Medical care for a mass gathering: the Suwa Onbashira Festival.

Introduction: The Suwa Onbashira Festival is held every six years and draws approximately one million spectators from across Japan. Men ride the Onbashira pillars (logs) down steep slopes. At each festival, several people are crushed under the heavy log.

Syringomyelia without hindbrain herniation: tight cisterna magna. Report of four cases and a review of the literature.

Idiopathic syringomyelia, which is not associated with any definite pathogenic lesions, has been treated mainly by shunting of the syrinx and rarely by craniocervical decompression. The authors report four cases of syringomyelia thought to be idiopathic syringomyelia but treated by craniocervical decompression with favorable results. Syringomyelia was present without hindbrain herniation.