The syndrome of occlusion of the anterior spinal artery consists of sudden paraplegia accompanied by anesthesia and by disturbances of urination and defecation. The anesthesia is dissociated, of the syringomyelic type, in which there is complete loss of the sensations of pain and temperature with preservation of the sensations of touch, position and vibration. The cause of this syndrome is destruction of certain portions of the spinal cord by a sudden occlusion of the anterior spinal artery or its branches. This symptom complex is so definite that it permits of an accurate clinical diagnosis, the symptoms varying somewhat with the level of the occlusion. Clinical, and especially pathologic, reports on this syndrome are exceedingly few. It was first described in 1904 by Preobrajensky,1 who believed that its most probable cause was syphilis. Syphilis was also the etiologic factor in the cases of Spiller2 and Margulis.3 In the