A retrospective case-control study conducted at a referral center in Mexico City using medical records of 85 patients diagnosed with SLE and seizures between 2005-2024.

The case group included 37 patients with NPSLE associated seizures, 32 females (86.5%), 5 males (13.5%); mean age of 26.2±9 years. Control group encompassed 48 patients with SLE and seizures from other causes, 40 females (83.3%), 8 (16.7%) males; mean age 28.2±11.5 years. The etiology of NPSLE seizures remained unknown in 12 cases (32.4%) after excluding all other causes, while 13 (35.1%) were associated with CSF Ribosomal P antibodies, 5 (13.5%) with thrombosis from antiphospholipid syndrome, and 7 (18.9%) with vasculitis. Most common etiologies in control group were posterior reversible encephalopathy syndrome 18 (37.5%) and hypertensive crisis 7 (14.5%), followed by structural 5 (10.4%) and metabolic causes 5 (10.4%). Generalized seizure onset was the most frequent in both groups, occurring in 20 (54%) cases and 34 (70.8%) controls. Borderline positive associations between cases of NPSLE seizures and a low C3 (OR = 4.2, 95% CI 1.1-16.1, p = 0.05), plus a low C4 (OR = 5.2, 95% CI 1.1-25.2, p = 0.05) were found. NPSLE cases had a higher mean SLEDAI-2K score (21.9 vs 15.8) p=0.05 at SLE diagnosis compared to controls.