Tethered cord syndrome accompanied by unilateral muscle atrophy in the calf muscle.

A 40-year-old man developed slowly progressive muscle atrophy in his calf muscle. The patient became aware of asymmetry of his right big toe during in his teens; muscle atrophy was revealed at the age of 25 years. Multi-image examinations revealed "tethered cord syndrome" with spina bifida occulta. Spinal magnetic resonance image revealed a pathogenetic mechanism of asymmetry of muscle atrophy in the calf muscle. This suggested that spinal MRI imaging is one of the most useful diagnostic methods for this disease.