O'Suilleabhain P, Low P A, Lennon V A
Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
Neurology. 1998 Jan;50(1):88-93. doi: 10.1212/wnl.50.1.88.
Autonomic dysfunction is a recognized feature of the Lambert-Eaton myasthenic syndrome (LES). However, the characteristic pattern of dysautonomia has not been clearly documented and its pathophysiologic basis is not known. We therefore abstracted autonomic symptomatology and results of quantitative tests for salivation, and vasomotor, cardiovagal, and sudomotor reflexes from records of 30 LES patients. Dry mouth (77%) and impotence (45% of men) were the most common symptoms. Composite Autonomic Scoring Scale results were abnormal in 93% of patients, and autonomic failure was severe in 20%. The frequency of specific test abnormalities were the following: sudomotor function, 83%; cardiovagal reflexes, 75%; salivation, 44%; and adrenergic function, 37%. Although voltage-gated N-type calcium (Ca2+) channels are implicated in autonomic transmission, the low frequency of serum antibodies to N-type Ca2+ channels found in the patients of this study (31% positive) argues against a pathogenic role in mediating LES-related dysautonomia. In contrast, 93% of the patients were seropositive for P/Q-type Ca2+ channel antibodies. A subset of these antibodies is thought to impair neuromuscular transmission. Autoantibodies of thyrogastric or glutamic acid decarboxylase specificity (markers of predisposition to type 1 diabetes mellitus) were found in 45% of patients, and type 1 antineuronal nuclear antibody (or anti-Hu, a marker of autoimmune neuropathy associated with small-cell lung carcinoma) was found in 3%. No autoantibody correlated with autonomic dysfunction severity. Sensorimotor neuropathy was documented in five patients, and was not significantly associated with autonomic neuropathy. Autonomic failure was most severe in older subjects with cancer (p = 0.02, age by cancer interaction).
自主神经功能障碍是兰伯特-伊顿肌无力综合征（LES）的一个公认特征。然而，自主神经功能障碍的特征模式尚未得到明确记录，其病理生理基础也不清楚。因此，我们从30例LES患者的记录中提取了自主神经症状以及唾液分泌、血管运动、心迷走和发汗反射的定量测试结果。口干（77%）和阳痿（男性患者中的45%）是最常见的症状。93%的患者复合自主神经评分量表结果异常，20%的患者存在严重的自主神经功能衰竭。特定测试异常的发生率如下：发汗功能，83%；心迷走反射，75%；唾液分泌，44%；肾上腺素能功能，37%。尽管电压门控N型钙（Ca2+）通道与自主神经传递有关，但本研究患者中血清N型Ca2+通道抗体的低发生率（31%阳性）表明其在介导LES相关自主神经功能障碍中不具有致病作用。相比之下，93%的患者P/Q型Ca2+通道抗体血清学呈阳性。这些抗体中的一部分被认为会损害神经肌肉传递。45%的患者发现了甲状腺胃或谷氨酸脱羧酶特异性自身抗体（1型糖尿病易感性标志物），3%的患者发现了1型抗神经元核抗体（或抗Hu，与小细胞肺癌相关的自身免疫性神经病变标志物）。没有自身抗体与自主神经功能障碍的严重程度相关。5例患者记录到感觉运动性神经病变，且与自主神经病变无显著相关性。自主神经功能衰竭在患有癌症的老年患者中最为严重（p = 0.02，年龄与癌症的交互作用）。
