Recovery of locomotor function after hemisection of the spinal cord in cats.

Cats were subjected to high lumbar hemisection of the spinal cord, on the right side. The initial paralysis of the right hindlimb became rapidly attenuated, and they walked again in one week or less after surgery. Minor residual deficits in gait remained, that may be permanent. Electrical stimulation of the bulbar reticulospinal formation showed residual crossed connections reaching the right lumbosacral cord via the left hemicord. Recovery from Brown-Séquard's syndrome may be primarily due to the survival of low crossing descending projections to the spinal cord.