Landmarks

Median view of the brain (nose would be on the right)

I'm currently studying neuroanatomy, the anatomy of the brain. Although the brain might appear homogenous and dull from its exterior, inside is a richly varied landscape. Lakes and rivers of cerebrospinal fluid course through the mountains and valleys of neural tissue. A few bridges of neural fibers span the division between cerebral hemispheres, allowing the higher brain's two halves to converse. Many structures were named (in Latin) for an object they resemble: an almond ("amygdala"), a belt ("cingulate cortex"), a knee ("genu of the corpus collosum"), a seahorse ("hippocampus"). Colors also were an inspiration: particular landmarks appear black ("substantia nigra"), white ("white matter"), gray ("gray matter"), red ("red nucleus"), and even cerulean ("locus coeruleus"). Even the tiniest anatomical features are named. Some names are whimsical: the "mammillothalamic fasciculus of Vicq d'Azyr", the "habenular trigone", and the "calcar avis".

The brain is valuable real estate, its compact structures multifaceted and intricate. By necessity our maps of the brain are exquisitely detailed.

Admittedly, it is a chore to be learning several hundred unique structures of the brain: their functions, their interconnections, and their relative positions. But it also is fabulous traveling this well-trod ground. It reminds me of looking up at the night sky and rediscovering the constellations traced out by those of old.

The reflex hammer

Perhaps the title of my blog will become a self-fulfilling prophecy.

Assorted neurological physical exam tools

I named my blog "The Reflex Hammer" as a nod to "The Lancet," a prominent British medical journal. Reflex hammers have always intrigued me. How is that the doctor tapping just below my knee causes my leg to swing out wildly? Although a humble instrument, the reflex hammer is so powerful that it briefly usurps a person's ability to control the movement of their own limbs. Because reflex hammers test the function of the nervous system, they are of particular importance to neurologists.

What I didn't realize when I picked the title of the blog was how exciting I would find neurology. The brain and spinal cord are composed of complicated neural pathways that each carry particular types of information. One part of the spinal cord carries sensory input about temperature. Another part of the spinal cord carries directions that go to muscles. Another part carries sensory input about proprioception, the position of the parts of the body in space. The pathways each travel a confusing and unique course, wending this way and that as they traverse the spinal cord and the regions of the brain.

When something goes wrong (for example, a patient loses the ability to look upwards), the neurologist must visualize the various neural pathways to reason through where the problem lies. Upon identifying the physical location of the lesion, he also must figure out what caused the lesion in the first place. Was it a stroke? A tumor? An infectious disease? Neurology has a reputation of being highly intellectual and of requiring studiousness, cleverness, organization, and careful thought. I think it suits my personality better than most fields.

As with most medical students, I am constantly testing the waters of different specialties to see which I like the most (and which I like the least). No longer will I reflexively rule neurology out.

But that's crazy talk!

Part of our psychiatry class involves interviewing a psychiatric patient. We know nothing about the patient when we start the interview.

I joined two classmates in interviewing one such patient. One classmate went first, and for his 15 minutes he did a good job laying a foundation. He got an overview of the patient's life story, social history, and medical history. The patient struck us as a bit odd, but his answers seemed credible and he seemed to be an ordinary guy who had fallen on hard times.

Then it was my turn, and my job was to assess his psychiatric state. I quickly managed to open the floodgates. He revealed his delusions about being the son of god, that within a few months everyone's eye color would change, that he was adopted but that his birth family is profoundly wealthy and runs the American government. His story contradicted itself, showing that his thoughts were not only unhinged from reality but disorganized as well.

It took longer than I expected for us to uncover this patient's profound psychiatric disorder, even though we knew he was a psychiatric patient. First impressions can be deceiving.

Case in point

Wednesday is fast becoming my favorite day of the week, because it's the day when the New England Journal of Medicine (a prominent medical journal) releases its newest issue. I immediately look at the latest installment of "Case Records of the Massachusetts General Hospital." It is a write-up of an interesting medical case seen in Harvard's main teaching hospital.

"Case Records" has been published continuously since 1924, and I think it is one of the most effective ways of learning medicine. A detailed write-up of the patient's history is presented. Then, a physician comes up with a differential diagnosis, predicts what disease he thinks it is, and explains his reasoning. Finally, the true diagnosis and outcome of the case are revealed, and an expert explains to the reader the mechanism of the disease at hand.

Reading through a case is rather engaging. After reading the patient history, I try to guess the diagnosis and then compare my reasoning to the physician's. The thrill of untangling the mystery of each case makes me want to learn about the disease. That there's a real human story behind each case makes the cases stick in my memory. By my tally, I've completed about 70 cases thus far.

Unfortunately, the cases take up an inordinate amount of time. Each one takes me anywhere from twenty minutes to four hours, because I try to read pertinent chapters in my textbooks as I go along. Some of my buddies poke fun at how ridiculous I look when I review a case in the med school library--I occupy a whole table, with all kinds of random medical books splayed about. Despite my best efforts, I haven't succeeded in getting my classmates to share my enthusiasm. After all, time spent studying cases is time not spent studying what will be on the test. It's not immediately obvious how I benefit.

Sometimes I present a professor with a case and ask them to explain a part that I didn't fully grasp. A handful of them have broken into a smile and revealed to me that they, too, used to study "Case Records" in their spare time when they were medical students. Now when I sit in the library poring over a case, I feel connected to an invisible community of eager medical students who, over the decades, have stolen off to the library to perform this same ritual, learning for learning's sake.

Harrison's Ch. 97: "Gynecologic Malignancies"

While I attempt to read the 397 chapters of Harrison's Principles of Internal Medicine, I am writing occasional reflections.

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Cervical cancer is not so scary to Americans anymore because of the Pap smear. Pap smears are good at detecting pre-cancerous cervical cells, and over the past 50 years its widespread adoption has dramatically reduced cervical cancer diagnoses and deaths in the developed world. Unlike most cancers, cervical cancer is usually caused by a viral infection. Certain strains of the human papilloma virus (HPV) predispose cervical cells they infect to malignancy. Now that vaccination against some of these HPV strains is available in the U.S., we can expect the cervical cancer rate to drop even further. It is a triumph of preventive medicine.

These triumphs have barely helped the developing world, though. One of the most preventable forms of cancer still kills surprisingly many.

A handful of researchers are trying to help. Doctors in the U.S. sometimes apply vinegar (acetic acid) to the cervix so that they can visualize cervical cancer cells with the naked eye. The acid turns the cancer cells white. It seems that vinegar could be similarly used in the developing world as a low-cost replacement for the Pap smear. If the health worker sees white lesions, he can freeze them off with a simple metal rod cooled by liquid carbon dioxide.

I think it's incumbent upon us to translate our high-tech scientific advances into low-tech tools that can benefit all.

When it rains, it pours

In 17th- and 18th-century England, milkmaids had a reputation for having pretty faces. This was because they rarely seemed to get smallpox, which left pockmarks on the skin of its survivors. Milkmaids did, however, catch from their cows a milder, related disease known as cowpox. English physician Edward Jenner famously hypothesized that the milkmaids' contracting cowpox made them immune to smallpox. Using this observation, he successfully created the first vaccine. This is where we get the word "vaccine": in Latin, vacca means "cow."

And so, having a disease (cowpox) sometimes protects you from another (smallpox). For example, getting oral herpes can sometimes offer slight protection against genital herpes. Although being born with no spleen (congenital asplenia) can cause problems, it does eliminate the chance of a ruptured spleen (which can be a life-threatening complication of a motor-vehicle accident).

Unfortunately, the opposite usually holds: most diseases simply invite more disease.

• Myasthenia gravis is a disease of muscle weakness. Some patients have difficulty swallowing (dysphagia) and aspirate their food, leading to pneumonia. 
• Untreated gonorrhea inflames the lining of the vagina in a way that makes a woman more susceptible to HIV infection. 
• Hypertension, diabetes, tobacco use, and smoking all lead to a host of ills.
• Being in the hospital exposes patients to a whole host of nosocomial (hospital-acquired) infectious diseases, like C. difficile, a bacterium that causes persistent diarrhea. 
• Autistic patients are more likely to have nutritional deficiencies because they tend to be picky eaters.

For the most part, "when it rains, it pours."

This used to depress me, but I've started seeing it differently. If I can diagnose a disease promptly and treat it appropriately, the patient will stand less of a risk of contracting the additional diseases that may follow. It's like a two-for-one.

Hypocrisy

New York City's mayor, Michael Bloomberg, has championed a proposal to ban the sale of sugary drinks larger than 16 ounces in regulated food establishments. Unsurprisingly, the beverage and movie theater industries are pushing back. From the New York Times City Room blog:

Robert Sunshine, a lobbyist for the movie theater industry in New York State, said that while his clients agreed that obesity was an epidemic, “we believe it should be handled through education.”

“No one,” he added, “should be told what they can do and what they can’t do.”

Oh really? Then what gives your clients the right to tell moviegoers that they can't talk on cell phones during films? Yeesh.

A happier kind of math

A patient I saw in free clinic was overdue for her breast and colon cancer screening, because she had lost her health insurance years ago. This is so commonplace that by now I am shocked when patients at our clinic are current on their screening. It's a shame, too, because cancer screening is one of the most effective health interventions we can provide a patient population. For example, by undergoing regular Pap smears, women increase their life expectancy by 2 to 3 months. Then again, since our patients are uninsured, few of them could manage to receive treatment if a screening test came back positive.

As for my patient, our clinic doesn't perform mammograms, which are the standard screening test for breast cancer. That left the doctor and me in the familiar position of estimating whether our patient should spend her own money on a mammogram at an outside clinic. On the one hand, our patient said she was short on cash. On the other hand, she had a family history that placed her at substantially higher risk of breast cancer. Had enough time elapsed since her last test to justify the expense of a new mammogram? We decided, probably not. It's a grim calculus, the sort of mathematics that I hate having to perform.

Yet this week, the discussion was different. The question was whether our patient could hold off until 2014, when the remaining provisions of President Obama's Affordable Care Act (ACA) take effect. Under the ACA, our patient's cancer screening will be fully covered. She won't even be charged a co-pay. I don't think I've ever finished a day in clinic feeling so optimistic.

Medical school has introduced me to patients in desperate straits. One of my first patients appeared to have a hormone-secreting tumor that had set her body's electrolyte balance awry. Surgically removing the tumor probably would have cured her. But she couldn't afford it. She couldn't even afford the imaging study that would have confirmed the presence of the tumor. Instead, when I had seen her, her electrolyte levels were so skewed as to be nearly incompatible with life. By now she is probably dead. I couldn't help but ask myself: why must this be?

I used to talk about "the uninsured" as an abstraction. Now I examine them in the exam room, and I am increasingly entrusted with their care. They are people, just like you and me. Their hearts beat and their stomachs growl. I feel responsible for them. I want to see them lead happy lives.

My recent experience in clinic was the moment when it truly sunk in: many of the uninsured patients I see are entering a new era. It won't be a perfect era. But it will be an era where I'll get to perform a happier kind of math.

Update: A classmate informs me that, thanks to a grant, a nearby clinic will perform patients' mammograms for free of charge.

Getting the patient on board

I spent several weeks seeing patients in an internal medicine clinic. Often the diagnosis and treatment were obvious, and the challenge was motivating the patients to take their medications and keep a healthy lifestyle. How could this be accomplished?

Interestingly enough, the patient interview can be used to encourage the patient to change their behavior for the better. "Motivational interviewing" involves structuring questions in a way that encourages the patient to alter their behavior for the better. If a patient smokes, I ask them if they have ever tried to quit. If they say yes (and nearly all of them do), I ask them why they had felt motivated to quit at the time. My follow-up question is whether the reasons they had back then still apply today. I might also ask the patient what their first step would be if they were to try quitting again. This line of questioning makes the patient more prepared to attempt to quit once more. Motivational interviewing is more pleasant and effective than simply admonishing patients that they need to stop smoking. [As a side note, the same concept underlies the contemptible practice of "push polling."]

During my interview, I like chatting to patients about their job, their hobbies, their kids, and their travels. Not only is it fun to get to know them, but it usually tells me things that I can later use to encourage them to adhere to their treatment plan.

One patient was the star running back of his high school football squad. For reasons that his doctor wasn't able to determine, his blood pressure was quite high. The high blood pressure had persisted for years, because the patient didn't feel like taking his blood pressure medications. He is hardly alone. It's particularly difficult to convince people to take their blood pressure medication. The side effects from the pills are immediate, but the injuries caused by high blood pressure often take decades to manifest. Most patients prefer feeling better now to the vague promise of feeling better later. How could the doctor convince this teenager to take his medication? Some chatting revealed an answer. The patient was angling to get a scholarship to a top football program. The doctor pointed out that until the patient brought his blood pressure under control, he would fail the medical clearances necessary for recruitment. Problem solved.

A diabetic teenager seen in clinic stubbornly refused to control his blood sugar. His girlfriend was with him in the exam room. The doctor casually mentioned that diabetes causes vascular problems that can disrupt several body parts: the kidneys, the toes, the penis, the retina, the fingers. The patient turned white as a sheet. "What happens to people's penises?" the patient asked. After the doctor discussed erectile dysfunction, the patient became much more keen on learning how to use his insulin.

The effective primary-care doctor apparently has to be something of a salesman.

Blocked thought

Years ago, I spotted an acquaintance I hadn't seen in a while. The conversation was odd. A few times, I would ask a question and he would begin to respond, only to trail off into silence and stare blankly into space. He would remain frozen until the moment I said something else, whereupon he would act normally. He seemed completely oblivious to the fact that he had trailed off and had never answered my question. Indeed, he didn't seem to remember that I had asked him a question at all.

These episodes felt interminable--in one instance I waited a good 30 seconds before catching his attention and changing the subject. I wondered for how many minutes he would have remained "paused" if I had never said anything.

I had forgotten this conversation until I came across a passage in our psychiatry textbook describing this exact phenomenon. It is called "thought blocking," and many patients who have it are schizophrenic. Intrigued, I asked a psychiatry professor about it (one of the perks of being in medical school). He told me that blocking sometimes happens because a hallucination distracts the patient. It also can be because certain impulses in the brain fail to arrive at their proper destinations. For example, one part of the brain is responsible for keeping the brain focused on certain tasks, like tying a knot to completion or answering a question in a conversation. This part of the brain might have had a faulty neural connection with the regions of the brain responsible for formulating and vocalizing the answer to my question. It's fascinating.

Currently in anatomy class, we are dissecting the brain. It is not a particularly large organ (perhaps it's the size of a cantaloupe?), nor is it terribly heavy (about three pounds). Yet it contains everything that makes us human. This pink blob is not only what makes us see and breathe, but also what underlies envy and love, music and literature, war and civilization. Discovering new things about the brain makes it all the more inscrutable: how is it that two almond-sized regions of the brain contain our most visceral emotions and fears? It's baffling. One of my textbooks points out that the number of neuron cells in one's brain approximates the number of stars in the Milky Way.

Wonderment at the splendor of the human brain goes back as far as Plato. Yet today, not only do we understand much more about the human brain, but the rate at which we are unlocking the mysteries of the mind continues to accelerate.

I often dwell on the sacrifices that medical school entails--financial, social, personal, relational, and emotional. But, we get to study the brain. We even get to marvel at it by picking it up and holding it in our own hands. It reminds me yet again that this enterprise of becoming a physician is a rare privilege.