Impact of Shoulder Subluxation on Peripheral Nerve Conduction and Function of Hemiplegic Upper Extremity in Stroke Patients: A Retrospective, Matched-Pair Study

Abstract Background: After stroke, the peripheral nerves of the hemiplegic upper extremity (HUE) could exist impairments which seriously delay the function recovery of the HUE. However, the impacts of shoulder subluxation (SS) on the HUE electromyography characteristics in post-stroke are rarely reported. Therefore, this study was to investigate the impact of SS on peripheral nerve conduction and function of the HUE in post-stroke patients.Methods: A retrospective, matched-pair study was conducted. 30 post-stroke in-patients (15 patients for each group) were selected and their peripheral nerves of bilateral upper limbs were used to be underdone by the electroneurographic examination. The characteristics of patients, such as age and type of stroke, were recorded and paired. The electroneurographic parameters of upper limb motor/sensory nerves contained: the compound muscle action potential (CMAP) amplitude and latency of suprascapular, axillary, musculocutaneous, radial, median and ulnar nerves; the motor conduction velocity/ the sensory nerve action potential (SNAP) amplitude and latency of median, ulnar and radial nerves. The Brunnstrom stage scale was used to evaluate the motor function of the HUE.Results: The CMAP amplitude of each nerve in the HUE of both groups was lower than that in the healthy side (P < 0.05). CMAP amplitude of peripheral nerves (except ulnar) in the HUE of SS group was decreased (P < 0.05). The CMAP latency of the suprascapular, axillary and musculocutaneous nerves was longer than that of the healthy side in the SS group (P < 0.05). The axillary nerve CMAP latency in the SS group was prolonged more (P < 0.05). The motor conduction velocity of the median nerve on the HUE in the SS group was lower than that of the HUE in the N-SS group (P < 0.05). The SNAP amplitudes of the nerves in the HUE in both groups were lower than those in the healthy side (P < 0.05). The Brunnstrom stage of HUE in the SS group was lower (P < 0.05).Conclusions: Stroke may lead to extensive damage of the HUE nerves, and SS may aggravate the damage of these nerves, delaying the recovery of upper limb function.