Background: Neurologic manifestations in antiphospholipid syndrome (APS) are common, and most often with an underlying thrombotic mechanism (ischemic stroke or transient ischemic attack [TIA]). The prevalence and range of neurological manifestations varies across studies, most of which lack a structured comprehensive neurological, cognitive and neuroimaging evaluation.

Objectives: To establish the prevalence and systematically characterize neurologic signs, symptoms, diagnosis and disability in our APS cohort.

Methods: We conducted a cross-sectional study to systematically evaluate adult (≥18 years) patients followed at the rheumatology clinic with a diagnosis of APS. We collected demographic, clinical, laboratory and imaging data. Patients were screened for neurological symptoms through a comprehensive neurological examination standardized with the Expanded Disability Status Scale (EDSS); headache characterization and headache impact assessment (HIT-6); and cognitive function screening using the Montreal Cognitive Assessment (MoCA) test. When appropriate, patients were submitted to a formal neuropsychological evaluation. Imaging studies were reviewed, and a brain MRI was obtained when clinically relevant. Recruitment for the study is still ongoing.

Results: We included 33 patients (91% female), with a median age of 50 years (IQR 45-61). Around two thirds (n=21, 64%) had APS secondary to connective tissue diseases (CTD). Full demographic and baseline characteristics are presented in Table 1. Before clinical evaluation, only 17 patients (52%) had a diagnosed neurological condition: stroke or TIA (n=7), headache (n=3), epilepsy (n=2), anxiety (n=9) and depression (n=7). On clinical evaluation, only 6 patients had a normal examination (EDSS=0), and the remaining majority (82%) had clinically evident neurological signs, mainly involving the pyramidal and cerebellar systems. Of note, 15% (n=5) had mild to moderate neurologic disability (EDSS>1.0). One patient had a multiple sclerosis-like white matter disorder on brain MRI deemed secondary to APS. 26 patients (79%) met diagnostic criteria for primary or secondary headache disorder, including 15 (46%) with migraine and 10 (30%) with tension-type headache. Of the patients that reported headaches, 21% had substantial or severe headache impact on their daily living (HIT-6≥56). Although none of the patients had a previous diagnosis of cognitive impairment or dementia, when asked 24/33 (73%) patients had subjective cognitive complaints, and 13 (40% of total) met criteria for mild cognitive impairment.

Conclusion: Clinically evident neurological signs, headache and cognition dysfunction were observed in most APS patients, with substantial disability, daily impact and burden. These data suggest that neurological dysfunction in APS is more common than previously reported and should be actively and systematically sought after in a close liaison between Rheumatologists and Neurologists.

REFERENCES: NIL.

Acknowledgements: NIL. This project was awarded a grant from Faculdade de Medicina da Universidade de Lisboa (18.ª Bolsa de Investigação Fundação AstraZeneca/FMUL, 2021). We would like to thank Sónia Figueiredo and the team from Centro de Investigação Clínica, Centro Académico de Medicina de Lisboa (CAML) for their help with logistics during patient recruitment and data storage.

Disclosure of Interests: None declared.