The Oxford Cognitive Screen for use with Australian people after stroke (OCS-AU): The adaptation process and determining cut scores for cognitive impairment using a cross-sectional normative study

Adaptation of Oxford Cognitive Screen into Turkish (OCS-TR): Validity and reliability study in stroke survivors

BACKGROUND

The existing cognitive screening tests used to assess cognitive disorders after stroke in Türkiye face limitations in scope and user applicability. Therefore, this study aimed to address these limitations by adapting the stroke-specific cognitive screening test, the Oxford Cognitive Screen (OCS), into Turkish. Additionally, validity and reliability studies were conducted.

METHODS

A total of 114 stroke survivors and 92 healthy individuals participated in the study. Data were collected using the "Participant Information Form," "Oxford Cognitive Screen Turkish Version (OCS-TR)," "Aphasia Language Assessment Test (ADD)," "Montreal Cognitive Assessment Test- Turkish (MOCA-TR)," "Barthel Activities of Daily Living Index (BGYAI)" and "Beck Depression Scale." The team followed an established and detailed step by step process guided by the OCS Concept Elaboration document. Statistical analyses were conducted with IBM SPSS Statistics. Validity and reliability studies, including content validity, known-groups validity, convergent and divergent validity, concurrent validity, internal consistency reliability, test-retest reliability, inter-rater reliability, intra-rater reliability, and parallel forms reliability were conducted to assess the robustness of the measurement instruments.

RESULTS

The language and cultural adaptation process underwent content analysis, adhering to ISPOR and ISOQOL guidelines, resulting in minimal content changes post-pilot study. Notable differences in subtest scores between healthy and stroke participants in both A and B forms of OCS-TR demonstrate known-groups validity, emphasizing superior performance in healthy participants. Strong convergent validity was evidenced by significant correlations with MOCA-TR (rs=0.18 to 0.81) and BGYAI (rs=0.19 to 0.51), while divergent validity was supported by weak correlations with overall BGYAI scores. Noteworthy correlations between specific subtests of OCS-TR and ADD underscore concurrent validity, with high inter- and intra-rater reliability,  internal consistency (α = 0.90 for stroke, α = 0.65 for healthy) and test-retest reliability (rs=0.89 to 0.99). Parallel forms reliability was high in both healthy and stroke participants, though significant differences were observed on specific subtests.

CONCLUSION

The results confirm that the OCS-TR scale can be considered a valid and reliable instrument for assessing cognitive functions in stroke survivors. This stroke-specific tool offers clinicians a comprehensive and inclusive brief cognitive screening tool tailored to the needs of stroke patients.

Investigating the frequency of neural autoantibodies in refractory focal epilepsy

OBJECTIVES

There have been conflicting reports about the frequency of neural autoantibodies in epilepsy cohorts, which is confounded by the lack of clear distinction of epilepsy from acute symptomatic seizures due to encephalitis. The aim of this study was to determine the frequency of neural autoantibodies in a well characterised population of refractory focal epilepsy of known and unknown cause.

METHODS

Cases were recruited from epilepsy outpatient clinics at the Princess Alexandra, Mater, Royal Brisbane and Women's and Cairns Base Hospitals from 2021 - 2023. Included cases were refractory to medical therapy, met the ILAE definition of focal epilepsy and were characterised using anatomo-electro-clinical correlation. Cases with prior encephalitis, inflammatory neurological disease or prior parenchymal brain insults were excluded.

RESULTS

A total of 100 patients were recruited. No cases with clinically significant neural autoantibodies were discovered. One was positive for serum anti-NMDAR antibodies, however autoantibodies were absent from CSF. Cases were also screened using a predictive score (McGinty et al.). From this, 2 cases were identified as seronegative autoimmune associated epilepsy and demonstrated significant reduction in seizure frequency with administration of immunotherapy. These cases had common features including temporo-perisylvian semiology especially ictal piloerection and high seizure frequency.

CONCLUSION

Clinically relevant neural autoantibodies are uncommon in well characterised chronic focal epilepsy populations. Despite this there are isolated cases that still demonstrate improved seizure control with the use of immunotherapy. Such cases highlight the need for further studies to understand the role of immunity in novel pathophysiological mechanisms in epilepsy.

The Korean Version of the Oxford Cognitive Screen (K-OCS) Normative Study

OBJECTIVE

To generate a Korean version of the Oxford Cognitive Screen (K-OCS) and obtain cutoff scores that determine the impairment of each subdomain. Post-stroke cognitive impairment (PSCI) negatively impacts the rehabilitation process and independence in daily life. Its obscure manifestations require effective screening for appropriate rehabilitation. However, in most rehabilitation clinics, psychological evaluation tools for Alzheimer's dementia have been used without such considerations. The OCS is a screening assessment tool for PSCI and vascular dementia that can evaluate the cognitive domains most often affected by stroke, including language, attention, memory, praxis, and numerical cognition. It comprises 10 subtasks and enables quick and effective cognitive evaluation.

METHODS

The K-OCS, which considers Korea's unique cultural and linguistic characteristics, was developed with the approval and cooperation of the original author. Enrollment of participants without disabilities was announced at Duksung Women's University, Yongin Sevrance Hospital, CHA Bundang Medical Center. The study was conducted between September 2020 and March 2022 on 97 male and female participants aged ≥30 years.

RESULTS

All the 97 participants completed the task. In this study, the 5th percentile score was presumed to be the cutoff value for each score, and the values are provided here. The cutoff score for each OCS subtask was similar to that of the original British version.

CONCLUSION

We suggest the usability of the K-OCS as a screening tool for PSCI by providing the cutoff value of each subtask.

What does cognitive screening reveal about early cognitive performance following endovascular clot retrieval and intravenous thrombolysis in acute ischaemic stroke?

Background Little is known regarding cognitive outcomes following treatment with endovascular clot retrieval (ECR) and intravenous tissue plasminogen activator (t-PA). We aimed to determine if there were any differences on a measure of cognitive screening between patients treated with ECR, t-PA, and those who were managed conservatively. Methods The medical records of ischaemic stroke patients admitted to Monash Medical Centre between January 2019 and December 2019 were retrospectively reviewed. Information extracted from medical records included age, sex, National Institutes of Health Stroke Scale at presentation, location of occlusion, treatment type, medical history, and cognitive screening performance measured by the Montreal Cognitive Assessment (MoCA). Results Eighty-two patients met the inclusion criteria (mean age = 66.5 ± 13.9; 49 male, 33 female). Patients treated with ECR performed significantly better on the MoCA (n  = 36, 24.1 ± 4.3) compared to those who were managed conservatively (n  = 26, 20.7 ± 5.5). Performance for patients treated with t-PA (n  = 20, 23.9 ± 3.5) fell between the ECR and conservative management groups, but they did not significantly differ from either. Conclusion Our retrospective chart review found that ischaemic stroke patients treated with ECR appear to perform better on cognitive screening compared to patients who are managed conservatively. We also found that patients treated with ECR and t-PA appear to have similar cognitive screening performances in the acute stages following ischaemic stroke, although this finding is likely to have been impacted by group differences in stroke characteristics and may reflect the possibility that the ECR group performed better than expected based on their stroke severity.