The main syndromes considered in this chapter are (1) a complete or almost complete sensorimotor myelopathy that involves most or all of the ascending and descending tracts (transverse myelopathy); (2) a combined painful radicular and transverse cord syndrome; (3) the hemicord (Brown-Séquard) syndrome; (4) a ventral cord syndrome, sparing posterior column function; (5) a high cervical–foramen magnum syndrome; (6) a central cord or syringomyelic syndrome; (7) a syndrome of the conus medullaris; and (8) a syndrome of the cauda equina. In addition, an important distinction is made between lesions within the cord (intramedullary) and those that compress the cord from without (extramedullary). Some of the anatomic and physiologic considerations pertinent to an understanding of disorders of the cord and of the spine can be found in Chaps. 3, 8 (Figs. 8-5 and 8-7), and Chap. 10, on motor paralysis, somatic sensation, and back pain, respectively. The typical spinal cord syndromes are represented most accurately by traumatic lesions of the spine and by tumor compression that originates in an adjacent vertebral body; these important processes are therefore described as models in the introductory section and again in a later part of the chapter.
This syndrome is best considered in relation to trauma, its most frequent cause, but it occurs also as a result of other acute damage including infarction or hemorrhage and with rapidly advancing compressive, necrotizing, demyelinative, or inflammatory lesions. Each of these categories of acute spinal cord disease is discussed in the following pages. For convenience we have included in this group radiation myelopathy, which is transverse but evolves subacutely.
Traumatic Injuries of the Spine and Spinal Cord
Throughout recorded medical history, advances in the understanding of spinal cord disease have coincided largely with periods of warfare. The first thoroughly documented study of the effects of sudden total cord transection was by Theodor Kocher in 1896, based on his observations of 15 patients. During World War I, Riddoch, and later Head and Riddoch, gave what are now considered the classic descriptions of spinal transection in humans; Lhermitte and Guillain and Barré are credited with refining those observations. Little could be done for patients in that era and fully 80 percent died in the first few weeks (from infections); survival was possible only if the spinal cord lesion was partial. World War II marked a turning point in the understanding and management of spinal injuries. The advent of antibiotics and the ability to control skin, bladder, and pulmonary infections permitted the survival of unprecedented numbers of soldiers with cord injuries and provided the opportunity for long-term observation. In special centers, and the care and rehabilitation of the paraplegic patient were brought to a high level. Studies conducted in these centers greatly enhanced our knowledge of the functional capacity of the chronically isolated spinal cord. Kuhn, Munro, Martin and Davis, Guttmann, Pollock, and Pollock and associates made particularly important contributions to this subject.
Mechanisms of Spinal Injury