The stages of Duchenne muscular dystrophy
Duchenne is a progressive condition. Its progression is different for everyone but there are five distinct stages to the condition with variation in when symptoms begin and the speed of progression. The information on this page can help you to understand the different stages of Duchenne.
Progression
Muscle weakness and loss in Duchenne usually begins in childhood and is often marked first by reduced strength, function, and flexibility in the hips, thighs, shoulders, and pelvis.
As the condition progresses, weakness is experienced more in the arms and the lack of dystrophin in the heart and breathing muscles means that heart function and breathing are also affected.
There are five distinct stages of Duchenne:
- Early ambulatory
- Late ambulatory
- Transfer stage
- Early non-ambulatory
- Late non-ambulatory
Patients with Duchenne should be monitored by regular neuromuscular clinic appointments, which are generally accessed around every six months to monitor the progression of the condition, track symptoms, and ensure the right care and support is provided at every stage.
The five stages of Duchenne and the main symptoms seen at each stage are outlined below. Understanding theses different stages can help families prepare and access the right care at the right time.
The speed of progression and symptoms are different for everyone with Duchenne. The progression of Duchenne is also not determined by genetic variant, as people with the same variant can experience different progression.
Diagnosis and the early ambulatory stage are in early childhood, with late ambulatory generally in late childhood and into adolescence as a child becomes a young adult. The early non-ambulatory stage generally begins in adolescence or in young adults and the late non-ambulatory stage generally starts in adults. However, the progression is changing over time with the routine use of corticosteroids and new emerging treatments.
Ambulatory
Early ambulatory
In the early ambulatory stage, people with Duchenne can stand from lying down and can run/walk ten metres or more and bear weight while standing.
Late ambulatory
In the late ambulatory state, people with Duchenne cannot stand from lying down but can still walk ten metres or more. They can still bear weight while standing.
Transfer
People with Duchenne then progress into what is known as the transfer stage. This is a relatively newly identified stage. It was recognised through the work of Duchenne UK’s HERCULES initiative, which studied the progression of DMD, known as the natural history, to identify commonalities and better understand the different stages.
At this stage in the condition, people with Duchenne can no longer walk ten metres and will generally rely on a mobility device to move around, but can still bear weight while standing, and remain standing for three seconds or more, to support transfers to a bed, sofa or toilet, maintaining important independence.
Non-ambulatory
Early non-ambulatory
In the early ambulatory stage, people with Duchenne can stand from lying down and can run/walk ten metres or more and bear weight while standing. People with Duchenne enter the non-ambulatory stage when they can no longer walk or transfer. In the early non-ambulatory stage people with Duchenne can no longer stand for three seconds or more or weight bear.
The non-ambulatory stage is generally marked by declining arm strength and function and increasing weakness in the respiratory muscles which affects breathing.
Declining arm function means people with Duchenne will begin to, and will eventually, loose what’s known as hand-to-mouth function (the ability to raise your arm and bring your hand to the height of your mouth).
Weakness in muscles that aid breathing will mean a person with Duchenne will begin to require ventilation support, first at night.
There are two distinct phases in the early non ambulatory stage which present in no fixed order:
- No hand-to-mouth function, with no use of ventilatory support
- Hand-to-mouth function, with night-time ventilatory support required
People with Duchenne will eventually lose hand-to-mouth function and require night-time ventilation.
Late non-ambulatory
In the late non-ambulatory stage people with Duchenne have no hand-to-mouth function and as muscle weakness progresses require full-time ventilatory support breathing.
