Chronic inflammatory demyelinating polyneuropathy with hypertrophic nerves.

Aim to describe the distinctive features of chronic inflammatory demyelinating polyneuropathy (CIDP) with giant nerves. Methods Case report with images and video. Results we present a case of CIDP with hypertrophic nerves and compare it to previous reports. The main clinical findings were insidious onset, gait ataxia and sensory symptoms. Electrodiagnostic studies showed very slow nerve conduction velocities, multiple conduction blocks, distal CMAP duration increase and absence of F-waves. The protein level in the cerebrospinal fluid was very high. Nerve ultrasound showed swelling of all peripheral nerves outside entrapment sites, with significant variability within different segments of the same nerve; nerves were massively enlarged (up to 10-fold normal values). Brain MRI showed hypertrophic cranial nerves, with gadolinium-enhancement. Spinal MRI showed hypertrophy of spinal roots and cauda equine, with gadolinium enhancement. Genetic test (PMP22 duplication/deletion, Whole Exome Sequencing panel for neuropathies) resulted negative. The patient had a relapsing-remitting course and responded to immunoglobulin treatment. Conclusions in CIDP with hypertrophic nerves there is discrepancy between severe nerve hypertrophy and mild clinical symptoms. Nerve enlargement seems inversely related to nerve conduction velocity and directly correlated with disease duration, but not associated with disease severity. This article is protected by copyright. All rights reserved.