Canadian Consensus Guidelines for the Diagnosis and Treatment of Autoimmune Encephalitis in Adults

Abstract

Autoimmune encephalitis is increasingly recognized as a neurologic cause of acute mental status changes with similar prevalence to infectious encephalitis. Despite rising awareness, approaches to diagnosis remain inconsistent and evidence for optimal treatment is limited. The following Canadian guidelines represent a consensus and evidence (where available) based approach to both the diagnosis and treatment of adult patients with autoimmune encephalitis. The guidelines were developed using a modified RAND process and included input from specialists in autoimmune neurology, neuropsychiatry and infectious diseases. These guidelines are targeted at front line clinicians and were created to provide a pragmatic and practical approach to managing such patients in the acute setting.

Autoimmune Encephalitis Following Check Point Inhibitor Therapy in a Patient with Metastatic Melanoma in Complete Remission

“…Second line treatment is based on Rituximab and Cyclophosphamide infusion. Early involvement of a specialist in autoimmune neurology is recommended in patients undergoing consideration for second-line therapy [7].…”

“…Autoimmune encephalitis was suspected as the patients has previously treated with Pembrolizumab and he did not fulfill the criteria for definite or possible paraneoplastic neurological syndrome since no evidence of malignant disease was found with Total Body CT and PET/CT, furthermore the clinical/laboratory findings were coherent with the recently published Canadian consensus guidelines for the diagnosis and treatment of autoimmune encephalitis in adults [7]. The patient was then treated with 2 plasmapheresis sessions, then high doses of steroids (Methylprednisolone 1 g daily iv for 5 days followed by Prednisone 62.5 mg daily by mouth), intravenous immunoglobulins at 0.4 g/kg/day iv for 5 days.…”

Brazilian consensus recommendations on the diagnosis and treatment of autoimmune encephalitis in the adult and pediatric populations

“…This treatment regimen has been ratified by a recent Canadian consensus on AIE. 63 Debate remains over whether other AIE subtypes, especially anti-LGI1, respond to treatment with steroids alone. Nevertheless, in most anti-LGI1 reports, 8,64-66 more than 50% of the patients received additional immunotherapy (mostly IVIG) besides corticosteroids, while other studies suggest IVIG may also be beneficial for this AIE subtype.…”

“…Other reports also support the use of RTX in adults and children. 6,7,24,[27][28][29]62,63,[67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] The third-line options are bortezomib and tocilizumab, and they should be offered to refractory patients. 67,72,73,[78][79][80][82][83][84][85][86][87][88][89][90] Regarding maintenance therapy, the consensus among the panelists was that the existing evidence does not support the use of oral immunosuppressants, such as azathioprine (AZA) or mycophenolate mofetil (MMF), in the treatment of AIE.…”