The concept of “ambulatory” and “non-ambulatory” in patients with Duchenne muscular dystrophy: definitions and criteria

Abstract

Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease due to a mutation in the gene encoding dystrophin synthesis. In patients, muscle damage and atrophy progresses, the ability to move independently decreases as well as respiratory and cardiac functions. At various stages of the disease, different methods of care and treatment of patients with DMD are used. The clinical effect of new methods of DMD target therapy may depend on the stage of development of the disease (ambulatory or non‑ambulatory). To date, there are no unified criteria for assessing the status of a patient in terms ambulatory. In clinical trials and real clinical practice, different approaches are used to assess the patient’s status. However, the conclusion about the functional capabilities is critical for patients with DMD as approaches in management of patients in ambulatory and non‑ambulatory stages differ significantly. This necessitates expert consensus to achieve consistency and avoid any of discrepancies on that issue.The paper reviews the available published data on the concepts of “ambulatory” and “non‑ambulatory” used in clinical trials, real clinical practice, international standards and recommendations. As a conclusion of this analysis, it is proposed in real clinical practice to interpret “ambulation” in DMD patients as ability to walk without the use of assistive devices and without specifying the distance and time, and “non‑ambulation” as condition in which the patient is forced to constantly use a wheelchair both indoors and outdoors.