Histopathology of transitory traumatic paraplegia in the monkey.

The microscopic appearance of the primate spinal cord within a 4-hour interval following the delivery of a direct force sufficient to produce a transitory paraplegia was investigated by light microscopy. The resulting hemorrhagic lesion involved primarily the central gray matter and was attributed to the direct effect of the trauma on the vessels in the gray matter with a consequent impairment of blood supply to the injured area. Chromatolysis, vacuolation, and alterations in cytoplasmic density and stainability were observed within the neurons. The edematous changes in the white matter, which were more marked in the internal layers relative to the external layers, appeared minimal and explain in part why the paraplegia was transient.