EEG characteristics of anti ⁃ leucine ⁃ rich glioma ⁃ inactivated 1 antibody ⁃ associated encephalitis

Abstract

Objective To summarize the clinical and EEG characteristics of anti ⁃ leucine ⁃ rich glioma⁃inactivated 1 (LGI1) antibody⁃associated encephalitis. Methods and Results The clinical data and EEG characteristics of 27 patients diagnosed with anti⁃LGI1 antibody⁃associated encephalitis in Beijing Tiantan Hospital, Capital Medical University from April 2014 to May 2019 were retrospectively analyzed. 1) Clinical features: the main manifestations were memory loss [70.47% (20/27)] and mental abnormality [51.60% (14/27)]. 2) Laboratory examination: serum anti⁃LGI1 antibody was positive in all patients, 92.59% (25/27) cerebrospinal fluid anti ⁃ LGI1 antibody was positive, some patients were accompanied by hyponatremia [66.67% (18/27)], elevated tumor markers [33.33% (9/27)], and cytomegalovirus IgG was positive [36.36% (8/22)]. 3) Imaging features: head FLAIR showed hyperintensity in 51.85% (14/27) mainly accumulated temporal lobe and hippocampus, and 18F⁃FDG PET showed high metabolism in 14/17 mainly accumulated temporal lobe, hippocampus and basal ganglia. 4) EEG characteristics: there were 19 cases (70.37%) of EEG abnormalities, including 10 cases of faciobrachial dystonic seizures (FBDS) alone, 4 cases of focal onset with disturbance of consciousness, 3 cases of FBDS with focal onset and disturbance of consciousness, one case of FBDS with focal onset, one case of focal onset alone. Abnormal waves occurred in 15 cases (55.56%), including focal slow wave activity in 9 cases, diffuse slow wave activity in 3 cases, focal radiating sharp wave activity with slow wave activity in 2 cases, focal fast activity with slow wave activity in one case. Abnormal electrical activity occurred in 8 cases (29.63%) within 10 s after the onset of the movement, including 4 cases in the frontal and anterior mesotemporal region, 2 cases in the parietal, occipital and posterior temporal region, one case in the central region, and one case in a wide range of low voltage. Epileptiform discharge was observed in 8 cases (29.63%), including 6 cases in the frontal and anterior mesotemporal regions, 2 cases in the parietal, occipital and posterior temporal regions. In 9 cases (33.33%), the origin of seizures could be determined, including 5 cases in the anterior mesotemporal region, 2 cases in the central and parietal regions, and 2 cases in the parietal, occipital and posterior temporal regions. Conclusions The abnormal rate of EEG in anti⁃LGI1 antibody⁃associated encephalitis was high, and the background changes were mostly slow background and low amplitude. There were mainly scattered sharp waves and slow waves in the interattack period, which was consistent with the EEG characteristics of marginal lobe encephalitis. Epileptiform discharges were predominate in frontal and temporal lobes during seizures and clinical periods.

DOI: 10.3969/j.issn.1672⁃6731.2023.12.012