Many faces of neurosarcoidosis: From chronic meningitis to myelopathy

Purpose of review Neurosarcoidosis occurs in 5% of patients with sarcoidosis and can be difficult to diagnose. In this review we discuss the most recent advances in our understanding of the disease, describing clinical characteristics, diagnostic process, treatment, and prognosis. Recent findings Clinical presentation is heterogeneous with most patients presenting with cranial nerve palsy, headache, or sensory abnormalities. Patients are classified according to probability of the diagnosis with the Zajicek criteria. In these criteria, histopathological confirmation of noncaseating granulomas in affected tissue outside the nervous system is key. Radiological abnormalities on neuroimaging are nonspecific. No biomarkers have been described that adequately identify patients with sarcoidosis. However, soluble interleukin-2 receptor is a relatively novel biomarker that may be useful. In addition to HRCT scan, 18 F-FDG PET-CT scanning can identify occult locations of disease activity and aid in obtaining pathological confirmation. Despite the use of new therapies, still a third of patients remains stable, deteriorate, or die. Summary Diagnosing and treating patients with neurosarcoidosis remains a challenge. Long-term prospective studies evaluating patients suspected of neurosarcoidosis are needed to assess sensitivity and specificity of ancillary investigations and diagnostic criteria. Furthermore, future studies are needed to evaluate the prognosis and the optimal treatment strategy.