Inclusion body myositis is a type of myositis, or muscle inflammation.
Inclusion body myositis mainly affects males, but females can get it too. It’s also known as inflammatory myopathy or sporadic inclusion body myositis.
The condition involves progressive muscle weakness. It primarily occurs in people older than 50 years old.
In this article, we review the symptoms, causes, and treatment options for inclusion body myositis. We also explain how a healthcare professional can diagnose the condition.
Inclusion body myositis is a progressive disease. Its symptoms typically appear slowly at first.
Common symptoms include:
- asymmetrical (one side) muscle weakness
- difficulty flexing fingers
- weak hand grip
- difficulty walking or climbing stairs
- difficulty getting up from a chair
- shrinking arm and thigh muscles
- tripping while walking
- difficulty swallowing
The exact cause of inclusion body myositis is unclear. However, it’s thought to be related to aging as well as the following mechanisms:
- Inflammation: People with inclusion body myositis often have certain inflammatory cells in their muscle tissue. These inflammatory cells suggest the condition is an autoimmune disorder, in which the body’s immune system attacks its own tissue.
- Degenerative changes: In some cases, inclusion body myositis has been associated with degenerative proteins in muscle fibers. These proteins may cause inflammation and muscle damage.
Is inclusion body myositis hereditary?
For some people with inclusion body myositis, genetics might play a role. This means they may inherit a gene for the condition from one of their parents.
In this scenario, the condition might not appear until an external factor triggers it. Possible triggers include viruses and medications.
Because of the progression of muscle weakness, inclusion body myositis can increase the risk of:
- frequent, unexplained falls
- poor mobility
- choking or difficulty eating
- tripping while walking
- trouble breathing
- difficulty performing daily tasks, such as writing or handling keys
- reduced independence
A healthcare professional can diagnose inclusion body myositis using the following methods:
- Physical examination: A healthcare professional will check your muscles and look for signs of weakness. They will also examine your muscle function as you do certain tasks, like walking.
- Muscle biopsy: A muscle biopsy is the gold standard test for diagnosing inclusion body myositis. It involves removing a sample of muscle tissue and checking for specific cellular material.
- Electromyogram: This test checks the electrical activity of your muscles at rest and during contraction.
- Nerve conduction test: A nerve conduction velocity test checks how fast a nerve impulse can travel through your muscle. It can help rule out other nerve disorders.
- Blood tests: A healthcare professional might check your blood levels of creatine kinase. This enzyme leaks out of muscle when it’s damaged. They might also test for certain electrolytes, hormones, and antibodies.
- Muscle MRI: A muscle MRI is an imaging test. It can help a doctor check the structure of your muscles.
There’s no cure or gold-standard treatment for inclusion body myositis. But you can improve and manage symptoms, such as:
- respiratory function
- muscle weakness
A combination of the following therapies can help manage symptoms:
Inclusion body myositis may be treated with medication, such as:
- intravenous immunoglobulin
Various forms of therapy can improve quality of life. Therapies include:
- Physical therapy: Physical therapy, including exercise, can help increase muscle strength and mobility.
- Occupational therapy: Occupational therapy involves learning techniques and methods for doing daily tasks.
- Speech therapy: A speech therapist can help reduce the risk of choking caused by swallowing difficulties.
Assistive devices can help prevent falls and support mobility. Your doctor might recommend using a:
If your swallowing difficulties are severe, you might need surgery. This may include myotomy or cricopharyngeal dilation.
Myotomy involves a surgeon cutting the muscles of the cardia, which allows food and liquids to enter the stomach.
In a cricopharyngeal dilation, a surgeon stretches the muscle at the top of the esophagus to allow food to pass easily.
In severe cases, gastrostomy (feeding tube) might be needed.
Since inclusion body myositis is a slowly progressive disease, life expectancy is usually not affected. This means people with the condition live as long as those without it.
Typically, people with inclusion body myositis die from complications rather than the actual disease. These complications include falling or choking.
Mobility can also vary widely. Some people might only need assistive devices when walking long distances. Others might need to use them all the time.
The presence of other disorders can also affect a person’s overall outlook.
Below are answers to frequently asked questions.
Does an inclusion body myositis diet work?
There’s no recommended diet for inclusion body myositis, which is supposed to prevent muscle weakness. Instead, it’s best to eat a generally balanced diet. This means getting plenty of vegetables and fruits, whole grains, and lean protein, and limiting very processed and sugary foods.
How long can you live with inclusion body myositis?
Inclusion body myositis does not reduce a person’s life span. Life expectancy is the same as those without the condition.
Is inclusion body myositis a form of ALS?
Although both conditions cause muscle weakness, inclusion body myositis is different from amyotrophic lateral sclerosis (ALS). Inclusion body myositis is an inflammatory muscle disease. ALS is a disease of the nervous system.
Is there an end stage to inclusion body myositis?
There is no end stage to inclusion body myositis, though it is a progressive disease.
Inclusion body myositis is an inflammatory disorder that causes progressive muscle weakness. It mainly occurs in males over 50 years old, but females can get it as well.
Typically, symptoms appear slowly over time. These often include weak hand grip, difficulty walking, muscle shrinkage, and difficulty swallowing. These symptoms can increase the risk of falls and choking.
There’s no cure for inclusion body myositis, but treatments like medication, assistive devices, and physical therapy can help manage symptoms. These treatments can help improve quality of life and reduce the risk of complications.