Misdiagnosis causes of Lambert-Eaton myasthenic syndrome and literature review
ZHAO Ning
LI Wenju
YANG Changbao
LIU Jie
JIAO Jie
YIN Jianyuan
LIU Yang
ZHAO Jianhui
Abstract：Objective To investigate the clinical characteristics and causes of misdiagnosis of Lambert-Eaton myasthenic syndrome(LEMS).Methods A retrospective analysis was performed on the clinical data of a LEMS patient misdiagnosed with motor neuron disease(MND)in 2024.Results The male patient presented with bilateral lower limb weakness for over 4 years without obvious cause.An ultrasound of the lower limb arteries at another hospital revealed occlusion of the right femoral artery,leading to vascular bypass grafting.Postoperatively,the bilateral lower limb weakness gradually worsened.After admission,magnetic resonance imaging(MRI)and neuroelectrophysiological examinations suggested a possible diagnosis of MND.Further investigations,including repetitive nerve stimulation(RNS)and tumor marker tests,confirmed the diagnosis of small cell lung cancer and LEMS.The misdiagnosis lasted over 4 years.The patient received no further treatment after the diagnosis.Conclusion LEMS is rare in clinical practice and prone to misdiagnosis.Clinicians should enhance their understanding of the epidemiological and electrophysiological features of the disease.For suspected patients,RNS should be promptly conducted to minimize or avoid misdiagnosis.
Keywords：Lambert-Eaton myasthenic syndromemisdiagnosismotor neuron diseaseelectromyographyrepetitive nerve stimulationelectrophysiology
Publication Date：2026-02-28
Online Publishing Date：2026-03-17(First online date of this platform, not the publication date of the document)
Pages：7( 1-7 )