Systemic Autoimmune Diseases with Neurological Manifestations: A Review of Lupus, Sarcoidosis and Vasculitis

Abstract

Systemic autoimmune diseases represent a heterogeneous group of disorders characterised by immune-mediated inflammation that can affect multiple organ systems, including the nervous system. Among these, systemic lupus erythematosus (SLE), sarcoidosis, and systemic vasculitides stand out for their significant neurological involvement, which contributes substantially to morbidity and mortality. This review aims to synthesise current knowledge on the neurological involvement of these systemic autoimmune diseases, emphasising clinical presentation, pathophysiology, diagnostic approaches, and management strategies. A systematic search of the literature was carried out in PubMed, Scopus, and Web of Science databases from January 1980 through July 2024. In SLE, neuropsychiatric lupus encompasses a broad clinical spectrum, with mechanisms including autoantibody-mediated neuronal injury, microvascular ischemia, and cytokine-driven neuroinflammation. Sarcoidosis, although primarily a granulomatous disease of unknown aetiology, frequently involves the nervous system in the form of neurosarcoidosis, presenting with cranial neuropathies, meningeal inflammation, and spinal cord disease. Epidemiological studies demonstrate that between 30% and 50% of patients with SLE develop neurological symptoms during the course of their illness, although reported prevalence rates vary due to differences in diagnostic criteria and study design. Neurosarcoidosis, although less frequent, is a clinically important manifestation that occurs in approximately 5% to 15% of patients with systemic sarcoidosis. The neurological spectrum is broad, encompassing cranial neuropathies, meningeal involvement, hypothalamic-pituitary axis dysfunction, and spinal cord disease. Timely recognition of neurological involvement is essential, as delays in diagnosis can result in irreversible deficits. Diagnostic evaluation typically integrates clinical assessment with neuroimaging, cerebrospinal fluid analysis, serological testing, and sometimes tissue biopsy to confirm immune-mediated pathology. Advances in immunopathogenesis research have improved understanding of the mechanisms linking systemic inflammation with neural damage, offering new diagnostic biomarkers and therapeutic targets. Management strategies require a multidisciplinary approach, combining immunosuppressive therapy with symptomatic neurological care. Corticosteroids remain the cornerstone, while biologics and targeted immunotherapies are increasingly employed to achieve disease control with fewer long-term adverse effects. This review highlights the clinical spectrum, pathophysiological mechanisms, diagnostic challenges, and therapeutic strategies of neurological involvement in lupus, sarcoidosis, and systemic vasculitis, emphasising the importance of early detection and tailored management to improve patient outcomes. In conclusion, neurological manifestations of systemic autoimmune diseases such as lupus, sarcoidosis, and vasculitis represent a domain of high clinical importance, significant morbidity, and persistent uncertainty.