Stroke is a major public health problem worldwide. According to [1] , stroke is the most common neurological disorder in developed countries, where it is the leading cause of acquired non-traumatic physical disability, the second leading cause of dementia after Alzheimer’s disease, and the third leading cause of death after myocardial infarction and cancer. A major cause of depression among patients and their families is the cost of care, estimated at 2.4% of total healthcare expenditure worldwide. Post-stroke cognitive dysfunction is the second most common cause of severe neurocognitive impairment after Alzheimer’s disease (AD) [2] . Despite the significant consequences, such as poorer prognosis in terms of vitality and function, cognitive deficits after stroke are poorly understood. The consequences of these disorders lead to a significant risk of disability and subsequent institutionalization in most developed countries [3] [4] . Researchers have shown that cognitive symptoms after stroke are frequent in the acute phase (around 80% of surviving patients), and persist in 38% to 73% of cases [5] [6] . However, this symptomatology is often neglected compared to other possible deficits (motor and/or sensory) [7] . In the least developed countries, the impact of cognitive disorders is still poorly assessed because they are not a priority in national health programs [8] . In Côte d’Ivoire, as in less developed countries, data on post-stroke cognitive disorders are still insufficient. Our study is designed to contribute to a better understanding of cognitive disorders after stroke. In the present study, we determine the frequency and the risk factors related to the cognitive status of post-stroke patients treated in the neurology department of the University Hospitals of Cocody and Treichville (Côte d’Ivoire).

During the period of the study, 724 patients were hospitalized. Among them, 309 patients (42.68%) were admitted for diverse neurological pathologies and 415 stroke patients (57.32%) were enrolled in the study. The latter’s were selected based on selection criteria. Eventually, 145 patients (34.94%) aged 30 to 87 years were evaluated as shown by the flowchart ( Figure 1 ).

In our study, 81.38% of patients had problems with executive function and 54.48% had problems with language. Vidović et al. found that language deficits after stroke are common, affecting up to 80% of patients, and may regress with appropriate rehabilitation [14] . Our results showed a frequency of 34.48% and 24.83% for disorders of short-term memory and working memory, respectively. According to [15] , about 30% develop memory problems in the year after stroke. Our study found 86.21% cognitive impairment. Other studies have also found around 80% impairment after stroke [6] . Burton and al., estimated that 80% would be impaired in the acute phase [16] . In foreign developed countries, a cross-sectional Chinese study conducted by [17] in Changsha (China) had a frequency of 41, 8%. A cross-sectional study conducted in India by [18] revealed a frequency of 66, 66%. Another Chinese study on post-stroke cognitive impairment (PSCI), revealed an overall prevalence of 80.97% [19] . A study conducted in Indonesia by Pinzon et al revealed a frequency of 68.2% [20] . According to Jokinen and collaborators, 83% of patients showed impairment in at least one cognitive domain [21] . In comparison, the frequencies of PSCI in reported studies in various countries move away from each other’s. The frequency observed in our study remains higher, but it is not so far from those of studies conducted in African developing countries. Studies similar to ours have been conducted in Ghana by [22] , in Nigeria by [23] , Uganda by [24] . These authors found frequencies of 72.8%, 67.4%, and 66.4%. The higher frequency in our study may be due to when the patients were assessed. In our study, patients were assessed in the subacute stage (at least 5 days after stroke), while in the studies mentioned, patients were assessed in the post-acute phase (at least 3 months after stroke). Timing of cognitive assessment is crucial for accurate diagnosis, as retested scores often show improvements [25] [26] . Some studies reported that cognitive problems continue to stabilise and even improve beyond the first 3 months after stroke [27] . Moreover, we performed assessment with the MoCA test, while authors of studies named above used the MMSE. Incidentally, Zhao and colleagues have shown that the MoCA is more sensitive to mild cognitive impairment than the MMSE [28] .

Although our study did not find a significant effect of age on the risk of cognitive impairment after stroke ( Table 1 ), other studies show that age influences cognitive decline after stroke. Age is a risk factor for both stroke and cognitive decline. There is evidence that cognitive decline after stroke increases with age after 65 [29] . Our study did not find that gender had a significant effect on the onset of cognitive impairment ( Table 1 ). Others researchers showed that gender was not identified as a factor associated with the onset of post-stroke cognitive impairment [30] [31] . In some studies, gender is linked to post-stroke cognitive issues [32] . Our research reveals education impacts cognitive function. High education levels protect against cognitive decline after a stroke [22] [33] . Indeed, a higher level of education increases the brain’s cognitive reserve, which may lead to better compensation for ageing and brain damage [34] . Some authors found education level doesn’t impact cognitive decline. Singh-Manoux, Zahodne & colleagues studied education’s effect on cognition in 7454 Whitehall II & 1023 Victoria Longitudinal Study participants [35] [36] . Both studies suggested that there was no significant difference of the rate of decline in cognitive function between each group of the education level. The education level is a conflictive risk factor. It could influence the expression of the cognitive impairment in patients. The cohort study conducted by Elbaz and collaborators, on 4010 participants suggested the higher education was associated with better cognitive performances [37] . Our study did not show that employment status was related to cognitive impairment ( Table 1 ). Yet, there is evidence suggesting that the occupation have effects on the prevalence of the cognitive impairment. Singh-Manoux and collaborators also suggested that the individuals with high occupations that were defined as the administrative positions had a more obvious cognitive decline than other occupations [35] . Another study conducted by Douiri and collaborators, proposed a higher prevalence of cognitive impairment after ischemic stroke in the manual workers [38] . Our study did not show that vascular diseases risk factors i.e. hypertension, diabetes, cardiopathy were related to post-stroke cognitive functioning impairment ( Table 2 ). On the contrary, a study has shown the effect of those factors on post-stroke cognitive impairment [39] . Table 3 showed that deep affected area is related to post-stroke cognitive impairment in hemorrhagic stroke (p = 0.005). Table 4 showed that affected area of posterior cerebral artery is related to post-stroke cognitive functioning impairment in ischemic stroke (p = 0.048). About it, Munsch and collaborators suggested that the onset of post-stroke cognitive impairment could be related to the location of cerebral infarction [40] .

Cross-sectional studies cannot establish causality. Timing of patient assessment (subacute phase) may overestimate cognitive problems (86.21% of survivors). Restricting the study to public health facilities may introduce bias due to the social status of the population. The study may be biased by the exclusion of a significant number of participants from the study consortium, particularly for illiteracy (n = 82, 19.76%) and aphasia (n = 35, 8.43%). In addition, the use of the MoCA test, which has not been validated in sub-Saharan African populations, could lead to misinterpretation of cognitive impairment in participants from these countries, potentially overestimating the impact. Despite these limitations, the study provides valuable data on cognitive impairment after stroke in sub-Saharan Africa. This can inform public awareness, policy recommendations and future research into effective interventions.

This study provides data on frequencies and related risk factors of cognitive status among patients in subacute stage of stroke in Abidjan. Global cognitive functioning and executive functions were highly impaired, language was moderately impaired while memory was less impaired. The level of education and the affected brain area were risk factors associated with the occurrence of cognitive functioning disorders. The interest of this study is the importance of early screening of cognitive disorders after a stroke for many cognitive functions have been found to be impaired. The cognitive care of stroke patients should benefit from these findings. We plan to integrate further aspects such as the patient’s lifestyle in the research of post-stroke cognitive disorders in order to find more associated factors.

We especially and attentively thank the family members of the Biology and Health Laboratory, Felix Houphouët-Boigny University and the medical staff of the University Hospital who contributed significantly to the completion of this project.

Informed consent was obtained from the patient.

NNA and ON contributed to writing this manuscript; ON and KKL contributed to revising the manuscript. TNA and KKL contributed to the study design. NNA performed all the data analyses.