What is the difference between myotonic dystrophy type 1 and type 2?
Causes. Myotonic dystrophy type 1 is caused by mutations in the DMPK gene, while type 2 results from mutations in the CNBP gene. The protein produced from the DMPK gene likely plays a role in communication within cells.
What are the signs and symptoms of myotonia congenita?
Other myotonia congenita symptoms include:
- Choking, gagging and reflux, especially in young children.
- Clumsiness and frequent falls.
- Difficulty chewing, swallowing (dysphagia) or talking.
- Double vision or a lazy eye.
- Enlarged muscles (hypertrophy), leading to an athletic appearance.
- Muscle cramps.
What causes myotonic discharges on EMG?
Electrical myotonia is the spontaneous discharge of muscle fibers that waxes and wanes in both amplitude and frequency on electromyography (EMG). Myotonia is thought to be due to increased excitability of muscle fibers, leading to discharge of repetitive action potentials in response to stimulation.
What is hand grip myotonia?
Grip myotonia can be observed by tightly gripping the clinician’s fingers, and then relaxing the hand after a sustained grip; the hand muscles will typically take 20 seconds or more to fully relax. Percussion myotonia can be demonstrated by a sustained contraction after the muscle is tapped with a reflex hammer.
Does exercise help myotonic dystrophy?
Studies show that moderate exercise is safe and may be effective for individuals with myotonic dystrophy. 1-4 Even though exercise does not cure myotonic dystrophy, it can help optimize function and maintain strength.
What organs are affected by myotonic dystrophy?
Myotonic muscular dystrophy is a common multi-system disorder that affects the skeletal muscles (the muscles that move the limbs and trunk) as well as smooth muscles (the muscles that control the digestive system) and cardiac muscles of the heart.
Is myotonia congenita a disability?
The legs are more severely involved than the face or arms, and severe myotonia of the lower extremities may result in disability. Severe myotonic episodes may be associated with transient muscle weakness, especially in the hands.
Does myotonia get worse over time?
Though myotonia congenita starts in childhood, it usually doesn’t get worse over time. You or your child should be able to lead a normal, active life with this condition. The muscle stiffness can affect movements like walking, chewing, and swallowing, but exercise and medicine can help.
What does myotonia feel like?
The main symptom of myotonia congenita is stiff muscles. When you try to move after being inactive, your muscles spasm and become rigid. Your leg muscles are most likely to be affected, but the muscles of your face, hands, and other parts of your body can also get stiff. Some people have only mild stiffness.
What muscles are affected by myotonia?
Although myotonia can affect any skeletal muscles, including muscles of the face and tongue, it occurs most often in the legs. Myotonia causes muscle stiffness that can interfere with movement.
How do you test for myotonia?
A doctor may check for myotonia by lightly tapping the area just under the thumb with a rubber hammer. In most people, there is little or no response. In people with myotonia, the thumb will abduct and relax slowly.
How do I examine myotonia?
Myotonia is the most useful finding on standard EMG and nerve conduction examinations. However, several specialized tests may also aid in making or confirming the diagnosis of a disorder associated with myotonia: repetitive stimulation, the “short” and “long” exercise tests, and the provocative cold test.