Neurosarcoidosis: correlation of cerebrospinal fluid findings with diffuse leptomeningeal gadolinium enhancement on MRI and clinical disease activity.

BACKGROUND: Cerebrospinal fluid (CSF) examination is considered important in the diagnosis of neurosarcoidosis, however, data on whether and how CSF parameters may be related to MRI findings and clinical disease activity of patients with neurosarcoidosis are scarce.

OBJECTIVE: To correlate CSF findings in patients with neurosarcoidosis with MRI findings and clinical disease activity.

MATERIAL AND METHODS: Results of 51 comprehensive CSF examinations of 25 patients with probable or definite neurosarcoidosis according to the Zajicek-criteria were analyzed retrospectively.

RESULTS: Patients with diffuse leptomeningeal gadolinium enhancement on MRI had significantly higher cell counts (≥50 cells/μl in 80%), total protein (≥200 mg/dl in 80%), CSF/serum albumin quotients (Q(Alb), ≥30 in 80%), and lactate (≥30 mg/dl in 70%), but significantly lower glucose levels (≤40 mg/dl in 67%) than patients without leptomeningeal enhancement. Irrespective of MRI findings, activated lymphocytes and plasma cells were detected in the initial CSF examination in 60% and 47% of patients, and an intrathecal synthesis of IgG, IgA, and IgM in 22%, 29%, and 22%. Patients with clinically active disease had significantly higher CSF cell counts, total protein, Q(Alb), and lactate, but significantly lower glucose levels than patients with stable disease.

CONCLUSION: CSF abnormalities in neurosarcoidosis are most pronounced in patients with diffuse leptomeningeal enhancement on MRI. CSF analyses may thus aid in the distinction of different radiographic and pathologic manifestations of neurosarcoidosis. Furthermore, CSF examinations may allow monitoring disease activity in patients with neurosarcoidosis.