[Chronic inflammatory demyelinating polyneuropathy in childhood--a case with markedly hypertrophic nerves and pes cavus].

We describe a 9-year-old boy with chronic inflammatory demyelinating polyneuropathy (CIDP), whose distal dominant, slowly progressive motor sensory involvement developed since infancy. Thickened peripheral nerves were visible in his neck and palpable in the extremities. The hand muscles were atrophic and both feet showed pes cavus deformity. He was unable to walk. Nerve conduction study revealed no sensory potentials. Compound muscle potential (CMP) was absent in the legs. In the arms, CMP showed markedly low amplitude and temporal dispersion. Motor conduction velocities were 1.7 to 2.7 m/sec, showing extremely high threshold to electrical stimuli. Conduction block was not convincing, nevertheless the asymmetric conduction abnormalities strongly suggested multifocality of the lesion. In the biopsied sural nerve no myelinated fibers were found. Considerable improvements in muscle power and electrophysiological findings were brought about by corticosteroid therapy. CIDP in childhood may masquerade hereditary neuropathies presenting hypertrophic peripheral nerves and pes cavus deformity. A careful nerve conduction study is thus desirable to find out electrophysiological multifocality.