| Abstract [eng] |
Introduction. Seronegative autoimmune encephalitis is an immune-mediated brain inflammation in which the patient presents with typical clinical features of autoimmune encephalitis, but disease-specific autoantibodies are not detected. As a result, diagnosis and treatment of the condition become more challenging. This paper presents two such clinical cases. Aim. To evaluate how patients with autoimmune encephalitis and no detectable autoantibodies are diagnosed and treated according to the latest diagnostic criteria. The objectives of the study were to describe the clinical symptoms, assess diagnostic test findings, and analyze treatment outcomes. Methods. A retrospective analysis was performed on two treated patients – a 20-year-old woman and an 80-year-old man – diagnosed with seronegative autoimmune encephalitis. Patients were selected based on the criteria for probable autoimmune encephalitis proposed by Graus et al. (2016). Data were collected from medical records. Evaluated parameters included symptom onset and progression, psychiatric and neurological symptoms, magnetic resonance imaging and electroencephalography findings, cerebrospinal fluid test results, autoantibody and oncological screening findings, treatment methods used, and outcomes. Results. In the case of the 20-year-old woman, the disease began with psychiatric symptoms (anorexia, depression, psychosis), followed by epileptic seizures. Brain magnetic resonance imaging revealed signs of limbic encephalitis (hippocampal edema), and electroencephalography showed encephalitis-specific ,,delta brush” activity; no autoantibodies were found. Based on the clinical presentation, seronegative encephalitis was diagnosed. High-dose methylprednisolone therapy and plasmapheresis were administered; after disease exacerbation, three courses of rituximab were given. The patient's condition gradually improved, eventually reaching full remission. The 80-year-old man experienced short epileptic seizures, progressive memory impairment, and depressive thoughts. Tests revealed signs of autoimmune encephalitis in the temporal lobes (magnetic resonance imaging changes, slowed EEG activity with sharp waves); no autoantibodies were detected. Seronegative autoimmune encephalitis was diagnosed, and treatment was initiated with high-dose corticosteroids, followed by maintenance therapy with azathioprine. Gradual improvement was observed during treatment: short „blackout” episodes resolved, cognitive function returned to the pre-illness level, and remission was achieved. Conclusions. Seronegative autoimmune encephalitis can occur in patients of various ages with different clinical manifestations. Despite negative autoantibody findings, early diagnosis based on clinical presentation and prompt immunotherapy can lead to favorable outcomes – long-term remission and functional recovery. To improve the diagnosis and treatment of these cases, physician vigilance in atypical disease courses and further research into new immunological markers are essential. |
