Neurosarcoidosis: Clinical, biological, and MRI presentation of central nervous system disease in a national multicenter cohort.

Introduction: Neurosarcoidosis (NS) is a systemic inflammatory granulomatous disease affecting of patients with sarcoidosis. Its diagnosis is difficult as there is no specific test for it. Because of its rarity, the management of NS has so far only been described in case series and short retrospective cohorts. The objective of this study is description of the clinical, paraclinical presentation and the therapeutic management of central nervous system (CNS) involvement in NS patients in France.

Methods: This multicenter, retrospective, observational study involved patients hospitalized between 2010 and 2019 with a diagnosis of sarcoidosis and CNS involvement.

Results: We included 118 patients (38 with isolated NS, 80 with NS associated with systemic sarcoidosis). NS was the initial presentation in 78% of patients, with cranial nerve involvement (36%), medullary symptoms (23%), and seizures (21%). Twenty-one percent of the patients had already been diagnosed with systemic sarcoidosis. The most frequent biological abnormality was lymphopenia (62.5%), while angiotensin-converting enzyme was increased in 21%. Meningitis was present in 45% and hyperproteinorachia in 69.5% of cases. MRI mainly revealed white matter abnormalities and leptomeningeal enhancement (34%). Corticosteroids were the most useful treatment, and immunosuppressive agents were used in steroid-resistant patients and to limit side effects. Methotrexate, cyclophosphamide, and anti-TNFα were also used, exhibiting good efficacy.

Conclusions: This cohort contributes to a better understanding of the clinical phenotype and associated imaging and biological abnormalities. Sharing of clinical, biological, and imaging data, as well as the therapeutic responses, of patients with NS helps to better understand and manage this disease that affects a small number of patients per center. A database project could be implemented in the future to enable this.