The dorsal columns

The concept of a dorsal column syndrome arose during the middle of the last and the beginning of the present Based on the pathologic alterations seen in certain disease states and on the scanty knowledge available at that time concerning ascending spinal tracts, it was hypothesized that patients with lesions located in the dorsal columns (DCs) had impaired vibratory and postural sensibility, diminished ability to distinguish 2 points and to recognize objects by means of manipulation, poor tactile localization, and ataxia. A cause-and-effect association between the presence of DC lesions and loss of these functions was at first tacitly assumed and then generally, if not universally, adopted as fact. As a result, the converse idea that the DCs were solely responsible for transmitting certain types of information-namely the impulses associated with various discriminative tactile sensibilities, vibration, and kinesthesia-became the traditional view of DC function.6-11 It was presumed that the DCs conveyed to the brain information necessary for the conscious analysis of the temporal and spatial features of cutaneous and proprioceptive stimuli. In recent years the role of the DCs has been carefully reinvestigated.12-'6 New anatomic, physiologic, and behavioral experimental methods have been used in addition, neuropathologic data that provide the basis for most of our clinical assumptions concerning the DCs have been reevaluated. These approaches have rendered untenable the traditional view of DC function. It is the purpose of this review to present and evaluate the modern evidence regarding the form and function of the DCs.