Narcolepsy type 1 (NT1) results from probable autoimmune disruption of hypothalamic hypocretinergic neurons. Secondary narcolepsy can occur as a result of other conditions affecting the central nervous system, including limbic paraneoplastic encephalitis (PE). We report the case of a 19-year-old patient presenting with acute-onset diurnal hypersomnolence, hyperphagia, sexual dysfunction and psychiatric disturbances. Further investigations revealed a limbic PE associated with mediastinal thymic seminoma. Tumour removal and immunosuppressive treatment resulted in a partial benefit on psychiatric disturbances but did not improve daytime sleepiness. A comprehensive sleep assessment led to the diagnosis of secondary NT1 with reduced CSF hypocretin-1 levels and revealed the presence of the HLA DQB1*0602 allele, typically associated with idiopathic narcolepsy, for which we hypothesize a possible immunopathogenic role. Sodium oxybate was successfully administered. Narcolepsy is often overlooked in patients with limbic PE. A prompt assessment and an adequate symptomatic treatment can improve the disease burden.

1 型发作性睡病 (NT1) 可能是由于下丘脑低促肾上腺素能神经元的自身免疫性破坏所致。继发性发作性睡病可能是由影响中枢神经系统的其他疾病引起的，包括边缘副肿瘤性脑炎 (PE)。我们报告了一名 19 岁患者的病例，该患者表现为急性发作的昼间嗜睡、食欲亢进、性功能障碍和精神障碍。进一步的研究显示边缘PE与纵隔胸腺精原细胞瘤相关。肿瘤切除和免疫抑制治疗对精神障碍产生了部分益处，但并没有改善白天的嗜睡。全面的睡眠评估导致继发性 NT1 的诊断，伴有脑脊液下丘脑分泌素 1 水平降低，并揭示了 HLA DQB1 * 0602 等位基因的存在，该等位基因通常与特发性发作性睡病相关，我们假设其可能具有免疫致病作用。成功施用羟丁酸钠。边缘系统 PE 患者的发作性睡病常常被忽视。及时评估和充分的对症治疗可以减轻疾病负担。