ICF based assessment of spasticity treatment in stroke patients

The overal aim of this thesis is to assess the efficacy of a spasticity treatment in stroke patients within the ICF framework. Particularly, the effects of BoNT A injections in spastic lower and upper limb muscles will be investigated on impairment, activity, and social participation. The main question is to know if these injections are really effective in improving function in these patients. Indeed, no study to date has showed a benefit of spasticity treatment in terms of functional improvement in activity or participation. Spastic hemiparesis is the classical clinical picture of neurological impairment that limits locomotion and manual ability in stroke patients, which are activities essential for daily life activities and social participation. The ICF defines locomotion as the individual’s ability to move about effectively in his environment, and manual ability as the capacity to manage daily life activities requiring the use of the upper limbs, whatever the strategies involved. Locomotion and manual ability are classified in the ICF activity domain. The Rasch-built questionnaires notably allow overcoming the limitations of the ordinal scales that permit only limited computation and low power non-parametric statistics (Merbitz et al., 1989; Wright and Linacre, 1989). At present, we have new Rasch-built linear and unidimensional scales assessing manual ability (ABILHAND, Penta et al., 2001) and social participation (SATIS-Stroke, Bouffioulx et al., 2008) in stroke patients with high sensitivity. But until now, none of the existing scales available to assess locomotion ability were developed following the Rasch model and locomotion activities are frequently measured by ordinal scales. Therefore, the first stage of this thesis is to develop, using the Rasch probabilistic model, a new questionnaire (ABILOCO) assessing the walking ability of adult stroke patients focusing on the ICF activity domain. The development of this Rasch-built measure of locomotion ability is presented in Chapter 2. Chapter 2 presents the development of ABILOCO, a Rasch-built measure of locomotion ability and its validation in stroke patients. ABILOCO is a self-reporting questionnaire, focusing on the activity domain of the ICF. This questionnaire originally included 43 items representing a large sample of activities corresponding to the ICF definition of locomotion and was submitted to 100 adult stroke patients. The Rasch model selected 13 activities to define a linear and unidimensional measure of walking ability. The development and the validation of ABILOCO are presented as published in the Archives of Physical Medicine and Rehabilitation. A second section of Chapter 2 demonstrates the validity and reproducibility of the ABILOCO questionnaire when administered as either a self-assessment or third-party assessment. This section is presented as published in the Archives of Physical Medicine and Rehabilitation. With ABILOCO, we have now a questionnaire assessing the walking ability of stroke patients focusing on the ICF activity domain and presenting all Rasch psychometric qualities. ABILOCO will be very usefull in Chapter 4 to investigate the efficacy of BoNT A injections in spastic lower limb muscles in stroke patients on the activity domain. Chapter 3 presents a study concerning the reliability of lower limb kinematics, mechanics and energetics in stroke patients during gait as published in the Journal of Rehabilitation Medicine. To date, no study has yet evaluated the medium-term reliability of gait variables among adult stroke patients. This work aims thus to assess the reliability of gait variables at short (1 day) and medium (1 month) intervals and provides useful norms for the study presented in chapter 4. Indeed this observational study uses among others these gait variables to assess the efficacy of BoNT A treatment in stroke patients. It is therefore important to know when a variation between measurements of these variables is the result of a gait modification induced by the treatment and when it is related to the variability of the measurement used. Chapter 4 investigates the efficacy of BoNT A injections in several muscles on stiff-knee gait in stroke patients following the ICF framework. Stiff-knee gait is a common pattern of impaired kinematics in these patients; it is characterised by a lack of knee flexion during the swing phase of the gait cycle. The physiopathology and treatment of stiff-knee gait has not been clearly established. The overactivity of the Rectus Femoris is often cited (Riley and Kerrigan, 1998; Sung and Bang, 2000; Stoquart et al. 2008) but the altered activity of other muscles (Triceps Surae or Vasti) could also take place in the physiopathology (Goldberg et al., 2004). To our knowledge, no previous study has evaluated BoNT A injections in multiple muscles for the treatment of stiff-knee gait. In addition, the effects of BoNT A injections have only been shown to improve impairments and the effects of BoNT A injection on patient activity and participation in social activities remains uncertain. The main aim of Chapter 4 is therefore to investigate the efficacy of BoNT A injections in spastic lower limb muscles on impairment, activity, and social participation in stroke patients. The secondary aim of Chapter 4 is to analyse whether simultaneous BoNT A injections into several spastic muscles are more useful in the treatment of stiff-knee gait, as opposed to one single injection into the Rectus Femoris (Stoquart et al., 2008). This work is presented in Chapter 4 as it was published in Stroke. Chapter 5 investigates the effect of BoNT A injections in several spastic upper limb muscles in chronic stroke patients. We know that many stroke patients present with hand disability secondary to spastic hemiparesis and that these injections effectively reduce neurological impairment (Simpson et al., 2008). However, the functional consequences of these reductions on activity and participation remain unclear as in the lower limb spasticity. We would logically hypothesize that a reduction in spasticity might lead to an improvement in patient activity. But very few studies (Elovic et al., 2008; Brashear et al., 2002) have examined the effects of managing poststroke upper limb spasticity on activity. Additionally, no study has specifically addressed the effect of upper limb BoNT A injections on social participation. Therefore, our aim with this stroke patient study is to investigate the effects on impairment, activity, and participation of BoNT A injections in spastic upper limb muscles. Similarly to the previous chapter, activity (manual ability) and participation are assessed with Rasch questionnaires, ABILHAND (Penta et al., 2001) and SATIS-Stroke (Bouffioulx et al., 2008), respectively. This chapter is presented as the article published in Stroke. Finally, the Chapter 6 discusses the results of the different chapters and presents perspectives for future research.