Early Ambulatory (childhood)
In the early ambulatory or walking stage, children will be showing what are typically regarded as the “classical” signs of Duchenne. These signs may be very subtle, and may include:
- Difficulty lifting the head or neck
- Not walking by 15 months
- Difficulty walking, running, or climbing stairs
- Tripping and falling frequently
- Difficulties with jumping and hopping
- Not speaking as well as other children the same age
- Needing help getting up from the floor or walking the hands up the legs in order to stand (see Gowers’ Manoeuvre, Figure 2 below)
- Calves that look bigger than normal (pseudohypertrophy)
- Walking with legs apart
- Walking on toes and waddling
- Walking with chest pointed out (or having a sway back, saddle back, or arched back)
- Elevated creatine kinase (called a “CK” or “CPK;” this is an enzyme released by the muscle when it is damaged. The level of CK is measured in the blood; if a CK is over 200, further testing for Duchenne is needed)
- Elevated liver enzymes (AST or ALT; an elevated AST or ALT can also be signs that further testing is needed for Duchenne. Further liver evaluations should never be done until testing for Duchenne is complete)
When there is suspicion of Duchenne, the first test is often a bloodtest to see if serum CK is elevated. People with Duchenne often have a CK level 10 to 100 times the normal value. If this is found, specific tests will be recommended in order to identify the change in the DNA (called the “genetic mutation”) that causes Duchenne. Input from specialists, specifically genetic counsellors, may be needed in order to interpret these genetic tests and to discuss how the results may impact your child and possibly other family members. Diagnosis is often made during the early ambulatory phase.
PSYCHOSOCIAL, LEARNING, AND BEHAVIOUR:
People living with Duchenne have a higher chance of learning and behavioural challenges. Some challenges are due to the lack of dystrophin in the brain; others may be due to adjusting to physical limitations. Some medications such as steroids, which are often started in the early or late ambulatory stage, can also play a role. Some children taking steroids may have difficulty with impulse control, anger, mood changes, attention and memory, and others may not. If delays in development and/or learning are found, an evaluation by a psychologist or neuropsychologist may help to define the specific issues, as well as give recommendations to help reach full potential. Emotional and behavioural issues are not uncommon and are managed best if they are addressed early. Developmental paediatricians and psychologists may be very helpful in these areas. Speech and language should also be evaluated, and therapies started as soon as possible, if needed. If your family is having difficulty accessing resources, social workers and care advisors can be very helpful in connecting you. Family support is essential, and input from specialists may be needed to address specific psychosocial, learning and behaviour issues.
An introduction to the physiotherapy team at this early stage will allow for exercise/stretching regimes to be introduced gradually to keep muscles flexible and prevent or minimise tightness at the joints. The rehabilitation team can also advise on appropriate exercise during playtime/breaktime, as well as adaptive physical education, to keep your child safe while supporting school participation. A physical therapy exercise program should focus on stretching and maintaining range of motion rather than strengthening. Night splints (often called “ankle foot orthoses,” or “AFOs”) may be recommended at this stage to provide a long stretch and prevent loss of ankle range of motion. A home stretching program recommended by your physiotherapist should become part of your daily routine.
Corticosteroids, or “steroids”, should be discussed preferably at diagnosis and may be started at this stage. In planning for the use of steroids, it is important to discuss the benefits of steroids, ensure all immunisations are complete, and discuss any risk factors for the side effects of steroids, as well as how they can be anticipated and minimised. This includes receiving nutrition education (preferably from a registered dietitian) to help avoid side effects such as weight gain and altered bone health.
BONE HEALTH AND HORMONES:
Taking steroids can lead to weak bones and may affect the levels of several hormones, such as growth hormone and testosterone (the male sex hormone). Nutrition is important for keeping bones strong, and diets containing Vitamin D and calcium should be encouraged. It may be appropriate to discuss your nutritional needs with a registered dietitian at your neuromuscular visits. Heights and weights should be checked at every neuromuscular visit and should be plotted on a graph to monitor growth and weight over time. Measuring the length of the bone in your forearm (“ulnar length”), or your lower leg (“tibial length”) or adding the lengths of your upper and lower arms together (“segmental arm length”) are alternate ways to record accurate “heights,” and should be tracked as well for baseline measurements. A baseline bone density level should be obtained, using dual energy X-ray absorption (or “DEXA”), when steroids are started.
HEART AND BREATHING MUSCLES:
Typically, issues with the heart and breathing muscles are not likely to be present at this stage, but surveillance should start at diagnosis to establish the baseline (what is “normal” for you) and then continue at regular follow-up visits. Starting pulmonary function testing at a young age will help you get used to the equipment and “practice” for subsequent visits. Cardiac monitoring (ECG and cardiac MRI or echocardiogram) is recommended at diagnosis and annually up to age 10, and then more frequently as necessary. It is also important that you have pneumococcal (pneumonia) and yearly influenza vaccinations (flu injections) to avoid illness.