Comparison of ultrasound findings in Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy for differential diagnosis

Background: Peripheral nerve ultrasound(US) has been used as a promising diagnosing technique for peripheral nerve disorders. This study aimed to compare the US findings of Guillain-Barre syndrome (GBS) with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: This case-control study was done on 25 patients with GBS at 3 weeks after onset of disease and 25 patients with CIDP. Demographic information and US results of median nerve at 2 points, ulnar nerve at 3 points, and tibial and peroneal nerves were collected. Results: Left median nerve diameter in patients with CIDP with the mean of 0.141 ± 0.047 was more than GBS group with the mean of 0.095 ± 0.034 (P 0.001). Both sides of median nerve diameter in patients with CIDP were higher than patients with GBS (P 0.05), but in the left side, it was more in patients with CIDP (P = 0.003). Conclusion: The diameter and circumference of median, ulnar, and tibial nerves in forearm and elbow of patients with CIDP are more than patients with GBS; therefore, it may be possible to use US findings based on these differences in diagnosis and differentiation of the two diseases.