[Chronic inflammatory demyelinating polyradiculoneuropathy associated with multifocal nerve hypertrophy--report of a case with MRI study].

We reported a 29-year-old woman who had chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with multifocal nerve hypertrophy. She developed chronic progressive muscular weakness of distal part of her extremities and sensory ataxia of limbs and trunk for five years. Steroid therapy improved most of her signs and symptoms. No recurrence has occurred for the subsequent four years until present time. Magnetic resonance imaging (MRI) revealed multifocal and nodular hypertrophy of her peripheral nerves in the extremities. MRI also detected the hypertrophy of posterior nerve ganglia and extradural nerve roots. Hypertrophic nerve trunk comprised of multifocal and nodular hypertrophy of the nerve fiber fascicles which were detected as abnormal high signal intensity area in MR T2-weighted images. Her sural nerve contained no onion-bulb formations and presented normal low signal in MR T2-weighted images. We concluded that the hypertrophic changes occurred multifocally in and among nerve fascicles predominantly at the proximal part of the nerves of the extremities. MRI is useful method to detect the hypertrophic change of peripheral nerves deep in the trunk and the extremities in CIDP.