Kayak Commercial of Brain Surgery

Errata

1. Thiago Alves, one of the stars of mixed martial arts and the Ultimate Fighting Championship has withdrawn from UFC 111 due to an irregularity found on a CT scan.  He is scheduled to undergo an angiogram on Wednesday.

The CT scan was a routine part of his preoperative medical clearance for the fight.  An “irregularity” was found in the left side of his brain.  It likely represents some kind of vascular anomaly, given the choice of an angiogram to further characterize the lesion.  It has been reported that it is not an aneurysm.  Some of the more common vascular anomalies include arteriovenous malformations, cavernomas, and dural arteriovenous fistulas.  An old stroke would also be visible on a CT scan.  The presence of a stroke could be suggestive of a traumatic vascular dissection, which could also be detected via angiogram.

Lateral cerebral angiogram after contrast injection into the common carotid artery

An angiogram defines the vascular anatomy providing blood supply to the head.  It is a relatively minor procedure.  A small catheter is inserted into an artery, usually in the groin or arm, and then directed to the cerebral blood vessels.  At that point, a small amount of contrast is injected into the blood vessels.  Fluorscopy pictures detect the contrast showing the anatomy and general flow characteristics of the blood vessels.  Abnormalities of the blood vessels can be readily observed.

The good news is that Alves is expected to be able to return to the octagon soon.

2.  Mexican americans, women, and persons who live alone are the least likely to pursue emergency medical assistance following a stroke reports Businessweek.

3.  Neurosurgery better than ‘Avatar’? An operation in Liege, Belgium was recorded in 3-D and transmitted to a local movie theater.  The audience was apparently able to interact with the surgeon in real-time.  I guess I don’t have to give up on my Hollywood aspirations quite yet after all.

The Perils of HFCS

I was wrong.  I was always of the philosophy that a calorie was a calorie was a calorie.  That obesity was based upon a simple formula:

weight change = [calories in] – [calories out]

In other words, if you spent more calories than you consumed, you lost weight.  If you consumed more calories than you spent, you gained weight.

However, a recent study published in the Journal of Pharmacology, Biochemistry, and Behavior suggests that all calories are not created equal.

All calories may not be created equal

The authors fed three groups of rats: one group was given regular chow ad lib.  The second group was given regular chow ad lib and supplemented with sucrose.  The third group was given regular chow ad lib and supplemented with high fructose corn syrup (HFCS).  Although the overall number of calories consumed by the sucrose group and the HFCS groups were the same, the HFCS group gained significantly more weight.

It gets even more interesting.  Fructose, on a per calorie basis, is much sweeter than sucrose.  That is why it has replaced sugar in many food items, particularly soft drinks.  The manufacturer can maintain the sweetness of the product while including fewer calories – tastes great and less filling, or at least fewer calories.

In the current study, however, the sucrose and the HFCS group consumed a similar number of calories overall.  But the HFCS group actually obtained a smaller percentage of their calories from the corn syrup.  The study suggests that the HCFS was able to drive more calories towards becoming fat than sucrose, even when HCFS made up a lower percentage of the total caloric intake.

Actually, this does make sense from a biochemical standpoint.  Fructose is not like the other sugars common in our diet.  Nicholas J Krilanovich described it nicely in a letter to the American Journal of Clinical Nutrition:

Basic biochemistry indicates that glucose and fructose have different chemical properties. Of the 3 major sugars that digest into the human bloodstream, the 2 that are vital to humans, galactose and glucose, are both aldoses, whereas fructose is a ketose—this sugar is the one that the human liver tries hard to keep at essentially a zero concentration in the blood. Murray et al (10) wrote that, “Biomedically, glucose is the most important monosaccharide and ingestion of large quantities of fructose has profound metabolic consequences …because it bypasses the regulatory step catalyzed by phosphofructokinase. This allows fructose to flood the pathways in the liver, leading to enhanced fatty acid synthesis, increased esterification of fatty acids, and increased VLDL secretion, which may raise serum triacylglycerols and ultimately raise LDL cholesterol concentrations.”

I am definitely going to pay more attention to the amount of HFCS I consume.  Perhaps, my math has been wrong all along.  I all likelyhood:

weight change does not equal [calories in] – [calories out]

Cavernous Hemangiomas

As previously noted, one of the top prospects in the Boston Red Sox organization, Ryan Westmoreland, has been diagnosed with a cavernous hemangioma.  He is going to undergo surgery.  I thought this might be an opportune time to discuss the nature, management, and prognosis of cavernous hemangiomas.

Cavernous hemangiomas, also known as cavernous malformations or
cavernomas, are uncommon vascular anomalies.  It is uncertain whether they occur de novo or can develop throughout life.  They consist of a bundle of large, thin-walled blood vessels without any intervening brain.

They cause problems because they can bleed into the brain.  Unlike the arteriovenous malformation (AVM), cavernous malformations are a relatively low-pressure system.  That means that they generally not capable of the high-pressure, extensive hemorrhages that characterize AVMs and aneurysms.  They can, however, cause problems.  Usually, when a cavernoma is found, it has a characteristic appearance on an MR scan commonly called a popcorn lesion.  The popcorn effect is due to the multiple small hemorhages surrounding  the cavernoma.  A cavernoma is most readily apparent on a gradient echo series because of the local hemosiderin staining.

The majority of cavernomas are supratentorial (80%), but they can also occur in the cerebellum, brainstem, and spinal cord.  Symptoms are derived from dysfunction of affected adjacent structures.  Supratentorial lesions rarely induce symptomatic hemorrhages.  More frequently, supratentorial cavernous hemangiomas induce seizures.

Hemorrhages from cavernomas of the brainstem and spinal cord frequently cause more symptoms.  In the brainstem and spinal cord, smaller hemorrhages are more likely to damage vital territory such as motor and sensory function.

The risk of symptomatic hemorrhage from a cavernous malformation is approximately 1% per year.

Surgery for cavernomas is not emergent.  Frequently, however, it is most convenient to pursue surgery shortly after a hemorrhage.  The hemorrhage can help in localization of the cavernoma.  It can also partially dissect the cavernoma free facilitating it’s removal.  This also permits the patient to recover from both surgery and the hemorrhage simultaneously instead of sequentially.

Most cavernomas are sporadic, although there is a familial form that is most common in hispanics.

10 Rules for Writing Fiction

The Guardian published a collection of rules for writing fiction from leading authors.  Although specifically directed at fiction, I think that much can be ported to other forms of writing.  Some of my favorites:

My most important rule is one that sums up the 10: if it sounds like writing, I rewrite it.

Read it aloud to yourself because that’s the only way to be sure the rhythms of the sentences are OK

You don’t always have to go so far as to murder your darlings – those turns of phrase or images of which you felt extra proud when they appeared on the page – but go back and look at them with a very beady eye. Almost always it turns out that they’d be better dead.

Do be kind to yourself. Fill pages as quickly as possible; double space, or write on every second line. Regard every new page as a small triumph –  Until you get to Page 50. Then calm down, and start worrying about the quality. Do feel anxiety – it’s the job.

Do change your mind. Good ideas are often murdered by better ones.

Reread, rewrite, reread, rewrite. If it still doesn’t work, throw it away.

Keep a diary. The biggest regret of my writing life is that I have never kept a journal or a diary.

Have more than one idea on the go at any one time. If it’s a choice between writing a book and doing nothing I will always choose the latter. It’s only if I have an idea for two books that I choose one rather than the other. I always have to feel that I’m bunking off from something.

The way to write a book is to actually write a book. A pen is useful, typing is also good. Keep putting words on the page.

The main rule of writing is that if you do it with enough assurance and confidence, you’re allowed to do whatever you like. (That may be a rule for life as well as for writing. But it’s definitely true for writing.) So write your story as it needs to be written. Write it honestly, and tell it as best you can. I’m not sure that there are any other rules. Not ones that matter.

Read widely and with discrimination. Bad writing is contagious.  Don’t just plan to write – write. It is only by writing, not dreaming about it, that we develop our own style.

Remember you don’t know the limits of your own abilities. Successful or not, if you keep pushing beyond yourself, you will enrich your own life – and maybe even please a few strangers.

Remember, writing doesn’t love you – it doesn’t care.

My main rule is to say no to things like this, which tempt me away from my proper work.

Don’t look back until you’ve written an entire draft, just begin each day from the last sentence you wrote the preceeding day. This prevents those cringing feelings, and means that you have a substantial body of work before you get down to the real work which is all in . . .the edit.

You know that sickening feeling of inadequacy and over-exposure you feel when you look upon your own empurpled prose? Relax into the awareness that this ghastly sensation will never, ever leave you, no matter how successful and publicly lauded you become. It is intrinsic to the real business of writing and should be cherished.

The nearest I have to a rule is a Post-it on the wall in front of my desk saying “Faire et se taire” (Flaubert), which I translate for myself as “Shut up and get on with it.”

Turn up for work. Discipline allows creative freedom. No discipline equals no freedom.

First Principles

Medicine is so complicated.  Even if you narrow it down to a specific specialty like neurosurgery, there is so much to know.  There are myriad neurosurgery textbooks.  Perhaps the most definitive is Youman’s, a mere four volumes of 1500 pages each.

You need to be able to manage a lot of information for many professions.  In order to do this, organization is critical.  But it can be done, and it is done by many.

Amongst the volumes of information available, some facts are more important than others.  I like to call the most important things “First Principles.”  Every concept, every dilemma, every problem facing a surgeon should be framed according to the appropriate First Principles.

Frequently, the First Principles are clearly defined.  In the field of medicine, the First Principles were described 2,000 years ago by Hippocrates.  When a physician addresses a patient, these principles are reviewed and guide subsequent actions.

This is the art of medicine: it lies in recognizing the key features of a situation and then identifying the appropriate First Principles to apply in the management.

Here are some of the first principles:

1. First, do no harm.
2. The needs of the patient come first.  (But not the wants of the patient.)
3. Apply your skills and abilities for the healing of the sick and afflicted to the best of your abilities.
4. Maintain personal standards in line with upholding the nobility of the profession.

Sun Tzu’s Art of War

• Know your enemy, and know yourself, and in 100 battles, you will never be in peril.
• To win 100 battles is not the height of skill – to subdue the enemy without fighting is.
• Avoid what is strong.  Attack what is weak.
• It is more important to out-think your enemy than to outfight him.
• Numbers alone confer no military advantage.
• Do not advance relying on sheer military power.
• Let your plans be as dark as night, then strike as a thunderbolt.
• There are five fundamental factors for success in war: weather, terrain, leadership, military doctrine, and most importantly, moral influence.
• To move your enemy, entice him with something he is certain to take.
• A victorious army sees the conditions for victory and then fights to achieve them.  A losing army fights and then looks for favorable conditions.
• All warfare is deception.

Risk of Hemorrhage from Known Aneurysms

The International Study on Unruptured Intracranial Aneurysms (ISUIA) has greatly changed our understanding of the risk of hemorrhage from aneurysms found on incidental imaging.

With improving technology, our ability to image the brain has vastly improved.  CT scans and MRI can sometimes identify details measuring mere millimeters.  We are now seeing smaller aneurysms in routine scans because our ability to detect them is so much better.  Furthermore, scans are being performed more frequently.  These two facts have posed a new dilemma for vascular neurosurgeons.  They are seeing vast numbers of incidental aneurysms in otherwise healthy and normal patients.

Aneurysms are deadly.  Mortality from aneurysmal subarachnoid hemorrhage is roughly 50%.  Some of those who survive will be permanently disabled.  Therefore, there is strong motivation to treat unruptured aneurysms.  However, treatment is not without risk either.  In the best hands, the risk of an adverse event, meaning major neurologic injury or death, associated with intervention is about 3%.

Obviously, a rational person would take the 3% risk over a 50% risk, right? Not so fast my friend! The problem is that when an incidental aneurysm is found, one that hasn’t ruptured, we do not know if it will ever rupture.  If it is going to rupture, the results can be catastrophic, and we would want to treat it.  But, if it is not going to rupture, clearly it should be left alone.

And thus Schroedinger’s Cat is brought from theory into the real world, where life itself hangs in the balance.  Fortunately, our understanding of the natural history of incidental unruptured intracranial aneurysms is improving, largely through the efforts of the International Study on Unruptured Intracranial Aneurysms (ISUIA or ish – oo – ah).  Historically, it was extremely difficult for a neurosurgeon to simply watch a patient with an unruptured aneurysm.  But we are finding that the risk of rupture of an incidental aneurysm is far less than what had previously been believed.  Now, an unruptured intracranial aneurysm can be observed or treated with smaller aneurysms more likely to be observed and larger aneurysms more likely to be treated.

Below is a summary table of the average risks of aneurysmal subarachnoid hemorrhage as observed in ISUIA.

Risk of Rupture per Year
Aneurysm size (mm) .	<10	10-25	>25
No Prior SAH (Group 1)	0.05	1	6 (first year then 1)
Prior SAH (Grp 2)	0.55	1	-

Simpson Grading of Meningioma Resection

Simpson Grade	Completeness of Resection	10 Year Recurrence
I	Complete removal including resection of underlying bone and dural attachments	9%
II	Complete removal and coagulation of dural attachments	19%
III	Complete removal without resection or coagulation of dural attachments	29%
IV	Subtotal resection	40%

Psychiatric Surgery

Psychiatric disorders can be utterly disabling.  Major depression can rob a patient from any enjoyment of life.  Schizophrenia can interfere with perception of reality.  Obsessive-compulsive disorder can force a patient to perform repetitive, irrational activities in spite of the patient’s recognition of the irrationality.

Neurosurgeons have long had an interest in psychiatric disease.  But, frequently, such interest has been at the fringe as opposed to a mainstream focus.  One reason for relegating psychiatric disorders to the fringe is the black eye that surgical approaches to psychiatric disorders received in the past.  The frontal lobotomy may have principally been promoted and performed by a neurologist, but the first operations were performed by neurosurgeons.  And who can blame the neurosurgical community for distancing itself from all of the negative publicity that the frontal lobotomy subsequently generated.

The frontal lobotomy failed for several reasons.  First and foremost, the brutal procedure was widely and wantonly performed without careful review and scrutiny of the outcomes.  The procedure was performed for almost any psychiatric disorder without adequate patient selection or identification of appropriate indications.  There are anecdotal reports of patients benefiting from the procedure, but this is hard to rationalize given all of the patients who were devastated.

Some things, however, Walter Freeman got right.  Psychiatric disease is organic.  It is not some spiritual or ethereal event, and it is definitely not deliberate on the part of the patients.  Actual physical, anatomic, and biochemical flaws are at the root cause.  These flaws have been very difficult to study because of a lack of model systems to study the disease.  Psychiatric disorders in animals poorly replicate their human equivalents.

On the other hand, neurosurgeons have long been involved in the treatment of movement disorders.  Patients with parkinsonism, dystonia, and essential tremor benefit greatly from new technologies such as deep brain stimulators.  This is due, in large part, to our excellent understanding of motor pathways in the central nervous system and the pathology that results in disease.  This allows us to intervene at key loci to restore more normal function.  Historically, this was accomplished by creating lesions in the brain, but now it is done with deep brain stimulators (DBS).  DBS has been widely successful because it is largely reversible, titratable, and quite safe.