P284 Early differential diagnostic between axonal and demyelinating form of Guillain-Barré syndrome in children

Abstract

Aim of our work was to determine specificity and sensitivity of conduction studies parameters for differential diagnostics between acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) in children. Methods 38 children were enrolled: 20 controls (7–14 years old) and 18 patients with AMAN or AIDP, later established according to current criteria. All patients undergo conduction studies on 3–7 day from the first symptoms occurrence. Conduction velocity (CV) and distal compound action potential (CMAP) amplitudes were evaluated for nn. Tibialis, Peroneus, Medianus, Ulnaris;CV and amplitude of sensory nerve action potential (SNAP) were registered for nn Medianus, Suralis, Peroneus superficialis et Ulnaris. ROC-analysis was applied for sensitivity and specificity evaluation. Results Significantly lower SNAP amplitude for n.Medianus was registered in AIDP group comparing with controls and AMAN. For AMAN development, SNAP amplitude for n. Medianus >8.9 μ V was a value with very good predictive ability (AUROC > 0.8), SNAP amplitude for n.Peroneus superficialis >3.6 μ B and CMAP amplitude for n.Peroneus ⩽0.4 m A were values with a good predictive ability (AUROC > 0.7). Conclusions Conduction studies parameters on the early stage of Guillain-Barre syndrome in children are specific enough for differential diagnostics between AMAN and AIDP in children. SNAP amplitudes for n.Medianus >8.9 μ V, n.Peroneus superficialis >3.6 μ A and CMAP amplitude for n.Peroneus ⩽0.4 m A and CV along the motor pathways remains within normal values are parameters that may indicate to AMAN diagnosis.