“Most people with spinal muscular atrophy are missing a piece of the SMN1 gene, which impairs SMN protein production. A shortage of SMN protein leads to motor neuron death, and as a result, signals are not transmitted between the brain and muscles. Muscles cannot contract without receiving signals from the brain, so many skeletal muscles become weak and waste away, leading to the signs and symptoms of spinal muscular atrophy.”

U.S. Library of Medicine (NIH)

Part III Other causes of muscle atrophy

Healthline through Dr. William Morrison Director, Musculoskeletal/General Diagnostic Muscle at Jefferson University Hospital, states atrophy is when muscles waste away. The main reason for muscle wasting is a lack of physical activity. This can happen when a disease or injury makes it difficult or impossible for you to move an arm or leg. A symptom of atrophied muscles is an arm that appears smaller, but not shorter, than the other arm.

You should schedule an appointment with your doctor if you think you are experiencing muscle atrophy. Your doctor will determine what treatment you need. In some cases, muscle wasting can be reversed with a proper diet, exercise, or physical therapy.

Symptoms of muscle atrophy

You may have muscle atrophy if:

  • One of your arms or legs is noticeably smaller than the other.
  • You are experiencing marked weakness in one limb.
  • You have been physically inactive for a very long time.

Contact your doctor to have a complete medical examination if you believe you may have muscle atrophy or if you are unable to move normally. You may have an undiagnosed condition that requires treatment. Your doctor will be able to provide you with diet and exercise options.

Causes of muscle atrophy

Unused muscles can waste away if you are not active. Even after it begins, this type of atrophy can often be reversed with exercise and improved nutrition.

Muscle atrophy can also happen if you are bedridden or unable to move certain body parts due to a medical condition. Astronauts, for example, can also experience some muscle atrophy after a few days of weightlessness.

Other causes for muscle atrophy include:

  • lack of physical activity for an extended period of time
  • aging
  • alcohol-associated myopathy, a pain and weakness in muscles due to excessive drinking over long periods of time
  • burns
  • injuries, such as a torn rotator cuff or broken bones
  • malnutrition
  • spinal cord or peripheral nerve injuries
  • stroke
  • long-term corticosteroid therapy

Diseases can cause muscles to waste away or can make movement difficult, leading to muscle atrophy. These include:

  • amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, affects nerve cells that control voluntary muscle movement
  • dermatomyositis, causes muscle weakness and skin rash
  • Guillain-Barré syndrome, an autoimmune disease that leads to nerve inflammation and muscle weakness
  • multiple sclerosis, an autoimmune disease in which the body destroys the protective coverings of nerves
  • muscular dystrophy, an inherited disease that causes muscle weakness
  • neuropathy, damage to a nerve or nerve group, resulting in loss of sensation or function
  • osteoarthritis, causes reduced motion in the joints
  • polio, a viral disease affecting muscle tissue that can lead to paralysis
  • polymyositis, an inflammatory disease
  • rheumatoid arthritis, a chronic inflammatory disease that affects the joints
  • spinal muscular atrophy, a hereditary disease causing arm and leg muscles to waste away

How muscle atrophy is diagnosed

Your doctor will ask about your complete medical history. Tell them about old or recent injuries and previously diagnosed medical conditions. List prescriptions, over-the counter medications, and supplements you’re taking. And give a detailed description of your symptoms.

Your doctor may also order tests to help with the diagnosis and to rule out certain diseases. These tests may include:

  • blood tests
  • X-rays
  • magnetic resonance imaging (MRI)
  • computed tomography (CT) scan
  • nerve conduction studies
  • muscle or nerve biopsy
  • electromyography (EMG)

Your doctor may refer you to a specialist depending on the results of these tests.

How muscle atrophy is treated

Treatment will depend on the diagnosis and the severity of your muscle loss. Any underlying medical conditions must be addressed. Common treatments for muscle atrophy include:

  • exercise
  • physical therapy
  • ultrasound therapy
  • surgery
  • dietary changes

Recommended exercises might include water exercises to help make movement easier. Physical therapists can also teach you the correct ways to exercise. A physical therapist can move your arms and legs for you if you have trouble moving.

Ultrasound therapy is a noninvasive procedure that uses sound waves to aid in healing. Also, surgery may be necessary if your tendons, ligaments, skin, or muscles are too tight and prevent you from moving. This condition is called contracture deformity.

Surgery may be able to correct contracture deformity if your muscle atrophy is due to malnutrition. And a torn tendon may cause muscle atrophy, but surgery may also be able to correct it.

Your doctor will advise you about proper nutrition and suggest proper dietary supplements if necessary.

Part II Causes and Diagnosing Spinal Muscular Atrophy


The SMA foundation states that the disease generally manifests early in life and is the leading genetic cause of death in infants and toddlers. … One in 40 to one in 50 people (approximately 6 million Americans) are carriers of the SMA gene.

Spinal muscular atrophy (SMA) affects 1 per 8,000 to 10,000 people worldwide. Spinal muscular atrophy type I is the most common type, accounting for about half of all cases. Types II and III are the next most common and types 0 and IV are rare.

Mutations in the SMN1 gene cause all types of spinal muscular atrophy described above. The number of copies of the SMN2 gene modifies the severity of the condition and helps determine which type develops.

The SMN1 and SMN2 genes both provide instructions for making a protein called the survival motor neuron (SMN) protein. Normally, most functional SMN protein is produced from the SMN1 gene, with a small amount produced from the SMN2 gene. Several different versions of the SMN protein are produced from the SMN2 gene, but only one version is functional; the other versions are smaller and quickly broken down. The SMN protein is one of a group of proteins called the SMN complex, which is important for the maintenance of motor neurons.  Motor neurons transmit signals from the brain and spinal cord that tell skeletal muscles to tense (contract), which allows the body to move.

Most people with spinal muscular atrophy are missing a piece of the SMN1 gene, which impairs SMN protein production. A shortage of SMN protein leads to motor neuron death, and as a result, signals are not transmitted between the brain and muscles. Muscles cannot contract without receiving signals from the brain, so many skeletal muscles become weak and waste away, leading to the signs and symptoms of spinal muscular atrophy.

Typically, people have two copies of the SMN1 gene and one to two copies of the SMN2 gene in each cell. However, the number of copies of the SMN2 gene varies, with some people having up to eight copies. In people with spinal muscular atrophy, having multiple copies of the SMN2 gene is usually associated with less severe features of the condition that develop later in life. The SMN protein produced by the SMN2 genes can help make up for the protein deficiency caused by SMN1 gene mutations. People with spinal muscular atrophy type 0 usually have one copy of the SMN2 gene in each cell, while those with type I generally have one or two copies, those with type II usually have three copies, those with type III have three or four copies, and those with type IV have four or more copies. Other factors, many unknown, also contribute to the variable severity of spinal muscular atrophy.

Spinal muscular atrophy is inherited in an autosomal recessive pattern, which means both copies of the SMN1 gene in each cell have mutations. In most cases, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In rare cases, a person with spinal muscular atrophy inherits an SMN1 gene mutation from one parent and acquires a new mutation in the other copy of the gene that occurs during the formation of reproductive cells (eggs or sperm) or in early embryonic development. In these cases, only one parent is a carrier of the SMN1 gene mutation.

Individuals who have more than the usual two copies of the SMN2 gene usually do not inherit the extra copies from a parent. They typically arise during a random error when making new copies of DNA (replication) in an egg or sperm cell or just after fertilization.


DNA testing is the preferred testing.

Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder. More than 1,000 genetic tests are currently in use, and more are being developed.

Several methods can be used for genetic testing:

  • Molecular genetic tests (or gene tests) study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.
  • Chromosomal genetic tests analyze whole chromosomes or long lengths of DNA to see if there are large genetic changes, such as an extra copy of a chromosome, that cause a genetic condition.
  • Biochemical genetic tests study the amount or activity level of proteins; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.

Genetic testing is voluntary. Because testing has benefits as well as limitations and risks, the decision about whether to be tested is a personal and complex one. A geneticist or genetic counselor can help by providing information about the pros and cons of the test and discussing the social and emotional aspects of testing.

Newborn Testing: To test if the routine newborn screening dried blood spots can be used to test if missing 2 copies of SMN1 gene, a status indicating spinal muscular atrophy


“Muscular dystrophy is a group of inherited diseases characterized by weakness and wasting away of muscle tissue, with or without the breakdown of nerve tissue. There are 9 types of muscular dystrophy, with each type involving an eventual loss of strength, increasing disability, and possible deformity.

The most well known of the muscular dystrophies is Duchenne muscular dystrophy (DMD), followed by Becker muscular dystrophy (BMD).”

John Hopkins Medicine

Part I Muscular Atrophy August Awareness-Staging 1-4

Spinal muscular atrophy is a genetic disorder characterized by weakness and wasting in muscles used for movement (skeletal muscles). It is caused by a loss of specialized nerve cells, called motor neurons that control muscle movement.  The weakness tends to be more severe in the muscles that are close to the center of the body (proximal) compared to muscles away from the body’s center (distal). The muscle weakness usually worsens with age. There are many types of spinal muscular atrophy that are caused by changes in the same genes. The types differ in age of onset and severity of muscle weakness; however, there is overlap between the types. Other forms of spinal muscular atrophy and related motor neuron diseases, such as spinal muscular atrophy with progressive myoclonic epilepsy, spinal muscular atrophy with lower extremity predominance, X-linked infantile spinal muscular atrophy, and spinal muscular atrophy with respiratory distress type 1 are caused by mutations in other genes.

Spinal muscular atrophy type 0 is evident before birth and is the rarest and most severe form of the condition. Affected infants move less in the womb, and as a result they are often born with joint deformities (contractures). They have extremely weak muscle tone (hypotonia) at birth. Their respiratory muscles are very weak and they often do not survive past infancy due to respiratory failure. Some infants with spinal muscular atrophy type 0 also have heart defects that are present from birth (congenital).

Spinal muscular atrophy type I (also called Werdnig-Hoffmann disease) is the most common form of the condition. It is a severe form of the disorder with muscle weakness evident at birth or within the first few months of life. Most affected children cannot control their head movements or sit unassisted. Children with this type may have swallowing problems that can lead to difficulty feeding and poor growth. They can also have breathing problems due to weakness of respiratory muscles and an abnormally bell-shaped chest that prevents the lungs from fully expanding. Most children with spinal muscular atrophy type I do not survive past early childhood due to respiratory failure.

Spinal muscular atrophy type II (also called Dubowitz disease) is characterized by muscle weakness that develops in children between ages 6 and 12 months. Children with this type can sit without support, although they may need help getting to a seated position. However, as the muscle weakness worsens later in childhood, affected individuals may need support to sit. Individuals with spinal muscular atrophy type II cannot stand or walk unaided. They often have involuntary trembling (tremors) in their fingers, a spine that curves side-to-side , and respiratory muscle weakness that can be life-threatening. The life span of individuals with spinal muscular atrophy type II varies, but many people with this condition live into their twenties or thirties.

Spinal muscular atrophy type III (also called Kugelberg-Welander disease) typically causes muscle weakness after early childhood. Individuals with this condition can stand and walk unaided, but over time, walking and climbing stairs may become increasingly difficult. Many affected individuals require wheelchair assistance later in life. People with spinal muscular atrophy type III typically have a normal life expectancy.

Spinal muscular atrophy type IV is rare and often begins in early adulthood. Affected individuals usually experience mild to moderate muscle weakness, tremors, and mild breathing problems. People with spinal muscular atrophy type IV have a normal life expectancy.

JOHN HOPKINS MEDICINE states these types of of MS/Atrophy:

Type Age at onset Symptoms, rate of progression, and life expectancy
Becker adolescence to early adulthood Symptoms are almost identical to Duchenne, but less severe; progresses more slowly than Duchenne; survival into middle age. As with Duchenne, disease is almost always limited to males.
Congenital birth Symptoms include general muscle weakness and possible joint deformities; disease progresses slowly; shortened life span.
Duchenne 2 to 6 years Symptoms include general muscle weakness and wasting; affects pelvis, upper arms, and upper legs; eventually involves all voluntary muscles; survival beyond 20s is rare. Seen in boys only. Very rarely can affect woman, who have much milder symptoms and a better prognosis.
Distal 40 to 60 years Symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs; progression is slow; rarely leads to total incapacity.
Emery-Dreifuss childhood to early teens Symptoms include weakness and wasting of shoulder, upper arm, and shin muscles; joint deformities are common; progression is slow; sudden death may occur from cardiac problems.
Facioscapulohumeral childhood to early adults Symptoms include facial muscle weakness and weakness with some wasting of shoulders and upper arms; progression is slow with periods of rapid deterioration; life span may be many decades after onset.
Limb-Girdle late childhood to middle age Symptoms include weakness and wasting, affecting shoulder girdle and pelvic girdle first; progression is slow; death is usually due to cardiopulmonary complications.
Myotonic 20 to 40 years Symptoms include weakness of all muscle groups accompanied by delayed relaxation of muscles after contraction; affects face, feet, hands, and neck first; progression is slow, sometimes spanning 50 to 60 years.
Oculopharyngeal 40 to 70 years Symptoms affect muscles of eyelids and throat causing weakening of throat muscles, which, in time, causes inability to swallow and emaciation from lack of food; progression is slow.


“Gastroparesis is rare.  Fewer than 200,000 cases a year.   Gastroparesis can affect digestion. The cause might be damage to a nerve that controls stomach muscles.  Symptoms include nausea and a full feeling after little food is eaten.  Diet changes and medications may offer relief.”


Part II Gastroparesis August Awareness Month

How is Gastroparesis Treated?
The treatment for gastroparesis in an individual depends on the severity of symptoms. Treatments are aimed at managing symptoms over a long-term.

Treatment approaches may involve one or a combination of:

  • dietary and lifestyle measures,
  • medications, and/or
  • procedures that may include surgery, such as
  • enteral nutrition,
  • parenteral nutrition,
  • gastric electrical stimulation (Enterra), or
  • other surgical procedures

Some people with gastroparesis have mild symptoms that come and go, which can be managed with dietary and lifestyle measures.

Others have moderate to more severe symptoms that additionally may be treated with medications to stimulate motility and/or reduce nausea and vomiting.

Some people have severe symptoms that are difficult to treat or do not respond to initial treatment approaches. They may require additional procedures to maintain nutrition and/or reduce symptoms.

Goals of Treatment
The goals of treatment are to manage and reduce symptoms, maintain quality of daily living, and minimize related problems such as:

  • Severe dehydration due to persistent vomiting
  • Bezoars (solid collections of food, fiber, or other material), which can cause nausea, vomiting, obstruction, or interfere with absorption of some medications in pill form
  • Difficulty managing blood glucose levels in people with diabetes
  • Malnutrition due to poor absorption of nutrients or a low calorie intake

Manage Risk and Benefit
No single treatment helps all persons with gastroparesis. All drugs and procedures have inherent risks, some more than others. Some of the risks are unavoidable, while others can be avoided and managed. For patients and families it is important to talk to the doctor or health care team about both benefit and risk.

As a patient, in the context of your personal illness status, consider:

  • How severe is your own condition – what effect is it having on your life
  • What is the possible benefit from the treatment suggested or prescribed to you
  • What are the chances that you will receive benefit from the treatment
  • How much benefit should you reasonably expect
  • What possible side effects or complications might there be from the treatment
  • What are the chances that you will experience a side effect or serious adverse event from the treatment
  • What can you do to reduce the chances of side effects or complications
  • How will you know when a side effect occurs
  • Exactly what should you do if a side effect or complication occurs

How to live with Gastroparesis:

Gastroparesis is a long-term condition that can impair quality of life and well-being. Living with gastroparesis affects not only those who suffer but also many others, especially family members and friends. It also touches on relationships in the classroom, in the workplace, or in social interactions.

It takes skills and strengths to deal with a challenging digestive condition like gastroparesis. It means being a kind of active researcher, always looking for what does and does not help, hurt, and work best.

It is important to understand the condition and to advocate for better health. If you or a friend or loved one has gastroparesis, it is also important to understand that you are not alone with this diagnosis.


“There are many causes of gastroparesis. Diabetes is one of the most common causes for gastroparesis. Other causes include infections, endocrine disorders like hypothyroidism, connective tissue disorders like scleroderma, autoimmune conditions, neuromuscular diseases, idiopathic (unknown) causes, psychological conditions, eating disorders, certain cancers, radiation treatment applied over the chest or abdomen, some chemotherapy agents, and surgery of the upper intestinal tract.”

American College of Gastroenterology

Part I Gastroparesis August Awareness Month


Should focus attention on important health messages about gastroparesis diagnosis, treatment, and quality of life issues. The goals include improving understanding of gastroparesis to help patients and families manage the condition, and encouraging preventive strategies.

The number of people with gastroparesis appears to be rising. Yet gastroparesis is poorly understood. More community awareness is needed about the condition.

The more awareness for gastroparesis, the greater the ability to impact positive outcomes, such as additional research and improved patient care for the functional GI and motility disorders.

Gastroparesis is also called delayed gastric emptying. The term “gastric” refers to the stomach.

Normally, the stomach empties its contents in a controlled manner into the small intestines. In gastroparesis, the muscle contractions (motility) that move food along the digestive tract do not work properly and the stomach empties too slowly.

Gastroparesis is characterized by the presence of certain long-term symptoms together with delayed stomach emptying in the absence of any observable obstruction or blockage. The delayed stomach emptying is confirmed by a test.

Signs and Symptoms:

The signs and symptoms of gastroparesis may differ among persons with the condition. Symptoms usually occur during and after eating a meal.

Symptoms that are characteristic of gastroparesis include:

  • Nausea and/or vomiting
  • Retching (dry heaves)
  • Stomach fullness after a normal sized meal
  • Early fullness (satiety) – the inability to finish a meal

Diagnosing Gastroparesis:

The symptoms of gastroparesis are similar to those that occur in a number of other illnesses. When symptoms persist over time or keep coming back, it’s time to see a doctor to diagnose the problem. An accurate diagnosis is the starting point for effective treatment.

Diagnosis of gastroparesis begins with a doctor asking about symptoms and past medical and health experiences (history), and then performing a physical exam. Any medications that are being taken need to be disclosed.

Tests will likely be performed as part of the examination. These help to identify or rule out other conditions that might be causing symptoms. Tests also check for anything that may be blocking or obstructing stomach emptying. Examples of these tests include:

  • a blood test,
  • an upper endoscopy, which uses a flexible scope to look into the stomach,
  • an upper GI series that looks at the stomach on an x-ray, or
  • an ultrasound, which uses sound waves that create images to look for disease in the pancreas or gallbladder that may be causing symptoms.

If – after review of the symptoms, history, and examination – the doctor suspects gastroparesis, a test to measure how fast the stomach empties is required to confirm the diagnosis.

Slow gastric emptying alone does not correlate directly with a diagnosis of gastroparesis.

There are several different ways to measure the time it takes for food to empty from the stomach into the small intestine. These include scintigraphy, wireless motility capsule, or breath test. Your doctor will provide details of the one chosen.

Gastric Emptying Study (Scintigraphy)
The diagnostic test of choice for gastroparesis is a gastric emptying study (scintigraphy). The test is done in a hospital or specialty center.

It involves eating a bland meal of solid food that contains a small amount of radioative material so that it can be tracked inside the body. The abdomen is scanned over the next few hours to see how quickly the meal passes out of the stomach. A radiologist will interpret the study at periodic intervals after the meal.

A diagnosis of gastroparesis is confirmed when 10% or more of the meal is still in the stomach after 4 hours.

Other methods for measuring gastric emptying include a wireless motility capsule and a breath test.

Wireless Motility Capsule
The ingestible wireless motility capsule (SmartPill) is swallowed and transmits data to a small receiver that the patient carries. The data collected is interpreted by a radiologist. While taking the test, people can go about their daily routine. After a day or two, the disposable capsule is excreted naturally from the body.

Breath Test
The breath test involves eating a meal that contains a nonradioactive component that can be tracked and measured in the breath over a period of hours. The results can then be calculated to determine how quickly the stomach empties.

Stay tune for Part II tomorrow!



“Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus, called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003. Over the next few months, the illness spread to more than two dozen countries in North America, South America, Europe, and Asia before the SARS global outbreak of 2003 was contained. ”

Center for Disease Control and Prevention – CDC