was not the first time I made a mental note to avoid making assumptions.

I enjoyed speaking to our visiting neurosurgery fellow from Turkey, whose amazement rivaled mine. “This would never happen in Turkey” was his common refrain. I never quite knew exactly what he meant by that, but I suspect it reflected some combination of wonder, respect, and horror.

At one point, late into my senior resident year, I was rudely awakened to the fact that I had become perhaps
too
jaded in dealing with the tragedies of neurological devastation. I had become overly accustomed to our clinics, going from exam room to exam room, one featuring a mother waiting quietly while she casually suctioned her daughter’s tracheostomy, another featuring a twelve-year-old boy whose legs were so rigid and contorted that it was nearly impossible for his mother to change his diaper.

I walked into yet another examining room after checking the brief info in the patient’s chart. It was a brand-new consult from out of town: eighteen years old, cerebral palsy, spasticity. Okay, okay, I’ve seen this before, I just need to get a good history before my attending walks in. Efficiency is key. I looked at the patient for a second: very skinny, special wheelchair, arms contracted, head support in place, mouth hung open. It was clear I wasn’t going to get the story from him, so I turned to the parents, my back toward the patient, and started to take down the history. The mother’s account went back eighteen years, recounting her pregnancy in detail. She was helpful but a bit long-winded, so I jumped in after a few minutes with some pointed questions. As a rule, I make an effort to let people finish their stories before I butt in, but sometimes I have to break my own rule. There were a number of other patients waiting and I didn’t really need to know all the specific dietary details that people can’t wait to tell a doctor about.

As I sat, dutifully recording the list of medications, allergies, and operations, my mentor walked in. I cringed. I was hoping to have at least the history done so I could present him with a nice summary. He sat down on the examining table, the only seat left in the cramped room. After introducing himself, he surveyed the compact scene—the patient, the parents—and then focused his gaze back on the patient. After what seemed like several, almost uncomfortably quiet, seconds, he looked the patient in the eye and asked: “So, when did you graduate from high school?” The young man’s face lit up like I had no idea it could.

My mentor had noticed something I had missed. The patient was wearing a large high-school ring, so large that it looked a little silly on his bony finger. His body, far more than his mind, had borne the brunt of his cerebral palsy. He was a proud, beaming high school graduate. His mother pointed out the specialized computer, attached to his wheelchair, that helps him communicate. For the remainder of the visit I sat in the corner, duncelike, humbled by the enormity of this ring now staring me in the face.

This teenage patient reminded me, as an analogy to the trite “you can’t judge a book by its cover,” that you can’t judge a person’s intelligence by his outward appearance. But can you judge a person’s intelligence by an examination of his brain? I was asked this question recently by a friend and my gut answer, never having studied the question in depth, was no. (This area of inquiry is more a Ph.D. concern than a clinical, practicing M.D. concern.) Obviously, I knew that certain conclusions could be made in the extreme cases—major congenital anomalies or devastating brain damage—but what about in the normal population? Can you look at the brain of, say, someone with an IQ of 90 and see any differences compared to the brain of someone who scored a 130?

Curious about whether my gut response had been correct, I looked around at what’s been written on the topic recently and found out that the answer may actually be yes. I say “may” because I’ve learned not to put definitive faith in any one particular study, and the quality of the work has been variable.

For more than a century, various researchers have looked at overall brain volume and intelligence, and some have found a correlation between larger brains and greater intelligence. My feeling here is that pursuing the question in this very simplistic way is just not that interesting. You might be able to find some sort of trend, but my hunch is that there would be so many exceptions to the rule that the rule wouldn’t be worth much. Einstein’s brain, for example, was apparently slightly smaller than average. Looking at brain volume as a whole, or head size, is far too crude a measurement. I have to admit, though, that I may have a bias here as my own head is not particularly large. Anyway, consider the fact that the brain of a sperm whale is five to six times larger than ours.

What about approaching the question in a more detailed way? What if a pathologist were to hold an isolated brain at autopsy, rotate it around in his hands, look at it from every angle, and examine all the convolutions under a bright light with a magnifying glass? That wouldn’t be good enough either. He still wouldn’t be able to conclude: “I’ve got a genius here!”

You would have to look even closer, and know where to look. Much of the recent work has been based on detailed MRI (magnetic resonance imaging) studies of living volunteers. One study from California, for example, describes numerous focal areas of the cortex, in all four lobes of the brain, in which the presence of more gray matter was correlated with higher IQ.
¹
  Another group, in London, found similar correlations, but in different areas.
²

Leaving aside the usual discrepancies between different research studies, a more important point is that examining structure alone has its limitations. Intelligence is a living, fluid entity probably better suited to study by
function-
based imaging techniques (in which images of the brain are obtained “in action” to see which areas “light up” while thinking.) One group, from South Korea, used functional MRI (fMRI) to examine brain activation during reasoning tasks. They scanned two groups of subjects: one from the “national academy for gifted adolescents” and another from various local high schools.
³
  They concluded that in the “gifted” students, the role of the posterior parietal areas was enhanced, based on its functions as part of the network that pertains to attention, reasoning, and memory.

Clearly, in order for the fragmented community of brain specialists to come to any meaningful conclusions about the physical brain and intelligence, much more needs to happen: existing studies need to be repeated or otherwise validated, the major questions need to be approached from multiple angles, and there needs to be communication across disciplines (the hard part).

For the time being, one attractive framework for thinking about the brain and intelligence focuses on flexibility as a key concept. Based on a review of numerous fMRI studies, scientists at Carnegie Mellon University believe that individual differences in intelligence may be based on the brain’s ability to adapt to a changing environment, as in variable cognitive demands.
⁴
  For example, people of superior intelligence may demonstrate more efficient use of brain resources, often requiring
less
cortical activation for a given task, exhibiting greater connectivity between brain regions, and having greater ability to recruit additional regions—quickly—as necessary.

All this, of course, has to be placed in the context of how important intelligence is in the first place. Isolated superior intelligence, buzzing around within the hard boundaries of an individual’s skull, does not impress me so much as seeing what someone can accomplish with whatever resources they happen to have. And I know that there are plenty of so-called smart people in the world who aren’t that smart at life, and that’s not so easy to detect in the scanner.

The brain is such a complex organ, each one having to develop from scratch, I’m amazed that so many brains actually do develop so perfectly normally. After conception, not only does the brain have to escape all of the possible chinks in the genetic code, it then has to receive plenty of oxygen during the entire birthing process. Once a child’s brain makes it past those hurdles, you would like to think it should be home free from then on. I wish. Other hurdles await. One child I took care of had a most unexpected roadblock to deal with: his own well-meaning mother. The disturbing deviations I saw in his brain were even more of a jolt than the congenital anomalies we see: his were entirely preventable.