Proximal neuropathies in patients with poststroke shoulder pain

Background Poststroke shoulder pain (PSSP) could be due to proximal neuropathy or upper trunk brachial plexus lesion. Aim The aim was to detect any electrophysiological abnormality in the proximal nerves supplying shoulder structures that could contribute to PSSP. Settings and design Cross-sectional study at institution: a university hospital, tertiary level of clinical care. Materials and methods Nerve conduction studies of the axillary, musculocutaneous, suprascapular, and lateral antebrachial nerves were done on both sides. In addition, electromyography of the deltoid, biceps brachii and infraspinatus on the hemiplegic side was performed on 30 stroke survivors with PSSP. Statistical analysis used Statistical Package for the Social Sciences (SPSS ver.20). Description and analysis of the obtained data were done using appropriate tests. Results Axillary and musculocutaneous motor nerve latencies on the hemiplegic side were significantly prolonged compared with the normal side (P=0.012, 0.029, respectively). Moreover, axillary and suprascapular nerve amplitudes on the hemiplegic side were significantly lower than those on the normal side (P=0.008, 0.002, respectively). Twelve (40%) patients had electrophysiological abnormalities. Upper trunk brachial plexopathy was the most common abnormality which occurred in six (20%) patients. In addition, isolated axillary or suprascapular nerve lesion occurred at a similar frequency (10%). Conclusion Proximal nerve lesions are not uncommon in PSSP patients