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

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.

Neurophysiology of Guillain-Barré syndrome in children

Our aim was to evaluate sensitivity and specificity of conduction studies parameters for prognosis and differential diag nosis in children with acute motor axonal neuropathy (AMAN) & acute inflammatory demyelinating polyneuropathy (AIDP). Methods. 40 children were included: 20 healthy controls (7-14 years) and 20 patients (8-15 years) with AIDP or AMAN. All underwent conduction studies on 3-7 day since the clinical symptoms onset. We registered and evaluated motor conduction velocity, compound muscle action potential (CMAP) amplitude of nn. tibialis, peroneus, medianus, ulnaris; sensory conduction velocity & sensory nerve action potential (SNAP) amplitude for nn. medianus, suralis, peroneus superficialis, ulnaris, H-reflex threshold & latency, reactivity of neural conductivity (RNC) in short-term hand ischemia in acute phase (3-14 day since the disease onset) and in early recovery period (15-30 day since the symptoms onset). ROC-analysis was performed. Results. In 95% of the patients with Guillain-Barré syndrome H-reflex was absent. In first 10 days SNAP amplitude of median nerve >8.9 µV, peroneal nerve >3.6 µV, CMAP of peroneal nerve ≤0,4 µV with normal motor conduction velocity indicates AMAN presence. Motor axons of peripheral nerves in children in acute and recovery phase of AIDP are resistant towards ischemia. Prognostic criteria for long period of walk recovery (more than 30 days) in these patients are RNC on 10th minute of local ischemia ≤2.5%, ulnar nerve CMAP amplitude ≤1,1 mV and distal CMAP amplitude from median nerve ≤1.6 mV. Conclusions. Conduction studies may be implemented on all phases of Guillain-Barré syndrome in children for prognosis and differential diagnosis between its axonal and demyelinating forms. H-reflex absence in children in the first 5 days of acute polyneuropathy may serve as additional diagnostic criteria for Guillain-Barré syndrome. RNC parameters may be implemented for the prognosis of the walk period recovery duration.