Spinal root and plexus hypertrophy in chronic inflammatory demyelinating polyneuropathy

MRI was performed on the spinal roots, brachial and lumbar plexuses of 14 p atients with chronic inflammatory demyelinating polyneuropathy (CIDP), Hype rtrophy of cervical roots and brachial plexus was demonstrated in eight cas es, six of whom also had hypertrophy of the lumbar plexus. Of 11 patients w ho received gadolinium, Eve of six cases with hypertrophy and one of five w ithout hypertrophy demonstrated enhancement. All patients with hypertrophy had a relapsing-remitting course and a significantly longer disease duratio n. Gross onion-bulb formations were seen in a biopsy of nerve from the brac hial plexus in one case with clinically evident nodular hypertrophy, We con clude that spinal root and plexus hypertrophy may be seen on MRI, particula rly in cases of CIDP of long duration, and gadolinium enhancement may be pr esent in active disease.