The controversial health topic du jour is chronic cerebrospinal venous insufficiency or CCSVI as an explanation for multiple sclerosis, postulated by Dr. Paolo Zamboni. CCSVI can be described as narrowing in the veins which take blood away from the brain. This results in a backup of venous blood in the brain, perhaps leading to a buildup of toxins which may or may not include iron, ultimately culminating in multiple sclerosis. Or does it?
The traditional explanation for MS is that the body's immune system attacks nerves, destroying a necessary component for signal transmission. Myelin, as it's known, wraps around a nerve and prevents electrical signals passing down the nerve from weakening. Without it, a person trying to walk is no more able to move their leg than you are able to use a train without tracks.
Clearly, these two theories do not mesh. While there is a great deal of established research on the conventional MS disease pathway, CCSVI does not have a track record outside of a few unblinded, non randomized trials. Nevertheless, a cottage industry based on CCSVI has sprung up, with many MS patients paying out of pocket to undergo a vein widening procedure known as the "liberation treatment" in hopes of finding salvation from a debilitating and ultimately deadly condition. A great clamoring has arisen from MS patients the world over for their governments to investigate and pay for the procedure, even as Dr. Zamboni himself says it is premature to get the surgery outside of a trial.
The problem I have with the liberation procedure is it just smells like so much snake oil. Hasn't this all been done before? Remember the Q-Ray? Liquid Oxygen? The Toronto Maple Leafs? All the classic signs are there: anecdotal evidence of effectiveness, appeals to emotion, desperate people crying out for help, claims of a conspiracy among large corporations to keep the status quo. They're all the same arguments homeopathy practitioners use to justify what they do.
Let's take a look at the arguments for. Trials? Dr. Zamboni's claim of 95% of MS sufferers having narrowed veins has not been replicated in independent investigations. The real number may be as low as 40%, and that's with 20% of non-MS sufferers having narrowed veins as well. This is on top of the fact that it is difficult to define what constitutes a "narrowed" vein, and that it's not clear whether vein stenoses are cause or effect from MS.
Further, there are zero randomized, controlled trials showing clear improvement in people who are liberated. I know lots of people don't care about trials, but if you want government funding or large scale research to move in a direction, this is not only fundamental but vital. All that's been presented is a collection of tales about people who were liberated, with no measure of how many got better/worse, how much better/worse. Not to mention if anyone died from the procedure. It's happened. These stories might be good enough to make a commercial, but not good enough to convince a doctor to send his patients for the treatment. Nuh-uh..
Additionally, most of the people who receive the procedure are of the relapsing-remitting type of MS, which gets better and worse for all sorts of reasons, including pregnancy, seasonal change, getting a cold, and stress. If getting stressed affects the degree of MS disability, I'm sure that sticking a wire in someone's leg, moving it up into their internal jugular vein and jiggling it around isn't a completely MS symptom neutral procedure. Doesn't mean it's a cure though. These people on the procedure weren't off their normal MS drugs either, which makes it pretty hard to figure out which therapy was the one doing the heavy lifting.
Finally, what about the rest of MS? Does living in Canada cause narrowed veins? Because there are more in Canada than anywhere else. Do women have more narrowed veins than men? Not according to the research, but more women have MS.
I realize I must sound horribly pessimistic and negative to someone with MS, perhaps even dangerous to someone who may have been liberated with good results. If anything, the arguments for CCSVI and liberation only go to show how desperate MS patients are for a cure. But let me put it to you this way. You've aligned with an unknown, unproven, untested theory. Fine, you believe whatever you want. But if you're wrong, you've just helped waste a king's ransom in research money that would have brought us a real cure sooner.
Sunday, September 26, 2010
What happens in a heart attack?
What happens in a heart attack?
The most common presentation of someone who's had or having a heart attack is squeezing/crushing chest pain which is worse with exertion, shortness of breath, nausea and sweating. However, the vast majority of people with those symptoms who show up in the emergency department end up not having a heart attack. It could be indigestion, muscle strain, pneumonia, etc. Also, many heart attack patients don't have any symptoms that are remotely close to what is described in medical school as being typical. Thus, the first thing that happens in a heart attack is trying to figure out if it's a heart attack or not.
A heart attack (or myocardial infarction) is when there is insufficient blood supply to the heart. This can be caused most commonly by a clot that gets stuck in one of the vessels supplying the heart, or by narrowing of the vessel by cholesterol plaques. The cure for this is to either break up the clot (thrombolysis), use a flexible needle to snake into the blocked vessel and expand it open with an inflatable balloon (percutaneous coronary intervention), or open heart surgery with replacement of the blocked vessels with normal vessels from somewhere else in the body (coronary artery bypass graft).
This is how people get to those treatments.
The first health care providers to get to a patient are the paramedics. If there's chest pain, they pretty much always do a quick electrical scan of the heart, called an electrocardiogram, or ECG/EKG. If there's a pattern known as ST segment elevation, it's as emergency as emergency gets. These people need to get to a hospital for thrombolysis, or PCI, or CABG if PCI is not possible. Not all hospitals have PCI and CABG available but they all have thrombolysis medication. Generally, thrombolysis is tried first unless the patient can get to a PCI capable hospital fast enough. If thrombolysis doesn't work, patients are sent to a PCI and CABG ready facility.
But let's say the paramedics don't see any ST elevation on their ECG. The patient is then brought to the emerg where they're treated with a chest pain protocol which usually involves aspirin, oxygen, nitroglycerin and something for pain if the paramedics haven't already given it. In addition another ECG is done just in case the heart attack was missed. Again, if ST elevation is seen, get the clot buster/PCI going. The faster a heart attack is treated, the better off the patient is.
A set of blood work called a troponin is also drawn. This is a chemical in the blood that is released from damaged heart muscle. If it's positive, it usually means a heart attack has happened. However, the kind of heart attack you get with a positive troponin and a normal ECG is not treated with emergency thrombolysis/PCI/CABG, but the patient is admitted to the hospital for treatment and investigation, potentially leading to PCI or CABG in the days following admission. Troponins can take up to six hours to turn positive, so a rule of thumb is that anybody being investigated for a heart attack needs to have a second set of troponin drawn six hours after their symptoms were the worst. It's a big pain to wait and yes the emergency room is boring, but hey. Let's not mess around with yer ticker.
Chest xrays and additional bloodwork are also completed, just to make sure there isn't another disease that feels like a heart attack going on.
I can't count how many people I've seen who had chest pain that sounded just like a textbook heart attack, but had negative ECGs, negative bloodwork and negative chest xray. These people don't get kicked out the door with a clean bill of health. They get seen by a cardiologist sometime after they leave the ER for an examination and stress tests to make one hundred percent sure there isn't a heart problem. Just because you didn't have a heart attack doesn't mean you don't have heart disease.
The most common presentation of someone who's had or having a heart attack is squeezing/crushing chest pain which is worse with exertion, shortness of breath, nausea and sweating. However, the vast majority of people with those symptoms who show up in the emergency department end up not having a heart attack. It could be indigestion, muscle strain, pneumonia, etc. Also, many heart attack patients don't have any symptoms that are remotely close to what is described in medical school as being typical. Thus, the first thing that happens in a heart attack is trying to figure out if it's a heart attack or not.
A heart attack (or myocardial infarction) is when there is insufficient blood supply to the heart. This can be caused most commonly by a clot that gets stuck in one of the vessels supplying the heart, or by narrowing of the vessel by cholesterol plaques. The cure for this is to either break up the clot (thrombolysis), use a flexible needle to snake into the blocked vessel and expand it open with an inflatable balloon (percutaneous coronary intervention), or open heart surgery with replacement of the blocked vessels with normal vessels from somewhere else in the body (coronary artery bypass graft).
This is how people get to those treatments.
The first health care providers to get to a patient are the paramedics. If there's chest pain, they pretty much always do a quick electrical scan of the heart, called an electrocardiogram, or ECG/EKG. If there's a pattern known as ST segment elevation, it's as emergency as emergency gets. These people need to get to a hospital for thrombolysis, or PCI, or CABG if PCI is not possible. Not all hospitals have PCI and CABG available but they all have thrombolysis medication. Generally, thrombolysis is tried first unless the patient can get to a PCI capable hospital fast enough. If thrombolysis doesn't work, patients are sent to a PCI and CABG ready facility.
But let's say the paramedics don't see any ST elevation on their ECG. The patient is then brought to the emerg where they're treated with a chest pain protocol which usually involves aspirin, oxygen, nitroglycerin and something for pain if the paramedics haven't already given it. In addition another ECG is done just in case the heart attack was missed. Again, if ST elevation is seen, get the clot buster/PCI going. The faster a heart attack is treated, the better off the patient is.
A set of blood work called a troponin is also drawn. This is a chemical in the blood that is released from damaged heart muscle. If it's positive, it usually means a heart attack has happened. However, the kind of heart attack you get with a positive troponin and a normal ECG is not treated with emergency thrombolysis/PCI/CABG, but the patient is admitted to the hospital for treatment and investigation, potentially leading to PCI or CABG in the days following admission. Troponins can take up to six hours to turn positive, so a rule of thumb is that anybody being investigated for a heart attack needs to have a second set of troponin drawn six hours after their symptoms were the worst. It's a big pain to wait and yes the emergency room is boring, but hey. Let's not mess around with yer ticker.
Chest xrays and additional bloodwork are also completed, just to make sure there isn't another disease that feels like a heart attack going on.
I can't count how many people I've seen who had chest pain that sounded just like a textbook heart attack, but had negative ECGs, negative bloodwork and negative chest xray. These people don't get kicked out the door with a clean bill of health. They get seen by a cardiologist sometime after they leave the ER for an examination and stress tests to make one hundred percent sure there isn't a heart problem. Just because you didn't have a heart attack doesn't mean you don't have heart disease.
Saturday, September 25, 2010
Duck season is like flu season except the flu hunts you
As another September draws to a close, the perennially uninformed, misinformed, well intentioned and probably insane in the head brain appear, shaking themselves free of the logic that dictates their lives otherwise, as maples shedding leaves. "The flu shot will give me the flu!" "I never get the flu!" "The flu will give me autism!" they cry, their strident voices echoing inside empty heads. When I hear their call, I prepare. It's flu season. TIME TO HUNT (the arguments).
1. You'll get influenza from the influenza vaccine.
To me, this argument sounds like this: Steak and milk are dangerous because when combined in your body you will get a cow in your stomach. Influenza vaccine is not made with living virus, only bits and pieces of it. It will not give you the real deal. Some people get flu-like symptoms, which is usually protracted and less severe than the real flu. Both consist of muscle aches and feeling unwell, but it's pretty much only gen-u-ine rootin' tootin' hemagglutinin' influenza that kills people (see below).
2. I never got the flu before.
Oh, really? Do you wear your seatbelt? Did you ever buy home insurance? Do you throw away your lifejacket on your plane to get more space for your carry on? We wear seatbelts, buy home insurance, and sometimes check for our lifejackets because we want to prevent something catastrophic. Ever try to put your seatbelt on after you've crashed? Doesn't make a lot of sense. Although with the airlines the way they are nowadays, you might be tempted to sneak some more room with the lifejacket one seat over. Get your flu shot because you don't know you won't get the flu this year.
3. I will get autism from vaccines.
This all started with a Dr. Wakefield who wrote a paper to The Lancet that made vague but terrifying connections between the measles, mumps, rubella vaccine and autism, as well as inflammatory bowel disease. After his paper was published, the rate of vaccination fell in many countries resulting in skyrocketing rates of measles mumps and rubella, which seriously injured and in some cases killed young children. Several celebrities with autistic children caught on to the paper and began promoting the link as publicly as possible, resulting in an extremely passionate and emotional anti-vaccination lobby. Several studies were done to try to replicate Dr. Wakefield's findings, none of which were successful.
Later on it was discovered that his results were faked, that he had paid children at a birthday party to be part of his study, and that ten of the thirteen colleagues who had wrote their names on his paper had requested their names be removed.
Then it was found that he had abused mentally delayed children.
Then he wasn't allowed to be a doctor anymore.
Then The Lancet retracted his article.
But none of this matters, because that was the MMR vaccine.
(Note: Yes there are downsides to the vaccine. There are downsides to everything. You get up in the morning you could get hit by a bus. Downside. You take some organic antioxidant all natural supplement and choke on the pill and die. Downside. You may have an allergic reaction to the vaccine. This is treatable, and most often is avoidable and does not result in death. You may also get a rare reaction called Guillain-Barre syndrome where you become paralyzed. This is one doctors WILL own up to. But it's extremely rare. I bet you dollars to donuts there are more people reading this who know someone who died from the flu but not from GBS.)
1. You'll get influenza from the influenza vaccine.
To me, this argument sounds like this: Steak and milk are dangerous because when combined in your body you will get a cow in your stomach. Influenza vaccine is not made with living virus, only bits and pieces of it. It will not give you the real deal. Some people get flu-like symptoms, which is usually protracted and less severe than the real flu. Both consist of muscle aches and feeling unwell, but it's pretty much only gen-u-ine rootin' tootin' hemagglutinin' influenza that kills people (see below).
2. I never got the flu before.
Oh, really? Do you wear your seatbelt? Did you ever buy home insurance? Do you throw away your lifejacket on your plane to get more space for your carry on? We wear seatbelts, buy home insurance, and sometimes check for our lifejackets because we want to prevent something catastrophic. Ever try to put your seatbelt on after you've crashed? Doesn't make a lot of sense. Although with the airlines the way they are nowadays, you might be tempted to sneak some more room with the lifejacket one seat over. Get your flu shot because you don't know you won't get the flu this year.
3. I will get autism from vaccines.
This all started with a Dr. Wakefield who wrote a paper to The Lancet that made vague but terrifying connections between the measles, mumps, rubella vaccine and autism, as well as inflammatory bowel disease. After his paper was published, the rate of vaccination fell in many countries resulting in skyrocketing rates of measles mumps and rubella, which seriously injured and in some cases killed young children. Several celebrities with autistic children caught on to the paper and began promoting the link as publicly as possible, resulting in an extremely passionate and emotional anti-vaccination lobby. Several studies were done to try to replicate Dr. Wakefield's findings, none of which were successful.
Later on it was discovered that his results were faked, that he had paid children at a birthday party to be part of his study, and that ten of the thirteen colleagues who had wrote their names on his paper had requested their names be removed.
Then it was found that he had abused mentally delayed children.
Then he wasn't allowed to be a doctor anymore.
Then The Lancet retracted his article.
But none of this matters, because that was the MMR vaccine.
(Note: Yes there are downsides to the vaccine. There are downsides to everything. You get up in the morning you could get hit by a bus. Downside. You take some organic antioxidant all natural supplement and choke on the pill and die. Downside. You may have an allergic reaction to the vaccine. This is treatable, and most often is avoidable and does not result in death. You may also get a rare reaction called Guillain-Barre syndrome where you become paralyzed. This is one doctors WILL own up to. But it's extremely rare. I bet you dollars to donuts there are more people reading this who know someone who died from the flu but not from GBS.)
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