NMP012 Electrophysiologic features of childhood Guillain Barre syndrome in Iran

Guillain-Barre syndrome (GBS) is classified into acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal polyneuropathy (AMAN), and acute motor sensory axonal polyneuropathy (AMSAN), but little is known about the incidence of the subtypes and electrophysiologic changes in Northwest of Iran. The aim of this study is to present the electrophysiologic pattern and incidence of various subtypes of childhood GBS. Electrophysiologic features of 72 children (aged 1–15 years old) were studied prospectively during two years in Tabriz Children Hospital. Electrodiagnostic tests were performed in the first 2 weeks of the disease onset. Motor nerve conduction study was performed on the tibial, peroneal, median, and ulnar nerves. Sensory nerve conduction study was performed on the median and sural nerves, F-waves were also studied on the tibial, median, and ulnar nerves. Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, distal latencies, nerve conduction velocities and F-wave latencies were measured. In this concern, any conduction block and temporal dispersion were noted. Needle electromyography was performed, motor unit action potential changes, and spontaneous activity were studied. Patients were classified into AIDP, AMAN, and AMSAN on the basis of electrodiagnostic criteria. About half of the patients (47.2%) had AIDP form, 44.4% had AMAN, and 5.6% had AMSAN. Moreover, Fisher variant was observed in 2.8% of the cases. The most common electrophysiologic findings were low amplitude CMAP and abnormal Fwaves, i.e. 97.2% and 88.9% respectively. Twelve patients (16.8%) required assisted ventilation, 75% of them had AMAN form of GBS. AMAN form of childhood GBS is relatively common in Iran in comparison to Western countries. Respiratory failure resulting in mechanical ventilation is more probable in this form.