Objective To explore the clinical and electrophysiological characteristics of patients with subacute combined degeneration of spinal cord (SCD).

Methods The clinical manifestations, laboratory examination results, electrophysiological characteristics, and MRI and follow-up data of 12 SCD patients diagnosed and treated in the Xiamen Branch, Zhongshan Hospital, Fudan University from January 2018 to March 2020 were retrospectively analyzed.

Results Of the 12 patients, 5 had a history of total gastrectomy, 3 had chronic superficial gastritis, 3 had a long-term vegetarian history, 1 had a long-term drinking history; 9 had limb numbness, 12 had unsteady walking, 10 had sensation signs, 12 had Romberg sign, 6 had pathologic reflexes; 9 had megaloblastic anemia, 11 had plasma vitamin B₁₂ deficiency, 1 had folic acid deficiency, 12 had homocysteine increased; 9 had T₂ hyperintensity in the spinal cord and 11 had abnormal electrophysiological manifestation. All patients were treated with vitamin B₁₂ or mecobalamin, and the clinical symptoms were improved after treatment.

Conclusions Vitamin B₁₂ deficiency is the main cause of SCD. For people with a history of gastric disease, long-term drinking, and long-term vegetarian diet, combined blood routine test, vitamin B₁₂, homocysteine, electrophysiological examination, and cervical and thoracic magnetic resonance imaging are helpful to improve the diagnosis rate of SCD. Early diagnosis and early vitamin B₁₂ treatment can help improve SCD symptoms.