Inclusion Body Myositis
Overview
Let’s learn what Inclusion body myositis (IBM) is -
Inclusion body myositis (IBM) is one of the most common muscle diseases called inflammatory myopathies and is seen among patients older than age 50.
They are characterised by chronic, progressive muscle inflammation seen with muscle weakness. Loss of ambulation and dysphagia are the complications of the disease. Inclusion body myositis can be associated with cytosolic 5′-nucleotidase 1A antibodies.
Symptoms of IBM vary but usually include progressive weakness in muscles of the hand, forearm, thigh, and lower leg. Diagnoses of IBM can be challenging because the symptoms are not unique to the condition.
Symptoms
IBM Symptoms vary but normally -
• Asymmetric and distal muscle weakness are more likely to appear, with a very slow disease progression, unlike other idiopathic inflammatory myopathies
• Both proximal leg and distal arm muscle groups are usually involved - proximal muscles are closer to the torso, and distal muscles are further away from the torso. Mild muscle pain, called myalgias appear very frequently.
• There is progressive muscle atrophy (wasting of the muscles), and the patient's strength is reduced.
• There could be symptoms such as progressive weakness in muscles of the hand, forearm, lower leg, and thighs.
• Diagnosing IBM can be challenging because the symptoms are not unique to the specific condition.
• A muscle biopsy could be needed to narrow down the diagnosis.
Causes & Risks
The cause of inflammatory myopathies (IBM)is unclear.
• IBM causes muscle weakness that may worsen over time and damage the muscles. The rate of this decline varies among individuals.
• This degenerative muscle condition is more common in older adults, especially men over 50.
• The body’s immune system turns against its own muscles and damages muscle tissue in an autoimmune reaction. The cause of the muscle degeneration that occurs in IBM is unclear as well.
• Sex and genetic forms are both thought to be risk factors for this disease. It can be either dominant or recessive.
• It is also found that hypertension, myocardial infarction, congestive heart failure, pneumonia, anaemia, or diabetes mellitus are all at increased risk of developing this condition.
Test & Diagnosis
• The doctor diagnoses inclusion-body myositis (IBM) by considering an individual’s personal history, family medical history, and the results of a careful physical examination.
• After a physical exam to check the pattern of weakness in a patient’s muscles, a doctor who suspects myositis likely will order a blood test to check the level of creatinine kinase, an enzyme that leaks out of muscle fibers when the fibers are being damaged.
• Patients with proximal leg weakness and distal arm or leg weakness must be referred to a neurologist and have a muscle biopsy.
• A physician will conduct other laboratory tests including serum electrolytes, enzymes, and hormones, and order a muscle biopsy
• In some cases, the doctor may ask for a blood test for specific antibodies, and proteins produced by the immune system in myositis and other autoimmune diseases.
• An electromyogram is done in which tiny needles are inserted into the muscles to test their electrical activity.
• Inflammatory myopathies show a distinctive pattern of electrical activity that can help differentiate them from other types of muscle disease.
Treatment
• Immunosuppressant drugs are currently used to prevent organ rejection in kidney transplant patients.
• A small clinical trial using the medicine in patients with inclusion body myositis showed some hopeful results.
• Arimoclomol is a compound that can stimulate the repair of certain proteins in muscle cells, preventing these proteins from clumping.
• This compound proved beneficial in a small initial clinical trial with sporadic inclusion body myositis patients and is currently being studied in a larger trial.
• Medications are prescribed to suppress the immune system to halt inflammation.
• Corticosteroids are often prescribed at first because they can act quickly to put an end to the inflammation.
Living With
Imagine a life with Inclusion Body Myositis (IBM). It involves facing various challenges that impact daily life.
IBM leads to progressive weakness in specific muscles, especially those in the legs and arms. This weakness can result in difficulties with mobility, climbing stairs, lifting objects, or performing routine tasks.
With the progression of the disease, individuals might experience challenges in activities of daily living. Muscle weakness in IBM leads to increased reliance on assistive devices or caregivers. In some individuals, IBM can affect the muscles involved in swallowing and speaking, leading to difficulties in swallowing food and liquids or articulating speech.
People with IBM experience muscle pain and discomfort, which affect their overall well-being.
Complications
IBM has numerous complications that significantly impact an individual's health.
They include:
• The progression causes muscle weakness, particularly in the muscles of the legs and arms. This weakness leads to difficulties in mobility.
• Muscle weakness and atrophy can result in significant functional limitations, affecting activities of daily living such as dressing, bathing, eating, or maintaining balance.
• People face a decline in independence, requiring assistance from caregivers.
• IBM may present difficulties in swallowing food and liquids or articulating speech.
• With advancement in the disease, IBM may affect the muscles responsible for respiratory function, leading to breathing difficulties.
• Efforts to compensate for weakened muscles can lead to increased fatigue, affecting energy levels.
• Coping with the progressive nature of IBM, functional limitations can result in emotional stress.
