When do you start cyclophosphamide for the treatment of anti-NMDA receptor encephalitis?  

First-line immunotherapy for anti-NMDA receptor encephalitis includes high-dose steroids, intravenous immunoglobulin (IVIg), and plasma exchange (PLEX), sequentially or concurrently. Second-line immunotherapy includes a trial of rituximab first and then cyclophosphamide due to the serious side effec...

Cyclophosphamide has fallen a bit out of favor with the increased use of B-cell depleting therapy and the emergence of anti-IL6 monoclonal antibody treatment, as well as its side effect profile. It is still used for refractory cases, but there should be confirmation that there is ongoing neuroinflam...