A case of myasthenia gravis in childhood associated with chronic inflammatory demyelinating polyradiculoneuropathy.

We report a 14-year-old girl who developed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) during the course of myasthenia gravis. Myasthenia gravis, which was clinically of ocular type, but with waning phenomenon of the extremities, occurred at 2 years and 4 months of age. Muscle weakness of the lower extremities gradually developed over the next 6 years. The electrophysiological and pathological findings fulfilled the criteria of "possible CIDP" with severe axonal involvement. The signs of myasthenia gravis and CIDP fluctuated synchronously. A common immunological abnormality was suggested to underlie this rare association of myasthenia gravis and CIDP in childhood.