Spinal origin of human lead neuropathy: this paper marks the 150th anniversary of Paralysie de Plomb ou Saturnine by L. Tanquerel des Planches.

One hundred fifty years ago a young but distinguished French scientist, L. Tanquerel des Planches, published a most comprehensive work dealing with almost every known clinical, epidemiological, and occupational aspect of lead poisoning, Traité des Maladies de Plomb ou Saturnines exposing in its second volume, Paralysie de Plomb ou Saturnine his invaluable experience on lead palsy. Among his ideas, based on a rather unique accumulation of human cases of lead palsy, the theory of the neurotoxic action of lead on the spinal cord is of outstanding importance. This site and the mode of action of lead have long been unsettled, although both the nineteenth century classics in neurology and the classics in industrial medicine of the first half of the twentieth century have contributed to solving the pathophysiology of lead palsy. The contributions from these reports, which concur with Tanquerel's assumptions, are presented and discussed. It must be emphasized, however, that only with the advent of electrophysiology has it become possible definitely to recognize the spinal cord involvement as the cause of lead neuropathy. The hypothesis of the axonal degeneration of the "dying back" variant, starting in the biochemical lesion of perikaria of the anterior horn cells in the spinal cord, is in full agreement with both the electromyographic signs of denervation and the electroneurographic normal range of conduction velocity. This presumptive conclusion confirming the spinal origin of human lead neuropathy is very much in line with the concepts of Tanquerel des Planches.