New Insights on How we Know Where We are and Going

New Insights on How we Know 

Where We are and Where We are Going

Ever wonder how we know where we are at any point in time, or how we move our bodies to just the spot we want them to be?

We do it so effortlessly, and with no real thinking we are aware of, it seems simply natural.  But as with all functions, something has to direct them and make them happen,

Recent insights in neuroscience have revealed that the way the brain operates our motions is nothing less than astounding.

A recent review in Scientific American (Jan. 2016) reports that inside our brains are sets of neurons, individual cells, that each have the remarkable ability to map our space, and know where we are in it.

Where in the brain is our map-making centers?

These cells reside in a part of the brain at the level of our ears, deep inside the brain, in two structures- the hippocampus and the entorhinal cortex.  The hippocampus is named after a mythic creature in Greece that had the head of a horse and rear of a dolphin, and seems to have the shape of a sea-horse.  The hippocampus is where many of our long-term memories are formed.   The entorhinal cortex is just in front of the hippocampus, and just behind the cells that receive signals from our noses to register the perception of smells, hence the word rhinal (or of the nose), in its name.  It is the area of the brain that connects the hippocampus to the main cortex.

So much for the technicalities, the amazement comes from what the special cells in the hippocampus and entorhinal cortex do.  To really appreciate what comes next, one has to stop a moment to consider what we are talking about are single, individual nerve cells knowing where you are.

What do the special map-making cells actually do?

The special cells come in two forms, at least- grid cells and place cells.

Grid cells fire only when one approaches the angle of a hexagon in space.  This is worth explaining. The existence of grid cells reveals that our brain converts our space into flat sheets of hexagons.  One on sheet the hexagon may be about one foot in length per side of the hexagon.  Other sheets of hexagons created in our minds could be several yards in length per side of the hexagon.   

Once the brain has laid a set of hexagons on the space around us, wherever we are, then the grid cells only fire when we walk to an actual angle of one of these hexagons.

This neat process allows the brain to know precisely in which direction we are moving, and how quickly.

A subset of grid cells only fires if one approaches the side of one of the maps' hexagons that lies along an actual wall, or divide, an actual boundary to the space on is in.

Another set of cells in the brain only fire if one moves in a particular direction, thereby allowing us to perceive, to know, what direction we are moving in.

Another set of cells is devoted entirely to firing only at set speeds of motion, allowing us to know how fast we are moving.

All these special cells combine to give as complete a picture as possible of where we are and where we are going.  It is the combination of all this information that determines if one last special cell to be mentioned, fires.  That cell is called a place cell, and it fires only when all sorts of conditions- where one is in the hexagon at hand, the direction of motion, the speed of motion, the colors and details of the space- come together to define an actual place.  To me, this is the most incredible fact- there are such nerve cells in our brains that only fire when we are in an actual, real, place.   It is as though one cell can actually, and does, have the power to recognize, in this case recognize a space or place. 

Incredible.

Just to help understand all this a bit more, grid cells will fire whenever anyone approaches a corner of any hexagon mapped to any place the person is at.  They fire when you are inside, or outside; in the bathroom, or bedroom; while you are home or away.   But place cells only fire in specific places, hence the name place cells.

Space and memory

You may have noticed much of this mechanism takes place in or near the hippocampus, the brain's memory machine.  There is no coincidence here.  Once the brain has mapped a space you are in with its hexagons, and lined up the special place cells to fire in specific places, those patterns are kept in mind, placed in memory.  

These areas of the entorhinal cortex that preserve place memory are often the first to go in Alzheimer's disease, explaining why getting lost out in the world is such a common and early experience when this dread disease begins.

BOTTOM LINES

The brain has incredible approaches to knowing where we are and where we are going.
It starts with mapping any room or place we are in with a set of hexagons, then tracks how we are moving in those hexagons.  That and other information combine to allow single cells to remember any spot we have been.

The ability to know where you are and where you are going is extraordinary, the fact that much of this sense and perception is mediated by single, individual nerve cells is even more amazing.

We at Advanced Pediatrics hope everyone has a wonderful holiday, wherever your brain's maps may take you!

To your health,

Dr. Lavin

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*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.

Stomach flu is here- What you Need to Know

Stomach flu is here- Vomiting is usually OK

The community is, right now, experiencing a massive epidemic of stomach flu.

Kids with stomach flu typically vomit, have diarrhea, and fever.

Stomach flu is a miserable experience but it rarely presents any danger.

The way it works is that a virus is caught, like any virus, but in the case of stomach flu the virus goes to the gut.

The first stop is the stomach where it causes lots of swelling and inflammation.  Once this hits you will see vomiting.  As the virus goes along the gut the intestine gets red, swollen, and inflamed and this causes diarrhea.

Stomach flu is overwhelmingly harmless in a healthy populatoin, in the sense that nearly everyone who gets it recovers without the need for medical interventions.   The main risk faced is dehydration, which is discussed below.  But even in the unlikely event that should occur, the treatment for the mild dehydration seen in stomach flu is very effective.

On the vomiting

The vomiting from stomach flu lasts about 2-6 days and often frightens parents.

Sometimes the vomiting can be quite intense.  So bad that nothing is kept down and what appear to be great quantities of fluid keep getting vomited all day and all night.

The most helpful thing to do for intense vomiting is to retreat to giving small amounts of fluid, about one teaspoon, every five minutes.  One teaspoon every five minutes over 8 hours is 16 ounces of fluid a day, plenty to prevent dehydration.   Why one teaspoon?  Because that's a small enough amount it might be absorbed in the mouth and esophagus, before it hits the stomach, so you can drink it, absorb it, and not vomit it.

We would recommend resorting to the one teaspoon every five minutes approach only if the vomiting is so severe it is clear that your child is not able to stay hydrated.  Once the vomiting eases off and your child can hold meals down, no restrictions on eating or drinking what they can.

On the diarrhea

The diarrhea usually lasts longer than the vomiting.  Where vomiting might go on for a few days, diarrhea can to on for a few weeks.  As long as there is on blood or mucus in the stool, it is likely viral diarrhea, not a dangerous or worrisome event.  It tends to cause less dehydration than vomiting because you can drink enough water to match the water lost in diarrhea.

How do you know when you are dehydrated?

Nearly everyone with stomach flu gets dry, but that's different than dehydrated.  You are dehydrated when you have lost so much more water than you take in that functions begin to suffer.    Signs of dehydration include markedly reduced or cessation of urination, dry and cracked lips, sunken eyes, and marked lethargy.

Dehydration leads to not peeing, looking very sagged and tired, and a sallow-sunken-dry-cracked face.

Treatment

There is no drug that cures stomach flu.

Water is the best treatment as it resolves the only danger stomach flu can pose- dehydration.

The most frequently used drug used for nausea and vomiting is Zofran, or odansetron.  This is a powerful drug, and does present risks, so we recommend it not be used for any but the most severe stomach flus.  To use it with every stomach flu vastly increases the chance some serious harm could occur from uncommon side effects.

There are no drugs that can stop the diarrhea, like a runny nose with a cold, it simply has to run its course.

BOTTOM LINES
1.  Stomach flus, like colds, are a universal human experience.
2.  They can happen anytime of the year, but the community experiences waves of them.  We are in one now.
3.  The stomach flu is not the flu of the flu vaccine, so that vaccine does not prevent it.  There is a vaccine for one cause of stomach flu, the rotavirus, but as that vaccine has been used, the noravirus has simply taken its place, so there is still plenty of stomach flu around.
4.  Stomach flu is a viral infection, typically starting with 1-3 days of heavy vomiting followed or also including a week or so of diarrhea, with fever often.
5.  Drugs for nausea and vomiting should not be used for every stomach flu as this would greatly increase the harm from such drugs.
6.  The best treatment is water as it treats the only real danger from uncomplicated stomach flus- dehydration.  Water can be give orally, but if that fails, there is always the IV route which can always quickly and safely restore water.
7.  We at Advanced Pediatrics are happy to help if your child comes down with a stomach flu, particularly if you need help knowing if dehydration is appearing.

To your health,
Dr. Arthur Lavin

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*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.

Bronchitis and sinusitis- What do these words mean?

Bronchitis and Sinusitis- 

What do these Words Mean?

Every winter, when colds and flus create floods of runny noses and blasts of prolonged coughing, the words bronchitis and sinusitis erupt.   It makes sense to take a moment and understand what these words mean, and how they are currently used, and misused.

-Itis and Inflammation

The best place to start is with the common medical suffix, -itis.  This ending keeps showing up in all sorts of places when we talk about illness and disease.  Some uses are very familiar, like dermatitis, or appendicitis, or arthritis.   But in every instance, the ending -itis always means the same thing, inflammation.

Inflammation means that some tissue is red, swollen, tender, warm, and or has lost some function.  Perhaps the most familiar example of inflammation is a mosquito bite, where the skin gets red, warm, tender, swollen.  The inflammation is so mild there is no loss of function in this example.  But the point is that inflammation is a response to a threat in the body.  That threat can be a chemical in the mosquito's bite, and infection, or the body's own self attacking itself for no good reason.

In the case of bronchitis and sinusitis, the inflammation is in the airways of the lung (bronchitis) or the sinuses of the head (sinusitis).  And for both, the cause is an infection.  This is where it gets interesting.

Bacterial v. Viral infection

The real confusion in the use of the terms bronchitis and sinusitis comes from the widely assumed meaning, namely that if you say the word bronchitis or the word sinusitis, you have proven you have a bacterial infection.    But the truth is that bronchitis and sinusitis can be caused be either viruses or bacteria.   If a virus infects your lung's airways or sinuses, you have a viral bronchitis or sinusitis.  If a bacteria infects either, it's a bacterial bronchitis or sinusitis.

A major difference between any respiratory viral infection (except influenza) and any bacterial infection is that there is no antibiotic or medication that can decrease the impact of a viral illness, but regular antibiotics kill bacteria very well.

Bronchitis
Now to the illnesses themselves.   Bronchitis literally means, inflamed airways of the lungs.  This can happen, as noted, as a result of either a viral or bacterial infection.   It turns out that, with few exceptions, every time you get a cold, you have a viral bronchitis.  After all, a cold is when the virus inflames the lining of the nose, throat, and lungs, and when the lungs get inflamed, you have a viral bronchitis.   It's the lung inflammation in a cold that causes the horrible experience of a cough.  And you can't really get your lungs inflamed without the airways being affected.   So, all colds are bronchitis.

But that's not what is meant when a doctor tells someone has bronchitis.  When that happens, what is usually implied is that a cold has developed into something more complicated, that a bacterial infection has erupted.

Now, the question is, how does one tell if your child has a viral bronchitis (a cold) or a bacterial bronchitis?

It turns out this is very hard to tell, since both cause the same symptoms.

There are no findings on exam, or blood tests, or X-rays that can tell the difference.

At a certain point, the question really turns on how long your child has been ill, since typical cold symptoms last up to about 25 days, and symptoms persisting longer than that may be due to bacteria getting involved.  Or, sometimes it is clear that the illness is getting much worse when it should be getting better.  As you can see, this question is truly best answered by a judicious weighing of all the facts, more than a test.

Sinusitis
The exact same discussion goes for sinusitis.

Literally the word simply means inflamed sinuses, that is sinus linings that become red, swollen, and make a lot of mucus.  But the word is usually used as a code word to imply that someone has a bacterial infection and that antibiotics are needed and will cure the condition.

Unfortunately, as with bronchitis, most sinusitis situations are caused by infections with viruses.

In fact, a cold can be truly thought of as a viral sinusitis.  A cold is a situation where a virus attacks the lining of the airways.  That attack destroys the linings of the nose and its sinuses, throat, and lung.  This is physically no different than a shallow burn.   The viral burn in the sinuses cause the lining to get very red, swollen, and make loads of mucus.  This is clearly a sinusitis.

But, as noted above, viruses are not killed or slowed by antibiotics, and antibiotics do nothing to heal the burn created by the virus.  So if your child's sinus infection is due to a virus, an antibiotic offers no help, only harm from side effects.

And, as with bronchitis, X-rays and CT scans and MRI's do not help.  These imaging technologies cannot tell the difference between mucus from a virus and pus from bacteria.

So once again ,the distinction relies on the course of illness.  Colds typically last 1-3 weeks.  So, unless some unusual experiences are noted, someone with a runny nose, fever, achy and feeling ill, for less than 10 days almost certainly has a viral infection, and antibiotics will not help.

BOTTOM LINES
1.  Everyone gets colds.  These are viral infections that cannot be helped in any way by antibiotics.
2.  Bronchitis and sinusitis are terms broadly used to imply that a person's illness has advanced beyond a cold to a bacterial infection that antibiotics could help.
3.  If someone has been ill with runny nose, fever, cough, and feeling achy and ill for less than 10 days, unless some other unusual symptoms are present, it is very, very likely the illness is a viral infection, and antibiotics will not work.  These viral infections can cause some symptoms, especially cough, to last well beyond 10 days, often for 3-4 weeks!
4.  So the words bronchitis and sinusitis turn out not to mean one has a bacterial infection, only the course of the illness can determine that.
5.  We at Advanced Pediatrics are happy to help you determine if your child's runny nose, cough, or such illness is typical for a viral infection, or if other signs have appeared to suggest bacteria are now involved.   This will help determine if an antibiotic would help or hurt the situation.

To your health,
Dr. Arthur Lavin

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*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.

Inflammation- A Universal Function and Experience

Inflammation-  

A Universal Function and Experience

Inflammation is the heart of a wide range of experiences, from mosquito bites to arthritis.

Every person alive has had some experience of inflammation.  And, as it is at the heart of so many troubles we all experience, I thought it would be interesting to share what we know about it.

What is inflammation?

The word inflammation means just what it sound like, to catch on fire.

The idea is that all complex living organisms, from algae, to plants, to insects, to us, need some way to destroy dangerous cells, to protect our own cells.   All of such life actually monitors every square inch of living tissue at all times, and when a germ, or an errant cell appears, the body stands ready to zap it.

What does zapping it mean?  It means delivering compounds that literally burn the unwanted germs and cells.  

Our immune system makes high powered peroxides and other such compounds that actually deliver oxygen to an unwanted material as surely as a fire delivers oxygen to wood.

But here's the problem.  It's very powerful to have a cellular flame-thrower handy to obliterate intruders, but how do you keep that fire from burning your self?

That's the key problem, the most important balance inherent in inflammation- how to keep the destruction available at every place in the body, ready to burn at any moment, keep the destruction off when not needed, and only focused on the harmful when on. 

Good inflammation

Inflammation is vital to some of the most basic of functions of life- healing, recovery from infections, and even cancer prevention.  

Any time we get a cut, it is inflammation that largely destroys the germs that pour into the cut.  Without that protection, no cut would heal, every infection (including colds) would be fatal, and we would all have many cancers at a much younger age.  How does inflammation protect us from these fates?

The most important function the immune system plays is to identify who is friend and who is foe.  The immune system looks at every cell, at every compound, in the body and asks, at every moment:  is this cell or material me or not me?

The ability of the immune system to be present in every place and at every time is what allows us to be protected in every spot of the body, no matter when.

Consider a cut.  A cut breaks the seal the skin makes to keep literally trillions of bacteria out of our body.  So when we have a cut, bacteria pour in, right there, right then.  Only because our immune system is ready to go on the attack anywhere and anywhen, any cut is controlled.  Cuts can get infected, but over 99% do not, even without doctors.   This is an essential mechanism for healing.

Infections are all examples of germs, typically viruses and bacteria, finding a way past such defenses and getting a foot hold in our tissues.  Uncontrolled they can destroy vital organs and pose a dangerous threat. 

Perhaps the least well known and least appreciated powers of inflammation is to eliminate our own cells, cells that have gone astray.  The most dramatic example of this gift from inflammation is the control of emerging cancer cells.  It is our own immune system, and ultimately, its powers of inflammation that keep a very large number of cancer cells from ever getting the chance to grow and spread.

Short-term bothers from inflammation

Nearly every misery from cold and flus, stomach flus, insect bites, irritating plants, and injuries, comes from inflammations.  These sorts of bothers are short-term inflammations, they only happen during the illness, irritation, or injury.  Once the cold, or poison ivy, or bruise, is gone, the symptoms of the inflammation go away too.

One of my favorite illustrations of short-term inflammation is the mosquito-bite.  I actually hate them like everyone else, but they contain all the features seen in all short-term inflammations:
1.  Something happens to provoke inflammation- the mosquito bites you
2.  The inflammation only happens where the provocation occurs- at the site of the  bite and nowhere else.
3.  The classic signs of inflammation are all present:  swelling, pain or itch, redness, warmth.
4.  Once the irritation of the bite goes away, so does the inflammation- that is bites clear in a short period of time.

The exact same sequence is seen with colds:
1.  Something happens to provoke inflammation- the virus infects you
2.  The inflammation only happens where the provocation occurs-
       if the virus infects the nose- a runny nose
       if the virus infects the throat- a sore throat
       if the virus infects the lungs- a cough
       the exception is that viruses can cause inflammation to release chemicals that a cause a couple of body wide troubles-  tiredness, aches and pains, and fever.
3. The classic signs of inflammation are all present when it is active:  swelling, pain or itch, redness, warmth.
4.  Once the irritation of the virus goes away, so does the inflammation- fever, aches and pains, tiredness, runny nose, sore throat, cough-  all go away completely once the virus goes and the inflammation heals.

The same sequence is seen in every short-term inflammations- including the bruises, stomach flus, and other short term illnesses, including migraine headaches.

Long- Term Inflammation

In contrast to the short-term inflammations, the long-term inflammations persist, linger, and sometimes last a lifetime.  We do not understand how such long-term inflammations get started, and we certainly have no idea how they get sustained.

A bigger contrast to the short-term inflammations is that nearly all long-term inflammations serve no good purpose.   They represent the darker side of our ability inflame.  They hurt, they cause suffering, and cause damage to the body, all for no very good reason.

Familiar examples include the chronic, recurring inflammations of the gut (e.g., Crohn's disease), brain (multiple sclerosis), insulin producing cells of the pancreas (diabetes), joints (arthritis), lungs (asthma) you get the idea.

Perhaps the most benign of the long-term inflammations are the allergic variety.  They can cause much suffering, but tend to be intermittent, and cause no actual long-term damage to the body in most instances.  And, in contrast to the other long-term inflammations noted, there are often good treatments with few side effects available for allergy-related inflammations.

What Role Should Inflammation Have in our Life?

It is tempting to hope that one day we will eliminate inflammation, and rid ourselves of all the awful diseases long-term inflammation cause.  Not to mention all the miseries the short-term inflammations bring to us.

But keep in mind that inflammation is a necessary weapon to protect our bodies from infections and even cancers.

So the goal will ultimately be to have some fine tuning control over the mechanisms of inflammation in our body.  That fine tuning would turn off attacks on the valuable, healthy parts of our body, and eliminate the suffering such attacks create, but would leave intact, and even enhance, the power of our body's inflammatory mechanisms to keep us free of infection and cancer.

This is a very tall order, but one of the reasons for this tour of inflammation is to help us be familiar with one of the great powers of our body, to understand how it works for us, and how so much of what causes our health to be challenged is related to this particular power we all carry inside, inflammation.

BOTTOM LINES
1.  Everyone has heard of inflammation, but it is helpful to understand a bit more about just what it is.
2.  Inflammation is the power of the body to attack, and literally burn away, threats to our health.
3.  Inflammation is vital to keeping our body clear of infection, and surprisingly, of cancer.
4.  Short-term inflammations cause the universal bothers of viral symptoms such as runny noses, malaise, aches, fever, diarrhea; the itch of insect bites and plant reactions; as well as the pain of bruises and migraine headaches.
5.  Long-term inflammations are the more serious challenges to health that come from uninvited and unwelcome, sustained attacks on our own bodies, such as seen in Crohn's disease, arthritis, and multiple sclerosis.
6.  Science right now is working on preserving and even strengthening our protective uses of inflammation, and preventing or turning off unwanted flares of this powerful mechanism.


To your health,
Dr. Arthur Lavin

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*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.