Upper limb muscles

The muscles of the superior limb arise from three different developmental primordia – the caudal branchial arches, the hypaxial body wall, and the limb bud. The first two groups, the branchial arches and body wall muscles, form attachments with the pectoral girdle and help stabilize and move the proximal end of the limb. The muscles of the limb proper (brachial, antebrachial, and hand muscles) and some of the shoulder joint muscles, which migrate secondarily back onto the trunk wall, are all derived from the embryonic limb bud. This is a highly varied group of muscles with a wide range of functions. The muscles range from large muscles that play major roles in supporting and stabilizing the limb, yet produce very small ranges of movement, to other muscles that produce the greatest range of movements in the entire body. Because of its diverse embryonic origins, the muscles of this group receive their nerve supply from different sources. Some of the muscles are supplied by cranial nerves (branchial arch muscles), another is innervated by body wall ventral rami (levator scapulae), and the remainder are supplied by the ventral rami that form the large brachial plexus that courses through the entire upper limb.

Risk Factors for Alzheimer's Disease

While the specific cause or the cure for Alzheimer's disease is not known, the disease appears to develop when the combined effects of certain risk factors reach a threshold level. Many of these risk factors are known but there are likely others that are yet to be identified. When the threshold level is reached, the brain's ability to repair and maintain itself is overwhelmed, and the disease process begins. 

Risk factors increase the chances of getting Alzheimer's disease. Age and genetics are two risk factors that can not be changed. However, it may be possible to reduce many of the other known risks for the disease through lifestyle choices. 

Age 
Advancing age is the most significant risk factor for Alzheimer's disease. Most people who develop Alzheimer's disease are over the age of 65. However the disease process is thought to begin years before cognitive and memory impairments are apparent. It is important to remember that most people do not get Alzheimer's disease as they age. It is not a normal part of aging. Whatever other risk factors are present, Alzheimer's disease never sets in until some minimum adult age is reached. 

Genes 
The familial form of the disease (FAD), passed on directly from generation to generation, accounts for only about 7% of the total incidence of Alzheimer’s disease. While the common form of the disease (sporadic Alzheimer's disease) also has some genetic links much is still unknown. The majority of cases have no single identifiable cause. The role of genetics continues to be studied. 

Other Risk Factors Include:

• Unhealthy eating habits
• Diabetes
• High blood pressure
• High cholesterol levels
• Strokes
• Obesity
• Stress
• Chronic inflammatory conditions
• History of clinical depression
• MCI (mild cognitive impairment)
• Low levels of physical activity
• Low socio-economic status
• Inadequate exercising of the brain
• Low levels of formal education
• Brain injury
• Smoking

Diagnosing Alzheimer’s disease

Since there is no single definitive medical test for identifying Alzheimer’s disease, arriving at the correct diagnosis can take time and patience. Diagnosing Alzheimer's requires a detailed evaluation, including:

A thorough history of symptoms from the patient and spouse or family, including past and present functioning. Determining classic patterns can help your doctor eliminate other causes of Alzheimer’s symptoms, and also distinguish Alzheimer’s from other forms of dementia.

A physical and neurological exam, including cognitive tests to assess such things as orientation (ability to recall details about self, place, and time), attention span, speed of information processing, working memory, and mood and personality.

Other tests, such as brain imaging and blood tests, to rule out other medical causes.

To diagnose Alzheimer's disease from your symptoms, a doctor will look for:

Significant memory problems in immediate recall, short-term, or long-term memory.

Significant thinking deficits in at least one of four areas: expressing or comprehending language; identifying familiar objects through the senses; poor coordination, gait, or muscle function; and the executive functions of planning, ordering, and making judgments.

Decline severe enough to interfere with relationships and/or work performance.

Symptoms that appear gradually and become steadily worse over time.

Other causes to be ruled out to ensure memory and cognitive symptoms are not the result of another medical condition or disease, such as mild cognitive impairment.

Alzheimer's Disease

Alzheimer's disease is a progressive, degenerative disease of the brain, which causes thinking and memory to become seriously impaired. It is the most common form of dementia. 

The disease was first identified by Dr. Alois Alzheimer in 1906. He described the two hallmarks of the disease: 

• Plaque: Numerous tiny dense deposits scattered throughout the brain which become toxic to brain cells at excessive levels.
• Tangles: Twisted fibers that interfere with vital processes eventually "choking" off the living cells.

When brain cells degenerate and die, the brain markedly shrinks in some regions. 

The Effects of Alzheimer's Disease

Alzheimer's disease eventually affects all aspects of a person's life: how he or she thinks, feels and acts. Since individuals are affected differently, it is difficult to predict the symptoms each person will have, the order in which they will appear, or the speed of the disease's progression. 

In general the following will gradually be affected by the disease: 

Mental Abilities
A person's ability to understand, think, remember and communicate will be affected. The ability to make decisions will be reduced. Simple tasks that have been performed for years will become more difficult or be forgotten. Confusion and memory loss, initially for recent events and eventually for long-term events, will occur. The ability to find the right words and follow a conversation will be affected. 

Emotions and Moods 
A person may appear uninterested and apathetic, and may quickly lose interest in the hobbies they previously enjoyed. The ability to control mood and emotion may be lost. Some individuals are less expressive and are more withdrawn. However, it is now becoming clear that a person even in the later stages of the disease may continue to feel joy, anger, fear, love, and sadness. 

Behaviour 
Changes will develop in the way the person reacts to his or her environment. These actions may seem out of character for the person. Some common reactions include repeating the same action or words, hiding possessions, physical outbursts and restlessness. 

Physical abilities 
The disease can affect a person’s physical co-ordination and mobility, leading to a gradual physical decline. This will affect the person's ability to independently perform day-to-day tasks such as eating, bathing and getting dressed. 

Tuberculosis

Tuberculosis (TB) is an infectious disease that usually infects the lungs, but can attack almost any part of the body. Tuberculosis is spread from person to person through the air. When a person with TB in their lungs or throat coughs, laughs, sneezes, sings, or even talks, the germs that cause TB may spread through the air. If another person breathes in these germs, there is a chance that they will become infected with tuberculosis. 

It is not easy to become infected with tuberculosis. Usually a person has to be close to someone with TB disease for a long period of time. TB is usually spread between family members, close friends, and people who work or live together. TB is spread most easily in closed spaces over a long period of time.

If it is not treated, TB can be fatal. But TB can almost always be treated and cured if you take medicine as directed by your healthcare provider. Once you begin treatment, within weeks you will no longer be contagious. That means you can't spread the disease to others. If you take your medicine just as your healthcare provider tells you, all the TB germs should be killed.

What are the Symptoms of TB?

A person with TB infection will have no symptoms. A person with active TB disease may have any, all or none of the following symptoms:

• A persistent cough
• Constant fatigue
• Weight loss
• Loss of appetite
• Fever
• Coughing up blood
• Night sweats

These symptoms can also occur with other diseases so it is important to see a healthcare provider and to let them find out if you have TB. A person with TB disease may feel perfectly healthy or may only have a cough from time to time. If you think you have been exposed to TB, get a TB test.

How is TB Detected?

TB can be detected through a skin test or a TB blood test.

The skin test is done by injecting a small amount of fluid called tuberculin into the skin in the arm. You will be told to return within 48 to 72 hours to have a healthcare worker check the arm to see if a bump has developed. The healthcare worker will measure the bump and tell you if your reaction to the test is positive or negative. If it's positive, it usually means you have been infected with the TB germ.

The TB blood test measures how your immune system reacts to the germs that cause TB.

If you have a positive test for TB infection, it only means that you have been infected with TB germs. It does not tell whether you have developed TB disease. You will be given other tests, such as a chest x-ray and a check of your sputum (coughed up mucus), to see whether you have TB disease.

Progressive Muscular Atrophy

A progressive neurological disease in which the lower motor nerve cells (motor neurons) deteriorate. PMA is not rapidly progressive.

What is PMA?

PMA affects only the lower motor neurons, causing atrophy and fasciculations.

PMA is noted by an absence of upper motor neuron difficulties such as spasticity, brisk reflexes, or the Babinski sign.

Patients with PMA survive longer than patients with ALS and in some cases symptoms can be restricted to the arms or legs for a long period of time before spreading elsewhere in the body.

Types of Progressive Muscular Atrophy?

There may be two subtypes, one with a patchy distribution and one with a leg distribution. In the first case, progression is unpredictable, whilst in the latter there is a prolonged latency period between the progression from legs to arms, and then again to the bulbar region.

Other PMA Related Resources:

• PMA Online Support Group - ideal for individuals wanting to learn more about PMA, or for individuals wanting to chat with others that have been affected by PMA.
• PMA description - This PMA support group discussion has more information about PMA. Join the group to add your questions or comments about PMA.

Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes disease (or Perthes disease) is a temporary condition in children in which the ball-shaped head of the thigh bone, referred to as the femoral head, loses its blood supply. As a result, the femoral head collapses. The body will absorb the dead bone cells and replace them with new bone cells. The new bone cells will eventually reshape the femoral head of the thigh bone. Legg-Calvé-Perthes disease causes the hip joint to become painful and stiff for a period of time.

Legg-Calvé-Perthes disease goes through four phases of changes that affect the head of the femur. The phases include:

• Phase 1 - Blood supply is absent to the femoral head and the hip joint becomes inflamed, stiff, and painful. Portions of the bone turn into dead tissue. The ball of the thigh bone becomes less round in appearance on x-rays. This phase can last from several months up to one year.
• Phase 2 - The body cleans up the dead bone cells and replaces them with new, healthier bone cells. The femoral head begins to remodel into a round shape again. The joint is still irritated and painful. This phase can last from one to three years.
• Phase 3 - The femoral head continues to model itself back into a round shape with new bone. This phase lasts for one to three years.
• Phase 4 - Normal bone cells replace the new bone cells. This last phase can last a few years to complete the healing process.

What causes Legg-Calvé-Perthes disease?

The cause of Legg-Calvé-Perthes disease is unknown. It is five times more likely to occur in boys than girls.

Legg-Calvé-Perthes disease commonly affects first-born children and is typically seen in children 4 to 10 years of age. The majority of cases affect only one hip.

What are the symptoms of Legg-Calvé-Perthes disease?

The child typically complains of pain in his/her hip that is aggravated by activity. Sometimes, they will also experience pain in their thigh or knee area. The child usually walks with a limp and reports that rest will alleviate the pain.

The symptoms of Legg-Calvé-Perthes disease may resemble other conditions or medical problems of the hip. Always consult your child's physician for a diagnosis.

How is Legg-Calvé-Perthes disease diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for Legg-Calvé-Perthes disease may include:

• x-rays - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
• bone scans - a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation.
• magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
• arthrograms - a diagnostic imaging test to study the non-bony structures of joints.
• blood tests

Treatment for Legg-Calvé-Perthes disease:

Specific treatment for Legg-Calvé-Perthes disease will be determined by your child's physician based on:

• your child's age, overall health, and medical history
• the extent of the condition
• your child's tolerance for specific medications, procedures, or therapies
• expectations for the course of the condition
• your opinion or preference

The goal of treatment is to preserve the roundness of the femoral head and to prevent deformity while the condition runs its course. Treatment options are dependent upon the amount of hip pain, stiffness, and x-ray changes over time, as well as how much of the femoral head has collapsed.

Typically, the first step of treatment is to regain hip motion and eliminate pain that results from the tight muscles around the hip and the inflammation inside the joint. Treatment may include:

• rest
• activity restrictions
• medications such as ibuprofen
• bed rest and traction
• casting or bracing (to hold the femoral head in the hip socket, permit limited joint movement, and allow the femur to remold itself into a round shape again)
• surgery (to hold the femoral head in the hip socket)
• physical therapy (to keep the hip muscles strong and to promote hip movement)
• crutches or wheelchair (in some cases)

Long-term outlook for a child with Legg-Calvé-Perthes disease:

The ultimate goal in Legg-Calvé-Perthes disease is to diagnose the condition early in order to allow as much time as possible to let the femoral head remodel back into a round shape. Other treatment goals include controlling pain, maintaining hip motion, and preventing continued hip deformity.

The two most critical factors that determine the outcome are the child's age and how much of the femoral head is affected by this condition.

The more severe the case, the greater the likelihood that the child may experienc