What Is Tibial Muscular Dystrophy?

Tibial muscular dystrophy is a form of muscular dystrophy, a group of chronic, progressive conditions that cause weakness and muscle mass. It is a rare disorder that affects adults. Symptoms usually begin around age 35 and progress slowly.

Tibial muscular dystrophy causes gradual and progressive weakness of the anterior tibialis muscle in the front of your lower leg. This leads to difficulty walking.

This article provides an overview of tibial muscular dystrophy, including how it is diagnosed and what treatment options are available.

Symptoms of Tibial Muscular Dystrophy

Tibial muscular dystrophy affects the ankle and shinbone (tibia). The initial symptoms of tibial muscular dystrophy are weakness in the front of your lower leg (the shin) and difficulty lifting your ankle up from the ground.

Foot drop is a common symptom of tibial muscular dystrophy. Foot drop occurs when a person has difficulty picking up their foot to walk due to weakness. This can lead to tripping or falling.

Causes

Tibial muscular dystrophy is caused by a genetic mutation in the gene TTN. This gene is essential in the production of a protein called titin. When the TTN gene is defective, the titin that is produced does not interact with other proteins in the muscle cells. This defect causes muscle weakness.

There are a few different types of mutations of the TTN gene. The FINmaj mutation causes tibial muscular dystrophy in people of Finnish descent. Other less common mutations cause the disease in other populations. It is not fully understood why the TTN gene mutations cause weakness only in the lower shin musculature.

Diagnosis

It is important to see your healthcare provider if you start to notice symptoms of tibial muscular dystrophy such as ankle weakness or foot drop.

Your provider will likely order several diagnostic tests, including:

• Electromyography
• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scan
• Muscle biopsy

Other conditions, such as lumbar sciatica or multiple sclerosis, may cause similar symptoms, so your healthcare provider will need to explore other possible causes.

Since tibial muscular dystrophy is caused by a genetic mutation, the only way to diagnose the condition is through genetic testing. This is done via a simple blood test.

Treatment

There is no known cure for tibial muscular dystrophy. The goal of treatment is to maintain the muscular function of the ankle and leg. Treatment may include:

• Exercise: It is possible to strengthen the affected muscle with exercise. Work with a physical therapist to develop a strengthening program for your tibialis anterior muscle. A resistance band may be helpful.
• Ankle-foot orthotics: If you have developed foot drop, your healthcare provider may recommend wearing a special orthotic device that is placed inside your shoe and wrapped around your lower leg. This device lifts up your ankle to assist with walking.
• Surgery: For severe and debilitating tibial muscular dystrophy, surgery may be performed. The surgery involves a transfer of your tibialis posterior tendon to the front of your foot. That way, this tendon now lifts your foot off the ground while walking.

Each person experiences a different progression of tibial muscular dystrophy. Some people become quite debilitated by the disease, while others are able to keep walking with the aid of an orthotic device. Be sure you work closely with your healthcare provider to understand how your specific condition is progressing.

Prognosis

There is no known cure for tibial muscular dystrophy. It is a progressive disease, but it can be well-managed with treatment.

Many people with tibial muscular dystrophy will experience some difficulty with walking, but most will be able to retain normal ambulation throughout their life. For a small percentage of people, walking may become difficult or impossible.

Summary

Tibial muscular dystrophy is a progressive weakness in your tibialis anterior muscle. It is caused by a mutation in a specific gene that produces a protein necessary for proper muscular function. Treatment options include physical therapy, strengthening exercises, orthotic devices, and surgery.

A Word From Verywell

Being diagnosed with a progressive disease can feel overwhelming and even frightening. It may be helpful to remember that many people with tibial muscular dystrophy are able to continue walking with the help of an orthotic device. If you notice your condition worsening, talk with your healthcare provider.