myopathy

Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even paralysis.

Causes of muscle disorders include:

• Injury or overuse, such as sprains or strains, cramps or tendinitis
• A genetic disorder, such as muscular dystrophy
• Some cancers
• Inflammation, such as myositis
• Diseases of nerves that affect muscles
• Infections
• Certain medicines

Sometimes the cause of muscle disorders is unknown.

Muscular dystrophy (MD) is a group of more than 30 genetic diseases. They cause weakness of the muscles. Over time, the weakness gets worse and can cause trouble walking and doing daily activities. Some types of MD can also affect other organs.

There are many different types of MD. Some of the more common types include:

• Duchenne muscular dystrophy, which is the most common childhood form. It is severe and affects boys more often than girls. The symptoms usually start between ages 3 and 6.
• Becker muscular dystrophy, which is similar to Duchenne but is less severe and gets worse more slowly. It often starts in the teenage years.
• Congenital muscular dystrophies, which are present at birth or before age 2. They can be mild or severe.
• Facioscapulohumeral muscular dystrophy, which often starts in the teenage years. At first, it affects the muscles of the face, shoulders, and upper arms.

Each of the types of MD can be different in many ways, such as:

• Who is more likely to get them
• Which muscles they affect
• When they appear, such as in infancy, childhood, middle age, or later
• What the symptoms are
• How serious the symptoms are
• How quickly they get worse
• Whether they run in families
• Whether they affect other organs

Even within the same type of MD, people can have different symptoms.

MD is genetic, meaning that it caused by a change in one or more genes. Gene changes are also called gene variants or mutations. The gene changes in MD affect proteins that strengthen and protect muscles.

There are different gene changes that cause each type of MD. And sometimes people who have the same type of MD can have different gene changes.

Muscular dystrophy can run in families, or you can be the first in your family to have a muscular dystrophy.

To find out if you or your child has MD, your health care provider may use:

• A medical and family history
• A physical exam
• Blood and urine tests, including genetic tests and tests for certain enzymes that may be released by damaged muscles
• Muscle biopsies
• Electromyography and nerve conduction studies to find out if muscles are responding the right way to nerve signals
• Heart testing, such as an electrocardiogram (EKG), since some types of MD can cause heart problems
• Exercise tests to measure muscle strength and breathing and detect any increased rates of certain chemicals following exercise
• Imaging tests such as an MRI to look at muscle quality and bulk and measure fatty replacement of muscle tissue

There is no cure for muscular dystrophy. Treatment can help with the symptoms and prevent complications. It usually includes a combination of therapies, such as:

• Physical therapy to help keep muscles flexible and strong
• Occupational therapy to relearn lost motor skills and learn ways to work around weakened muscles
• Respiratory care, such as breathing exercises, oxygen therapy, and ventilators
• Speech therapy to help with speech and swallowing problems
• Assistive devices, such as wheelchairs, splints and braces, and walkers
• Medicines to help delay damage to muscles or minimize the symptoms of MD
• Surgery to treat some of the conditions associated with MD, such as heart problems, scoliosis, and cataracts

NIH: National Institute of Neurological Disorders and Stroke

Myositis means inflammation of the muscles that you use to move your body. An injury, infection, or autoimmune disease can cause it. Two specific kinds are polymyositis and dermatomyositis. Polymyositis causes muscle weakness, usually in the muscles closest to the trunk of your body. Dermatomyositis causes muscle weakness, plus a skin rash.

Other symptoms of myositis may include:

• Fatigue after walking or standing
• Tripping or falling
• Trouble swallowing or breathing

Doctors may use a physical exam, lab tests, imaging tests and a muscle biopsy to diagnose myositis. There is no cure for these diseases, but you can treat the symptoms. Polymyositis and dermatomyositis are first treated with high doses of a corticosteroid. Other options include medications, physical therapy, exercise, heat therapy, assistive devices, and rest.

NIH: National Institute of Neurological Disorders and Stroke

Cardiomyopathy is the name for diseases of the heart muscle. These diseases enlarge your heart muscle or make it thicker and more rigid than normal. In rare cases, scar tissue replaces the muscle tissue.

Some people live long, healthy lives with cardiomyopathy. Some people don't even realize they have it. In others, however, it can make the heart less able to pump blood through the body. This can cause serious complications, including:

• Heart failure
• Abnormal heart rhythms
• Heart valve problems
• Sudden cardiac arrest (SCA)

Heart attacks, high blood pressure, infections, and other diseases can all cause cardiomyopathy. Some types of cardiomyopathy run in families. In many people, however, the cause is unknown. Treatment might involve medicines, surgery, other medical procedures, and lifestyle changes.

NIH: National Heart, Lung, and Blood Institute

When you play the piano or hit a tennis ball you are activating the cerebellum. The cerebellum is the area of the brain that controls coordination and balance. Problems with the cerebellum include:

• Cancer
• Genetic disorders
• Ataxias - failure of muscle control in the arms and legs that result in movement disorders
• Degeneration - disorders caused by brain cells decreasing in size or wasting away

Treatment of cerebellar disorders depends on the cause. In some cases, there is no cure but treatment may help with symptoms.

NIH: National Institute of Neurological Disorders and Stroke

Dementia is a loss of mental functions that is severe enough to affect your daily life and activities. These functions include:

• Memory
• Language skills
• Visual perception (your ability to make sense of what you see)
• Problem solving
• Trouble with everyday tasks
• The ability to focus and pay attention

It is normal to become a bit more forgetful as you age. But dementia is not a normal part of aging. It is a serious disorder that interferes with your daily life.

The most common types of dementia are known as neurodegenerative disorders. These are diseases in which the cells of the brain stop working or die. They include:

• Alzheimer's disease, which is the most common form of dementia among older people. People with Alzheimer's have plaques and tangles in their brain. These are abnormal buildups of different proteins. Beta-amyloid protein clumps up and forms plaques in between your brain cells. Tau protein builds up and forms tangles inside the nerve cells of your brain. There is also a loss of connection between nerve cells in the brain.
• Lewy body dementia, which causes movement symptoms along with dementia. Lewy bodies are abnormal deposits of a protein in the brain.
• Frontotemporal disorders, which cause changes to certain parts of the brain:
  • Changes in the frontal lobe lead to behavioral symptoms
  • Changes in the temporal lobe lead to language and emotional disorders
• Vascular dementia, which involves changes to the brain's blood supply. It is often caused by a stroke or atherosclerosis (hardening of the arteries) in the brain.
• Mixed dementia, which is a combination of two or more types of dementia. For example, some people have both Alzheimer's disease and vascular dementia.

Other conditions can cause dementia or dementia-like symptoms, including:

• Creutzfeldt-Jakob disease, a rare brain disorder
• Huntington's disease, an inherited, progressive brain disease
• Chronic traumatic encephalopathy (CTE), caused by repeated traumatic brain injury
• HIV-associated dementia (HAD)

Certain factors can raise your risk for developing dementia, including:

• Aging. This is the biggest risk factor for dementia.
• Smoking
• Uncontrolled diabetes
• High blood pressure
• Drinking too much alcohol
• Having close family members who have dementia

The symptoms of dementia can vary, depending on which parts of the brain are affected. Often, forgetfulness is the first symptom. Dementia also causes problems with the ability to think, problem solve, and reason. For example, people with dementia may:

• Get lost in a familiar neighborhood
• Use unusual words to refer to familiar objects
• Forget the name of a close family member or friend
• Forget old memories
• Need help doing tasks that they used to do by themselves

Some people with dementia cannot control their emotions and their personalities may change. They may become apathetic, meaning that they are no longer interested in normal daily activities or events. They may lose their inhibitions and stop caring about other peoples' feelings.

Certain types of dementia can also cause problems with balance and movement.

The stages of dementia range from mild to severe. In the mildest stage, it is just beginning to affect a person's functioning. In the most severe stage, the person is completely dependent on others for care.

Your health care provider may use many tools to make a diagnosis:

• A medical history, which includes asking about your symptoms
• A physical exam
• Tests of your thinking, memory, and language abilities
• Other tests, such as blood tests, genetic tests, and brain scans
• A mental health evaluation to see whether a mental disorder is contributing to your symptoms

There is no cure for most types of dementia, including Alzheimer's disease and Lewy body dementia. Treatments may help to maintain mental function longer, manage behavioral symptoms, and slow down the symptoms of disease. They may include:

• Medicines, which may temporarily improve memory and thinking or slow down their decline. They only work in some people. Other medicines can treat symptoms such as anxiety, depression, sleep problems, and muscle stiffness. Some of these medicines can cause strong side effects in people with dementia. It is important to talk to your health care provider about which medicines will be safe for you.
• Occupational therapy to help find ways to more easily do everyday activities
• Speech therapy to help with swallowing difficulties and trouble speaking loudly and clearly
• Mental health counseling to help people with dementia and their families learn how to manage difficult emotions and behaviors. It can also help them plan for the future.
• Music or art therapy to reduce anxiety and improve well-being

Researchers have not found a proven way to prevent dementia. Living a healthy lifestyle might influence some of your risk factors for dementia.

Genes are sections of DNA in your cells that are passed down (inherited) from your parents. You inherit two copies of each gene, one from each parent. Genes carry information that controls what you look like and how your body works.

There are about 20,000 genes that provide instructions for making proteins, which your body needs to work correctly.

Some genes don't make proteins themselves but instead help control how other genes work. They act like switches, turning other genes on or off. This means they help decide when, where, and how much of a protein is made in your body.

Changes in your genes are also called gene variants or mutations. These changes can be inherited, occur as you age, or result from environmental factors such as chemicals or radiation. Often, these changes have no effect, but sometimes, even a small change in the DNA can alter the instructions for making proteins. If genes don't make the right proteins, or don't make them correctly, this can cause a genetic disorder.

Gene therapy uses genes to treat or prevent disease by correcting genetic problems. It works by changing your genetic material, rather than relying on traditional treatments like medicine or surgery.

New genetic material can be delivered into cells in two main ways:

• ex-vivo treatment. Cells are removed from your body, modified by adding genetic material, and then placed back into your body.
• in-vivo treatment. Genetic material is delivered directly into your body, often through an injection.

A common form of gene therapy involves inserting a normal gene to replace an abnormal gene. Other approaches include:

• Repairing an abnormal gene
• Altering the degree to which a gene is turned on or off

Newer techniques offer different ways to correct genetic problems:

• Genome editing (also called gene editing). Instead of adding new genetic material into cells, this approach changes the DNA that's already in your cells. A well-known example is CRISPR-Cas9. This promising technique is still being studied and may soon be used to treat genetic disorders.
• Cell-based gene therapy combines gene therapy and cell therapy. An example of this would be CAR T cell therapy. Cells, which are often immune system cells, are genetically altered to help treat a disease and then introduced into the body.

Gene therapies are currently only approved to treat a small number of diseases, such as:

• Leber congenital amaurosis, an inherited eye disorder.
• Spinal muscular atrophy, a genetic muscle disorder.

While gene therapy holds great promise, it comes with risks and challenges. Studies are still ongoing to ensure these treatments are safe and effective. Some challenges include:

• Immune system reactions. Your body may see the new material as a threat and react to it.
• Unintended effects. Changes to DNA could affect other genes in harmful ways.
• High costs. Gene therapies are often expensive and are not widely accessible.

Metabolism is the process your body uses to make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system (enzymes) break the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body tissues. If you have a metabolic disorder, something goes wrong with this process.

Lipid metabolism disorders, such as Gaucher disease and Tay-Sachs disease, involve lipids. Lipids are fats or fat-like substances. They include oils, fatty acids, waxes, and cholesterol. If you have one of these disorders, you may not have enough enzymes to break down lipids. Or the enzymes may not work properly and your body can't convert the fats into energy. They cause a harmful amount of lipids to build up in your body. Over time, that can damage your cells and tissues, especially in the brain, peripheral nervous system, liver, spleen, and bone marrow. Many of these disorders can be very serious, or sometimes even fatal.

These disorders are inherited. Newborn babies get screened for some of them, using blood tests. If there is a family history of one of these disorders, parents can get genetic testing to see whether they carry the gene. Other genetic tests can tell whether the fetus has the disorder or carries the gene for the disorder.

Enzyme replacement therapies can help with a few of these disorders. For others, there is no treatment. Medicines, blood transfusions, and other procedures may help with complications.

Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body tissues, such as your liver, muscles, and body fat.

A metabolic disorder occurs when abnormal chemical reactions in your body disrupt this process. When this happens, you might have too much of some substances or too little of other ones that you need to stay healthy. There are different groups of disorders. Some affect the breakdown of amino acids, carbohydrates, or lipids. Another group, mitochondrial diseases, affects the parts of the cells that produce the energy.

You can develop a metabolic disorder when some organs, such as your liver or pancreas, become diseased or do not function normally. Diabetes is an example.

Movement disorders are neurologic conditions that cause problems with movement, such as:

• Increased movement that can be voluntary (intentional) or involuntary (unintended)
• Decreased or slow voluntary movement

There are many different movement disorders. Some of the more common types include:

• Ataxia, the loss of muscle coordination
• Dystonia, in which involuntary contractions of your muscles cause twisting and repetitive movements. The movements can be painful.
• Huntington's disease, an inherited disease that causes nerve cells in certain parts of the brain to waste away. This includes the nerve cells that help to control voluntary movement.
• Parkinson's disease, which is a disorder that slowly gets worse over time. It causes tremors, slowness of movement, and trouble walking.
• Tourette syndrome, a condition that causes people to make sudden twitches, movements, or sounds (tics)
• Tremor and essential tremor, which cause involuntary trembling or shaking movements. The movements may be in one or more parts of your body.

Causes of movement disorders include:

• Genetics
• Infections
• Medicines
• Damage to the brain, spinal cord, or peripheral nerves
• Metabolic disorders
• Stroke and vascular diseases
• Toxins

Treatment varies by disorder. Medicines can cure some disorders. Others get better when an underlying disease is treated. Often, however, there is no cure. In that case, the goal of treatment is to improve symptoms and relieve pain.