Department of Neurology, the First Medical Centre, Chinese PLA General Hospital, Beijing, China.
BMC Neurol. 2022 Mar 19;22(1):106. doi: 10.1186/s12883-022-02625-1.
Lambert-Eaton myasthenic syndrome (LEMS) is a type of paraneoplastic syndrome that may initially manifest itself with proximal weakness and gait abnormalities. Approximately up to 50% of LEMS patients have a primary autonomic dysfunction.
We present here a case of a 75-year-old male with symmetric proximal muscle weakness, dry mouth and constipation. The cutaneous response to scratch and upright tilt-table testing were positive. A repetitive nerve stimulation test showed that there was a decremental response of compound muscle action potential (CMAP) amplitude at 3 Hz while an incremental response at 20 Hz. The presence of antibodies against voltage-gated calcium channels (VGCC) confirmed the diagnosis. Because of the prominent symptom of autonomic disorder, the patient further underwent the test of skin sympathetic response (SSR). Lower amplitude and longer response duration were found in palms, while it evoked no response in soles.
In this case, we present the detailed results of SSR test on a patient suffering LEMS with autonomic disorder. Since autonomic dysfunction has a significant impact on clinical management and SSR test is an effective detection method, we recommend that SSR test be performed on patients with LEMS regularly.
Lambert-Eaton 肌无力综合征（LEMS）是一种副肿瘤综合征，最初可能表现为近端肌无力和步态异常。约有 50%的 LEMS 患者存在原发性自主神经功能障碍。
我们在此介绍一例 75 岁男性，表现为对称性近端肌无力、口干和便秘。划痕和直立倾斜试验的皮肤反应阳性。重复神经刺激试验显示，3Hz 时复合肌肉动作电位（CMAP）幅度的递减反应，而 20Hz 时的递增反应。电压门控钙通道（VGCC）抗体的存在证实了诊断。由于自主神经紊乱的突出症状，患者进一步进行了皮肤交感反应（SSR）测试。手掌处发现振幅较低和反应持续时间较长，而足底则无反应。
在本例中，我们详细介绍了自主神经紊乱的 LEMS 患者 SSR 测试的结果。由于自主神经功能障碍对临床管理有重大影响，且 SSR 测试是一种有效的检测方法，我们建议对 LEMS 患者定期进行 SSR 测试。
