Spinal root and plexus hypertrophy in chronic inflammatory demyelinating polyneuropathy

TLDR

MRI of spinal roots, brachial, and lumbar plexuses was performed on 14 patients with chronic inflammatory demyelinating polyneuropathy. Hypertrophy of cervical roots and brachial plexus was observed in eight patients (six also had lumbar plexus hypertrophy), gadolinium enhancement appeared in most hypertrophic cases, all hypertrophic patients had a relapsing–remitting course and longer disease duration, and biopsy of one brachial plexus nerve revealed onion‑bulb formations.

Abstract

MRI was performed on the spinal roots, brachial and lumbar plexuses of 14 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Hypertrophy of cervical roots and brachial plexus was demonstrated in eight cases, six of whom also had hypertrophy of the lumbar plexus. Of 11 patients who received gadolinium, five of six cases with hypertrophy and one of five without hypertrophy demonstrated enhancement. All patients with hypertrophy had a relapsing–remitting course and a significantly longer disease duration. Gross onion-bulb formations were seen in a biopsy of nerve from the brachial plexus in one case with clinically evident nodular hypertrophy. We conclude that spinal root and plexus hypertrophy may be seen on MRI, particularly in cases of CIDP of long duration, and gadolinium enhancement may be present in active disease.