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Cushing’s Syndrome – Could You Be Exercising and Dieting and Still Be Fat? (As Seen On House MD)

Roy — Thu, 29 Jul 2010 08:54:51 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: Medium

What is it?

Cushing’s syndrome is a condition in which there is too much of the hormone cortisol in the body.

Who gets it?

Cushing’s syndrome isn’t very common, and happens to about 13 out of every million people each year.

What causes it?

Cortisol is a steroid hormone produced in our body. It’s released in response to stress or when its level in the blood is low. Its function in our body is to raise blood sugar, suppress the immune system and help with the body’s metabolism.

To understand why Cushing’s syndrome happens, you first have to understand how our body releases and handles cortisol.

The brain makes a hormone called CRH, which tells a gland under the brain, called the pituitary gland, to make another hormone called ACTH. ACTH causes our adrenal glands (which sit above our kidneys) to produce cortisol.

Now what causes cushing’s syndrome?

Taking steroid medicine – These aren’t the steroids you may know that athletes take. Steroids are types of drugs used to suppress our immune system and that are given in diseases such as lupus, asthma, and rheumatoid arthritis. Taking these for a long time is the most common cause of Cushing’s syndrome.
Tumors on the pituitary gland – Like the case on the House episode. This is the second most common cause, and has a slightly different name: Cushing disease. This isn’t cancer and doesn’t spread like cancer does. What this tumor does is produce extra amounts of ACTH which cause the adrenal gland to produce more cortisol than it should.
Tumors on the adrenal gland – These can sometimes be cancer. These tumors produce extra amounts of cortisol themselves.
Tumors elsewhere – These can be lung tumors and others, that simply produce ACTH, causing the adrenal gland to produce extra cortisol.

How does it feel?

The most common symptom is weight gain, especially around the waist, and around the upper back (something called a buffalo hump). It also caused a rounding of the face called moon face.
Fatigue
Muscle weakness
Flushing of the face
Skin changes: The skin bruises easily. You get acne. You get pink or purple stretch marks (called striae) on the belly skin, thighs, breasts, and arms.
Slow healing of wounds and infections
Mood changes, such as depression, anxiety and irritability.
Thicker or more visible body and facial hair.
Irregular or absent periods in women.
Diabetes
High blood pressure
Bone loss, which can lead to fractures

And more…

This video from The National Geographic shows an excellent example and explains it:

www.youtube.com/watch?v=vxSAhLyKVqw

How is it discovered?

There are blood tests that can find out if you have Cushing’s syndrome. Once these are done, a CT scan of your adrenal and an MRI of the pituitary gland are done to find a possible tumor.

Other tests may be possible, which are beyond the scope of this article.

How is it treated?

If the condition is caused by steroid medicine, your doctor will lower your dose or stop them altogether. You should never stop taking steroids on your own, as that can be dangerous to your health.

If a tumor is causing it, it can be removed in surgery, or by other means.

What happens after treatment?

If the surgery removes the tumor completely, people may be cured, although it can sometimes return.

The bottom line – How do I avoid it?

If you take steroids, awareness of the signs of the condition can help you avoid its continuation down the road.

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Ornithine Transcarbamylase Deficiency– What If You Couldn’t Eat Steaks? (As Seen on House MD)

Roy — Fri, 23 Jul 2010 09:00:26 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Ornithine transcarbamylase deficiency (OTD) is a rare genetic disorder causing a problem with eating protein.

Who gets it?

OTD is a rare condition – it affects about 1 in every 80,000 people. The condition is genetic, meaning it is passed on in families. It also usually happens to males, due to the mode it is inherited.

Usually the condition becomes apparent in the first few days of life. Sometimes, though (like in the House episode), the condition can manifest later in life.

What causes it?

We live and function thanks to millions of reactions that happen in our body each day. One of those reactions happen inside a cycle of reactions called the urea cycle.

The urea cycle. Drawing by Yikrazuul

The urea cycle is a sequence of reactions that happen in our liver cells. It processes excess nitrogen, which is generated when our body uses protein. In order to get rid of the excess nitrogen, the cycle turns it into urea, which the kidneys can get rid of in our urine.

Each of the steps in the cycle happens through the action of a special machine, called an enzyme. In OTD, one of those enzymes is damaged or missing. Since the body can’t get rid of the excess nitrogen, it is accumulated in the body, turning into a dangerous substance called ammonia.

Ammonia is dangerous for our nervous system and so the condition causes neurological problems. The excess can also damage the liver.

How does it feel?

The condition, as we mentioned above, usually becomes evident in the first days of life. The baby will be lacking energy, vomit, or refuse to eat. Its breathing rate and body temperature will be poorly controlled. Sometimes seizures can occur, and even a coma is possible.

In adults the symptoms aren’t very different. They can include loss of appetite, irritability, heavy or rapid breathing, weakness, vomiting, disorientation, sleepiness, and also coma and death. (Remember that the guy on the House episode had recurrent comas).

How is it discovered?

A blood test is done which shows that the person has too much ammonia in their blood. There’s also a test done on a urine sample that can give a clue to the condition.

Also, a genetic test can find out if the person has the defective gene (although it doesn’t work all the time).

How is it treated?

Since the body can’t handle large amounts of nitrogen (it can’t turn it into urea like it normally should), the treatment includes measures that lower the amount of nitrogen in the body.

This includes not eating lots of nitrogen (protein is very nitrogen-rich. That is why a low-protein diet is subscribed. Remember the mobster in the House episode couldn’t eat steaks?).

Treatment includes saying goodbye to steaks. Photo by FotoosVanRobin

Treatment also includes lots of food and water when a person is ill (since otherwise the body tends to break down its own protein at these times) and some medications that can lower the nitrogen in the body.

What happens after treatment?

The baby’s brain can be damaged from the disease (by the ammonia) if not treated on time. It’s important to catch the disease on time, and then to keep with the strict diet throughout life.

The bottom line – How do I avoid it?

As with other inherited diseases, you can’t really prevent it once the person is born with a defective gene. Parents that know they carry the defective gene and can transfer it to their children can use genetic testing to test if the developing embryo has the defective gene (a process called preimplantation genetic diagnosis).

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Bulimia Nervosa–How An Outside Image Can Kill (As Seen on House MD)

Roy — Tue, 13 Jul 2010 14:24:19 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Photo by Fox.

Danger level: High

What is it?

Bulimia nervosa (BN) is an eating disorder in which people eat a large amount of food in a short time and then get rid of the food they just ate.

Who gets it?

Like other eating disorders, mostly women (there are probably 10 times more women with the condition than men). It usually starts in teenage years or early twenties.

It is believed that in the US about 1-3% of women of high school or college age have the condition.

What causes it?

As with other mental illnesses, the exact cause isn’t known. It may be a mix of a few elements -

Society – The modern Western world gives more and more importance to body image. Magazines and TV shows are scattered with images of thin individuals. Some people tend to equate thinness with success and worthiness. Add to that pressure from friends and the surroundings.

A mannequin. With display windows showing such slim bodies, many women feel overweight. Photo by The Life of Bryan
Emotional health – People with eating disorders may have psychological problems contributing to the condition, such as low self esteem, perfectionism (like the woman on the House episode), impulsiveness, family or relationship conflicts, and so on.
Biology – It turns out there are genetics involved. If you have siblings or parents with the condition you may be more likely to develop it yourself.
Occupation – If you have a job or do a sport that give an importance to body size, such as ballet, modeling, or gymnastics, you may be more likely to develop bulimia (other things considered…).

How does it feel?

People with bulimia repeatedly eat in binges – this means they eat large amounts of food within a short time. They tend to do it secretly. The food tends to contain high calories, such as ice cream and cake, and can sometimes reach thousands of calories. They may eat such large quantities that their stomach and esophagus may be damaged or torn in the process.

After eating comes the purging phase, in which they get rid of what they just ate. Ways of doing that include vomiting on purpose, taking laxatives (like the woman on the House episode), doing hard diets or fasting, over-exercising, or any combination of the above.

The vomiting can erode our teeth, since vomit includes acid. It can also enlarge our salivary glands and cause damage to the esophagus. It can change the level of salts in our body, putting the body in risk of abnormal heart rhythms and sudden death.

And, as was seen on the House episode, laxatives such as ipecac are dangerous to the heart.

This video tells the story of Sarah Siskin, who died of bulimia:

www.youtube.com/watch?v=yHZesejU6tU

How is it discovered?

When the doctor sees a person in the right age (and gender) that expresses concern about gaining weight combined with weight fluctuations, signs of laxative use, and other signs (such as scars on the knuckles from inducing vomiting, swollen salivary glands, etc.) their suspicion rises.

The only way to be sure of the diagnosis is by having the patient tell, which doesn’t always happen.

How is it treated?

There are 2 ways to treat bulimia:

Psychological: A therapy called cognitive-behavioral therapy is usually used, in which the wrong thoughts that led to the behavior are faced with, and people are helped to give them up.

Medication: A type of antidepressant drug is given and may help.

What happens after treatment?

There’s no sure path. With some people the disease may be related to life crises and pass when they do. For others, it may be fluctuating over many years. That also depends on how compliant the person is with their treatment.

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Leprosy – The Biblical Disease is Still With Us (As Seen On House MD)

Roy — Sat, 10 Jul 2010 08:26:51 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by a bacteria. It affect the skin, eyes and nerves.

Who gets it?

That depends on where you’re from. Most cases of leprosy today happen in developing countries, mostly India and Brazil, although with travel it can happen anywhere.

In the US there are about 6,000 people with the disease, and about 95% of them got it abroad. About 200-300 new cases are reported each year, especially in states with large immigrant populations (such as California, New York and Florida).

Around the world about 2-3 million people are estimated to have the disease. About 86% of people with the disease live in one of 11 countries: Bangladesh, Brazil, China, Congo, Ethiopia, India, Indonesia, Nepal, Nigeria, Philippines, and Tanzania.

Leprosy around the world. Pink areas have the greatest amount of leprosy patients, followed by red, orange and yellow. In green areas the disease is rare.

There are a few risk factors – things that can put you at risk of getting infected:

Close contact – If you’re in contact with someone sick with leprosy.
Age – You’re more likely to get it if you’re older (and perhaps also if you’re between the ages 5-15).
Problems with the body’s defense systems – Most people will not develop the disease if they’re exposed to someone ill. Even if they do, they may develop a very mild form of the disease that heals by itself.
Those who do develop the disease do so because a genetic defect in their body’s normal response, which should normally fight the bacteria.

What causes it?

Leprosy is caused by a germ called Mycobacterium leprae. It is spread by sick people through droplets from their nose and mouth, much like the common cold or the flu. Unlike them, though, it is not very contagious.

Mycobacterium leprae under a microscope. The germs are the red stuff scattered all over the picture.

Usually after we get infected with a germ, it takes time for it to grow, multiply and cause a disease. That time can take a few days with a cold. With leprosy, on the other hand, that time can be very long, and takes between 6 months and 40 years (!).

The leprae germ likes cool places in the body, so its best tourism sites are our superficial nerves, skin, the linings of the inside of our upper airways, the eyes, and the testicles. There they cause damage.

How does it feel?

Since, as mentioned above, it takes the bacteria a long time to multiply, the symptoms usually don’t appear before 1 year after infection (usually 5-7 years).

Skin – The disease causes characteristic rashes to appear. They can be a few flat, whitish areas which are numb to touch, in the milder form of the disease (called tuberculoid leprosy). In the more severe form of the disease (called lepromatous leprosy) there are many small bumps or large raised rashes of many sizes and shapes. There are also more areas of numbness and even weak muscles. It can also affect other areas in the body, such as our nose, kidneys, and testicles.

There can also be swellings and lumps on the skin.

Nerves – The sense of touch deteriorates so that the person can’t feel pain and temperature changes. These people may get burns or cuts and don’t notice it. This may lead to loss of toes or fingers. The damage to the nerves can also cause muscle deformation (causing things like clawed fingers).

These are the main symptoms, although there are more.

You can see some visuals of how this affects the body here. Be warned, though, that these aren’t easy pictures to look at.

How is it discovered?

The symptoms (such as the rash) give the doctor a clue. Doing a biopsy of infected skin (which means cutting a small sample and looking at it under a microscope) confirms the suspicion.

How is it treated?

Antibiotics are the treatment for leprosy. They can’t reverse the damage, but can stop any new damage from happening.

The leprosy bacteria are hard to kill and so treatment may continue for a long time – anywhere between 6 months of treatment to many years (and even a lifelong treatment in some cases).

What happens after treatment?

That depends on the type of disease (tuberculoid vs. lepromatous) – the more severe the form of the disease, the less chance there is for a cure. After cure, the disease may (rarely) return, which will require another treatment.

The bottom line – How do I avoid it?

As we said above, leprosy isn’t very contagious. Only the lepromatous form of the disease, if untreated, is contagious (even then, not as much as other infections). Once treatment has begun, the disease is no longer contagious.

To avoid getting infected, avoid contact with bodily fluids and the rash of infected people. Sometimes the vaccine against tuberculosis may protect you against leprosy, but it’s not used very often.

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Cadmium Poisoning – A Health Hazard That Can Hide Under Your Nose (As Seen on House MD)

Roy — Fri, 02 Jul 2010 17:20:32 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Cadmium is a chemical element (remember your periodic table of chemical elements? its name there is Cd). It has no function in our body and is toxic, even in low amounts.

Who gets it?

Exposure to cadmium can occur in the workplace or outside of it. In the workplace it can be encountered in battery manufacturing plants, in iron and steel production, and in many other occupations.

Outside the workplace, cadmium can be found in the air, water or soil, especially in industrial areas. It may also be found in certain foods, such as kidneys and livers of adult animals and in certain seafoods, such as mussels, oysters and crabs. And lastly, it can be found in small amounts in tobacco (another reason to quit smoking).

In Japan many people have consumed rice that was grown in cadmium contaminated irrigation water, causing a toxicity they called itai-itai disease (simply translated to “ouch ouch sickness”).

Cadmium can be found in air, water or soil. In fact, on the House episode, the source was the soil in which marijuana the couple consumed grew. Photo by john.duffell

This video is from January this year, when cadmium was found in metal toys, which were eventually pulled off the shelves:

www.youtube.com/watch?v=vvcfTtg1WXY

How does it feel?

One of the symptoms of cadmium exposure is something called osteopenia, or loss of calcium from bones, making them weak and brittle. Osteopenia is a usual phenomenon when we get old. When it happens prematurely, something is wrong…

The osteopenia causes spinal pain and bone pain. The bones get deformed, affecting the way the person walks. Fractures can also happen easily.

Other symptoms include kidney failure, pulmonary problems, loss of the sense of smell, and even cancer.

How is it discovered?

The most useful test for exposure to cadmium (as seen on the House episode) is a urine check, in which cadmium levels will be high. A molecule called β₂-microglobulin will be high in the urine as well. A blood test for cadmium can also discover it.

How is it treated?

There really is no effective treatment. The person exposed to cadmium should stop the exposure before irreversible damage happens to their kidneys.

If the bones are brittle, calcium and vitamin D can be used to try and strengthen them.

The bottom line – How do I avoid it?

There are a number of steps you can take to avoid cadmium poisoning:

Quit smoking!
Identify potential sources of cadmium around your home, at work, and where your children play.
If you have a vegetable garden, use fertilizers tested for cadmium.
Properly store and dispose of cadmium-containing products (such as batteries, metals, fungicides, fertilizers, etc.).
Keep nickel-cadmium batteries out of the reach of small children and dispose of them properly.

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Naphthalene Poisoning – When Mothballs Kill More Than Just Moths (As Seen on House MD)

Roy — Wed, 30 Jun 2010 16:27:40 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Photo by Fox

Danger level: High

What is it?

Naphthalene is a type of chemical, best known as the primary ingredient in mothballs. Exposure to large amounts can damage or destroy red blood cells.

Who gets it?

Naphthalene poisoning occurs mostly in children who suck or chew mothballs. Naphthalene poisoning can also happen by inhalation, since mothballs change slowly into gas form.

Skin exposure to naphthalene has also been shown to cause poisoning – it happened to babies that were dressed in clothes stored with naphthalene mothballs.

About a year ago we covered here a condition called G6PD deficiency. People with this condition are more likely to be poisoned by exposure to naphthalene.

Mothballs. Photo by Billie Hara

In the House episode, there was a connection between termites and naphthalene. Researchers have found that termites use naphthalene to protect their nests. So, theoretically, exposure to termites may also lead to naphthalene poisoning.

What causes it?

We’ve covered anemia before on A Disease A Day. It’s a condition in which red blood cells – the cells used to transfer oxygen to body organs – are decreased. There are many reasons for that. The reason in naphthalene poisoning is hemolytic anemia – a condition in which the blood cells get destroyed.

The destruction of blood cells probably causes their precipitation in blood vessels, clogging them, and thus causing blood not to reach its target organs. When an organ doesn’t get enough blood (or, actually, the oxygen the blood delivers) it simply dies, or in medical terms – goes through necrosis.

That’s what happened in the House episode – the boy’s liver started dying.

How does it feel?

The poisoning has symptoms that can occur right after the poisoning and long term effects:

Right after:

Hemolytic anemia
Damage to the liver or kidney
In infants, neurological problems
The poisoning is actually “felt” – people complain of headaches, nausea, vomiting, diarrhea, weakness, confusion, anemia, yellowing of the skin, convulsions and even a coma.
Cataracts can happen in the eye. A cataract is a condition in which the lens of the eye turns yellow and opaque, limiting our ability to see.

Long term effects:

There are many, and we won’t go into detail here. They contain cataracts, lung inflammation and other effects.

How is it discovered?

The doctor can find out if you are poisoned by naphthalene by listening to your story, seeing your symptoms, and taking a blood test, which will show that you have hemolytic anemia (among other things).

How is it treated?

If you think you have been poisoned, seek medical help immediately. The medical care given in cases of a poisoning include flushing the area thoroughly, giving oxygen if needed (or ventilation if the condition is more serious). If naphthalene was ingested, a gastric lavage (“stomach pumping” or “gastric irrigation”) may be performed, in which the contents of the stomach are cleaned out.

Also milk and fatty meals should be avoided for 2-3 hours to avoid further absorption of the naphthalene.

These are just the preliminary measures. Other treatment measures are beyond the scope of this article.

What happens after treatment?

Supportive treatment is needed in case of a naphthalene poisoning. Otherwise, death can occur.

The bottom line – How do I avoid it?

Not ingesting mothballs and avoiding skin contact is an obvious recommendation.

How do you decrease your chances of inhaling it?

You can remove the mothballs and ventilate the house by opening doors and windows.
When you remove them use gloves so that you don’t come in contact with the mothballs.
If you know you have a real problem and someone in your house has symptoms, you may want to leave the house while it ventilates, and even use a fan to increase air circulation during that time.

In any case, if you have any questions, you should contact your local poison control center (in the US the number is 1-800-222-1222).

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Rabies – All You Need To Know (As Seen on House MD)

Roy — Fri, 25 Jun 2010 08:16:22 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Rabies is an infection caused by a virus, which affects the brain and the spinal cord.

Who gets it?

Since, as you’ll read here, there’s a vaccine for rabies, nowadays humans are rarely affected in developed countries. In the US, between 1980-2003 there were about 40 cases of human rabies. In the rest of the world, unfortunately, there are many more human infections – as many as 55,000 people die of rabies each year. 56% of them in Asia and 44% in Africa.

What causes it?

The rabies virus can infect animals such as bats, raccoons, skunks, dogs, foxes, and coyotes. The virus then lives in the animal’s saliva and is transmitted through biting or scratching.

In the US it is usually spread by bats. In other countries, stray dogs are more commonly the cause of infection.

The infected animal will behave weird – it may act shy although it’s usually friendly, or have no fear of humans when it’s wild. It may also drool, foam at the mouth, or show signs of paralysis. When the infected animal bites or scratches a human, the virus can be transferred and infection occurs. The risk of getting rabies is greater if the person is bitten more than one time, or if the bite is close to or on the head.

A dog with rabies.

How does it feel?

The first symptoms look as if you have the flu – they contain fever, cough or a sore throat. Later other symptoms appear, including agitation, anxiety, confusion, difficulty swallowing, excessive salivation, fear of water (called hydrophobia – it’s caused because of the difficulty in swallowing), hallucinations, trouble sleeping, partial paralysis. And eventually, coma and death.

It’s important to note that once symptoms appear, it’s too late for a cure. Still, you have time from the bite to get a cure – the time from exposure to the virus until symptoms appear is usually 2-3 months (although in rare cases it may be shorter or longer).

How is it discovered?

Although there are ways to make sure someone bitten has rabies, the doctor comes at the conclusion you have rabies by the story, since no time can be wasted.

The virus can be discovered by taking a sample of saliva, of spinal fluid, or of tissue from our nervous system. Although a blood test can also discover rabies, it’s usually only positive later in the disease.

How is it treated?

Wound cleansing and immunization done as soon as possible after a contact with an animal can prevent the onset of the disease in virtually 100% of cases.

If you think you’ve been exposed to rabies, first wash the animal bite or scratch with soap and water. Then call your doctor and local health department right away.

Then comes decision time:

If the animal that beat you has a low chance for having rabies (such as a pet) – The animal will be captured and watched for signs of rabies. At that time the doctor may not want to wait until symptoms appear in the animal and you may get a series of shots against rabies.
If the animal has a high chance for having rabies (such as a bat or a wild or stray animal) you will start getting the shots right away. If possible, the animal will be watched for signs of rabies or will be killed for testing. If the animal is found to not have rabies, you can stop getting the shots.

What happens after treatment?

As mentioned above, the disease is curable if treated on time. If, on the other hand, no treatment is given, it is nearly always deadly.

The bottom line – How do I prevent it?

There are a few things you can do to prevent rabies:

Have your pet dog, cat, or ferret, vaccinated against rabies.
Avoid any contact with bats.
Don’t touch or pet wild animals (such as raccoons, skunks, foxes, coyotes).
Don’t handle a dead animal.

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Arteriovenous Malformation – The Blood Vessel Defect That Can Change Your Life (As Seen on House MD)

Roy — Sat, 19 Jun 2010 08:46:30 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Arteriovenous malformation (or AVM for short) is a defect in the blood vessels causing an abnormal connection between veins and arteries.

Who gets it?

AVM isn’t very common, and not much data exists about who gets it. It is known, though, that in the United States about 300,000 people have it.

It usually occurs in young adults, even though the origin of the disease goes back to being a fetus.

What causes it?

To understand what AVM is, you first need to understand the basics of blood vessels in the body.

Our circulatory system (the system through which blood is delivered to organs in the body) is composed mainly of arteries and veins. Arteries (appearing red in the drawing below) carry oxygen-rich blood to our organs. Arteries divide into smaller and smaller arteries until the become the smallest blood vessels, called capillaries.

Capillaries join together and form veins (appearing blue in the drawing). The veins’ role is to take up waste products from the organs.

In AVM, defects in the circulatory system cause direct connections between arteries and veins, without the capillaries in between. When these happen in our nervous system (the brain or the spinal cord), 3 things can happen that lead to problems:

1. Hemorrhage – Due to the defect, blood can spill from the vessels to the surrounding area, including the brain (if the AVM is in the brain).

2. Seizures – Again, if the AVM is in the brain.

3. Neurological defect – A defect in the brain or spinal cord functions can happen and advance over months and years. This is what happened on the House episode.

Why does these happen? No one knows for sure. It may be because the area with the AVM “steals” blood from the normal blood vessels. Or because the AVM presses on the area outside of it.

(Remember that AVMs can occur anywhere in the body. In this article we deal with the nervous system simply because the House episode showed an example of this location).

How does it feel?

Most people don’t even know they have AVM, since no symptoms appear.

When they do appear, symptoms can include persistent headaches or seizures. If the AVM bleeds, it can cause a very severe headache and a stroke or even death.

When the AVM presses the surrounding area it can cause neurological problems depending on the area of the brain or spinal cord it’s located at. In the House episode, for example, it caused paralysis.

How is it discovered?

A CT scan or an MRI are used to discover AVMs. An angiography (a technique used to image the inside of blood vessels) of the area can also be used.

An angiography showing AVM in the brain. Photo by Dr Marina-Portia Anthony

How is it treated?

AVMs are treated by a surgery, by irradiation of the AVM, or by a process called embolization. In embolization, the doctor plugs the AVM by inserting a coil or glue that will block off the area.

What happens after treatment?

Without treatment, 2-4% of AVMs will bleed each year. Treatment should stop these complications from happening.

The bottom line – How do I avoid it?

Since you are born with AVMs, there is no known way you can avoid it.

This video shows how dangerous AVMs can be through the story of Amit, who had headaches which were first thought to be flu-related:

www.youtube.com/watch?v=IZGxW9RQQzk

Related posts:

Organophosphate Poisoning – Getting Poisoned by Pesticides (As Seen on House MD)

Roy — Sun, 13 Jun 2010 15:41:00 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

The poisoned kid, now cured. Photo by Fox.

Danger level: High

What is it?

Organophosphates are chemicals used widely at home and outside: they exist in insecticides, herbicides, and even in nerve gas. Poisoning with these materials is a dangerous yet common condition.

Who gets it?

In 2007, The American Association of Poison Control Centers’ received 96,307 calls related to pesticide exposures, many of which involved organophosphates. Throughout the world, pesticide poisonings are among the most common poisonings.

No pesticides here. Photo by Transguyjay

What causes it?

Our muscles don’t contract just because they want to. We send them a message to do that, starting in our brain and going down our spine, and finally, through nerves, to the muscle itself. The final connection between the nerve and the muscles is called the neuromuscular junction.

One of the molecules in our body responsible for the action that goes on in the junction is called acetylcholine. This molecule sends a message to the muscle from the nerve, which tells it to contract.

Things get a little (but just a little) complicated when an enzyme (sort of a micro-machine) in the body by the name of acetylcholinesterase breaks acetylcholine down when it’s finished doing its work.

So what do organophosphates have to do with all of this? They inactivate the enzyme, so it can’t break acetylcholine down. This leads to acetylcholine building up and over-working.

How does it feel?

Organophosphate poisoning affects the whole body:

1. Heart – It can cause a slow heart rate (like on the House episode), and low blood pressure.

2. Respiratory system – It can cause a runny nose, can cause spasms in our airways (making it difficult to breath) and also excessive secretions in them, also making it difficult to breath. This all leads to coughing and difficulty breathing.

3. Intestines – Secretions all over our gastrointestinal system (from the mouth to the intestines) can occur. Nausea and vomiting are common, as is also abdominal pain, diarrhea and incontinence.

4. Urine – Incontinence can happen (inability to urinate).

5. Eyes – Organophosphate poisoning can lead to blurred vision and to constricted pupils.

6. Increased sweating.

These are the main effects, but they can be accompanied by brain problems, such as seizures (as was seen in the House episode) and confusion, and also muscle cramping and weakness, along with other symptoms.

How is it discovered?

The poisoning is suspected when someone comes with the group of symptoms described above. Apart from that, a blood test can be done that measures how active the enzyme acetylcholinesterase is.

How is it treated?

Besides helping the poisoned person stay alive (by keeping their airways open, etc.) an antidote is also used. That antidote is usually atropine. What it does is compete with acetylcholine for the spot in the neuromuscular junction, attaching to the muscle before acetylcholine does, so that the effects of acetylcholine subside.

There are other drugs used here which we will not go into at this time.

What happens after treatment?

Usually treating the condition on time should help, although mortality can happen as well (in as much as 25% of cases).

The bottom line – How do I avoid it?

The best prevention is avoidance of contact with chemicals like pesticides. You should take the usual precautions like making sure there’s adequate ventilation when using pesticides indoors, washing all fresh fruit and vegetables before eating, using gloves when working with pesticides, etc.

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Sleeping Sickness – A Fly Bite That Ends in A Coma (As Seen on House MD)

Roy — Fri, 07 May 2010 14:55:12 +0000

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)

Danger level: High

What is it?

Sleeping sickness (also called human African trypanosomiasis (HAT)) is a disease caused by a parasite, which causes, among other things, disturbances in the normal sleep cycle.

Who gets it?

The disease, as its name implies, is confined to Africa. From there it’s imported to other countries by travelers. Worldwide, 25,000 new cases are reported to the World Health Organization (WHO) each year.

In sub-Saharan Africa the disease threatens millions of people. In 1986, the WHO estimated that 70 million people live in areas where transmission of the disease is possible.

What causes it?

The disease is caused by a parasite called Trypanosoma brucei. The parasite infects a fly called a tsetse fly. From there there’s a cycle through which a human gets infected:

The fly bites a human, injecting the parasite into their skin. The parasite then travels to the blood stream, from where it can travel to different organs and multiply there.

How does the fly get infected, you may ask? It simply bites an infected human, and then the cycle goes on.

Apart from being bitten by a fly, humans can get infected in other ways:

When a sick mother is pregnant – The parasite can travel through the placenta and on to the fetus.
Blood transfusion – This is rare.
Sexual contact – This is how the woman on the House episode got it. We tried very hard, but couldn’t find a resource (except for Wikipedia…) that claimed this is a possible way of getting infected. So the case on House may have just been pure fiction.

Once the parasite has gotten into the body and multiplied there, its next stop is the central nervous system (the brain), where it causes damage, leading to the symptoms of the disease.

How does it feel?

Sometimes the site of the fly bite can develop into a red sore, called a chancre.

A chancre.

From the skin bitten site, the parasite travels to the lymphatic system, which is responsible for fighting infections in our body. There they multiply, causing our lymph nodes (small organs inside the body not usually seen without an infection) to grow. In this disease, this usually happens in the back of the neck, and is called Winterbottom’s sign.

Sometimes the infected person can also feel headaches, fever (like the woman in the episode had), weakness and joint pain. Other symptoms may follow as well.

The final stage, as mentioned before, is infection of the brain. At that stage the person has headaches, difficulty concentrating, personality changes, psychosis, tremor, seizures, and problems walking. The symptom that gave the disease its name is a change in the sleep cycle – causing the infected person to be sleepy throughout the day. The end of this stage is usually a coma, followed by death.

This somewhat dramatic video shows it graphically:

www.youtube.com/watch?v=4aVUrGO97Zg

How is it discovered?

The doctor takes a sample of blood, chancre, lymph node fluid or of other tissues in the body and examines it under a microscope. Under it, the parasite can be seen.

The parasite (in purple) under a microscope.

Sometimes other blood tests may help discover a response to the parasite, hinting that it exists in the body.

How is it treated?

There are specific drugs that can be given to treat the disease, and they should be given as soon as it’s discovered, to prevent further deterioration. Names of such drugs include suramin, pentamidine, eflornithine and melarsoprol.

What happens after treatment?

Treating the disease on time should cure you. It’s important to note, though, that you can get infected again.

The bottom line – How do I avoid it?

There are some things you can do if you intend to travel to danger areas in Africa and want to protect yourself:

Wear protective clothing: Including long-sleeved shirts and pants. The clothing should be thick, as tsetse flies can bite through thin fabrics. They should also be khaki or olive colored, as tsetse flies are attracted to bright and very dark colors.
Use insect repellants (although they haven’t been proven to work).
Use bed netting when sleeping.
Inspect your vehicle for flies before entering it, and don’t ride in the back of open vehicles.
Avoid bushes, as the flies use them for rest.

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