Cognitive rehabilitation for attention deficits following stroke

Why is this review important?
Attention is defined as the ability to focus cognitive resources on certain aspects of the environment excluding others and as the neural readiness to respond to stimuli. Different domains of attention are classified as: alertness/arousalselective attentionsustained attention(visuo) spatial attention, and divided attention.

In particular, alertness/arousal is the ability and readiness to respond to stimuli, selective attention is the ability to focus on specific stimuli while ignoring irrelevant ones, sustained attention is the ability to maintain concentration over a prolonged period of time, (visuo) spatial attention is the ability to detect-deploy attention to all sides of the space, and divided attention is the ability to multitask. 
 
After stroke 24% to 51% of the patients at hospital discharge may have attention problems affecting daily life activities, mood, and quality of life. To improve cognition is a top 10 research priority for stroke survivors.
 
Attention impairments are associated with other neurological aspects, such as anterior lesions, which may affect filtering out distraction, and posterior ones, which may be linked to difficulty in understanding instructions. So, for optimal recovery, cognitive rehabilitation needs to be customised with the affected attentional domain. 
 
Interventions may target 'restitution' (restore cognitive function) and/or 'compensation' (reduce cognitive impairment using strategies that minimise attention skills), though the outcomes of these cognitive rehabilitation programmes are still unclear.
 
Who will be interested in this review?
Patients with stroke having attention problems, loved ones/caregivers of stroke survivors, health professionals dealing with stroke or working with cognitive disorders, general practitioners, and policymakers.
 
What is the aim of this review and what does it talk about?
This review analyses the evidence on the effects of cognitive attention rehabilitation in people with stroke. 
 
The outcomes include the ability to perform daily activities, mood, and quality of life.
 
Six post-stroke clinical rehabilitation trials (randomized controlled trials) published before February 2019 were included in the review that compared cognitive training with a control group (who received their usual care or no cognitive rehabilitation). These studies involved 223 participants who reported attentional problems after stroke and were given cognitive interventions that targeted attention abilities. Outcomes were measured immediately after training and at follow-up and were compared with alternative management interventions like computerised activities (with low attentional demand) or social interaction. The interventional studies were excluded from the analysis that focused on visuospatial attention. Also listening to music, meditation, yoga, or mindfulness were not considered as cognitive rehabilitation.
 
What does available evidence tell us?
The overall quality of evidence was very low to moderate due to the small number of studies, small sample size, and risk of bias in reporting intervention outcomes. There were insufficient data to evaluate whether treatment is more effective in the post-acute or acute recovery phase. Moreover, the review could not address whether treatment success was modulated by the severity of attentional impairments or whether effects varied with frequency of intervention (number of sessions per week), intensity of intervention (total hours of intervention), and type of intervention.
 
What is the authors’ conclusion?
Cognitive rehabilitation for attention deficits following stroke may improve some specific aspects of attention immediately after treatment, but the effectiveness remains unconfirmed. There was no evidence to indicate whether the benefits persist in the long term. However, improving attention in the short term may enable people to engage better in rehabilitation and improve their ability to cope with tasks in which they are required to do two things at the same time, such as walking and talking. It is important that when rehabilitation for attention is carried out, the benefits are monitored closely, because at present no specific rehabilitation approach can be recommended. 
 
What should be done next?
Future studies with higher methodological quality and better reporting need to assess whether the effects persist and generalise to attentional skills in daily life.

Comment by Sunita Gudwani