Progression

Progression

Duchenne Muscular Dystrophy is a rapidly progressing form of muscular dystrophy. Although disease progression can vary among individuals, it’s generally regarded as following a series of five stages. Each of those five stages are outlined below:

Diagnosis

Birth – Approximately age 7 years old

In this stage, difficulties with developmental milestones like sitting, talking, or walking are likely. Children often exhibit large calves (pseudo hypertrophy) and may use a Gower’s Manoeuvre (walking their hands up their legs to stand) when getting up from the floor. A creatine kinase (CK) level is often extremely elevated, along with elevated liver enzymes (AST, ALT). During this period, children experience rapid growth, so the symptoms may be difficult to recognize.

Assessment of height and weight should also be checked at clinic visits that are typically scheduled to occur every six months. It’s crucial to monitor cardiac function throughout disease progression, so it’s imperative to work closely with a cardiologist to check for fibrosis, cardiomyopathies, or dysfunction. Cardiac MRI’s and echocardiograms are often used to visualize the heart. An MRI or echocardiogram (“echo”) can be used to establish baseline cardiac function. Constipation is also a frequent concern due to longer transit time, abdominal muscle weakness, dehydration, and immobility. It is important to discuss these concerns with a gastroenterologist who can offer solutions to help remedy the issue.

Working with a physical therapist and doing hydrotherapy can be very beneficial toward preventing contractures, muscle imbalances, and deformities. This may involve prescribing a stretching routine, braces, or use of other durable equipment. Physical therapists can also help identify potentially hazardous obstacles, decrease falls, and prevent overexertion while also finding age and ability appropriate activities and exercises.

Early Ambulatory

Approximately ages 6-9 years old

During this time, continued monitoring of strength, range of motion, and function should happen at least every six months. As the disease progresses, an increase in muscle weakness may become more apparent. Difficulty walking, having a wobbly gait, or toe walking may become more evident. Monitoring of this, specifically, the Achilles tendon, is needed to determine if surgery is necessary. Assessment of potential concerns like constipation, gastroesophageal reflux disease (GERD), swallowing dysfunctions, and gastroparesis should also be checked. As the disease advances, monitoring of the lateral spine and the risk of scoliosis should be discussed. Bone health is vital to prevent fractures, and a puberty assessment with an endocrinologist beginning at age nine can be beneficial.

Late Ambulatory

Approximately ages 10 – 14 years old

The greatest impact on mobility and fatigue is seen during this time. Difficulty keeping up with peers, climbing stairs, and fatigue with long distances are often seen. A scooter to maneuver longer distances could be helpful, along with a long-term plan of a potential power wheelchair. Muscles needed for core strength also show weakening at this point, and an assessment of scoliosis may be necessary. Cardiac function should continue to be closely assessed with a cardiac MRI or echocardiogram. Initiation of an ACE Inhibitor or Angiotensin Receptor Blocker (ARB) typically begins at age ten to help protect the heart. The use of hands and fingers typically remains during this stage. The initiation of learning assistive technology could be a great resource during this time.

Early Non-Ambulatory

Adolescents & Young Adults

This stage brings about unique challenges that can be especially difficult since young adults who want greater independence are also faced with an increase in health care needs and physical reliance on others. Communication to address concerns or any other emotions that come about is essential to a successful transition. As young adults lose ambulation, they begin to rely more heavily on mobility devices, and the use of a power wheelchair eventually becomes necessary. Respiratory concerns typically begin after loss of ambulation with increased risk of hypoventilation, pneumonia, infections, and respiratory failure.

A pulmonologist is vital to help with any concerns and can assist with solutions for these issues. A cough assist machine, and possible nocturnal ventilation may be used. If progressive muscle weakness interferes with self-feeding and swallowing, a gastronomy tube can be placed to alleviate concerns. Social contact, and specifically, engagement with peers, may lessen at this stage, so it’s important to watch for mental health concerns and follow up with a psychologist or psychiatrist to alleviate or cope with any related distress.

Late Non-Ambulatory

Adults

This stage encompasses adulthood when the upper body and core strength continue to weaken even further. Although it may be challenging, it is important to remain as active as possible in a career, community, or social life. Continued monitoring of cardiac, bone health, breathing, digestive, urinary concerns, and pubertal changes from the care team is vital. There may be an increase in breathing difficulties, and support in the form of daytime ventilation may be needed. Life-threatening heart and lung issues are potential concerns since Duchene boys typically pass away in their late 20’s to early 30’s due to complications related to the heart and lungs. In Duchene, the average life expectancy has improved with advances in respiratory and cardiac management. In past decades, survival was not seen past the teenage years, but with technological improvements, cardio protective management, and ventilator support, survival is much longer, with the average life expectancy currently between 26-30 years of age.