Performance of Upper Limb (PUL) in Duchenne Muscular Dystrophy

This is a multicentric study involving a large number of patients that could not be collected in a single Unit.

The aim of the project is to collect a large number of patients that will allow to assess the suitability of different measures assessing upper limb function. As DMD is a relatively rare condition, such goal can only be reached in a multicentric setting. All the participating centres (Rome Gemelli, Messina, Rome Bambin Gesù, Pavia, Genoa, Naples, Turin, Bologna, Padua, Milan, Bosisio Parini, Pisa) have a good record of cooperation in similar projects having already been involved in the validation of the North Star in DMD and of the Hammersmith Functional motor Scale for SMA.

The projects will be developed through different steps, related to different specific aims:

1. Interobserver reliability/quality and quantity of training One of the aims of the study is to assess reliability of the selected measures in a multicentric setting and the quantity of training required to be sure of the reliability among observers after the training sessions. Following our experience in the training of the North Star Ambulatory Assessment (NSAA) in the same network, the investigators have become aware that a single training session may not be sufficient to be sure that interobserver reliability will be maintained after the training sessions (Mazzone et al, 2009).
2. Natural history data collection The PUL will be applied to the whole cohort with repeated assessments at 6, 12, 18 and 24 months . This will allow to monitor possible changes over time and the rate of changes in patients with different level of ability and age. This will also help to evaluate the responsiveness to change and the level of sensitivity of the measure over an interval that would be useful for a study of a putative agent that could improve muscle power.
3. Correlation with other measures Another aim of the study is to relate possible changes in upper limb function with other measures of care and function such as the EK scale, that provides information on aspects of function, such as transfer or self feeding that are important in everyday life. Correlation with respiratory function will also be performed.
4. improving statistical properties of the scales. There has been increasing evidence in the last few years that Rasch analysis may help to improvethe statistical properties. The data collected will offer the opportunity to perform these new psychometric techniques.