Clinical features of limbic encephalitis with LGI1 antibody.

OBJECTIVE: The objective of this study was to analyze the clinical manifestation, course, evolution, image manifestation, and treatments of LGI1 limbic encephalitis (LE).

PATIENTS AND METHODS: Studies confirmed that LE with the complex antibody of voltage-gated potassium channels is LGI1 LE. Since then, LE cases have been reported. In this study, 10 typical LE cases were searched in PubMed. These cases and one additional case, which we reported herein, were retrospectively analyzed.

RESULTS: All the patients suffered from recent memory deterioration. The following cases were observed: eight with faciobrachial dystonic seizures (FBDS), six with different kinds of epileptic seizures (four complex partial seizures, one myoclonus seizure, and one generalized tonic-clonic seizure), four with FBDS and different kinds of epileptic seizures at the same time, five with mental disorders (one visual hallucination, one paranoia, one depression, one anxiety, and one dysphoria), five with hyponatremia, and two with sleep disorder. The brain MRI of nine patients revealed abnormalities in the mediotemporal lobe and the hippocampus. The LGI1 antibodies in the blood and/or cerebrospinal fluid (CSF) were positive. The content of the CSF protein of two patients increased slightly. The tumor marker of all the patients was normal, but capitate myxoma was detected in the combined pancreas duct of one patient. Gamma globulin and hormone treatments were administered to nine patients. Of these patients, six received a combination of antiepileptic drugs. The clinical symptoms of all the patients improved.

CONCLUSION: LGI1 LE is an autoimmune encephalitis whose clinical manifestations are memory deterioration, FBDS, epileptic seizure, mental disorders, and hyponatremia. Brain MRI shows that this autoimmune disease mainly involves the mediotemporal lobe and the hippocampus. This condition can also be manifested with other autoimmune encephalitis cases but can be rarely associated with tumors. After patients with LGI1 LE receive gamma globulin and hormone treatments, their clinical prognosis is good.