Acute axonal neuropathy subtype of Guillain Barré syndrome in a French pediatric series: Adequate follow-up may require repetitive electrophysiological studies

Different subtypes of Guillain Barré Syndromes (GBSs) are defined by their electrophysiological characteristics, acute inflammatory demyelinating neuropathy (AIDP), and acute motor/motor-sensory axonal forms (AMAN/AMSAN) with either reversible nerve conduction failure (RCF) or axonal degeneration. Our aim was to describe initial clinical and electrophysiological characteristics of axonal forms of GBS in a pediatric population and their short- and long-term evolution. Electroneuromyogram (ENMG) results were collected at diagnosis and at two months of evolution and interpreted using the recently proposed pattern of RCF vs axonal degeneration. Clinical evaluation was standardized using the GBS disability scale ("GBSds") at diagnosis, and then at 3, 6, and 12 months of evolution. Outcome was compared to those of patients with AIDP diagnosed within the same period. Eleven patients were included, among whom eight patients presenting with AMAN and three with AMSAN. Two subgroups were identified according to severity. Three patients had a severe form (GBSds ≥2 at 12 months), two of them presenting an axonal degeneration on ENMG studies. Seven patients had a less severe form (GBSds ≤1 at 12 months), five of them with RCF on ENMG studies. Axonal forms had a more severe evolution than demyelinating forms (n = 17) at 3 months (median GBSds 3 and 2, respectively), 6 months (2 and 0), and 12 months (1 and 0), (p < 0,05). Axonal forms of GBS in children have a more severe global outcome than demyelinating forms. Axonal degeneration in two successive early ENMGs may be a prognostic factor of poor outcome.