Myotonic Dystrophy Foundation

Breathing

When a child is born with the congenital myotonic dystrophy (DM1), the first concern is to address immediate breathing difficulties. Respiratory insufficiency is the leading cause of mortality in newborns and aggressive intervention is often required.

In severe cases, continuous ventilation or intubaton (where a tube is inserted to help with breathing) may be required to address respiratory insufficiency, a condition where the lungs cannot take in enough oxygen or expel enough carbon dioxide to meet the needs of the body.

Subsequently, a continuous positive airway pressure (N-CPAP) device may be used to deliver air through a specially designed nasal mask. Unlike intubation, the mask does not breathe for the child but provides airflow with enough pressure to open his or her airway.

After the newborn phase, pulmonary function is typically assessed on an ongoing basis. However, regular lung function testing (measuring lung capacity based on the ability to exhale or blow out) is usually not done until adolescence, when the patient is able to force air from the lungs effectively.

Chronic upper airway infections are common and may result in hearing loss. Ongoing assessment by an audiologist is warranted in cases where these infections are frequent.

Feeding

Newborns are often not able to suck or swallow properly. A feeding tube may be required to ensure the infant receives adequate nutrition, occasionally for as long as six months. In cases where weak face, tongue, and jaw muscles cause ongoing swallowing issues, a speech and language therapist who specializes in swallowing disorders may be recommended.

Accidental inhalation of food particles or fluids into the lungs can cause aspiration pneumonia and chronic lung complications in some children. As a result, regular swallowing and nutritional assessments are generally done. If issues exist, modification of food consistency and caloric supplementation may be recommended over the longer term.

Heart

Cardiac problems are not commonly detected in newborns but may develop later in life. Although cardiac issues specific to congenital myotonic dystrophy DM1 may not result in obvious symptoms, they can contribute to the reduced life expectancy seen in patients with this disease. Annual monitoring of cardiac function is important. Yearly electrocardiograms (ECGs) are often recommended, as well as echocardiograms if cardiomyopathy (damage to the heart muscle that impairs its ability to pump blood effectively) is suspected.

When cardiac issues are diagnosed, devices that detect and regulate heart rhythm (such as a pacemaker or implantable cardioverter defribrillator [ICD]) may be surgically inserted. These devices have been shown to be life-saving in individuals where severe abnormalities were detected using electrophysiological (EP) studies; however, debate exists as to who should receive EP assessment and whether a combined pacemaker/ICD should be used instead of a pacemaker alone in certain patients.

Muscle

Hypotonia (extreme muscle weakness resulting in floppiness, or a rag doll appearance, characteristic of newborns with congenital myotonic dystrophy type 1 (DM1) is typically not treated and gradually improves over the first years.

Clubfoot, also known as talipes equinovarus, and other contractures, where permanent tightening of muscle causes abnormal joint rigidity, are also prevalent in congenitally affected newborns. Children with congenital myotonic dystrophy type 1 (DM1) almost always learn to walk --- a walker can sometimes be helpful --- but their motor development is often delayed. As a result, physiotherapy and orthopedic surgery may be recommended. Molded ankle-foot orthotics can help prevent gait issues and can improve stability when walking. Jaw and mouth deformities may also need surgical corrections if speech and chewing problems are severe and attributable to such deformities.

In cases where severe facial muscle issues exist or hearing is impaired, speech therapy may also be recommended.

Myotonia and other muscle complications associated with myotonic dystrophy are not typically present in newborns with congenital myotonic dystrophy. However, the symptoms of adult onset myotonic dystrophy may become apparent later in life and ongoing monitoring of muscle function is therefore typically done. See Adult Onset Myotonic Dystrophy: DM1 Management for further information on the monitoring and management of these symptoms.

Cognitive Impairment

While normal mental development is possible, Intellectual disabilities (formerly known as mental retardation) can present the greatest concern for patients and their families. Individualized support for the particular learning disabilities and cognitive delays may be warranted. In less common cases of psychiatric disorders (attention deficit hyperactivity disorder, antisocial behavior, anxiety disorders, or other behavioral problems in childhood), psychiatric assessment and treatment might be suggested.

Anesthetic

The neuromuscular, cardiac, and respiratory symptoms of myotonic dystrophy result in elevated risk of complications associated with the use of anesthesia. Certain drugs used in surgery suppress respiratory function, cause severe myotonic reactions, and exacerbate cardiac arrhythmias. Post operative pulmonary complications are also common. Therefore, careful monitoring of cardiac and respiratory function is essential during and after the use of anesthesia.

Anesthesiologists MUST be informed of a diagnosis of myotonic dystrophy.  Please see Anesthesia Guidelines for further information.

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More technical information on the symptoms, diagnosis and management of congenital myotonic dystrophy can be found by clicking here.