07/18/15
Pinched Nerve

What is a Pinched Nerve?

Pinched Nerve

There are 31 pairs of spinal nerves along the spine from the upper neck to the lower back and sacrum. Each pair exits at the level of an intervertebral disk, a flexible element situated between two rigid bones (vertebrae).

When a nerve is pinched, it becomes incapable of propagating an electrical charge in the normal fashion. For all intents, the nerve might be seen as short-circuiting. As with any wire that shorts, its function is compromised. There are two major kinds of nerves: sensory and motor. Sensory nerves provide sensation: touch, temperature, pressure, pain, etc. Motor nerves provide for movement, that is, they control muscles.

Pinching a motor nerve produces weakness. The worse the pinching, the greater the weakness. It turns out skeletal muscles are incapable of survival without nerve input in the long run, so that prolonged severe pinching leads to death of muscle cells. As the individual cells die, the muscle shrinks. This is the cause of atrophy, or muscle wasting. In a worst case scenario, a patient comes in with profound weakness and loss of muscle mass.

Pinching a sensory nerve leads to a volley of abnormal sensations. Tingling, numbness, and especially pain. The pain is generally quite disagreeable, described variously as sharp, shooting, lancinating, burning, or even a dull ache. It may be constant or intermittent, and is generally worse with activity or simply standing. Sometimes patients complain of a deep “toothache” type of discomfort. In severe cases, a patient cannot put weight on the affected leg without severe pain. In all of these cases, the pain follows the distribution of the pinched nerve, which in the most common situation is down the back of the thigh and calf, often across the top or bottom of the foot. The pain almost always runs down the leg from the back towards the foot and not vice versa. Pain running up the leg is very unlikely to be a pinched nerve. In addition, pain from a pinched nerve (the medical term is radicular pain or radiculopathy) is rarely focused around a joint, such as the knee or the hip. Joint pain often indicates a problem in the joint itself.

In reality, nerves are not entirely sensory or entirely motor, but a mixture of the two. Thus, pinched nerves often create both sensory and motor symptoms. This means most patients have both some element of radicular pain, numbness, tingling, or achiness, and a sense of weakness. Often times one aspect predominates, usually the sensory symptoms. When sensory symptoms predominate, patients may become very uncomfortable and often seek medical care early.

Cases where the weakness predominates are not rare however. In the extreme case, this is called painless weakness—a dangerous situation. Human beings respond faster to pain than to weakness. If something hurts, we tend to seek medical attention. However, if there is weakness in the absence of pain, many if not most patients ignore the weakness until it is far advanced. Read far advanced as irreversible, even with surgery. Such permanent weakness can be crippling, or at least life-changing.

As an illustration of the above, consider the difference between heart attack and stroke. Both of these are exactly the same problem—lack of blood flow—but they occur in different parts of the body. When the heart is deprived of blood flow, the result is chest pain. Heart attacks hurt and this causes the patient to seek medical attention immediately, which often prevents permanent injury. But when the brain is deprived of blood, there is no pain (the brain is the only organ in the body that does not feel pain!). The result in many cases is painless weakness of an arm or leg—which people tend to ignore, sometimes for days! In any case, delay of just a few hours is generally enough to produce permanent injury. This is, of course, a stroke.

Painless weakness caused by a pinched nerve is less dramatic, but still devastating if ignored. Patients often ignore such weakness until they notice wasting—atrophy of the thigh or calf—or they begin to fall down from the profound muscle weakness.

By far the most common cause of a pinched nerve is a herniated disk. The disk is a soft tissue element that sits between the bones of the spine, not unlike a stack of coins in which quarters (bones) and nickels (disks) alternate. The disk is the flexible element that allows the spine to bend and rotate, which means disks get a lot of wear and tear. This wear eventually catches up with a person, which is why the incidence of herniated disks increases with age. They are vanishingly rare in children (though I have operated on one in a thirteen year-old).

lumbar HNP

A fragment of herniated disk pinching nerves in the lumbar spine. The nerves are the small gray dots amid the white background in the center.

Because of wear and tear, pinched nerves are most common in the more flexible parts of the spine, the lower lumbar and mid to lower cervical spine. They are unusual in the more rigid thoracic spine.

The disk itself is composed of an outer ring of fibers and an inner meat the consistency of crab. Some folks liken this arrangement to a jelly donut, though the filling is not so squishy and does not readily flow out. Nonetheless, when the outer fibers breakdown, the inner material herniates out. Most herniations are inconsequential, since only those that actually pinch a nerve are troublesome. In fact, by some estimates, as many as 80% or more of disk herniations have no clinical significance.

Even when the herniation does pinch a nerve, surgery is not usually necessary. In most cases the pinched nerve resolves (perhaps the herniation goes back in) and the symptoms disappear. Perhaps 80% of disk herniations resolve this way, usually within a few days to six weeks or so.

Surgery for a lumbar herniation is indicated for several reasons.

First, surgery should be considered in any case with more than just mild weakness. Weakness indicates a true insult to the nerve and it is generally impossible to know if the weakness is getting better or worse at the time of initial evaluation. Because of the risk of permanent weakness with prolonged pinching, surgery is generally offered.

Second, surgery should be strongly considered whenever there is objective evidence of bladder dysfunction. The nerves to the urinary bladder are at risk only with very large lumbar herniations. True bladder dysfunction related to lumbar herniation is rare. The average neurosurgeon probably sees it only two or three times a year (out of several hundred patients). The risk of permanent injury to bladder function is high in these instances and surgery should be strongly considered on an urgent basis.

The third reason to consider surgery is for intractable pain. Radicular pain in most patients can be made tolerable with medication, enough to get them through the acute period whereupon the pain resolves on its own. In the occasional patient, the pain is so severe as to warrant surgery early on. This is a subjective call on the part of the patient and surgeon working together.

The final reason to consider surgery is for the convenience of the patient. There are many times when the pain resolves incompletely and after many months folks just get tired of it. Such residual discomfort generally (though not always) resolves with surgery. Another instance of convenience to the patient is for financial reasons, such as when the family bread winner cannot afford to miss work on and off for months waiting for pain to resolve. It is often easier and more certain a cure to operate and so return a person to gainful employment early on.

What exactly is the surgery to fix a lumbar disk herniation?

Although this will be answered more fully in another article, suffice it to say the surgery is generally straight forward, takes less than one hour, is done as an outpatient, and results in more or less immediate relief of pain. There is no risk of paralysis and only a slight risk of injuring a nerve at surgery (well under 1% with an experienced surgeon). It generally does not involve fusing the spine.

06/12/15
risk

How much risk is too much risk under the knife?

How Much Risk Is Too Much Risk
Under The Knife?

risk

I. Why Sane People Don’t Play Russian Roulette

Imagine this little scenario if you will. You’re sitting on a plane which, for the time being, remains parked at the gate as your fellow passengers board. You get yourself situated and start to look around. Let’s say you’re in Los Angeles and need to get to New York, which is maybe four hours by air. As you look about, you notice a small crack in your window. Maybe two inches long. Okay, you think, I can deal with that. The window is at least double-paned, after all. But you look past it and notice some corrosion as well, on the leading edge of the wing. And maybe a few popped rivets besides. More uncomfortable now? Do you bring it to someone’s attention? Do you get off the plane? How much risk are you willing to take for the convenience of getting to New York in a few hours, rather than a few days (by train or car)? What if you are only flying to San Fran, about sixty minutes? Can you abide the risk then? Does the benefit of getting to your destination quickly outweigh the risk of the plane falling out of the sky? What is the risk/benefit ratio?

Another scenario. You’re at home in the rural countryside and realize you forgot to pick up something for dinner. There’s nothing convenient in the kitchen. You know there’s a supermarket ten miles down the road. But it’s snowing. Hard. And you don’t have snow tires. Do you eat the few crumbs left in the kitchen or do you go out in the snow? How bad would the weather have to be for you not to take that risk? Would it matter if you had not eaten anything that day? Or for three days? What if you had only a motorcycle? Or a front wheel drive vehicle? Or a Hummer? Or even just a horse? Would you go if it was sunny? What if it wasn’t a supermarket, but a 5 star restaurant at the end of that snowy road? Would a greater benefit cause you to assume a greater risk?

In other words, how much risk is too much? At what point does the benefit outweigh whatever risk there is?

In each of these scenarios—in all of these scenarios—the risk, the benefit, or both, are subject to change. Most every decision we encounter in our daily lives has both some inherent risk and some tangible (or intangible) benefit. Judging the ratio of these two entities is what allows us to arrive at the decisions we make. We do this a hundred times a day without thinking about it. 

Do you walk out to the curbside mailbox to check your mail? Tangible benefit and low risk—unless it’s raining. Or snowing. Or sleeting. If the ground is a sheet of ice, is the risk of falling and breaking your hip worth it? What if you’re waiting on a letter from a long lost friend? Or a job offer?

Do you change the light bulb over the sink? Can you reach it or do you have to stand on a ladder? Is there water in the sink? Is the ladder a sturdy one? Is there someone to hold it? Is the light just burnt out or actually shattered (the glass is gone, you have only the wire remnants in the socket)? 

One more example: you want a drink of water. Benefit: your throat will be soothed and, ultimately, so will your kidneys. But what if you have to cross a wet and slippery floor to do so? You could trip and break your leg. Unlikely, of course, but it happens more often than you think. Still, maybe this one heavily favors getting up and going after a drink of water. The risk/benefit ratio if favorable—that is, the benefit far outweighs any risk involved. Maybe by a thousand or hundred thousand times. If we set the risk at 1, we can show the benefit like this: 1/1000 or 1/100,000. The ratio is a very small fraction. So we see that the smaller the ratio, the better or more favorable things are. We lean towards recouping the benefit. We get that drink.

But what if the risk is high and the benefit very low? Ever play russian roulette? I hope not. In that unfortunate parlor game, whether you load the the six-shooter with one or five bullets, the benefit is hard to see, about as low as you can imagine. For reference, let’s set the benefit at 1. The risk, death or something worse (permanent coma, for instance) might be 100,000 or 1,000,000. 1,000,000/1. So the higher the risk/benefit ratio, the worse things are and the less likely we are to pursue the cause. The revolver stays in the drawer or, better yet, the locked case.

II. This Might Be A Wash—Or It Might Not

So, risk/benefit ratios are a part of everyday thinking. If the risk/benefit is low (1/10 or 1/100), the equation favors the benefit and we act accordingly. If the risk/benefit is high (10/1 or 100/1), the opposite is true. Too much risk makes the benefit seem paltry and we don’t care to play. The six-shooter stays in the drawer.

But what if the risk/benefit ratio is not immediately obvious? For example, I like The Walking Dead. I know it’s going to give me nightmares—that’s the risk I take watching it—but it’s pure fun to couch-out and let my brain vege for an hour during each episode. The benefit is intangible in this case. I’m not sure what the risk/benefit is here, but for me that’s ok. I’ll take the chance on a nightmare.

We make these kinds of decisions all the time. Decisions in which the risks and benefits are approximately equal (or at least we think they are). Most of the time these are a wash. Do I drink the milk even though it smells kinda bad? Do I do the laundry now or later? Do I have spaghetti or tacos for dinner? Do we take a shower first and then screw, or vice versa? Do I have that walnut sized brain tumor operated on now, or do I wait and see if it’s going to grow before having it removed?

Huh? What?

Did you say brain tumor?

Yes, I did.

I also asked what happens when the risk/benefit ratio is not immediately obvious. I said that most of the time this means the benefits are approximately equal. And that’s true. But it doesn’t mean the risks and benefits are small.

And that brings me to surgery—and to what I really want to talk about: the risks and benefits surrounding a given operation, which are often huge. Both the risks—and the benefits. 

Welcome to my world.

So what happens when a patient comes in with a benign brain tumor? (Never mind how we know it’s benign, as in noncancerous and not immediately life-threatening or significantly threatening in any other way; that, perhaps, is a subject for another post). Obviously the risks of brain surgery are high (not, in general, as high as you might think, but high enough). But aren’t the benefits high too? Would not being rid of that tumor be pretty damn beneficial? 

So, does one outweigh the other in this situation? What exactly are the risks of brain surgery? And what is the tangible benefit of having the tumor removed? And therein lies the rub, because quantifying these risks and benefits are not always as easy as you would think. In other words, sometimes it’s a wash.

Take the risks, for instance. The risks of brain surgery might include (this is not an exhaustive list) stroke, seizure, infection, hydrocephalus, subarachnoid hemorrhage, deep venous thrombosis, pulmonary embolus, heart attack, pneumonia, aphasia, mutism, incoordination, coma, death, etc., etc., etc. And each of these, take infection for instance, might include others, like superficial wound infection, skin flap sloughing, loss of the bone flap, epidural abscess, subdural empyema, meningitis, ventriculitis, cerebritis, intraparenchymal brain abscess, etc. To be fair, most of these things are rare (some quite rare), but their incidence is not zero so they should at least be acknowledged in the calculations. 

Ok, that’s not really true. A digression. It can be shown that if a certain risk (or benefit) is so rare as to be statistically improbable in a given population, one really shouldn’t base their decision on that particular risk or benefit. One important example comes immediately to mind. In elective surgery outside the brain and heart, intra-operative deaths today are exceedingly rare and so the idea one might die during, say, a breast reduction, is not reasonable and should not be considered when deciding for or against surgery. Even with elective heart or brain surgery, this particular risk is often vanishingly small.

But, returning to our example, what about the benefits of having that tumor gone? Well, one benefit is you know it’s gone. There is that. But even under the best of circumstances (a benign tumor that is easily and totally resected by an experienced surgeon), most folks who have a brain tumor removed continue to get surveillance MRIs or CTs for years to come, looking for recurrence. Still, for most folks there is some peace of mind at having the ‘brain tumor’ out. How do you quantify peace of mind? If the tumor was at all painful, hopefully the pain is gone. In some situations, say a tumor of the fifth cranial nerve (never mind what that is), that pain may have been severe and that alone might really sway the risk/benefit ratio in the first place. But we aren’t talking about that here. This is a benign tumor, not immediately threatening to the patient, remember? We aren’t talking about something pushing on the optic nerves and threatening blindness either. That would really push the risk/benefit ratio down towards benefit.

So, the list of risks is long and torturous. The list of tangible benefits not so much (many, if not most, benign brain tumors take years to grow to any significant size before they might cause trouble). The intangible benefit—peace of mind—is something else altogether. Starting to get the picture?

High risk/(low or moderate tangible benefit + unquantifiable intangible benefit) = ? 

Now, this might be a wash, or it might not. Very few neurosurgeons would operate an 85 year old man with a walnut-sized tumor they knew or strongly suspected to be benign pressing against the frontal lobe. But the same tumor in a 24 year old woman with her entire life ahead of her—including another 20+ years of fertility and hormonal fluctuations (which can affect even benign tumors): operate.

One more note. You can see from the example in the preceding paragraph how the risk/benefit ratio is often fleeting and always dependent on multiple factors, only some of which it is possible to take into account. Like age (younger often, but not always, favors surgery). Or the presence of co-morbidities, such as diabetes, smoking, end stage heart or liver disease, or morbid obesity, all conditions which always increase the risk, sometimes prohibitively so such that surgery is very unlikely to have a favorable outcome—in such instances the surgeon will decline to operate. Why operate when you know the result will be worse than what you started with?

But given all of that, what if the benefits of surgery are high and the risks are only small or moderate? Should we operate then? Should we always operate then?

Crucible Cover

A short story on Kindle—just 99¢. Click on image.

III. The Bottom Line

We’ve seen that when the benefits are very high, saving a life for instance, or eliminating intolerable pain, or preventing paralysis or blindness, surgeons are willing to operate even when the risks are very high as well. This is because one can reasonably presume that the higher the benefit of surgery, the greater the downside of no surgery. Operating on a tumor against the brainstem (arguably the highest priced real estate in the body) is dangerous, but the alternative, the downside of not operating—a slow and agonizing decline in which the patient will be severely incapacitated long before they are anywhere near death)—is unthinkable. Or how about a tumor growing inside the heart of a young adult? The risks of surgery in such a condition are extraordinary, but the potential benefit is as well—regaining an entire lifetime. The downside of no surgery in this situation is no future at all, which, for most of us, is unacceptable.

In such circumstances, most surgeons—and indeed most patients—are willing to go towards heroic measures. Fortunately, such cases are the minority, even for neurosurgeons and cardiac surgeons.

But what if the benefits of surgery are high and the risks are only small or moderate? Should we operate then? Should we always operate then?

Human beings are fallible creatures. We make mistakes. Mistakes are intangible and can’t be foreseen. If they could be, we might reasonably be able to quantitate them on an individual level. But we can’t quantitate them in that way. What we can do is quantitate them on a population-based statistical level.

We know, simply based on statistics, that no matter how good a person is, if they do something enough times, they are going to make mistakes. That’s part of the definition of being human. Humans make mistakes. They make more mistakes early on, while learning something, a procedure or an operation, but even later, when they have perfected it, they make mistakes. Otherwise, we’d all be robots.

Ever watch a major league umpire call balls and strikes. They’ve seen thousands of pitches, but still only get it right most of the time. 

So back to the question. What if the benefits of surgery are high and the risks are only small or moderate? Should we operate then? Should we always operate then?

No. 

Consider the individual with true sciatica, pain down the leg, and the usual cause of true sciatica, a pinched nerve in the lower back. This patient is in agony. There is an operation that can fix that, a lumbar microdiskectomy. It takes less than an hour, is done as an outpatient so our patient won’t even have to spend a night in the hospital, and the pain will be gone immediately (or very close to immediately). Neurosurgeons see these patients everyday. Now, assuming I could operate on everyone of these (I couldn’t, there isn’t enough time in all the world under the sun for that), should I?

No.

The risk is minor. Wound infection, a rare diskitis (more serious infection), recurrent pinching, the rare nerve injury, a transient spinal fluid leak, and the small but not zero risks of being put under and then awakened again.

So, high benefit, low to moderate risk. What’s not to like? Why not operate?

Two reasons. First, neurosurgeons know most of these pinched nerves get better on their own in four to six weeks or so. Operating on them at two weeks means I’d be subjecting a lot of folks to unnecessary risks, no matter how small. One fundamental tenant of surgery is to never operate unless you can improve upon the natural history of the disease or condition. No matter how good a surgeon I or anybody else might be, we will leave a scar in our wake. While not usually a problem, it could be. If the condition resolves on its own, there’s no scar to deal with. This is why surgeons in general and neurosurgeons in particular prefer pain patients to have tried nonoperative (conservative) measures before operating. To give time for mother natural to cure the condition without surgery, which is usually a better deal for the patient—if the patient can wait (which may or may not be the case).

And second? Because humans are fallible creatures. That’s right, that’s what it comes down to in the end. Humans make mistakes. That’s why the pilot of your airplane uses printed checklists for just about every phase of flight, so he or she won’t forget something. Surgeons use checklists too. It’s called a timeout. We use it to make sure we have the correct patient, the correct side and part of the body for surgery (wouldn’t want to take out the wrong kidney or off the wrong leg—don’t laugh, it’s happened), a correct list of allergies, the correct instruments to do the case (don’t want to get halfway into something and realize somebody left the crucial hammer or bolt at home), etc.

But, unfortunately, there is no checklist for the meat of the case. And here’s the real clincher: you don’t even have to make a mistake. Humans are not stamped out as carbons of one another. Even though the anatomy books say it should be one way, it may actually be another way in a given patient. 5% of folks have an extra lumbar vertebrae, six instead of the usual five. Sometimes, two nerve roots exit together at the same level, rather then the rule of one nerve root per exit. Things like this mean a surgeon can do their best on any given day and still have a lousy outcome. A patient can have an unusual susceptibility to infection, or be an unrecognized bleeder, or have an unanticipated allergic reaction to a drug. Anesthesiologists live in fear of something called malignant hyperthermia, which can drive a patient’s temperature to 106 in a matter of minutes and kill him in a matter of hours—even though they did everything right.

I can do this operation 1,000 times, and if I am perfect 99% of the time ten patients will still suffer some type of adverse outcome.

These sorts of things are the stuff of nightmares—and malpractice suits.

Most elective operations, probably better than 95%, go well in this modern age. Probably 90% of the remainder, those in which something out of the ordinary does happen, don’t cause any permanent harm. But sometimes, even under the best of circumstances and with the best of intentions, shit happens. 

So the bottom line is this. Don’t live in fear of surgery. If the benefits are high but the risks are just as great, much of the time surgery is reasonable and appropriate. Organ transplants, for instance, often fall into this category. If the benefit is marginal or small and the risks high, surgery is rarely offered.

But if the benefits are high and the risks only small or moderate, take a moment and reassess. Talk to your surgeon. Does the benefit really significantly cover the risk? If it does, and you feel the same, and you can accept the very small chance of some adversity creeping in where it isn’t wanted, then go for it.

Otherwise, understand it’s a wash and wait it out.

06/3/15
brain cancer

Brain Cancer

brain cancerBrain cancer is a disease that affects all ages and all races.

The death this week of Beau Biden, the son of the Vice President and an accomplished man in his own right, has shined a light on this terrible disease.

First, a few clarifications. Properly used, the very word cancer implies a malignant condition, that is, an aggressive disease in which abnormal cells grow with little restraint. Cancer is a diverse disease, some forms more treatable than others, but what all have in common is a genetic modification that allows unimpeded growth and an apparent lack of stickiness. Normal cells have a quality of stickiness that allows them to adhere to each other during the growth process. When things become too crowded, growth slows and stops. Tumor cells lack both the stickiness and the signal that stops growth. In vitro, which means in a petrie dish, these abnormal cells will grow into heaps of cells that die only when they outstrip their nutrient supply. In the body—in vivo—cancer cells overgrow and easily break apart from each other and migrate—called a metastasis—to other areas of the body (either through the blood or via invasion of local tissue). Think of these migrating cells as seeds in the wind. Where they might land is anybody’s guess, but when they find fertile soil (inside the brain or the liver or the lung, etc.), they grow and the whole process starts all over again.

brain met tumor

A metastatic brain tumor.

Incidentally, certain patterns are recognizable in how cancer cells metastasize through the body. It’s not really anybody’s guess where they might land. We’ve learned a great deal about the process of metastasis over the years. For example, one can think of the lungs as a great filter through which these cancer cells must pass. Why do cancer cells from the rest of the body have to pass through the lungs? Because of the way the circulatory system is organized. The heart is divided into two halves. The left side sends blood throughout the body with each squeeze. This is  oxygenated blood. Where does it get the oxygen? From the lungs, and it’s the job of the right side of the heart to send it’s entire output there. The returning blood, oxygenated blood, enters the left side of the heart and is eventually squeezed out to all points but the lungs.

With the above in mind, it’s easy to imagine the lungs being inundated with cells from all over the body. Some of these will be tumor cells and will grow into metastatic cancer balls. Once in the lungs however, these “mets” are free to break off into the now oxygenated blood returning to the left side of the heart—and then to all points north, including the brain. This is very common and it’s why brain mets often are a harbinger of a cancer out of control. If the cancer has made it to the brain, it can make it anywhere.

coronal meningioma

A benign brain tumor. This could be removed safely for a cure.

Brain tumors may be either malignant or benign. Benign tumors neither metastasize nor invade local tissue, and so, in theory at least, are curable with surgical excision alone. Unfortunately, even benign tumors inside the head are not always accessible to the surgeon and so as they expand they may cause trouble, and even death.

Malignant brain tumors, aka brain cancers, come in a variety of forms. The most common malignant brain tumor isn’t actually from the brain—it’s the metastasis alluded to above, a tumor from elsewhere in the body. Generally, these metastatic intracranial lesions can be controlled with surgery or radiation. But as noted above, they are often an indication the original disease hasn’t been controlled. Death often results from progression of the original disease and not the brain metastases.

brain tumor axial

A primary malignant brain tumor, a so-called butterfly glioma. This cannot be safely removed completely.

Primary malignant brain tumors, commonly referred to as brain cancer, are generally malignant tumors of the supporting substance of the brain, the glial cells. The most common glial cell is the astrocyte, which produces a tumor called an astrocytoma. When somebody speaks of a primary brain tumor that is a cancer, it is often an astrocytoma they are referring to. They come in four general varieties, grade I to grade IV, which in truth smear into one another. The higher the grade, the more malignant the tumor and the worse the prognosis. Grade IV astrocytomas generally become more common with advancing age but certainly do occur with some frequency after the age of thirty or so. Grade I and II are more common in younger people and children. Unfortunately, these lesser grade tumors often occur in areas where their removal is difficult or impossible. They are very slow growing however, and associated with many years of survival. Cure is possible in many cases.

The Grade IV astrocytoma is also known as glioblastoma multiforme, or GBM for short. It is the bane of the neurosurgeon’s existence because it is invariably fatal. It rarely metastasizes, but is highly aggressive in invading surrounding brain tissue and cannot be cured with surgery alone. Treatment involves a combination of surgery, radiation, and chemotherapy. Survival is measured in months to a year or longer. Sometimes much longer. GBM is one of the most malignant tumors the body is capable of producing. This is likely the kind of tumor that killed Beau Biden, as well as Sen. Ted Kennedy. It is also the tumor that likely killed William J. Casey, Director of the CIA during the Iran-Contra scandal (he was dramatically incapacitated and rendered unable to speak just hours before he was to testify before Congress; whatever he knew or participated in went to the grave with him, which has been fodder for the conspiracy theorists ever since).

Brain cancer endstage

CT of advanced brain cancer. On a normal CT, the right & left halves should mirror each other, unlike this. There is diffuse infiltration. The tumor is the dark area on the left image, which shows up as the blurred white borders on the right image, after IV contrast injection of the patient. The 3 black voids in the middle of each image are the ventricles. They are shifted over to one side, which is bad. Very bad actually. This patient is likely comatose and near death.

We know GBM is highly invasive because we can see it on brain studies, like MRI and CT. In the days before such modern imaging, brain surgeons tried doing lobectomies (removing an entire anatomic section of brain), and even hemispherectomies (removing fully half the brain!). Such radical therapy didn’t work however, and examination of brains removed at autopsy after such failed operations demonstrated why. GBM is a highly invasive disease that sends out tiny fronds of tissue to remote and distant parts of the brain. Even though we can’t see these fronds either grossly or on scans, we know they are there because after such radical operations, the tumors would recur on the other side of the head, making regrowth and subsequent death only a matter of time.

I often use the following analogy with my patients when discussing malignant brain tumors. Consider the brain itself to be a bucket of white paint. If the tumor is imagined to be red paint, one can see that even a single drop of the red paint admixed with the white will be impossible to remove once a little stirring occurs. This is the problem in treating brain cancer—remove 99.999% of the malignant cells, and the few remaining will eventually rise again to wreak havoc. This is why some brain cancer patients appear to be cured, even for long periods of time, only to succumb to a recurrence of their tumor.

Of course, the above is greatly simplified. Surgery is not the only treatment for primary brain tumors, or even the first-line treatment. Surgery kills the vast majority of cells by removing the greatest tumor burden. Chemotherapy and radiation therapy, or some combination of them, tries to remove the remainder. In general these kill only dividing cells however, and at any given moment only a fraction of the tumor cells are in the proper state of cell division to be affected by these potent drugs and radiation. This situation can be addressed by repeated courses of therapy—regular courses of therapy every week or month for some extended period of time. Each new course hopefully kills off more and more of the malignant cells, while not doing too much damage to the normal cells. Of course, the body’s normally rapidly dividing cells—hair, digestive tract—are killed with the tumor. This is the source of hair loss, nausea, diarrhea, etc.

Can brain cancer be prevented? The answer is yes and no. Some forms can almost certainly be watched for and prevented, such as hereditary cancers and those occurring after radiation to the head for some other reason. But for the most part, we don’t know why people get brain cancer and thus we don’t know how to prevent it. This includes cell phones by the way. Although the subject is somewhat controversial amongst the lay public, there does not appear to be any evidence to suggest that cell phones have increased the incidence of primary brain tumors.

There will be 70,000 new cases of primary brain tumors diagnosed in the US this year. 4,600 of these cases will be children (brain tumors are the most common solid cancers in children; leukemia is the most common cancer overall in children and also the leading cause of cancer related deaths in children and young adults). My own brother contracted leukemia in high school and died of complications from his treatment just after we graduated high school.

About 700,000 people are currently living with brain tumors in the US. The vast majority of these will not die of their disease.

About 14,000 people die of brain cancer each year.

03/24/15
back is killing me

9 Reasons Back Surgery Might Help

9 Reasons Your Back Pain Might Improve With Surgery—Or Not

back is killing me

Back pain is a fact of life—if you are a human being (and presumably if you are reading this you are) sooner or later you will have back pain. That’s the bad news.

The good news is that for most of us, it will run its course and we will be none the worse for it. Most of us will have a single bout, perhaps two, lasting a few hours to several days, and that will be it. Some of us will have more, and sometimes that will be recurring pain (every few months or once every few years as an example), or chronic low level discomfort that’s just enough to interfere with life’s enjoyment but not at all incapacitating.

Others will be saddled with incapacitating pain, though even then most folks will find a happy medium and be able to function with certain accommodations, as with any other chronic illness (diabetes, heart disease, kidney failure) or condition (rheumatoid or osteoarthritis, fibromyalgia, emphysema).

But for an unlucky few, and unfortunately the masses of people on this earth mean the numbers work out to hundreds of thousands each year, back pain just might be an indicator for back surgery. This sort of back pain typically doesn’t get better without surgery—or at least doesn’t get better quickly enough for we busy humans. That’s the bad news.

The good news is that for these few, back surgery is overwhelmingly successful.

Here are nine reasons your back pain might need to be treated with surgery.

1. If it’s associated with leg pain.

Back pain that’s associated with leg pain may indicate a pinched nerve. Although even then most of these won’t need surgery, if the pain becomes unrelenting or lasts more than two months, see a physician. This kind of pain generally responds well to surgery, especially if the leg pain is worse than the back pain.

In the overall scheme of things, back pain that is purely and truly back pain is rarely an indication for surgery, though there are always exceptions. There are hundreds of ligaments, bones, and nerves in the back and any one (or group) of them can be a pain generator. This sort of pain might be from a stress fracture, a pulled ligament, a small muscle tear, or any of a thousand other sources—most of little consequence in the long run and most of which will heal and resolve on their own, though it will almost always take longer than you would like or expect.

2. If it’s off the midline to one side or the other.

Back pain that’s off the midline may indicate a pinched nerve or arthritic joint on one side of the back. If it’s always in the same place, it might respond to fusing the joint, deadening the nerve, or decompressing (unpinching) a pinched nerve.

3. If it’s always in the same place and does not roam around.

Pain that will respond to surgery does not roam around. The intensity may vary, and frequently does, but the location of the pain is a constant. Usually it is one sided and off the midline of the spine.

Roaming back pain rarely responds to back surgery and seems more likely related to muscle strain or spasm, or perhaps has no relation to the back at all. 

4. If it’s associated with leg weakness as opposed to pain or numbness.

One of the most frequent back problems is a pinched nerve, and while these don’t always require surgery they certainly can. Leg weakness with back pain is one indication of a pinched nerve and generally indicates that surgery should be strongly considered, especially if it is severe or not getting better with time. In general, if weakness is present, see a physician sooner rather than later.

5. If it’s been present for more than 6-8 weeks and doesn’t seem to be getting better.

Most back pain is self-limited and improves even without therapy, though it takes time since something is wrong and that something takes time to heal. Sometimes pain itself is a diagnostic tool though, and pain that isn’t obviously improving after two months is such a tool and should be thoroughly investigated. 

By the same token, chronic back pain that has been present for more than 2-3 years and is stable is generally unlikely to have a surgically treatable cause, even if severe at times. However, such pain should be thoroughly investigated at some point (at least once) since exceptions do exist.

6. If it’s always present in the morning and does not improve as the day advances.

Back pain that is worse in the morning after just getting out of bed and improves with activity rarely responds to surgical intervention. This is often age related. There’s a reason professional athletes retire around age forty. 

On the other hand, if you have back pain from the time you get up and it consistently does not improve (or even worsens) with activity, you should see a physician if it persists over weeks or months.

7. If the pain increases with walking—until you MUST sit down or else.

Pain that consistently worsens with activity to the point of intolerability, especially if just sitting down for a few minutes improves or alleviates it (sitting for five or ten minutes, not an hour or two), may indicate narrowing in the spinal canal—a condition which responds very well to surgery.

8. If the pain is associated with trouble walking—and you can improve the walking by leaning over a shopping cart.

This is known as a positive shopping cart sign and is so suggestive of a problem that can be fixed that if you have noticed this you should discuss it with your physician. Note that the trouble walking may be pain or weakness or both. Sometimes patients complain of “rubbery legs.”

Typically a person notices these symptoms when grocery shopping—they have to both push the cart and lean forward over it in order to shop. Just hanging on to the cart has no effect, the uncomfortable pain persists. Typically, those with a surgically treatable problem get great relief leaning over the cart as they move around the store. In fact, leaning over the cart becomes a must and is the difference between being able to do their own shopping or not being able to shop at all.

As the severity of the condition progresses, even leaning over the cart becomes ineffective and patients stop doing their own shopping. They become homebound.

9. If the “back pain” is really buttocks and leg pain.

In general, the more leg pain one has, the more likely their problem is to be treatable with surgery. Surgery for back pain alone is, in general, a disappointing experience (except in cases of fracture, tumor, infection, or perhaps scoliosis), but back pain associated with leg pain is a different story.

To understand why, one has to consider the generalized nature of back pain, which makes it difficult to narrow down an exact cause and thus limits what surgery can do. However, the occurrence of leg pain often indicates a pinched nerve and since each nerve has a stereotypic course, the location of the leg pain often marks which nerve is pinched—and hence the location of the back problem—with more or less precision. Surgery can then unpinch, or decompress, the nerve.