AUTHOR=Feng Xuedan , Zhang Yujing , Gao Yu , Zhang Jing , Yu Shasha , Lv Jing , Zu Yu , Wang Lin , Wang Xiangbo 

TITLE=Clinical characteristics and prognosis of anti-γ-aminobutyric acid-B receptor encephalitis: A single-center, longitudinal study in China

JOURNAL=Frontiers in Neurology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.949843

DOI=10.3389/fneur.2022.949843

ISSN=1664-2295

ABSTRACT=<sec><title>Objective</title><p>Anti-γ-aminobutyric acid-B receptor (GABA<sub>B</sub>R) encephalitis is a rare type of autoimmune encephalitis. There are only a few, small, published studies regarding prognosis, so prediction of prognosis is of limited accuracy. We identified 37 cases of anti-GABA<sub>B</sub>R encephalitis in China. Here, we present these patients' clinical characteristics and long-term outcomes.</p></sec><sec><title>Methods</title><p>We collected and retrospectively analyzed the clinical data of 37 patients with anti-GABA<sub>B</sub>R encephalitis from Beijing Fengtai You'anmen Hospital.</p></sec><sec><title>Results</title><p>The study cohort comprised 37 patients of anti-GABA<sub>B</sub>R encephalitis of median age 61 years (range: 11–77), 28 of whom were male. The main clinical manifestations were epilepsy (91.9%, 34/37), psychiatric disorders (94.6%, 35/37) and cognitive impairment (97.3%, 36/37). Tumors were identified in 18 (48.6%) patients. First-line immunotherapy was administered to 34 patients, 31 of whom (90.6%) responded favorably. During a median follow-up of 18 months (range: 1–72 months), 21 patients had good outcomes [Modified Ranking Scale (mRS ≤2)], 16 (43.2%) died (mRS 6), and 7 (18.9%) relapsed. Age (<italic>P</italic> = 0.005), disturbance of consciousness (<italic>P</italic> = 0.018), admission to the Neurology Intensive Care Unit (<italic>P</italic> = 0.003), mechanical ventilation (<italic>P</italic> = 0.009), more numerous clinical manifestations (<italic>P</italic> = 0.008), comorbid malignancy (<italic>P</italic> = 0.008), multiple anti-neuronal antibodies (<italic>P</italic> = 0.029), and hyponatremia (<italic>P</italic> = 0.023) differed significantly between patients with good outcomes (mRS 0–2) and those with poor outcomes (mRS 3–6).</p></sec><sec><title>Conclusion</title><p>Men aged 50–70 years accounted for most of the patients with anti-GABA<sub>B</sub>R encephalitis in our case series. The main clinical manifestations were epilepsy and neuropsychiatric dysfunction. The participants often had concomitant lung cancer, particularly small-cell lung cancer. Patients with lung tumors and/or serious manifestations usually had a poor prognosis with high mortality. Early identification and treatment of tumors improved the poor prognosis to some extent.</p></sec>