<p><strong>Background and Objective: </strong>The aim of this study was to report the short-term outcomes of early idiopathic brachial plexus neuritis after low-dose corticosteroid combined with antiviral agent.</p>
<p><strong>Methods:</strong> Five patients with early brachial plexus neuritis presenting from April to June 2019 were included in this study. According to individual patient conditions, electromyography (EMG), nerve B-ultrasound and/or brachial plexus magnetic resonance imaging (MRI) were performed. After the diagnosis was confirmed, modified conservative treatments were initiated, including low-dose corticosteroid therapy and antiviral therapy for 2 weeks each while neurotrophic therapy for 4 weeks.</p>
<p><strong>Results: </strong>Of the five patients, only two patients had symptoms of pain at onset, and three patients had sensory disturbances. Two patients reported a common cold before onset. The lesion involved the upper trunk of the brachial plexus in two patients. MRI showed slightly intense signals, of which one patient also had supraclavicular lymph node augmentation. The other three patients suffered ipsilateral radial nerve (RN) palsy. At 1 month of modified treatment, four patients recovered well with almost complete shoulder and hand movements; however, their muscle strength was still weaker comparing with the contralateral side. One patient restored full range of motion after surgery in 2 months.</p>
<p><strong>Conclusion:</strong> Early treatment is the key to good prognosis in patients with brachial plexus neuritis. Antiviral therapy combined with lowdose corticosteroid therapy may be superior to traditional treatment alone. In terms of early diagnosis, the clinical value of imaging examinations such as ultrasound and MRI is more specific as compared to that of EMG.</p>