The recovery of cognitive problems after stroke is still poorly understood, but preliminary data from our cognitive screening programme suggests that there are differences for contrasting cognitive domains. Differential recovery rates are observed, with grossly speaking some problems, such as language problems appearing more persistent over the medium time (6 months), some domain problems such as hemispatial neglect demonstrating good recovery in a large proportion of stroke survivors (though not all – see separate project on neglect recovery), and some difficulties such as memory deficits demonstrating a greater prevalence at follow up than acutely (perhaps linked to increased prevalence of neurodegeneration linked to overall cerebrovascular burden). Furthermore, knowing which problems are particularly detrimental to regaining daily functioning and quality of life, can inform the direction of rehabilitation and health economics research programmes.
For example, a better understanding of the recovery of vision problems after stroke will help patients and therapists to make informed choices when setting targets for treatment and preparing for certain outcomes. For instance, if a therapist knows that difficulty in recognising people is due to impairments in visual perception that are unlikely to recover instead of a memory problem, then they can help the patient to adopt adequate coping strategies such as the use of jewellery, clothing, voice or gait to recognize a familiar person rather than starting memory training.
Additionally, it may also be important to distinguish between ‘domain-specific’ and ‘domain-general’ problems. By ‘domain-specific’ we refer to problems in a particular process that contributes only to the domain in question – for example, a problem in spatial orienting which affects spatial attention but not (say) language comprehension. By ‘domain-general’ we refer to a process that supports a variety of cognitive domains – examples being working memory and sustained attention, which support language, memory, number processing etc. Patients with a problem in a domain-general function as well as poor memory and spatial attention fare worse in measures of longer-term outcome than patients with the same level of memory and spatial attention problem. Similarly aphasic patients have worse recovery if there is a deficit in these domain-general processes along with any primary language problem. These data suggest that domain-general processes may be important, but exactly how this translates into functional measures is not clear.
The aim of this research is to evaluate how cognitive measures taken at an acute stage evolve over time post stroke, how domain-specific impairments relate to each other and how cognitive impairments relate to real-life functional measures like activities of life and participation levels. In the longer term, having a better understanding of the natural time course of cognitive recovery, and its link to functional outcomes, is essential in being able to assess any added contributions when interventions are introduced to improve performance.
This study (REC reference 18/SC/0550) is actively recruiting at the John Radcliffe Acute Stroke Unit, supported by the UK Clinical Research Network.
- Demeyere, N., & Céline R, G.. (2019). Ego- and allocentric visuospatial neglect: dissociations, prevalence, and laterality in acute stroke.. Neuropsychology, 33(3), 490–498.
- Lay report here
- Moore, M. J., Vancleef, K., Shalev, N., Husain, M., & Demeyere, N.. (2019). When neglect is neglected: nihss observational measure lacks sensitivity in identifying post-stroke unilateral neglect. J neurol neurosurg psychiatry, jnnp–2018
- Lay report here