Diseases of the nervous system may be confined to the spinal
cord. Here they produce a number of distinctive syndromes that relate
to the special physiologic and anatomic features of the cord, such
as its prominent function in sensorimotor conduction and relatively
primitive reflex activity; its long, cylindrical shape; its small
cross-sectional size; its tight envelopment by meninges; the peripheral
location of myelinated fibers next to the pia; the special arrangement
of its blood vessels; and its relationship to the vertebral column.
Woolsey and Young estimate that 30 diseases are known to affect
the spinal cord, of which half are seen with regularity. These processes
express themselves in a number of readily recognized ways and, as
will be evident, certain diseases preferentially evoke only certain
constellations of features and not others. The syndromic grouping
of the spinal cord disorders, which is in keeping with the general
plan of this book, facilitates clinical diagnosis and reduces the
number of ancillary examinations.
The main syndromes to be 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).
The anatomic and physiologic considerations pertinent to an understanding
of disorders of the cord and of the spine can be found in Chaps. 3, 9 (particularly Figs. 9-4 and 9-6),
and 11, on motor paralysis, somatic sensation,
and back pain, respectively.
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.
Trauma to 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 these observations. Little could be done for those
patients and fully 80 percent died in the first few weeks ...