RESUMEN
Objective To summarize the clinical,electrophysiological profile and prognosis in paraneoplastic syndrome with SRY-like high-mobility group superfamily of developmental transcription factors (SOX) 1 antibody.Methods The clinical profile,laboratory examination,electrophysiology,tumor,treatment and prognosis of three patients of paraneoplastic syndrome with SOX1 antibody in Tangdu Hospital,Air Force Military Medical University from 2016 to 2018 were retrospectively analyzed.Results Proximal lower limbs weakness was the first symptom in all the three patients,weakness normally spreading proximally to distally,involving feet and hands,finally reaching the oculobulbar region,and dry mouth was the most common autonomic dysfunction.Compound muscle action potential (CMAP) amplitude was low in all the patients,and the CMAP amplitude became even lower at low stimulating frequencies.An increase in CMAP amplitude with high-frequency stimulation was found in two patients during the follow-up.Lambert-Eaton myasthenic syndrome (LEMS) and motor axonal peripheral neuropathy were considered.Acetylcholine receptors antibody was positive in one case and voltage-gated calcium channel antibody was positive in another case.Two cases were found complicated with small cell lung carcinoma,one case with small cell carcinoma of the esophagus.After treatment of intravenous immunoglobulin,chemotherapy and pyridostigmine,the prognosis of the patients was different.Conclusions SOX1 antibody as an antibody in paraneoplastic syndrome,is most common in small cell lung cancer with LEMS,sometimes with axonal peripheral neuropathy.LEMS needs to be considered when patients manifest proximal limb weakness and dry mouth,and screening for tumors is needed.