Autoimmune encephalitis with LGI1 antibodies: a report of two cases.

Autoimmune encephalitis associated with anti-LGI1 antibodies (ang. leucine-rich glioma- inactivated 1) is one of the most common forms of limbic encephalitis. The aim of this paper was to present two cases of this disease with different clinical course and prognosis. We described the medical history of a 64-year-old man and a 75-year-old woman in whom the presence of anti-LGI1 antibodies in serum and/or cerebrospinal fluid was detected. Both patients had typical facial-brachial dystonic seizures, memory impairment and hyponatremia. In the first case, in the early phase of the disease, MRI showed bilateral changes in the temporal lobes (mainly in the hippocampi), while in the second case, neuroimaging did not show typical changes for autoimmune encephalitis - vascular and atrophic changes dominated. In the first case, combined therapy (steroids and intravenous immunoglobulins) was used and significant improvement was achieved. In the second case, only intravenous immunoglobulins were used. Differential diagnosis of rapidly progressing neurological disorders should include autoimmune encephalitis. One of the forms of this disease is autoimmune encephalitis with the presence of anti-LGI1 antibodies, which should always be suspected in patients with dystonic facial-brachial seizures and memory disorders, especially with concomitant hyponatremia. Determination of antineuronal antibodies should be a standard procedure in such cases. Fast and accurate diagnosis allows for the initiation of effective treatment. Oncological vigilance should also be maintained - in some patients the presence of cancer is detected.