<scp>SCLC</scp> and <scp>anti‐GABABR</scp> encephalitis: A retrospective analysis of 60 cases in <scp>China</scp>

Anti-gamma aminobutyric acid B receptor (anti-GABABR) encephalitis is a rare autoimmune neurological syndrome observed in lung cancer patients. More research on the clinical characteristics of small cell lung cancer (SCLC) and anti-GABABR encephalitis should be carried out to improve diagnosis and treatment.We retrospectively investigated the clinical characteristics, auxiliary examination results, and treatment responses in patients with SCLC and anti-GABABR encephalitis at Beijing Chaoyang Hospital from January 2010 to December 2020. The study also retrospectively analyzed cases of SCLC and anti-GABABR encephalitis well documented in China.A total of 60 cases of SCLC and anti-GABABR encephalitis were analyzed in the study, two in our hospital, and 58 previously reported in the literature. The male:female ratio was 3:1, with a median age at presentation of 61 years (range: 40-81 years). Twenty-eight patients initially presented with seizures, four with cognitive disorder, and three with psychiatric symptoms. The major symptoms were epileptic seizures (n = 56; 96.9%), cognitive impairment (n = 47; 81.0%), psychiatric disorders (n = 45; 77.6%), and conscious disturbance (n = 32; 55.2%). Fifty-five patients underwent immunotherapy, and 23 patients underwent oncologic treatment in the literature. After a median follow-up duration of 8.8 (range, 0.5-37.0) months, nine patients showed good outcomes (modified Rankin Scale score, mRS ≤2), eight patients showed poor prognosis (mRS 2), and 18 patients died.The clinical characteristics of SCLC and anti-GABABR encephalitis are seizures, cognitive impairment, and psychiatric disorders which affect middle-aged to elderly men in China. The long-term prognosis is relatively poor.