Todd, Faraday, and the electrical basis of epilepsy.

Abstract

To consider the origins of our understanding of the electrical basis of epilepsy in the light of the Lumleian lectures to the Royal College of Physicians in London for 1849, "On the pathology and treatment of convulsive diseases," by Robert Bentley Todd (1809-1860). I have reviewed Todd's neglected Lumleian lectures and his observations and concepts of the electrical basis of epilepsy in relation to the influence of Michael Faraday (1791-1867), his contemporary in London, and in relation to later nineteenth century writings on the subject by Jackson, Ferrier, and Hitzig, all of whom overlooked Todd's lectures. Todd was a clinical scientist as well as Professor of Physiology and Morbid Anatomy, with a special interest in the nervous system, at King's College, where he came into contact with Michael Faraday, the greatest electrical scientist of all time, at the nearby Royal Institution. On the basis of his own clinical and experimental studies and his cutting-edge knowledge of neuroanatomy, neurophysiology, neuropathology, and electrical science, Todd brilliantly developed his concepts of the electrical basis of brain activity and of epilepsy in particular. With his microscope, he perceived each nerve vesicle and its related fibres (neurone in later terminology) as distinct entities for the generation of nervous polarity (force) and its transmission in the white nerve fibres throughout the nervous system by unknown molecular mechanisms. In epilepsy, an increase in electrical tension, especially in the grey matter of the hemispheres, led to periodic, sudden explosive discharges, based on Faraday's concept of disruptive discharges. Todd was the United Kingdom's first outstanding neurologist and neuroscientist before these disciplines existed. Influenced by Faraday, he proposed and confirmed the electrical basis of nervous discharges in epilepsy more than 20 years ahead of Jackson, Ferrier, and Hitzig, who did not refer to his priority, although Ferrier also worked at King's College, and Jackson also gave his own famous Lumleian lectures on the same subject in 1890. Todd deserves the credit for laying the foundations of our modern understanding of epilepsy.