S41. Study of electromyography, ultrasound and magnetic resonance imaging in idiopathic brachial plexus

Abstract

Introduction The brachial plexus consist of the fifth to the eighth cervical nerves and the first anterior thoracic anterior branch. The terminal branches of the brachial plexus mainly include the axillary nerve, the radial nerve, the musculocutaneous nerve, the median nerve and the ulnar nerve, dominating the feeling and motor function of the upper limbs. Idiopathic brachial plexus neuritis is a more common brachial plexus neuropathy, but it is easy to misdiagnosis and missed diagnosis in clinic, resulting in irreversible damage to the upper limb function of patients and seriously affecting the life of the patient. Methods The clinical data of 19 patients diagnosed with idiopathic brachial plexus neuropathy in Beijing Tsinghua Changgung Memorial hospital from January 2015 to October 2017 were analyzed retrospectively. All patients underwent rigorous neurological examination. Nicolet EDX electromyography and evoked potentials were used to evaluate the limb nerve conduction of the patients. All patients were performed with brachial and/ or cervical MRI, and shoulder muscle examination by GE 3.0T MR scanner. Brachial plexus sonography was performed on patients with Philips iU22 Color Doppler Ultrasound. Some patients had a lumbar puncture cerebrospinal fluid examination. Most patients undergo standardized rehabilitation. Results Of the 19 patients, 14 were males and 5 were females, with duration of 2 weeks to 9 months, ranging in age from 25 years to 83 years. All patients have shoulder pain, and gradually muscle weakness, muscle atrophy. Eleven patients had uncomfortable symptom in the left upper extremity and 8 in the right.EMG results suggested that 17 patients had injury in the upper and middle stem of the brachial plexus, lower stem injury in 1 case. One patient had clinical symptoms with normal EMG analysis, but the lateral cord of brachial plexus was abnormal in the ultrasound examinations. Vulnerable nerves followed by axillary nerve in 14 cases, 13 cases of musculocutaneous nerve, suprascapular nerve in 13 cases, 3 cases of radial nerve, median nerve in 1 case, ulnar nerve in 1 case. High-frequency ultrasound results showed abnormality in 17 cases, with thickening of the edema of the nerves or significant edema with changes of the hourglass. A total of 18 cases were performed MRI examination, of which 12 cases were abnormal, no abnormalities in 6 cases (6/18). The direct signs of MRI examination included the performance of nerve thickening, increased signal. The indirect signs included visible atrophy and diffuse T2 high signal in supraspinatus, subocular muscles and deltoid muscle. Conclusion Electromyography combined with ultrasound and magnetic resonance imaging can evaluate the function and morphology of brachial plexus, and greatly improve the diagnosis rate of idiopathic brachial plexus neuritis.