Corneal Confocal Microscopy Identifies Corneal Nerve Loss in Patients With Guillain–Barré Syndrome

ABSTRACT Introduction/Aims Patients with Guillain–Barré syndrome (GBS) commonly present with sensory loss and weakness, but they may also have neuropathic pain, elevated thermal thresholds, and intraepidermal nerve fiber loss. The primary aim of this study was to assess for evidence of small nerve fiber damage in patients with GBS.  Methods Nine patients with GBS and 15 age‐matched healthy controls underwent CCM to quantify corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), and corneal nerve branch density (CNBD), Douleur Neuropathique en 4 (DN4) to assess neuropathic pain, electrochemical skin conductance (ESC), vibration perception threshold (VPT), and nerve conduction studies. Results CNFD ( p  = 0.008), CNFL ( p  = 0.011), CNBD ( p  = 0.005), and ESC on the hands ( p  = 0.024) and the feet ( p  = 0.046) were lower, whereas DN4 ( p  = 0.007) was higher in patients with GBS compared to healthy controls. Discussion Patients with GBS have evidence of small nerve fiber damage as evidenced by corneal nerve fiber loss, neuropathic pain, and sudomotor dysfunction. CCM may add to the toolbox for the evaluation of small nerve fiber involvement in patients with GBS.