A syndrome associated with traumatic injury to the cervical or upper thoracic regions of the spinal cord characterized by weakness in the arms with relative sparing of the legs and variable sensory loss. This condition is associated with ischemia, hemorrhage, or necrosis involving the central portions of the spinal cord. Corticospinal fibers destined for the legs are spared due to their more external location in the spinal cord. This clinical pattern may emerge during recovery from spinal shock. Deficits may be transient or permanent.