Traumatic Rupture of a Skull Base Dermoid Cyst Mimicking Chronic Meningitis.

Cranial dermoid cysts are rare, embryologic tumors containing fat, hair, and other ectodermal elements. They occur most frequently in the posterior fossa and are typically diagnosed as incidental findings on brain imaging done for an unrelated reason. Traumatic rupture of a previously unidentified intracranial dermoid cyst can mimic symptoms of post-concussion syndrome and should be ruled out with magnetic resonance imaging (MRI). Surgical intervention after traumatic rupture may not result in complete symptom control due to the persistence of dermoid cyst debris in the subarachnoid space. Here, we present the clinical scenario and radiological features of a ruptured dermoid cyst due to trauma, highlighting a rare complication of a classically benign lesion.

Extended B-cell depletion beyond 6-months in patients receiving ocrelizumab or rituximab for CNS demyelinating disease.

OBJECTIVES: To investigate the duration of B-cell depletion in a cohort of patients receiving ocrelizumab or rituximab for multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSD). METHODS: We retrospectively searched our database for patients diagnosed with MS or NMOSD, who were receiving ocrelizumab or rituximab and had available CD19 measurements. We collected demographic data, infusion doses, infusion dates, CD19 absolute counts and percentages, and their collection dates. We paired each infusion with the subsequent CD19 measurements recorded before the next infusion, discarding measurements done during a washout period of 30 days after each infusion. We applied three definitions for B-cell depletion, the most stringent of which was an absolute B-cell count ≤20 cells/uL. RESULTS: From 695 patients with demyelinating diseases in our database, over the period of January 1st 2010 to March 1st 2020, we identified 188 patients (178 with MS and 10 with NMOSD), who had received ocrelizumab or rituximab and had available CD19 measurements. 1054 CD19 measurements were captured. B-cell depletion, as defined above, was recorded as far out as 22.8 months after an ocrelizumab infusion, and 22.3 months after a rituximab infusion. Out of 90 B-cell measurements done ≥8 months (>210 days) after ocrelizumab infusion, 45(50%) measurements showed B-cell depletion. Similarly for rituximab, out of 113 measurements, 49(43%) showed B-cell depletion. CONCLUSIONS: This study demonstrates that B-cell depletion after ocrelizumab and rituximab continues beyond the traditional 6-month re-infusion interval in many patients. Our report provides data that can support clinical trials testing increasing the interval of re-infusion with ocrelizumab and rituximab beyond 6-months guided by B-cell measurements.