A 62-year-old man presented with a 3-month history of progressive weakness in his limbs, anorexia, and weight loss. He reported smoking cigarettes and experiencing chronic lumbar pain and right leg paresis because of a past stroke. Neurological examination showed right facial droop involving the forehead, absent gag reflex, right VI cranial nerve paresis, paraparesis with hyperreflexia, and bilateral Babinski sign without sensory alteration or a sensory level. A cranial and spinal cord magnetic resonance imaging (MRI) with gadolinium revealed T2-weighted and fluid-attenuated inversion recovery (FLAIR) hyperintensities in the right frontoparietal white matter and centrum semiovale (Figure 1A). Abnormal hyperintensity was also present in the middle third of the corpus callosum, and it extended along the right pyramidal tract to the spinal cord, mainly at cervical and upper dorsal level (Figure 1B and Figure 2). Mild contrast enhancements were present in cranial and spinal cord lesions. A right pulmonary hilum tumor, paratracheal and precarinal mediastinal adenopathy, and several costal and pleural metastases were also identified by MRI. The biopsy results were compatible with small cell lung cancer. Examination of the cerebrospinal fluid (CSF) revealed elevated protein content of 0.13 g/dL (to convert to grams per liter, multiply by 10.0), mild pleocytosis (15 leukocytes/mm³, of which most were lymphocytes), and a normal glucose level. Glutamic acid decarboxylase 65 (GAD65) antibodies were detected in serum (1342 U/mL) and CSF (28 870 U/mL). The remaining onconeuronal antibodies (anti-Hu, anti-Yo, anti-Ri, anti-CV2, antibodies against paraneoplastic antigen Ma2 [anti-Ma2, also known as anti-Ta], amphiphysin, recoverin, Sry-like high mobility group box [anti-SOX1], titin, anti-Zic4, anti-Tr [target of Delta/notch-like epidermal growth factor-related receptor (DNER)]) were not present. An extensive CSF workup, including cytological testing and testing for oligoclonal IgG bands and anti–neuromyelitis optica antibodies, had negative results. The patient was diagnosed with definite paraneoplastic neurological syndrome based on the presence of paraneoplastic encephalomyelitis (PEM) and small cell lung cancer along with serum and CSF GAD65 antibodies. He received a 1-g bolus of methylprednisolone daily for 5 days, with partial neurological improvement. Because of the advanced stage of his neoplasia, 2 cycles of carboplatin-etoposide were performed as palliative chemotherapy. He died 4 months after diagnosis.

一名62岁的男子出现了3个月的四肢进行性无力，厌食和体重减轻的病史。他报告吸烟，由于过去的中风而经历了慢性腰痛和右腿轻瘫。神经系统检查显示右面部下垂累及前额，无前额反射，右VI颅神经轻瘫，轻瘫伴反射亢进，双侧Babinski体征无感觉改变或感觉水平。用g进行的颅和脊髓磁共振成像（MRI）显示，右额顶叶白质和中心半卵中存在T2加权和液衰减倒置恢复（FLAIR）高强度（图1A）。call体中部也出现了异常的高信号，并沿右锥体束延伸至脊髓，主要在颈背和上背水平（图1B和图2）。颅骨和脊髓病变中存在轻微的对比增强。MRI还确定了右肺门肿瘤，气管旁和前纵隔纵隔腺病，以及一些肋和胸膜转移灶。活检结果与小细胞肺癌相容。对脑脊液（CSF）的检查显示蛋白质含量增加了0.13 g / dL（转换为每升克，乘以10.0），轻度胞吞（15白细胞/ mm）活检结果与小细胞肺癌相容。对脑脊液（CSF）进行检查后发现蛋白质含量增加了0.13 g / dL（换算为每升克，乘以10.0），轻度的胞吞作用（15个白细胞/毫米）活检结果与小细胞肺癌相容。对脑脊液（CSF）进行检查后发现蛋白质含量增加了0.13 g / dL（换算为每升克，乘以10.0），轻度的胞吞作用（15个白细胞/毫米）³，其中大部分是淋巴细胞）和正常的葡萄糖水平。在血清（1342 U / mL）和CSF（28870 U / mL）中检测到了谷氨酸脱羧酶65（GAD65）抗体。其余的脑膜上抗体（抗Hu，抗Yo，抗Ri，抗CV2，抗副肿瘤抗原Ma2的抗体[anti-Ma2，也称为anti-Ta]，两性蛋白，recoverin，Sry样高迁移率族盒[anti-SOX1]，titin，anti-Zic4，anti-Tr [Delta /缺口样表皮生长因子相关受体（DNER）的靶标]不存在。广泛的脑脊液检查，包括细胞学检查和寡克隆IgG带及抗视神经脊髓炎抗体的检测，均产生阴性结果。基于副肿瘤性脑脊髓炎（PEM）和小细胞肺癌以及血清和CSF GAD65抗体的存在，该患者被诊断为明确的副肿瘤性神经综合症。他每天服用1克甲基强的松龙，持续5天，部分神经功能得到改善。由于他的瘤形成晚期，进行了2个周期的卡铂-依托泊苷作为姑息化疗。他在诊断后四个月死亡。