Clinical data
Ten patients were diagnosed with anti-LGI1 encephalitis at Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (HUST) between January 2013 and July 2019. These included one patient with ovarian teratoma and nine without. Among the nine cases without teratoma, the average age at onset was 47.3±15.6 years, and the sex ratio was 1:2 female:male.
Clinical data were abstracted from patient records, including acuity of onset, symptoms at onset and during disease course (e.g. seizures, cognitive dysfunction, psychiatric symptoms and sleep disorders), presence of comorbid tumor, serum sodium levels, CSF results, MRI, EEG, neuropsychological assessment ((Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Barthel Index (BI)), response to therapy and clinical course.
For neuropsychological assessment, we used the following evaluation scales: 1) MMSE: cognitive impairment was determined when the score was under 26; 2) MoCA: cognitive impairment was considered if the score was under 24; 3) HAMA and HAMD: anxiety or depression was considered while the score was equal or over 7 and further divided to: mild (7-14), moderate (14-21) and severe (>21); 4) BI: we define the patients with daily dysfunction while the score was under 80.
All assessments was conducted by two experienced neuropsychologists and the results showed later was the average results.
For the CSF results, we defined normal as cell count < 8 cells/mL, protein level ≤0.30g/L. For onset, we defined acute within 2 weeks, sub-acute as 2 weeks to 2 months and chronic as > 2 months for the time from onset to peak.
Neuroimaging scanning protocol
All MRI sequences were performed on the 3.0-T MR scanner (Discovery MR750, GE Healthcare, Milwaukee, Wisconsin) with a 32-channel phased-array head coil. All subjects underwent a standard structural brain scan, including axial T1 FLAIR (TR/TE/TI 2991/24/868ms, matrix size 320×320, FOV 24×24cm2, slice thickness 5mm, gap 1.5mm), T2-weighted FSE (TR/TE 4579/102ms, matrix size 320×224, FOV 24×24cm2, echo train length 20, slice thickness 5mm, gap 1.5mm), T2-FLAIR (TR/TE/TI 8000/160/2100ms, matrix size 256×256, FOV 24×24cm2, slice thickness 5mm, gap 1.5mm), diffusion-weighted imaging (DWI), and a contrast-enhanced T1-weighted spin echo sequence in axial, sagittal and coronal planes following a bolus injection of 0.2 mmol/kg of Gd-DTPA. Some patients also underwent arterial spin labeling (ASL) using a pseudocontinuous labeling (pCASL) with a high level background suppression (TR/TE 4788/14.7ms, post label delay (PLD) 1525ms, slice thickness 4mm, NEX=3, time duration 4min38s).