Tag Archives: Stanford University School of Medicine

Episcleritis

Definition:
Episcleritis is irritation and inflammation of the episclera, a thin layer of tissue covering the white part (sclera) of the eye. It occurs without an infection.
click  for  photo
Episcleritis is an inflammatory condition affecting the episcleral tissue between the conjunctiva (the clear mucous membrane lining the inner eyelids and sclera) and the sclera (the white part of the eye) that occurs in the absence of an infection. The red appearance caused by this condition looks similar to conjunctivitis, but there is no discharge. There is no apparent cause, but it can be associated with an underlying systemic inflammatory or rheumatologic condition such as rosacea, lupus or rheumatoid arthritis.

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It may also be associated with conditions such as gout and herpes simplex infection, so when episcleritis occurs it’s important to make sure these conditions aren’t a factor.

On rare occasions, it may become apparent that external substances, such as chemicals, are responsible for an attack.

Episcleritis is more likely to affect people in their 30s and 40s, and women are more likely to be affected than men.

Symptoms:
Typical symptoms include generalized or local redness of the eyes that may be accompanied by mild soreness or discomfort but no visual problems.

In general the symptoms are:
•A pink or purple color to the normally white part of the eye
•Eye pain
•Eye tenderness
•Sensitivity to light
•Tearing of the eye

When someone develops episcleritis, their eye (or eyes) appears red and may feel sore, tender and uncomfortable. In this respect, it’s similar to conjunctivitis (inflammation of the conjunctiva, which covers the episclera). But unlike conjunctivitis, episcleritis doesn’t cause a discharge, although watering may occur. Those affected may also find they become sensitive to bright light.

It comes in two forms: simple and nodular.

Simple episcleritis is characterised by intermittent bouts of inflammation that occur every couple of months and last between one and two weeks.

Some people report that these bouts are more likely to affect them in the spring and autumn, and although triggers often remain unidentified, some people find that stress or hormonal changes kick off the process.

Click to see the picture

Nodular episcleritis causes longer bouts of inflammation that are more painful than simple episcleritis. This type is more often associated with underlying medical conditions such as rheumatoid arthritis.

Causes:
Episcleritis is a common condition that is usually mild.

The cause is usually unknown, but it may occur with certain diseases, such as:

*Herpes zoster
*Rheumatoid arthritis
*Gout
*Sjogren syndrome
*Syphilis
*Tuberculosis
*Herpes simplex infection
*Inflammatory bowel disease and Lupus.

Diagnosis:
Diagnosis of episcleritis is made clinically. A work-up may be needed in some cases to uncover a possible underlying medical condition.

Treatment:
The condition usually disappears without treatment in 1 – 2 weeks,  but topical or oral anti-inflammatory agents maybe prescribed to relieve pain or in chronic/recurrent cases. Corticosteroid eye drops may relieve the symptoms faster.
You may Click to see:Alternative Treatment of  Episcleritis

Prognosis: Episcleritis usually improves without treatment. However, treatment may make symptoms go away sooner.

Possible Completions:
In some cases, the condition may return. Rarely, irritation and inflammation of the white part of the eye may develop. This is called scleritis. Episcleritis, is associated with an underlying disorder about 70% of the time, and Scleritis can produce serious damage to the Eye; Episcleritis never does.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.bbc.co.uk/health/physical_health/conditions/episcleritis1.shtml
http://www.nlm.nih.gov/medlineplus/ency/article/001019.htm
http://www.hopkinsmedicine.org/wilmer/conditions/episcleritis.html
http://lmk23.tripod.com/episcleritis.html

Anaphylax

 

ALTERNATIVE NAMES:  Anaphylactic reaction; Anaphylactic shock; Shock – anaphylactic

DEFINITION:
Anaphylaxis is an acute multi-system severe type I hypersensitivity reaction. The term comes from the Greek words ava ana (against) and  phylaxis (protection).It is  a life-threatening type of allergic reaction and it can occur within seconds or minutes of exposure to something you’re allergic to, such as the venom from a bee sting or a peanut.

The flood of chemicals released by your immune system during anaphylaxis can cause you to go into shock; your blood pressure drops suddenly and your airways narrow, blocking normal breathing. Signs and symptoms of anaphylaxis include a rapid, weak pulse, a skin rash, and nausea and vomiting. Common triggers of anaphylaxis include certain foods, some medications, insect venom and latex.

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Due in part to the variety of definitions, between 1% and 15% of the population of the United States can be considered “at risk” for having an anaphylactic reaction if they are exposed to one or more allergens. Of those people who actually experience anaphylaxis, up to 1% may die as a result. Anaphylaxis results in approximately 1,500 deaths per year in the U.S. In England, mortality rates for anaphylaxis have been reported as up to 0.05 per 100,000 population, or around 10-20 a year. Anaphylactic reactions requiring hospital treatment appear to be increasing, with authorities in England reporting a threefold increase between 1994 and 2004.

Based on the pathophysiology, anaphylaxis can be divided into “true anaphylaxis” and “pseudo-anaphylaxis” or “anaphylactoid reaction.” The symptoms, treatment, and risk of death are the same; however, “true” anaphylaxis is caused by degranulation of mast cells or basophils mediated by immunoglobulin E (IgE), and pseudo-anaphylaxis occurs without IgE mediation.

Classification:
Biphasic anaphylaxis:..CLICK & SEE
Biphasic anaphylaxis is the recurrence of symptoms within 72 hours with no further exposure to the allergen. It occurs in between 1–20% of cases depending on the study examined. It is managed in the same manner as anaphylaxis.

Anaphylactic shock:...CLICK & SEE
Anaphylactic shock is anaphylaxis associated with systemic vasodilation which results in low blood pressure. It is also associated with severe bronchoconstriction to the point where the individual is unable to breathe.

Pseudoanaphylaxis:….CLICK & SEE
The presentation and treatment of pseudoanaphylaxis is similar to that of anaphylaxis. It however does not involve an allergic reaction but is due to direct mast cell degranulation. This can result from morphine, radiocontrast, aspirin and muscle relaxants.[11]

Active anaphylaxis:….CLICK & SEE
Active anaphylaxis is what is naturally observed. Two weeks or so after an animal, including humans, is exposed to certain allergens, active anaphylaxis (which is simply called “anaphylaxis”) would be elicited upon exposure to the same allergens.

Passive anaphylaxis:....CLICK & SEE
Passive anaphylaxis is induced in native animals which receive transfer of the serum experimentally from sensitized animals with certain allergens. Passive anaphylaxis would be provoked in the recipient animals after exposure to the same allergens.

SIGNS & SYMPTOMS :
Anaphylaxis can present with many different symptoms due to the systemic effects of histamine release. These usually develop over minutes to hours.[9] The most common areas affected include: skin (80% to 90%), respiratory (70%), gastrointestinal (30% to 45%), heart and vasculature (10% to 45%), and central nervous system (10% to 15%).

Skin:
Skin involvement may include generalized hives, itchiness, flushing, and swelling of the lips, tongue or throat….

Respiratory:
Respiratory symptoms may include shortness of breath, wheezes or stridor, and low oxygen.

Gastrointestinal:

Gastrointestinal symptoms may include crampy abdominal pain, diarrhea, and vomiting.

Cardiovascular:
Due to the presence of histamine releasing cells in the heart, coronary artery spasm may occur with subsequent myocardial infarction or dysrhythmia.

Nervous sys:

temA drop in blood pressure may result in a feeling of lightheadedness and loss of consciousness. There may be a loss of bladder control and muscle tone, and a feeling of anxiety and “impending doom”.

CAUSES:
Anaphylaxis can occur in response to any allergen. Common triggers include insect bites or stings, foods, medication and latex rubber

Tissues in different parts of the body release histamine and other substances. This causes the airways to tighten and leads to other symptoms.

Some drugs (morphine, x-ray dye, and others) may cause an anaphylactic-like reaction (anaphylactoid reaction) when people are first exposed to them. Aspirin may also cause a reaction. These reactions are not the same as the immune system response that occurs with “true” anaphylaxis. However, the symptoms, risk for complications, and treatment are the same for both types of reactions.

Anaphylaxis can occur in response to any allergen. Common causes include:

•Drug allergies :Any medication may potentially trigger anaphylaxis. The most common to do so include antibiotics (?-lactam antibiotics in particular), aspirin, ibuprofen, and other analgesics. Some drugs (polymyxin, morphine, x-ray contrast and others) may cause an “anaphylactoid” reaction (anaphylactic-like reaction) on the first exposure. This is usually due to a toxic reaction, rather than the immune system mechanism that occurs with “true” anaphylaxis. The symptoms, risk for complications without treatment, and treatment are the same, however, for both types of reactions. Some vaccinations are also known to cause “anaphylactoid” reactions....CLICK & SEE

•Food allergies :The most common are peanut, tree nuts, shellfish, fish, milk, and egg. Severe cases are usually the result of ingesting the allergen…...CLICK & SEE

•Insect bites/stings : Venom from stinging or biting insects such as Hymenoptera or Hemiptera may induce anaphylaxis in susceptible people…..CLICK & SEE

Pollens and other inhaled allergens rarely cause anaphylaxis. Some people have an anaphylactic reaction with no known cause…..CLICK & SEE

Less common causes of anaphylaxis include:

*Latex
*Muscle relaxants used during general anesthesia
*Exercise

Anaphylaxis triggered by exercise varies from person to person. In some people, aerobic activity, such as jogging, triggers anaphylaxis. In others, less intense physical activity, such as walking, can trigger a reaction. Eating certain foods before exercise or exercising when the weather is hot, cold or humid has also been linked to anaphylaxis in some people. Talk with your doctor about any precautions you should take when exercising.

Anaphylaxis symptoms are sometimes caused by aspirin, other nonsteroidal anti-inflammatory drugs — such as ibuprofen (Advil, Motrin, others) and naproxen sodium (Aleve, Midol Extended Relief) — and the intravenous (IV) contrast used in some X-ray imaging tests. Although similar to allergy-induced anaphylaxis, this type of reaction isn’t triggered by allergy antibodies.

If you don’t know what triggers your allergy attack, your doctor may do tests to try to identify the offending allergen. In some cases, the cause of anaphylaxis is never identified. This is known as idiopathic anaphylaxis.

Anaphylaxis is life-threatening and can occur at any time. Risks include a history of any type of allergic reaction.

DIAGNOSIS:
Anaphylaxis is diagnosed with high likelihood based on clinical criteria. These criteria are fulfilled when any one of the following three is true:[14]

1.Symptom onset within minutes to several hours of allergen exposure with involvement of the skin or mucosal tissue and any of the following: hives, itchiness, or swelling of the airway; plus either respiratory difficulty or a low blood pressure.

2.Any two or more of the following symptoms within minutes to several hours of allergen exposure: a. Involvement of the skin or mucosa b. Respiratory difficulties c. Low blood pressure d. Gastrointestinal symptoms

3.Low blood pressure within minutes to several hours after exposure to known allergen

Apart from its clinical features, blood tests for tryptase (released from mast cells) might be useful in diagnosing anaphylaxis.

Allergy testing may help in determining what triggered the anaphylaxis. In this setting, skin allergy testing (with or without patch testing) or RAST blood tests can sometimes identify the cause.

TREATMENT :
Anaphylaxis is an emergency condition requiring immediate professional medical attention. Call 911 immediately.

Check the person’s airway, breathing, and circulation (the ABC’s of Basic Life Support). A warning sign of dangerous throat swelling is a very hoarse or whispered voice, or coarse sounds when the person is breathing in air. If necessary, begin rescue breathing and CPR.

1.Call 911.
2.Calm and reassure the person.
3.If the allergic reaction is from a bee sting, scrape the stinger off the skin with something firm (such as a fingernail or plastic credit card). Do not use tweezers — squeezing the stinger will release more venom.
4.If the person has emergency allergy medication on hand, help the person take or inject the medication. Avoid oral medication if the person is having difficulty breathing.
5.Take steps to prevent shock. Have the person lie flat, raise the person’s feet about 12 inches, and cover him or her with a coat or blanket. Do NOT place the person in this position if a head, neck, back, or leg injury is suspected, or if it causes discomfort.

PROVIDING FIRST AID:
Although emergency medical help is essential, there are things that must be done to improve survival chances. If the person affected is conscious and having breathing difficulties, help them sit up. If they’re shocked with low blood pressure, they’re better off lying flat with their legs raised.

If the person is unconscious, check their airways and breathing, and put them in the recovery position.

If you know that the person is susceptible to anaphylaxis, ask if they carry a preloaded adrenaline syringe. If necessary, help the person inject it into their thigh muscle.  If available, antihistamines and steroids should also be given.

DO NOT:
•Do NOT assume that any allergy shots the person has already received will provide complete protection.
•Do NOT place a pillow under the person’s head if he or she is having trouble breathing. This can block the airways.
•Do NOT give the person anything by mouth if the person is having trouble breathing.
Paramedics or physicians may place a tube through the nose or mouth into the airways (endotracheal intubation) or perform emergency surgery to place a tube directly into the trachea (tracheostomy or cricothyrotomy).

The person may receive antihistamines, such as diphenhydramine, and corticosteroids, such as prednisone, to further reduce symptoms (after lifesaving measures and epinephrine are given).

You may click to see :

Natural Allergy Relief For Oak Pollen

Anaphylactic reactions in children – a questionnaire-based survey in Germany

PROGNOSIS:
Anaphylaxis is a severe disorder that can be life-threatening without prompt treatment. However, symptoms usually get better with the right therapy, so it is important to act right away.

Possible Complications:
•Airway blockage
•Cardiac arrest (no effective heartbeat)
•Respiratory arrest (no breathing)
•Shock

RISK FACTORS:

There aren’t many known risk factors for anaphylaxis, but some things that may increase your risk include:

*A personal history of anaphylaxis. If you’ve experienced anaphylaxis once, your risk of having this serious reaction is increased. Future reactions may be more severe than the first reaction.

*Allergies or asthma. People who have either condition are at increased risk of having anaphylaxis.

*A family history.
If you have family members who have experienced exercised-induced anaphylaxis, your risk of developing this type of anaphylaxis is higher than it is for someone without a family history.

PREVENTION:
Immunotherapy with Hymenoptera venoms is effective against allergies to bees, wasps, hornets, yellow jackets, white faced hornets, and fire ants.

The greatest success with prevention of anaphylaxis has been the use of allergy injections to prevent recurrence of sting allergy. The risk to an individual from a particular species of insect depends on complex interactions between likelihood of human contact, insect aggression, efficiency of the venom delivery apparatus, and venom allergenicity. Venom immunotherapy reduces risk of systemic reactions below 3%.[citation needed] One simple method of venom extraction has been electrical stimulation to obtain venom, instead of dissecting the venom sac.

A potential vaccine has been developed to prevent anaphylaxis due to peanut and tree nut allergies if they are exposed to a small amount of peanuts or nuts. Although it shows some promise to reduce the likelihood of anaphylaxis in affected individuals, the vaccine has not yet been approved for marketing and distribution. Desensitization techniques are also being studied for peanut allergies.

•Avoid triggers such as foods and medications that have caused an allergic reaction (even a mild one) in the past. Ask detailed questions about ingredients when you are eating away from home. Also carefully examine ingredient labels.

•If you have a child who is allergic to certain foods, introduce one new food at a time in small amounts so you can recognize an allergic reaction.

•People who know that they have had serious allergic reactions should wear a medical ID tag.

•If you have a history of serious allergic reactions, carry emergency medications (such as a chewable form of diphenhydramine and injectable epinephrine or a bee sting kit) according to your health care provider’s instructions.

•Do not use your injectable epinephrine on anyone else. They may have a condition (such as a heart problem) that could be negatively affected by this drug.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.nlm.nih.gov/medlineplus/ency/article/000844.htm
http://www.mayoclinic.com/health/anaphylaxis/DS00009
http://www.bbc.co.uk/health/physical_health/conditions/in_depth/allergies/allergicconditions_anaphylaxis.shtml
http://en.wikipedia.org/wiki/Anaphylaxis
http://www.bailey-law.com/files/anaphylaxis.html
http://www.absoluteastronomy.com/topics/Anaphylaxis

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Reduce Salt to Save Lives, Money

 

A new study has found that reducing salt in processed foods could prevent strokes and heart attacks and also save billions of dollars in medical costs.
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According to researchers at the Stanford University School of Medicine and the Veterans Affairs Palo Alto Health Care System , the U.S. food service industry should make a voluntary effort to reduce salt.

In the study, the researchers developed a computerised model that simulates the effects of reduced sodium intake on a large population of people between the ages of 40 and 85.

Based on a similar, salt-reduction campaign in the United Kingdom, the researchers estimated that a collaborative industry effort could lead to a 9.5 per cent decline in Americans’ salt intake.

That, in turn, would lead to a very modest decline in blood pressure among American consumers, minimising a major risk factor for cardiovascular problems.

“In our analysis, we found these small decreases in blood pressure would be effective in reducing deaths due to cardiovascular disease,” Crystal Smith-Spangler, MD, a postdoctoral scholar at the VA and first author of the study, said.

“The numbers of affected people are huge, so even a small decrease is significant if you have large numbers of people involved,” Smith-Spangler said.

By the researchers’ calculations, some 5,13,885 Americans would be spared from potentially fatal strokes in their lifetimes, and another 4,80,358 would not suffer heart attacks as a result of the reduced salt campaign.

In the study, the researchers relied on data from a variety of sources, including the Framingham Heart Study and the 2006 Medical Panel Expenditure Survey, to develop a hypothetical model of health benefits and costs of two different methods to reduce salt intake on a large scale.

Source::The findings are published in the March 2 Annals of Internal Medicine .

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Narcolepsy

Definition:
Narcolepsy is chronic sleep disorder, or dyssomnia. The condition is characterized by excessive daytime sleepiness (EDS) in which a person experiences extreme fatigue and possibly falls asleep at inappropriate times, such as whilst at work or at school. A narcoleptic will most probably experience disturbed nocturnal sleep and also abnormal daytime sleep pattern, which is often confused with insomnia. When a person with narcolepsy falls asleep or goes to bed they will generally experience the 4th stage of sleep REM (rapid eye movement/dreaming state), within 10 minutes; whereas for most people, this shouldn’t occur until generally 30 minutes of slumber.
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Cataplexy, a sudden muscular weakness brought on by strong emotions (in most cases, there are many people who will experience cataplexy without having a emotional trigger), is known to be one of the other problems that some narcoleptics will experience. Often manifesting as muscular weaknesses ranging from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or a total collapse. Usually only speech is slurred, vision is impaired (double vision, inability to focus), but hearing and awareness remain normal. In some rare cases, an individual’s body becomes paralyzed and muscles will become stiff.

The term narcolepsy derives from the French word narcolepsie created by the French physician Jean-Baptiste-Édouard Gélineau by combining the Greek narke numbness, stupor and lepsis attack, seizure.

Symptoms
The main characteristic of narcolepsy is excessive daytime sleepiness (EDS), even after adequate night time sleep. A person with narcolepsy is likely to become drowsy or fall asleep, often at inappropriate times and places. Daytime naps may occur with little warning and may be physically irresistible. These naps can occur several times a day. They are typically refreshing, but only for a few hours. Drowsiness may persist for prolonged periods of time. In addition, night time sleep may be fragmented with frequent awakenings.

Four other classic symptoms of the disorder, often referred to as the “tetrad of narcolepsy,” are cataplexy, sleep paralysis, hypnagogic hallucinations, and automatic behavior. These symptoms may not occur in all patients. Cataplexy is an episodic condition featuring loss of muscle function, ranging from slight weakness (such as limpness at the neck or knees, sagging facial muscles, or inability to speak clearly) to complete body collapse. Episodes may be triggered by sudden emotional reactions such as laughter, anger, surprise, or fear, and may last from a few seconds to several minutes. The person remains conscious throughout the episode. In some cases, cataplexy may resemble epileptic seizures. Sleep paralysis is the temporary inability to talk or move when waking (or less often, falling asleep). It may last a few seconds to minutes. This is often frightening but is not dangerous. Hypnagogic hallucinations are vivid, often frightening, dreamlike experiences that occur while dozing, falling asleep and/or while awakening.

Automatic behavior means that a person continues to function (talking, putting things away, etc.) during sleep episodes, but awakens with no memory of performing such activities. It is estimated that up to 40 percent of people with narcolepsy experience automatic behavior during sleep episodes. Sleep paralysis and hypnagogic hallucinations also occur in people who do not have narcolepsy, but more frequently in people who are suffering from extreme lack of sleep. Cataplexy is generally considered to be unique to narcolepsy and is analogous to sleep paralysis in that the usually protective paralysis mechanism occurring during sleep is inappropriately activated. The opposite of this situation (failure to activate this protective paralysis) occurs in rapid eye movement behavior disorder.

In most cases, the first symptom of narcolepsy to appear is excessive and overwhelming daytime sleepiness. The other symptoms may begin alone or in combination months or years after the onset of the daytime naps. There are wide variations in the development, severity, and order of appearance of cataplexy, sleep paralysis, and hypnagogic hallucinations in individuals. Only about 20 to 25 percent of people with narcolepsy experience all four symptoms. The excessive daytime sleepiness generally persists throughout life, but sleep paralysis and hypnagogic hallucinations may not.

Although these are the common symptoms of narcolepsy, many people with narcolepsy also suffer from insomnia for extended periods of time. The symptoms of narcolepsy, especially the excessive daytime sleepiness and cataplexy, often become severe enough to cause serious problems in a person’s social, personal, and professional life. Normally, when an individual is awake, brain waves show a regular rhythm. When a person first falls asleep, the brain waves become slower and less regular. This sleep state is called non-rapid eye movement (NREM) sleep. After about an hour and a half of NREM sleep, the brain waves begin to show a more active pattern again. This sleep state, called REM sleep (rapid eye movement sleep), is when most remembered dreaming occurs. Associated with the EEG-observed waves during REM sleep, muscle atonia is present (called REM atonia).

In narcolepsy, the order and length of NREM and REM sleep periods are disturbed, with REM sleep occurring at sleep onset instead of after a period of NREM sleep. Thus, narcolepsy is a disorder in which REM sleep appears at an abnormal time. Also, some of the aspects of REM sleep that normally occur only during sleep — lack of muscular control, sleep paralysis, and vivid dreams — occur at other times in people with narcolepsy. For example, the lack of muscular control can occur during wakefulness in a cataplexy episode; it is said that there is intrusion of REM atonia during wakefulness. Sleep paralysis and vivid dreams can occur while falling asleep or waking up. Simply put, the brain does not pass through the normal stages of dozing and deep sleep but goes directly into (and out of) rapid eye movement (REM) sleep.

This has several consequences. Night time sleep does not include as much deep sleep, so the brain tries to “catch up” during the day, hence EDS. People with narcolepsy may visibly fall asleep at unpredicted moments (such motions as head bobbing are common). People with narcolepsy fall quickly into what appears to be very deep sleep, and they wake up suddenly and can be disoriented when they do (dizziness is a common occurrence). They have very vivid dreams, which they often remember in great detail. People with narcolepsy may dream even when they only fall asleep for a few seconds.

Causes
Although the cause of narcolepsy was not determined for many years after its discovery, scientists had discovered conditions that seemed to be associated with an increase in an individual’s risk of having the disorder. Specifically, there appeared to be a strong link between narcoleptic individuals and certain genetic conditions. One factor that seemed to predispose an individual to narcolepsy involved an area of Chromosome 6 known as the HLA complex. There appeared to be a correlation between narcoleptic individuals and certain variations in HLA genes, although it was not required for the condition to occur. Certain variations in the HLA complex were thought to increase the risk of an auto-immune response to protein-producing neurons in the brain. The protein produced, called hypocretin or orexin, is responsible for controlling appetite and sleep patterns. Individuals with narcolepsy often have reduced numbers of these protein-producing neurons in their brains. In 2009 the autoimmune hypothesis was supported by research carried out at Stanford University School of Medicine.

The neural control of normal sleep states and the relationship to narcolepsy are only partially understood. In humans, narcoleptic sleep is characterized by a tendency to go abruptly from a waking state to REM sleep with little or no intervening non-REM sleep. The changes in the motor and proprioceptive systems during REM sleep have been studied in both human and animal models. During normal REM sleep, spinal and brainstem alpha motor neuron depolarization produces almost complete atonia of skeletal muscles via an inhibitory descending reticulospinal pathway. Acetylcholine may be one of the neurotransmitters involved in this pathway. In narcolepsy, the reflex inhibition of the motor system seen in cataplexy is believed identical to that seen in normal REM sleep.

In 2004 researchers in Australia induced narcolepsy-like symptoms in mice by injecting them with antibodies from narcoleptic humans. The research has been published in the Lancet providing strong evidence suggesting that some cases of narcolepsy might be caused by autoimmune disease. Narcolepsy is strongly associated with HLA-DQB1*0602 genotype. There is also an association with HLA-DR2 and HLA-DQ1. This may represent linkage disequilibrium. Despite the experimental evidence in human narcolepsy that there may be an inherited basis for at least some forms of narcolepsy, the mode of inheritance remains unknown. Some cases are associated with genetic diseases such as Niemann-Pick disease or Prader-Willi syndrome.

How common is narcolepsy
The prevalence of narcolepsy is similar to that of Parkinson’s disease and multiple sclerosis. In the United States, the National Institute of Neurological Disorders and Stroke estimates narcolepsy affects one in every 2,000 people. However, in some countries (for example, Israel), the prevalence of narcolepsy is much lower (one per 500,000) while in other countries (for example, Japan), it is much higher (one per 600). The American Sleep Association estimates that approximately 125,000 to 200,000 Americans suffer from narcolepsy, but only fewer than 50,000 are properly diagnosed.

Narcolepsy often remains undiagnosed or misdiagnosed for several years. This may occur because physicians do not consider the diagnosis of narcolepsy frequently enough. They may think of narcolepsy only in people who have the main symptom of excessive daytime sleepiness. Narcolepsy may not be considered in the evaluation of patients who come to doctors complaining of fatigue, tiredness, or problems with concentration, attention, memory, and performance, and other illnesses (seizures, mental illness, etc.).
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Narcolepsy has its typical onset in adolescence and young adulthood. There is an average 15-year delay between onset and correct diagnosis which may contribute substantially to the disabling features of the disorder. Cognitive, educational, occupational, and psychosocial problems associated with the excessive daytime sleepiness of narcolepsy have been documented. For these to occur in the crucial teen years when education, development of self-image, and development of occupational choice are taking place is especially damaging. While cognitive impairment does occur, it may only be a reflection of the excessive daytime somnolence.

The prevalence of narcolepsy is about 1 per 2,000 persons. It is a reason for patient visits to sleep disorder centers, and with its onset in adolescence, it is also a major cause of learning difficulty and absenteeism from school. Normal teenagers often already experience excessive daytime sleepiness because of a maturational increase in physiological sleep tendency accentuated by multiple educational and social pressures; this may be disabling with the addition of narcolepsy symptoms in susceptible teenagers. In clinical practice, the differentiation between narcolepsy and other conditions characterized by excessive somnolence may be difficult. Treatment options are currently limited. There is a paucity in the literature of controlled double-blind studies of possible effective drugs or other forms of therapy. Mechanisms of action of some of the few available therapeutic agents have been explored but detailed studies of mechanisms of action are needed before new classes of therapeutic agents can be developed. Narcolepsy is an underdiagnosed condition in the general population. This is partly because its severity varies from obvious to barely noticeable. Some people with narcolepsy do not suffer from loss of muscle control. Others may only feel sleepy in the evenings.

Diagnosis
Diagnosis is relatively easy when all the symptoms of narcolepsy are present, but if the sleep attacks are isolated and cataplexy is mild or absent, diagnosis is more difficult. It is also possible for cataplexy to occur in isolation. Two tests that are commonly used in diagnosing narcolepsy are the polysomnogram and the multiple sleep latency test (MSLT). These tests are usually performed by a sleep specialist. The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested, people with narcolepsy fall asleep rapidly, enter REM sleep early, and may awaken often during the night. The polysomnogram also helps to detect other possible sleep disorders that could cause daytime sleepiness.

For the multiple sleep latency test, a person is given a chance to sleep every 2 hours during normal wake times. Observations are made of the time taken to reach various stages of sleep (sleep onset latency). This test measures the degree of daytime sleepiness and also detects how soon REM sleep begins. Again, people with narcolepsy fall asleep rapidly and enter REM sleep early.
You may click to learn more     http://www.medicinenet.com/narcolepsy/page4.htm

Treatment
Treatment is tailored to the individual, based on symptoms and therapeutic response. The time required to achieve optimal control of symptoms is highly variable, and may take several months or longer. Medication adjustments are also frequently necessary, and complete control of symptoms is seldom possible. While oral medications are the mainstay of formal narcolepsy treatment, lifestyle changes are also important.

The main treatment of excessive daytime sleepiness in narcolepsy is with a group of drugs called central nervous system stimulants such as methylphenidate, racemic – amphetamine, dextroamphetamine, and methamphetamine, or modafinil, a new stimulant with a different pharmacologic mechanism. In Fall 2007 an alert for severe adverse skin reactions to modafinil was issued by the FDA.  Other medications used are codeine and selegiline. Another drug that is used is atomoxetine (Strattera), a non-stimulant and Norepinephrine reuptake inhibitor (NRI), that has little or no abuse potential. In many cases, planned regular short naps can reduce the need for pharmacological treatment of the EDS to a low or non-existent level.

Cataplexy and other REM-sleep symptoms are frequently treated with tricyclic antidepressants such as clomipramine, imipramine, or protriptyline, as well as other drugs that suppress REM sleep. Venlafaxine, a newer antidepressant which blocks the reuptake of serotonin and norepinephrine, has shown usefulness in managing symptoms of cataplexy[citation needed]. Gamma-hydroxybutyrate (GHB), a medication recently approved by the FDA, is the only medication specifically indicated for cataplexy. Gamma-hydroxybutyrate has also been shown to reduce symptoms of EDS associated with narcolepsy. While the exact mechanism of action is unknown, GHB is thought to improve the quality of nocturnal sleep.

In addition to drug therapy, an important part of treatment is scheduling short naps (10 to 15 minutes) two to three times per day to help control excessive daytime sleepiness and help the person stay as alert as possible. Daytime naps are not a replacement for nighttime sleep. Ongoing communication between the health care provider, patient, and the patient’s family members is important for optimal management of narcolepsy. Finally, a recent study reported that transplantation of hypocretin neurons into the pontine reticular formation in rats is feasible, indicating the development of alternative therapeutic strategies in addition to pharmacological interventions.

Learning as much about narcolepsy as possible and developing a support system or finding a support group may help patients and families deal with the practical and emotional effects of the disorder, possible occupational limitations, and situations that might cause injury. Individuals with narcolepsy should avoid jobs that require driving long distances or handling hazardous equipment or that require alertness for lengthy periods. They may find it helps to take a nap before driving if possible or have a scheduled nap break during a long driving trip.
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The National Sleep Foundation, University at Buffalo, and Mayo Clinic suggest it may help sufferers if they alert their employers, co-workers and friends in the hope that others will accommodate their condition and help when needed. The foundation say it may help if the sufferer breaks up larger tasks into small pieces and focuses on one small thing at a time, and if they carry a tape recorder, if possible, to record important conversations and meetings. The clinics say taking several short walks during the day may help sufferers.

What’s in the future for narcolepsy?

The discovery that a lack of hypocretins in the cerebrospinal fluid (CSF) may be related to the cause of narcolepsy could lead to the development of tests to determine the level of hypocretins in the CSF. Such tests could help in the diagnosis of narcolepsy. The expectation is that these tests will be simple (drawing blood), and will reflect the level of hypocretins in the CSF. In addition, the discovery of the role of hypocretins in the development of narcolepsy may lead to the development of new drugs for the treatment of narcolepsy.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.


Resources:

http://en.wikipedia.org/wiki/Narcolepsy
http://www.medicinenet.com/narcolepsy/article.htm

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Anger Alert for Heart

Episodes of anger may lead to potentially lethal abnormal heart rhythms in patients with heart disease and those who are survivors of heart attacks, a medical study has suggested.

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The study by researchers at the Yale University School of Medicine in the US is the first to show how emotion triggers a distinct pattern of electrical activity that contributes to arrhythmias — abnormal heart rhythms.

The researchers who monitored a group of 62 patients found that those with high levels of anger-induced electrical cardiac activity called T-wave alternans were more likely to experience arrhythmias than patients with low levels of this electrical activity.

Anger appeared to increase the risk of arrythmias by up to 10 times. The findings will appear shortly in the Journal of the American College of Cardiology.

“Our study identified individuals vulnerable to increased electrical instability due to emotion,” said Rachel Lampert, associate professor of medicine at Yale who has been exploring how mental stress can disturb heart rhythms.

The researchers studied patients with heart problems who had implantable cardioverter-defibrillators — small, battery-powered devices in the chest from where they constantly monitor the heart rate and rhythm.

When the device detects abnormal heart rhythms, it delivers an electrical shock to the heart muscle to stop the arrhythmia and return the heart to its normal rhythm.

The study examined incidence of arrhythmias over three years and found that patients with arrhythmias had higher T-wave alternans induced by anger than patients who had not experienced arrhythmias.

Arrhythmias of concern are rare in healthy people. “The implications of our findings are for the increasing number of people who have survived a heart attack or are living with heart failure,” Lampert told The Telegraph.

Cardiologists believe it is important to identify patients who are at risk of developing life-threatening arrhythmias. The results suggest that therapy to help patients deal with anger and other negative emotions may reduce arrhythmias, said Lampert.

Sources:
The Telegraph (Kolkata, India)

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