[Progressive muscular atrophy in a ten-year-old girl].

Chronic inflammatory demyelinating polyneuropathy, CIDP, is a rare differential diagnosis to the hereditary myopathies but because it can be treated effectively it is important to consider. A ten-year-old girl's proximal muscle groups debilitated progressively, and in four months she lost the ability to walk. Stretch reflexes were absent, creatine kinase low and spinal protein elevated. Muscle biopsy showed demyelinating atrophy. CIDP was diagnosed and she was successfully treated with immunoglobulin.