C40-13 Seizures Behind the Shield: Diagnostic Dilemmas of Neurosarcoidosis During Immunosuppressive Therapy

Abstract Introduction Neurosarcoidosis represents an uncommon but clinically significant manifestation of systemic sarcoidosis, affecting approximately 5-15% of patients. Cranial neuropathies are the most common initial presentation, with facial and optic nerve involvement frequently observed. Seizures, while less common, are associated with chronic disease and poorer prognosis. The occurrence and characterization of seizures in individuals already receiving corticosteroids and immunosuppressive agents remain insufficiently described in the literature. This report details a case of new-onset seizures in a patient with established pulmonary sarcoidosis undergoing treatment with prednisone and mycophenolate mofetil, highlighting the diagnostic and therapeutic challenges of neurosarcoidosis in the context of ongoing immunosuppression. Case Presentation A 40-year-old female with a pulmonary sarcoidosis on prednisone and mycophenolate mofetil presented to the emergency department after three episodes of witnessed new-onset generalized tonic-clonic seizures, each lasting about five minutes, accompanied by urinary incontinence and a postictal state. She denied prodromal symptoms but reported facial pain before the onset. On arrival, vital signs were notable for tachycardia and tachypnea. Laboratory evaluation revealed hyperkalemia, metabolic acidosis secondary to elevated lactate, consistent with postictal metabolic derangements. Infectious workup was unremarkable. Urine drug screen was positive for cannabinoids. Non-contrast CT of the brain was unremarkable, and EEG showed no epileptiform activity. MRI of the brain demonstrated scattered foci of patchy leptomeningeal enhancement over the bilateral cerebral hemispheres, with several enhancing areas corresponding to adjacent T2 and T2-FLAIR signal hyperintensity, without mass effect. Cerebrospinal fluid (CSF) analysis revealed mildly elevated protein (52 mg/dL), total nucleated cell count (6/μL), and red blood cells (27/μL), non-specific but consistent with low-grade central nervous system inflammation. CSF studies showed elevated IgG levels (1700 mg/L), with negative Gram stain, culture, and oligoclonal bands, and a normal ACE level. She was subsequently discharged home with levetiracetam 500mg twice a day. New-onset seizures, characteristic MRI findings, and CSF abnormalities in a patient with known pulmonary sarcoidosis underscore the importance of considering neurosarcoidosis as a differential diagnosis. Conclusion This case underscores the necessity of maintaining a high index of suspicion for neurosarcoidosis in individuals with a history of pulmonary or systemic sarcoidosis who develop new-onset seizures. The absence of classic neurological features- potentially obscured by corticosteroids or other immunosuppressants- further complicates timely diagnosis and management. Comprehensive evaluation and multidisciplinary collaboration are essential when atypical neurological symptoms arise in sarcoidosis patients, as early recognition and intervention are critical to optimizing outcomes. This abstract is funded by: None