I remember moments when I was back in school. The classroom was filled with buzzing and I was sitting there, staring out of the window. My head in the clouds, thinking of nothing…
Then, I was suddenly called to focus.

An experience, that I think happens to a lot of people every day. A call to focus, but what is that exactly? Why is it that a lack of focus has so much influence on us?

Staying focused

The ability to focus, for a required amount of time, is called attention. This focus can be on internal or external stimuli or experiences. Over the last couple of years, different models for attention have arisen. 

The International Classification of Functioning, Disability, and Health (ICF) distinguish attention into functions of sustaining attention, shifting attention, dividing attention, sharing attention, concentration and distractibility. (1)

Other models classify between attention subtypes such as orienting, switching and sustaining functions. However attention is classified, it is part of a complex neurocognitive system supported by neuro-networks, with sustaining attention as the base of cognitive function. Other cognitive domains, such as learning and memory build upon this base. 

But that means that other cognitive domains are influenced by a shortfall of attention. (2)

Clinical background and relevance of attention 

Cognitive impairments such as attention deficits, memory deficits or executive function deficits are common after stroke. They are called poststroke cognitive impairment and up to 87% of stroke survivors suffer from them in the acute phase after stroke. (3)

40% of stroke survivors still show cognitive impairments in a chronic phase after stroke. (4)

These mild cognitive impairments are often hard to differ from dementia that can also manifest after stroke. The negative impact of cognitive impairments on quality of life can be long term for patients and their families. Knowing this, therapeutic interventions and preventions should be a focus in every rehabilitation phase and should be continued at home. (5, 6, 7)

Neural Network

Attention is not simply located in one area of the brain. Attention stands for a complex neural network involving multiple structures in the brain. Knowing this explains the complexity of attention and the broad effect attention deficits have on all areas of daily life. Attention not only involves sustained, selective and alternation attention but is also highly dependent on inhibition, alerting, orienting and executive functions. (2, 8)

Motivation

Motivation has shown to be one of the keys to attention treatments. An additional motivation deficit can hinder the progress and makes it extremely difficult for a stroke survivor to go forward in the rehabilitation process. 

In addition, studies have shown that intrinsic motivation, and so the ability to exert effort, is not endless and will wane over the rehabilitation time. Common motivation/reward paradigms and task-engagement have shown to be an improving factor for attentional deficits and motivation. (2)

Attention deficits as a core aspect

Knowing about the complexity of the neural network behind attention and the high frequency of cognitive deficits after stroke the impact of attention deficits is clear. (2)

Neglect

Neglect is a complex neuropsychological deficit. It is a manifested attention deficit and a multicomponent syndrome. Sustained attention deficits and vigilance decrements are the core aspects of hemispatial neglect. Because of the key role in attentional processes of the right hemisphere, hemispatial neglect after a right hemisphere stroke is more common. 

The main symptoms are the neglecting of one side of the room and body, the lack of deficit awareness as well as motivational deficits. This complex syndrome has a negative impact on the rehabilitation outcome. Although a variety of neglect treatments have been developed, universal treatment has not been found yet. New studies suggest that positive motivation, in the form of reward can have a positive effect on neglect. (9, 10, 11)

Rehabilitation

Quality of life and independence is one main goal of stroke rehabilitation. Knowing that cognitive impairments have a negative impact on it makes them a rehab target. However, what happens after inpatient rehabilitation? (12)

Computerized cognitive rehabilitation of attention

Strategies for cognitive rehabilitation stretch from simple paper-pen exercises to computerized rehabilitation. Studies show the beneficial effects of computerized cognitive interventions after a stroke on attention, memory and executive functions. 

Although there are no guidelines yet, beneficial interventions and methods are already known. (13, 14)

Cognitive training through a customized telerehabilitation platform

Cognitive rehabilitation doesn’t stop after inpatient rehabilitation. Continued training at home has shown to be an effective way to treat cognitive deficits. Computerized cognitive rehabilitation on a PC or tablet can extend rehabilitation at home. Individualized programs can support patient-specific progress. (6)

Correlating deficits

Often attention deficits correlate with other deficits. Especially in an early phase, it’s hard to distinguish them. Two common deficits that can occur with attention deficits are mentioned below. (15)

Visual deficits

Visual deficits are defects that involve the quantity and quality of the visual field, they affect 20% to 57% of stroke patients. The extent of the deficits depends on the origin of the stroke. Visual field defects can be tested thought standardized assessments or screenings if the cognitive state allows it. The extent of the visual deficit has a direct effect on the quality of life, the mood, and the ability to participate in rehabilitation. (15)

Executive functions

The executive functions are the control and screening systems of our brain. They include everything from processing, organizing, problem-solving, self-monitoring and even more. They correlate directly with attention and memory. Many stroke survivors will experience executive dysfunction in some way, knowing that 75% of them have working memory deficits.

Due to the reduced capacity for new strategies, compensation involving the paretic limb can be made difficult. Improving these executive functions may increase performance and independence in daily life. (15)

Have you ever had experience with attention deficits? Do you have moments where a lack of attention affects your daily life?

Bibliography

  1. World Health Organization. (2001). International Classification of Functioning, Disability, and Health. Geneva. Retrieved from https://apps.who.int/iris/handle/10665/42407 
  2. Fortenbaugh, F. C., DeGutis, J., & Esterman, M. (2017). Recent theoretical, neural, and clinical advances in sustained attention research. Annals of the New York Academy of Sciences, 1396(1), 70–91. https://doi.org/10.1111/nyas.13318
  3. Li, J., You, S.-J., Xu, Y.-N., Yuan, W., Shen, Y., Huang, J.-Y., … Liu, C.-F. (2019). Cognitive impairment and sleep disturbances after minor ischemic stroke. Sleep and Breathing, 23(2), 455–462. https://doi.org/10.1007/s11325-018-1709-4
  4. Chiti, G., & Pantoni, L. (2014). Use of Montreal Cognitive Assessment in Patients With Stroke. Stroke, 45(10), 3135–3140. https://doi.org/10.1161/STROKEAHA.114.004590
  5. Thingstad, P., Askim, T., Beyer, M. K., Bråthen, G., Ellekjær, H., Ihle-Hansen, H., … Saltvedt, I. (2018). The Norwegian Cognitive impairment after stroke study (Nor-COAST): study protocol of a multicentre, prospective cohort study. BMC Neurology, 18(1), 193. https://doi.org/10.1186/s12883-018-1198-x
  6. Gil-Pagés, M., Solana, J., Sánchez-Carrión, R., Tormos, J. M., Enseñat-Cantallops, A., & García-Molina, A. (2018). A customized home-based computerized cognitive rehabilitation platform for patients with chronic-stage stroke: Study protocol for a randomized controlled trial. Trials, 19(1), 1–10. https://doi.org/10.1186/s13063-018-2577-8 
  7. Brainin, M., Tuomilehto, J., Heiss, W.-D., Bornstein, N. M., Bath, P. M. W., Teuschl, Y., … Quinn, T. (2015). Post-stroke cognitive decline: an update and perspectives for clinical research. European Journal of Neurology, 22(2), 229-e16. https://doi.org/10.1111/ene.12626
  8. Petersen, S. E., & Posner, M. I. (2012). The Attention System of the Human Brain: 20 Years After. Annual Review of Neuroscience, 35(1), 73–89. https://doi.org/10.1146/annurev-neuro-062111-150525
  9. Li, K., & Malhotra, P. A. (2015). Spatial neglect. Practical Neurology, 15(5), 333–339. https://doi.org/10.1136/practneurol-2015-001115
  10. Although & Malhotra, P. A. (2015). Spatial neglect. Practical Neurology, 15(5), 333–339. https://doi.org/10.1136/practneurol-2015-001115
  11. Olgiati, E., Russell, C., Soto, D., & Malhotra, P. (2016). Motivation and attention following hemispheric stroke. In Progress in Brain Research Volume 229 (pp. 343–366). https://doi.org/10.1016/bs.pbr.2016.06.011
  12. van Lieshout, E. C. C., van Hooijdonk, R. F., Dijkhuizen, R. M., Visser-Meily, J. M. A., & Nijboer, T. C. W. (2019). The Effect of Noninvasive Brain Stimulation on Poststroke Cognitive Function: A Systematic Review. Neurorehabilitation and Neural Repair, 33(5), 355–374. https://doi.org/10.1177/1545968319834900
  13. Bogdanova, Y., Yee, M. K., Ho, V. T., & Cicerone, K. D. (2016). Computerized Cognitive Rehabilitation of Attention and Executive Function in Acquired Brain Injury. Journal of Head Trauma Rehabilitation, 31(6), 419–433. https://doi.org/10.1097/HTR.0000000000000203)
  14. Linden, M., Hawley, C., Blackwood, B., Evans, J., Anderson, V., & O’Rourke, C. (2016). Technological aids for the rehabilitation of memory and executive functioning in children and adolescents with acquired brain injury. Cochrane Database of Systematic Reviews, (3). https://doi.org/10.1002/14651858.CD011020.pub2
  15. Chung, C. S., Pollock, A., Campbell, T., Durward, B. R., & Hagen, S. (2013). Cognitive rehabilitation for executive dysfunction in adults with stroke or other adult non-progressive acquired brain damage. Cochrane Database of Systematic Reviews, (4). https://doi.org/10.1002/14651858.CD008391.pub2