Michael Morgan, AVMs, and the Spetzler Grading System

Michael Morgan, a neurosurgeon from Sydney, Australia and specialist in arteriovenous malformations (AVM) spoke today.  He has seen approximately 600 patients with AVMs and operated on 529 of them.  In his hands, the risks of a surgical resection of a SM grade 1 AVM is less than the risks of gamma knife.  It is also more commonly definitive therapy.  It is far less risky than Onyx embolization.  However, Dr. Morgan is a unique surgeon and not every surgeon is going to be able to achieve similar results.

Other interesting points from his lecture:

• The risk of hemorrhage from AVMs with no prior history of hemorrhage is approximately 1% per year.
• The risk of hemorrhage from AVMs with a prior history of hemorrhage is approximately 6% per year.

Another BMA Video: Reduction of Cervical Dislocations

Non-operative reduction of a cervical dislocation can be extremely difficult.  Even with modern techniques and technology, it is occasionally not possible to reduce a cervical subluxation non-operatively.  However, with modern anesthesia, muscle relaxants, and traction systems, it has to be much easier than what it was in 1936.

Here’s another video produced by the British Medical Association; this time demonstrating an attempted cervical reduction of bilateral jumped facets at C5-6.  The x-ray is striking.  Cases of such severe subluxation without spinal cord injury are rare.  The attempted reduction is brutal and ineffective.  Modern reduction techniques are much more controlled and safe.

Also shown is a case of unilateral subluxation in an infant after a tonsilectomy.  Although there are no x-rays, no images of the reduction procedure, and no follow-up, the pre-reduction examination is striking and informative.

This Isn’t a Nutrition Blog…Or the Fat Addiction

I don’t want to turn this into a nutrition blog, but I find some of the recent studies coming out on the science very interesting.  The evidence that there is an epidemic of obesity in our country is overwhelming.  And, more and more evidence is accumulating that dieting is not the answer.  It’s going to take more than just telling people to eat better and exercise more.

One aspect of nutrition that has probably been under-appreciated is the interaction of nutrition and neuroscience.  Well, thanks to a new study published in Nature Neuroscience, that may not be the case much longer.

Addiction to certain drugs, like cocaine and heroin, are accompanied by changes in the level of specific neurotransmitter receptors in the brain.  In a process called negative feedback, as the neurotransmitter level increases, the number and sensitivity of its receptors decrease.

The neurotransmitter most closely associated with addictions is dopamine.  Dopamine is active in the “reward” or “pleasure” centers in the brain.  One of these reward centers is called the striatum.  The authors showed that in rats exposed to chronic high fat foods, the level of the dopamine receptor D2 in the striatum is decreased.  That means that it would take even more fatty food to get the same pleasure response.  In other words, this is the first clear evidence that fatty foods are addictive.

From a neurosurgical perspective, this is very interesting.  Neurosurgeons are able to modulate brain activity in specific regions of the brain by implanting electrical stimulators.  Current surgical techniques for the treatment of obesity (called bariatric surgery) are principally performed by general surgeons.  Procedures including gastric bypass, banding, stomach stapling, and others are accompanied by severe side effects.  They also carry risks of vitamin deficiencies.  Furthermore, although there are many successful outcomes from the surgery, there are failures as well.  A deep brain stimulator could be a very attractive alternative.

Video of a Craniotomy in 1932

Someone posted on Youtube footage from a craniotomy in 1932.  From the British Medical Association Library, the video shows a “Prefrontal Tuberculoma: Removal with complete recovery by Prof. R. E. Kelly and Dr. Henry Cohen.”

The film is full of historical gems:

• A diagnositic pneumoencephalogram which demonstrates compression of the right lateral ventricle with midline shift.
• A hand-powered Souter’s craniotome.  Even after watching it several times, I cannot completely understand how it worked.
• Manual dissection and excision of the tumor.
• Tumor histology with silver stains
• Post-operative follow-up evaluation of the patient.  Although the patient had a significant hemiparesis, he looked remarkably good.

It really is incredible.  Advance upon advance has dramatically changed the way modern neurosurgery is performed.  Yet, there is an eerie similarity in the video as well.  Maybe it’s because, like what Sir Isaac Newton said, if we see a little further, it is by standing on the shoulders of these giants.

(H/T Mindhacks)

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.

Errata

1.  I met Chris Shaffrey from the UVA Department of Neurosurgery.  He’s a specialist in spinal disorders with an emphasis on spinal deformity.  I came away very impressed, particularly with his evidence-based approach to spine surgery.

2.  X-rays can miss many fractures.  It has long been debated about the relative cost-benefit ratio of x-rays versus computed tomography (CT) for spinal fractures after trauma.  X-rays are much cheaper.  CT scans are much more thorough and sensitive.  This paper suggests that more fractures may be missed by traditional x-rays than had previously been thought.  Perhaps a CT scan is worth the additional cost.

3.  Vycor medical products has developed a novel brain retractor called the Viewsite.  Traditionally, malleable blade retractors have been used to retract the brain during a neurosurgical procedure.  These retractors have many limitations:  they concentrate the retractive force on a small segment of brain; they have sharp edges that can cut into the brain; they are opaque blocking visualization of tissues behind the retractor.  The Viewsite uses a novel circumferential retraction system to distribute the retractive force on a wider surface.  Here’s how the company describes it:

The ViewSite™ Brain Access System is a revolutionary approach in brain retraction. Each ViewSite system consists of an introducer and a working channel port that allows the surgeon a seamless entry to the targeted site while distributing brain tissue evenly in a 360° dispersion pattern. Other ViewSite benefits include superior binocular vision to see in and around the surgical site; multiple sizes in different widths and lengths to meet all surgical needs and compatibility with most surgical arms to avoid accidental displacement or movement during surgery.

Penetrating Trauma

An x-ray of the skull demonstrates a knife entering the right temple and transiting the brain until it protrudes from the left temple.

If you get stabbed in the brain with a knife, you are going to die, right?  Maybe not.  Brain trauma comes in a variety of forms, but can generally be divided into two categories:  blunt and penetrating.

Blunt trauma, the kind that typically results from car accidents or falls from height, is far more common.  The head strikes a hard surface, resulting in a rapid acceleration or deceleration.  This results in differential forces passing through the brain parenchyma.  The differential forces cause microscopic tears in the brain (sheer injuries) as it shakes around inside the skull.  Microscopic injury throughout the brain is called diffuse axonal injury.

Penetrating trauma, on the other hand, occurs when a bullet, knife, or other object passes through the skull into the brain.  Like blunt trauma, gunshot wounds can send shockwaves through the brain as the kinetic energy from the bullet get transferred to the brain.  This results in diffuse injury and is commonly fatal.  Knife injuries, however, are unique.  They don’t send shockwaves, therefore the injury to the brain is localizes to site of the wound.   That means that if a knife penetrates the brain but does not damage a major blood vessel (which would cause a stroke), only a relatively small amount of the brain gets damaged.  That is not to say that a knife wound to the head is not dangerous; it is.  However, the  majority of the risk comes from potential injury to important blood vessels.  There is no diffuse injury.

The patient seen above, was unlucky because he was stabbed in the head with a knife.  However, he was also extremely lucky.  The blade missed all of the important blood vessels.  In fact, the patient actually walked into the emergency department with the knife buried deep in his skull.  He had to be taken to surgery for removal of the knife and is currently convalescing.

During his recovery, he needs to be watched carefully for signs of infection or seizures – common consequences of penetrating trauma.  Usually, patients are given prophylactic therapy for both.

For more details, see the Telegraph article.

Errata

Today was match day.  Congratulations to all of those who matched in neurosurgery and welcome to the profession.  I know that we are very happy with the students who matched at our program.  The quality of the applicants this year was outstanding, as always.  There are so many qualified individuals that it really is hard to go wrong.  The residency is a long but rewarding seven years.

If you are looking for a book that will change the way you look at the world, you might want to check out Moneyball by Michael Lewis.  It tells the story of how Billy Beane and Paul DePodesta, management of the Oakland A’s baseball team, revolutionized the sport in the last decade.  The most interesting part is the way they did it:  they took 100 years of baseball history and tradition and threw it out the window.  Instead they reduced baseball to a series of probabilities and mathematical equations.  They used hard data to identify not only what the most successful plays are, but also to find the characteristics of the most successful players.  Then, they looked for players that fit that model.  And, to put it bluntly, they found that the entire major league had been looking for the wrong players.  For a few brief years, they were able to produce a highly successful baseball team disproportionate to their payroll.

It really makes you wonder, “How could I improve my life, achievements, etc., if I had better data?”

Errata

1.   Robert Ojemann has passed away… From boston.com

Dr. Ojemann came to Massachusetts General Hospital in 1957 as a resident in neurosurgery, was named professor of surgery at Harvard Medical School in 1979, and remained on the staff of MGH and the faculty of Harvard for the remainder of his career.

Brain tumors and cerebrovascular disease were Dr. Ojemann’s clinical and research focus. He published more than 200 articles and chapters on these and other topics and coauthored several books, including “Surgical Management of Cerebrovascular Disease,’’ one of the first books on the subject.

2.   Ryan Westmoreland, a minor league outfielder in the Boston RedSox organization will be undergoing brain surgery for a cavernoma tomorrow (Tuesday, March 16).

3.   March madness is here.  I have never had such trouble picking the bracket; not that I ever spent that much time on it before.  However, much of my angst arises from the fact that three of my final four favorites are all in the same bracket.  I wonder what the committee was thinking putting Georgetown, Kansas, and Ohio State together.  I’m not the only one. Gary Parrish, you took the words right out of my mouth.  And don’t even let me get started on the treatment of the “mid-majors.”

1. Being the No. 1 overall seed kind of sucks: Kansas spent four months assembling the nation’s best body of work, and for that Bill Self was rewarded with a region featuring the CBSSports.com National Player of the Year (Ohio State’s Evan Turner), three prospects expected to go in the top 10 of June’s NBA Draft (Turner, Georgia Tech’s Derrick Favors, and Georgetown’s Greg Monroe), eight other conference tournament champions (Ohio State, San Diego State, Northern Iowa, New Mexico State, Houston, Ohio, UC Santa Barbara, Lehigh), seven other Final Four coaches (UNLV’s Lon Kruger, Michigan State’s Tom Izzo, Maryland’s Gary Williams, San Diego State’s Steve Fischer, Georgetown’s John Thompson III, Georgia Tech’s Paul Hewitt and Ohio State’s Thad Matta), and five teams that own wins over top seeds (Tennessee beat Kentucky and Kansas, Georgetown beat Duke and Syracuse, Georgia Tech beat Duke, Maryland beat Duke, and Oklahoma State beat Kansas). Seriously, only two schools beat KU this season, and the committee stuck both of those schools with KU in the Midwest. So congrats on the overall No. 1, Jayhawks. And good luck trying to navigate through what is clearly the most difficult region (more on this later).

2. The plan is to make the good non-BCS teams eliminate the other good non-BCS teams: I suppose (or at least I hope) it’s a coincidence, but it seems every year one of the non-BCS teams most likely to make a run in this event gets paired with another non-BCS team that’s likely to make a run in this event. This year’s best example is a first-round game in the West between Butler and UTEP. I said last week that the three non-BCS schools with the best chance to make the Sweet 16 were New Mexico, Butler and UTEP, and now either Butler or UTEP is guaranteed to have its season end Thursday because of an unfortunate pairing.

3. Duke should be tested in the second round: I had West Virginia as a one seed instead of Duke, but it’s not like the Blue Devils didn’t have a reasonable claim. They won the ACC regular-season title and tournament title, finished with an RPI rated third and a schedule rated eighth. In other words, I’m OK with it. But I won’t be surprised if Duke gets challenged in the second round, because the Blue Devils will play either California (the Pac-10 regular-season champs that were a preseason top 15 team) or Louisville (a 20-win team that played a schedule rated seventh and beat top seed Syracuse twice).

Errata

Americans don’t like waiting for anything. It’s hard enough waiting for the microwave, or a red light. But how would you like to wait 17 months for your neurosurgeon?  That’s how long they are waiting in New South Wales.  It’s not the only place they are struggling.  Queensland is suffering from a shortage of neurosurgical services too.  I think I could appreciate the land down under.

Integra is launching a new system for minimally invasive spine surgery called Paramount.

Welcome to the next generation of advertising:  neuromarketing. Companies are using brain scans to look at consumer responses to products that they can’t get from satisfaction surveys.  As if subliminal messaging in advertising weren’t enough.