Department of Neurosciences, California Pacific Medical Center, San Francisco, California, USA.
Muscle Nerve. 2014 May;49(5):764-7. doi: 10.1002/mus.24126. Epub 2014 Apr 8.
All descriptions of the Lambert-Eaton syndrome are based on symptomatic patients. We incidentally encountered electromyographic evidence of this syndrome in a patient being studied for another reason. The patient had controlled hypothyroidism and smoked for 9 pack-years but never had symptoms of weakness or had evidence of cancer.
Detailed electrophysiological and serological evaluations were undertaken in this study.
Neuromuscular transmission tests were consistent with a presynaptic disorder. Autoantibodies specific for P/Q-type voltage-gated calcium channels (VGCC) were detected in the serum and persisted throughout 7 years of follow-up. Multiple IgG markers of thyrogastric autoimmunity also were detected.
This demonstration of asymptomatic Lambert-Eaton syndrome persisting for 8 years provided novel insight into the natural history of the disorder. It is plausible that patients with a subclinical syndrome would have abrupt neuromuscular decompensation when challenged with medications that compromise the safety factor for synaptic transmission.
所有 Lambert-Eaton 综合征的描述都是基于有症状的患者。我们在一位因其他原因接受研究的患者身上偶然发现了这种综合征的肌电图证据。该患者患有控制良好的甲状腺功能减退症，吸烟 9 包/年，但从未出现过无力症状，也没有癌症的证据。
本研究进行了详细的电生理和血清学评估。
神经肌肉传递测试与突触前障碍一致。血清中检测到针对 P/Q 型电压门控钙通道 (VGCC) 的特异性自身抗体，并在 7 年的随访中持续存在。还检测到多种甲状腺胃自身免疫 IgG 标志物。
本研究中无症状的 Lambert-Eaton 综合征持续 8 年，为该疾病的自然史提供了新的见解。当有药物挑战突触传递的安全系数时，有亚临床综合征的患者可能会突然出现神经肌肉失代偿，这是合理的。
