Behavioural assessment of neuropsychiatric outcomes in rodent stroke models

Stroke-associated mood disorders are less recognised than sensorimotor impairment, despite their high prevalence. Similarly, few experimental stroke studies assess non-sensorimotor functions. This study examined the prevalence and implementation of non-sensorimotor tests in three stroke-focused journals over the last twenty years. Of 965 experimental ischaemic stroke papers which used behavioural testing in rodents, 932 included sensorimotor testing, while 137 used non-sensorimotor tests (most commonly the Morris water maze, open field, Y-maze, and novel object recognition tests, but with a more diverse range of tests introduced in recent years). Cognition, anxiety and depression were assessed in 70%, 27% and 3% of these 137 papers. Non-sensorimotor deficits were typically observed after recovery of sensorimotor function. Potential confounding factors and challenges for data interpretation were identified in the most prevalent tests. More generally, experimental rigor (a priori power calculation, randomisation, blinding, and pre-defined inclusion/exclusion) improved over the years, but remained unsatisfactory with only 26% of studies providing some evidence of adequate statistical power. Furthermore, most studies focused on male animals, limiting external validity. This review confirms the disparity between sensorimotor and non-sensorimotor testing in experimental stroke but shows that the share of the studies including the latter is increasing. It is essential that research into the neuropsychiatric sequalae of stroke addresses methodological issues noted and continues to expand to improve patient outcomes post-stroke.