Is your child's muscles stiff and having difficulty opening their arms? Let's learn about (Myotonia Congenita)!

Have you ever noticed that sometimes when your little one grabs a toy tightly, it takes a while to let it go again? Or does it suddenly feel like they are stiff while running around playing? It's normal for a parent to feel a little scared when they see things like this. Today we are going to talk about a condition that can cause these symptoms, but is not very common.

What is Myotonia Congenita?

Simply put, Myotonia Congenita is a genetic condition . In this condition, our muscles are unable to relax quickly after contracting. Imagine your child is holding a toy ball tightly in his hand. Normally, when you tell him to let go, he will immediately let go. But a child with this condition has difficulty letting go of it all at once. The hand may feel stiff for a while.

This condition usually begins in childhood or adolescence . In addition to muscle stiffness, other symptoms may also occur, such as muscle hypertrophy, which is the appearance of muscle mass.

Doctors classify this as a `non-dystrophic myotonia disorder.` That means there is no major damage to the structure of your child's muscles. They are healthy. However, there is a slight problem with the electrical process that controls the contraction of the muscles. There are other diseases that occur with myotonia, called `dystrophic myotonias.` In these, the structure of the muscles is also affected.

It's normal to feel worried and scared when we see a change in our child's body. But what you need to know is that this condition, called myotonia congenita , usually doesn't get worse over time . With physical therapy and other treatments, these symptoms can be well managed.

What are the main types of Myotonia Congenita?

There are two main types of this condition, let's see what they are.

1. Becker disease

This is the most common type of myotonia congenita. It can cause muscle weakness in the arms and legs of a child. Symptoms of Becker disease usually appear between the ages of 4 and 12. However, this is different from Becker muscular dystrophy, so don't confuse it with Becker muscular dystrophy.

2. Thomsen disease

This is a rarer and milder form of myotonia congenita. Symptoms usually begin in the first few months of life and can last up to 2-3 years .

How common is Myotonia Congenita?

This is actually a very rare condition . This disease affects about one in a hundred thousand people. However, this condition is seen more frequently among people in Scandinavian countries like Finland, Norway, and Sweden. In those countries, it is reported that about one in ten thousand people have this disease.

What are the symptoms of Myotonia Congenita?

The main characteristic of this condition is that a muscle is slow to relax after it has contracted . This is what we call myotonia. This myotonia condition can be worse when starting work after a period of rest or in a cold environment.

Other symptoms your child may experience include:

• Feeding difficulties, choking, nausea, and reflux – especially in infancy. For example, some children may feel like they are getting too much food in their throat even after drinking a little milk.
• Frequent falls and lack of balance (clumsiness) – This can be seen even after you start walking and become well-accustomed to it.
• Double vision or lazy eye.
• Muscles become enlarged (hypertrophy) , which can make you look like an athlete.
• Muscle cramps.
• Muscle stiffness , especially in the child's legs. However, this stiffness may decrease with movement and when the body warms up. This is called the 'warm-up phenomenon' .
• Weakness , especially if your child has Becker disease.
• Scoliosis is an abnormal curvature of the spine.

Male children may be more severely affected than female children. Symptoms may also temporarily worsen during pregnancy and menstruation.

Symptoms of Thomsen disease usually start earlier and first affect the child's face and hands . Symptoms of Becker disease often start later and first affect the legs .

What causes Myotonia Congenita?

Myotonia Congenita is caused by a mutation in the gene CLCN1 . This gene affects the chloride channels in the muscle membrane of our muscles. This is why muscles have trouble relaxing after they have contracted.

Becker disease (BD) is inherited in an autosomal recessive pattern . This means that both biological parents of a child must carry the gene mutation, and both must pass it on to the child. However, those parents do not show symptoms. They are simply carriers of the gene.

Thomsen disease (TD) is an autosomal dominant condition . In this case, even if only one biological parent has the gene variation, the child can inherit it.

How is Myotonia Congenita diagnosed?

Doctors usually diagnose this condition in childhood. Your doctor will ask about your child's symptoms and your family's medical history. Then they will do some tests to check for problems with the gums. These may include:

• Telling the child to open and close their eyes quickly .
• Seeing if the child can hold something in their hand and quickly let it go, or if they can quickly open their hand by squeezing it .
• Gently tapping the baby's flesh with a small hammer (percussor) to see if it hardens.

Your doctor may also recommend several other tests to confirm the diagnosis or to rule out other conditions that cause similar symptoms. These tests include:

• Creatine Kinase (CK) blood test: CK levels may be elevated in myotonia congenita.
• Electromyography (EMG): This test measures electrical impulses from the muscles. This can help differentiate between muscle-related and nerve-related disorders. However, it is difficult to tell the difference between the two types of myotonia congenita based on EMG results.
• Genetic testing: This looks for genetic changes that cause myotonia congenita.
• Muscle biopsy: A biopsy performed in myotonia congenita usually looks normal, but sometimes small abnormalities can be seen.

What are the treatments for Myotonia Congenita?

There is no cure for this condition. Your child may not need any special treatment. Rest and light exercise can help reduce muscle stiffness. Your doctor may also recommend physical therapy to help maintain muscle function.

In some cases, your child may benefit from medication. Your doctor may prescribe medications such as mexiletine or ranolazine to reduce the frequency and severity of seizures. Other medications such as lamotrigine and carbamazepine may also help, but they can sometimes cause unpleasant side effects.

Here are some other things you, your child, and your family can do to manage myotonia congenita symptoms and avoid triggers:

• Staying away from cold environments.
• Engaging in regular physical activity – symptoms may disappear once the child's muscles warm up a bit (this is called the 'warm-up phenomenon').
• Managing stress.
• If necessary, change the diet ; this means giving the child foods that are easy to swallow to reduce the risk of choking. For example, if they have difficulty eating hard foods, they can be crushed and softened.

Can Myotonia Congenita be prevented?

Myotonia Congenita is caused by a genetic mutation, so there is nothing you can do to prevent it . If someone in your family has the condition, or if you have it yourself and are planning to have children, it is a good idea to see a genetic counselor . He/she can then educate you about the risk of passing the condition on to your children.

What is the future of someone with Myotonia Congenita? (Prognosis)

Myotonia Congenita usually does not get worse over time . Your child's symptoms will remain mostly the same throughout their life. Physical therapy and avoiding things that make symptoms worse can help your child stay active and continue with normal activities. People with myotonia congenita can participate in sports and lead normal lives. In Becker disease, a child may develop some weakness as they get older.

What is the life expectancy of someone with Myotonia Congenita?

People with Myotonia Congenita have a normal lifespan . The condition does not affect other body systems.

When should my child see the doctor?

Myotonia Congenita is a long-term condition . Although it usually doesn't get worse or change, your child will need to see their doctor regularly if they are taking medication for it. Physical therapy needs may change as your child grows.

Importantly, myotonia congenita can affect your child's response to anesthesia . Therefore, if your child is scheduled to have surgery, you should tell your doctor about it. You should also inform the anesthesiologist who will be taking care of your child during the surgery.

"It's normal to feel a great sense of shock when your child's muscles don't work properly. You may worry about how much worse this will get, and how it will affect your child's life and your family's life. But the good news is that myotonia congenita can be managed well with physical therapy and small changes you can make at home and in your daily life. Remember, your doctor is always there to help you with your concerns and answer any questions you may have."

The most important things we need to remember from this story (Take-Home Message)

Okay, so let's look at some simple things to remember about the myotonia congenita we talked about:

• This is a rare genetic condition . The main characteristic is that once the muscles contract, they have difficulty relaxing quickly.
• There are two types of Becker disease: Becker disease and Thomsen disease.
• This usually does not get worse over time .
• Although there is no specific cure, symptoms can be well controlled with physical therapy, some medications, and lifestyle changes .
• The child can live a normal life and play sports .
• If your child needs surgery, you need to be especially careful about anesthesia .
• Don't be afraid to ask about this. Talk to your doctor and get the advice and support you need . Remember that you are not alone.

` Myotonia Congenita, Myotonia Congenita, Genetic Diseases, Muscle Stiffness, Pediatric Diseases, Becker's Disease, Thomson's Disease