International workshop on assessment of upper limb function in Duchenne Muscular Dystrophy

Twenty clinicians, physiotherapists and representatives from advocacy groups and industries from six countries convened for a Parent Project sponsored workshop on ‘Assessment of Upper Limb Function in Duchenne Muscular Dystrophy (DMD)’. Following previous meetings [1,2] highlighting the lack of outcome measures in non ambulant patients, a number of exploratory studies have been planned to investigate the suitability of the available measures.

The focus of this workshop reflects the need to harmonize the efforts from different groups in order to identify suitable tools and plan appropriate validation, activities and natural history studies.

The aims of the workshop were to:

• •bring ‘experts’ together to assess the suitability of the existing measures,
• •ascertain that these tools cover the whole spectrum of abilities in DMD,
• •identify possible gaps in the existing measures,
• •find a consensus on the tools to be adopted and evaluator training,
• •have common datasets to allow data sharing.

Eugenio Mercuri (Italy) gave a brief review on the existing measures used for assessing upper limb function in DMD [3]. Some of these measures are observer-rated, performance-based scales exploring the effect of progressive weakness on upper limbs including manual abilities and dexterity. The other tools are patient reported scales investigating different aspects of activities of daily living, such as transferring, feeding, or washing therefore providing a measure of the patients’ level of independence and ability to interact with the environment.

Craig Mc Donald (USA) reported a summary of recent meetings held in Washington and Baltimore in June 2010 and July 2011 [1]. These meetings allowed to map outcome measures in DMD and compare recent natural history data from 1900 patients from eight networks. The data showed a consistent improvement in natural history with a clear shift in age of decline, age of loss of ambulation, need for ventilation and survival. These shifts are thought to reflect improved standards of care and use of steroids.

A spectrum of functional milestones with meaningful relevance to patient and families was generated from previous meeting. In the present workshop these milestones were further discussed with the family representatives and modified to include actions such as sitting independently (Table 1).

Table 1.

Loss of Clinically Meaningful Milestones.

• Loss of standing from supine

• Loss of stair climbing

• Loss of the ability to rise from a chair

• Loss of ability to walk (Inability to walk 10 m)

• Loss of the ability to sit independently

• Loss of the ability to raise a hand to the mouth

Julaine Florence (USA) reported preliminary data from an on-going collaborative study in non-ambulatory DMD boys using the Brooke scale, the Jebsen and the 9 hole peg tests. Preliminary data at baseline showed that the measures could be completed in the majority of the boys assessed and had good test–retest and inter-observer reliability. The preliminary data also provided useful information on starting positions and procedures to be used in DMD.

Flaviana Bianco and Elena Mazzone (Italy) presented an exploratory study on upper limb function in 61 DMD patients. This study, rather than being a formal suitability study, explored whether the existing scales [4–7] were appropriate for DMD patients at different ages and spectrum of abilities ranging from ambulant boys with antigravity shoulder movements to older non ambulant boys with only limited finger movements. The study highlighted pros and cons of each measure, and possible shortcomings related to posture, pattern of weakness, contractures requiring compensatory strategies, also providing some suggestions on how to overcome some of these difficulties (Table 2).

Table 2.

Details of the existing measures for assessment of upper limbs.

	Used in DMD	Pros	Cons	Suggestions
Brooke upper extremity Scale	+	Easy, quick, not requiring equipment Provides functional classification	–Hand function not specifically assessed –Ordinal level data –Few classes	Modify scoring system (sublevels or weights)
Jebsen hand function test	+	Timed test Standardized Weight bearing items Normative data available	–Fatigue –Measures a constant group of UL muscles –Not all items clinically meaningful –No compensatory strategies allowed –No bimanual activities	Writing not suitable (age and IQ dependent) preferred hand testing only Modify scoring to allow compensatory strategies or partial achievement of the task
Motor function measure	+	Easy 4 point scoring system sensitive to change Includes ‘distal’ items assessing function relating to ADL	Floor and ceiling effect Not all items clinically meaningful Does not cover shoulder height activities	Modify items including more than one task (e.g. hands to head/hands to mouth)
Upper limb module	−	Reflects ADL Includes activities on different planes	Ceiling effect Activities thought for younger children	Modify scoring system (weights)
9 hole pg test	+	Timed item Standardized Assesses dexterity	Limited range of activities assessed

ADL: activities of daily living, UL : upper limbs, DMD: Duchenne muscular dystrophy.

Craig McDonald (USA) reported previous experience of the CNRG network on previous tools assessing upper limb function, including: Brooke scale, manual and quantitative muscle testing, hand grip and newly developed tools such as the kinematic assessment of Volume of Reachable workspace or a quality of life questionnaire (NeuroQol) [8,9]. The challenge of the NeuroQol is to determine changes over a short period of time, to be sensitive to treatment effect, and to bridge the gap between paediatric and adult age groups.

Laurent Servais and Valerie Decostre (France) reported the application of new devices, developed to assess different aspects of function and activity. The Actimyo is a light-weight, wireless device for home monitoring of upper limb movements. The device can be used across spectrum of abilities including very weak non ambulant patients. An update of a suitability study using other tools in non ambulant DMD showed that MyoPinch, MyoGrip and MOVIPLATE were the most sensitive and suitable tools that could be reliably used with no floor/ceiling effect [10].

Anna Mayhew (UK) reported a summary of a physiotherapist meeting recently held in Newcastle which helped to:

• •redefine a list of activities proposed in previous TREAT NMD meetings,
• •create a graded hierarchical system from strongest to weakest and from proximal to distal, following the gradient of weakness observed in DMD,
• •associate each activity with the items already available from different assessments and identifying possible gaps,
• •relate activities and items to clinically meaningful activities of daily living and life events.

The meeting also provided useful suggestions on how to modify the existing items in order to make them suitable for stronger younger boys and overcome ceiling effect.

The suitability of the available measures was discussed in a round table, taking advantage of the presence of family representatives and industries who provided their view on clinical meaningfulness and relevance of the measures for possible clinical trials.

• •The round table confirmed the need to identify measures covering upper limbs activities from antigravity shoulder movements to limited finger movements in order to have reliable measures also for non ambulant patients who are likely to be considered for clinical trials.
• •At the other end of the spectrum, such measures would also allow to follow stronger ambulant patients once they have lost ambulation.
• •Observer-rated measures are preferred because they are more easily standardizable but patient-reported measures can complement information on activities of daily living which cannot otherwise be observed in a clinical/research setting.
• •Further work is needed to modify the existing patient-reported measures in order to include the meaningful activities that cannot be assessed using observer rated measures.
• •Moviplate, pinch and hand-grip can be reliably used in both ambulant and non ambulant patients providing information on specific aspects of functional domains but functional scales should also be used to allow assessment of a wider spectrum of activities.
• •None of the functional scales previously used in DMD covers the whole spectrum of abilities found in ambulant and non ambulant DMD boys.
• •Not all the items in the available scales are suitable for DMD patients. In the Jebsen for example, writing a sentence is inappropriate because of frequent cognitive difficulties in DMD patients.
• •Other items may be suitable because easily and reliably performed but do not reflect clinical meaningful activities for DMD patients, the last two points probably reflecting that none of the available scales was specifically devised for DMD.

A general discussion on individual items brought to a further selection of those thought to be appropriate for assessing clinically meaningful activities in both ambulant and non ambulant patients (Table 3).

Table 3.

Upper limb motor performance module for DMD (PUL for DMD)^a.

Entry item	6 grades
This item defines the gross ability of an individual and is based on the Brooke Scale. It directs the evaluator to the appropriate items to assess next.
High level shoulder Dimension
Shoulder abduction to shoulder height	Graded with weights
Shoulder abduction above shoulder height	Graded with weights
Shoulder flexion to shoulder height	Graded with weights
Shoulder flexion above shoulder height	Graded with weights
Mid level elbow Dimension
Hand(s) to mouth	Graded with cup and weights
Hand(s) to table from lap	Function
Move weight on table	Graded with weights
Lifting light cans	Also a timed test
Lifting heavy cans	Also a timed test
Stacking light cans	Also a timed test
Stacking heavy cans	Also a timed test
Remove lid from container	Bimanual activity
Tearing paper	Bimanual activity
Distal wrist and hand Dimension
Tracing path	Function
Push on the light	Function
Supination	Function
Picking up coins	Function
Placing finger on number diagram	Function

^aItems have been collated and adapted from Brooke scale, Jebsen Test, Motor Function Measure, and Upper Limb scale for SMA.

The selected items will be used by all the participants in order to identify possible shortcomings in patients at different ages. A physical therapist working group will take into account the proposed amendments providing manuals and instructions for the selected items. The data collected by all centers will also be used for a preliminary Rasch analysis which will allow to identify redundancies/gaps, and more generally, to improve the statistical robustness of the new scale.