Response to Letter to the Editor re: ‘Executive dysfunction and balance function post-stroke: a cross-sectional study’

Abstract

Thank you for the opportunity to respond to these thoughtful comments related to our article on the association between executive function (EF) and balance function after first ever stroke [1]. The results of this study demonstrated that reduced scoring on the Behavioural Assessment of Dysexecutive Syndrome was independently associated with reduced balance function, measured using the Berg Balance Scale, among this sample of people with stroke.

We particularly welcome the authors’ comments on this article as the improvement of cognitive function post-stroke has been identified as a top research priority by stroke survivors, caregivers and health professionals [2].

In response the authors’ statement “Balance issues result in patients’ difficulty to follow physical post-stroke home treatments, inevitably increasing their executive dysfunction”, as previously outlined in our article, this is a cross-sectional study and inferences regarding causal effect are not backed up by the data.

We welcome the authors’ point regarding the need for cognitive interventions to target executive dysfunction (ED) post-stroke. As we discussed in our article, cognitive rehabilitation interventions are often divided into compensatory or restorative [[3][4][5][6]]. Compensatory interventions focus on teaching people to use their residual skills more efficiently or to compensate for their difficulties through the use of strategies, such as cognitive strategies to improve problem solving [[4][5]]. Restorative cognitive rehabilitation interventions aim to remediate specific executive processes [[5][6]]. This approach to cognitive rehabilitation is mediated by people with stroke working to improve a cognitive skill through improved awareness, performance opportunity and repetition [6]. Interventions that aim to restore EF post-stroke include: planning and organisational skills development, problem-solving strategies, self-awareness and self-regulation of behaviour, initiation of behaviours, inhibition of inappropriate responses [6]. The need for cognitive interventions to target ED post-stroke is also in line with the findings of a recent qualitative study, wherein physiotherapists reported that ED has a negative impact on physiotherapy rehabilitation post-stroke and that strategies need to be put in place in order to overcome the barriers of ED [7]. However, the use of such cognitive strategies in practice must be cautioned as there is insufficient high-quality evidence to reach any generalised conclusions regarding the effect of cognitive rehabilitation strategies on ED post-stroke [6].

While many RCT's of the effect of exercise interventions post-stroke have demonstrated positive effects on physical outcomes, their effect on cognitive outcomes remains under-examined. In a recent Cochrane systematic review update [8] the authors noted that only three of the 58 RCT's examining the effectiveness of fitness training interventions included a cognitive outcome-of which the results are inconclusive. It is evident that further research examining the effectiveness of exercise training on cognitive function post-stroke is required. Sound rationale for this investigation lies in the healthy older adult literature, wherein the positive effect of cardiorespiratory training EF is well-established via meta-analysis [9].

The authors’ recommendation for the examination of the effectiveness of a combined physical and cognitive intervention on EF post-stroke is valid. However, as the individual effectiveness of neither intervention on EF outcomes has not been established to date, it would be more beneficial to firstly complete these separate pieces of research before examining their combined effect on ED post-stroke.

Citation

Response to Letter to the Editor re: ‘Executive dysfunction and balance function post-stroke: a cross-sectional study’