044 Dramatic delayed recovery following severe anti-NMDAR encephalitis

Introduction Long term outcomes in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis are reported to be favourable in 80% of cases, but there is little information regarding recovery following prolonged severe neurological disability. Case 1 A 16-year-old female presented with headache, fever and acute encephalopathy. Anti-NMDAR antibodies were positive, with an ovarian teratoma. Treatment included oophorectomy, plasmapheresis, corticosteroids, cyclophosphamide, intravenous and intrathecal rituximab, and alemtuzumab. After 15 months hospitalisation, she remained in a vegetative state, with tracheostomy and percutaneous gastrostomy tubes, on multiple anticonvulsants. She received no further immunotherapy. MRI brain 2 years after illness onset demonstrated severe generalised cerebral atrophy. Three years after onset, she began to improve. At 5+ years she was seizure-free without anticonvulsants, fully independent and ambulatory, without overt cognitive deficits or personality change. MRI brain at 5 1/2 years demonstrated recovery of cerebral volume to within normal limits, but residual hippocampal atrophy. Case 2 A 21-year-old female presented with headache, fever and personality change. NMDAR-antibodies were positive. A malignant ovarian teratoma was treated with salpingoophorectomy and chemotherapy (bleomycin/etoposide/cyclophosphamide). She received plasmapheresis, immunoglobulins, corticosteroids, intravenous and intrathecal rituximab, and bortezomib. She was finally discharged after 21 months hospitalisation with tracheostomy and gastrostomy tubes, severe behavioural disturbance, minimal functional limb movement, and fully dependent care needs. Clinical recovery began 2 1/2 years after disease onset, and at 4 years she is fully independent with residual cognitive deficits, engaging in volunteer work. Conclusions These cases highlight the potential for dramatic delayed clinical improvement despite prolonged severe neurological disability in anti-NMDAR encephalitis.