Brown-Séquard, Charles-Édouard

(b. Port Louis, Mauritius, 8 April 1817; d. Paris, France, 1 April 1894)

physiology.

Brown-Séquard’s father, Charles Edward Brown, was an American naval officer; his mother, Charlotte Séquard, was French. He was a British subject by birth, but just before becoming professor at the Collége de France in 1878 he became a French citizen. Brown-Séquard’s early life was difficult. Born after his father’s death, he was raised by his mother in modest circumstances. After receiving the M.D. in Paris on 3 January 1846, he became the protégé of Pierre Rayer and began his work at the hospital of La Charité. Although he always remained interested in the life of Paris and its scientific movements, Brown-Séquard had a restless nature and was unable to have a real home. Before receiving his degree he had lived in Mauritius, and after completing his studies he went to the United States. He practiced medicine and gave private courses in Philadelphia, New York, and Boston in 1852. After his marriage to Ellen Fletcher of Boston, Brown-Séquard returned to Paris and later settled again in Port Louis, where he distinguished himself in fighting a cholera epidemic. In 1854 he accepted a professorship at Virginia Medical College in Richmond, but returned to Paris in 1855. In 1856 he again gave courses in Boston but suddenly decided to live in England, where he taught at the Royal College of Surgeons in 1858. As a physician at the National Hospital for the Paralysed and Epileptics, Brown-Séquard lived in London from 1860 to 1863. He was elected to the Royal Society in 1861. Becoming in England more and more the slave of professional practice, he fled to Paris and then to Boston. The Harvard Medical School offered him the chair of physiology and pathology, which he held from 1864 to 1867. After the death of his wife in 1867, Brown-Séquard again left the United States for Paris, where he gave the course in comparative and experimental pathology at the Faculté de Médecine in 1869. The following year he settled once more in the United States, and married Maria Carlisle, of Cincinnati, Ohio, in 1872. His activity then knew no respite: he founded a new journal and organized a physiology laboratory in New York; lectured in Boston, London, Dublin, and Paris; and wrote several dozen scientific articles. His travel increased after his second wife’s early death, and in 1877, in Geneva, he married an Englishwoman named Emma Dakin.

The high point of Brown-Séquard’s scientific career came following the death of Claude Bernard, when he became professor of medicine at the Collège de France (3 August 1878). He retained this post until his death but divided his time between Paris and Nice, leaving his assistant, Arsène d’Arsonval, to give the winter courses. In 1886 Brown-Séquard was elected to the Académie des Sciences.

While a student, Brown-Séquard had become particularly interested in problems of physiology and conducted original experiments on gastric digestion and the function of the spinal cord. In his thesis he suggested that in the spinal cord sensations are transmitted through the gray matter rather than through the dorsal columns. He also described the phenomenon that was later known as traumatic spinal shock: marked diminution in reflex activity immediately after sectioning of the cord and its subsequent recovery and even hyperesthesia. His thesis contained the germ of his main discovery: crossing of the nervous pathways for conduction of sensation in the spinal cord. In 1849 he showed that transverse hemisection of the cord produces motor paralysis and hyperesthesia on the corresponding side and anesthesia on the opposite side of the body below the lesion (the Brown-Séquard syndrome). This discovery was confirmed by clinical observations and proved to be very useful in the diagnosis of neurological lesions.

In August 1852, while in the United States, Brown-Séquard demonstrated the existence of vasoconstrictive nerves. When the severed cervical sympathetic trunk was stimulated by a galvanic current, the phenomena described by Claude Bernard as following the section (increasing of the skin temperature, dilation of the blood vessels, sensitization) disappeared and were replaced by inverse phenomena. It must be said that Bernard carried out the same experiment independently of Brown-Séquard and obtained the same results. It should be noted that the publication of Brown-Séquard’s experiment preceded that of Bernard’s; but, on the other hand, Brown-Séquard’s research in this field was directly inspired by Bernard’s work and was the logical sequel to the experiments made public just before Brown-Séquard left Paris.

Other of Brown-Séquard’s investigations concerned the artificial production of epileptic states through lesions of the nervous system (1856), and the irrigation of dead muscles with warm blood. He was successful in reviving the head of a dog eight minutes after decapitation by injecting oxygenated blood into the arterial trunks. In 1862 he demonstrated that section of the vagus nerve brought on dilation of the coronary arteries. Brown-Séquard was mistaken in opposing the theory of cerebral localizations, but it should be emphasized that we are greatly indebted to him for elaboration of the concept of nervous inhibition.

Brown-Séquard was a pioneer of endocrinology. In 1856 he proved that removal of the adrenal glands always caused death in animals. He also prolonged the survival of animals after adrenalectomy by injecting normal blood. These researches are open to criticism, and this is even more true of his celebrated experiments on “rejuvenation.” On 1 June 1889 Brown-Séquard presented a sensational report to the Société de Biologie: he believed that he had “rejuvenated” himself with subcutaneous injections of a liquid extracted from the testicles of freshly killed guinea pigs and dogs. His extravagant claim stimulated the development of modern organotherapy and exerted a strong influence on later research on sex hormones.

Brown-Séquard’s investigations show more intuition than critical sense. His great achievement was understanding that through “internal secretion” the cells become dependent on one another by means of a mechanism other than the action of the nervous system (1891).

BIBLIOGRAPHY

I. Original Works. A good bibliography is in his autobiographic Notice sur les travaux scientifiques de M. C. É. Brown-Séquard (Paris, 1883). His principal books are Recherches et expériences sur la physiologie de la moelle épinière (Paris, 1846), his thesis; Recherches expérimentalessur la transmission croisée des impressions dans la moelle épinière (Paris, 1855); Researches in Epilepsy (Boston, 1857); and Course of Lectures on the Physiology and Pathology of the Central Nervous System (Philadelphia, 1860). The most important results of Brown-Séquard’s research were first printed in the reports of the Société de Biologie (Paris) and of the Académie des Sciences. For instance, the Comptes rendus de la Société de biologie contains the description of the experimental hemisection of the spinal cord, 1 (1850), 70–73; and the first mention of the effects produced in man by injections of testicular extract, 41 (1889), 415–422. His fundamental experiments on the adrenal glands were published in the Comptes rendus de l’Académie des sciences, 43 (1856), 422–425, 542–546. He also published a great many articles in the three journals of which he was founder and editor: Journal de la physiologie de l’homme et des animaux, Archives de physiologie normale et pathologique, and Archives of Scientific and Practical Medicine.

II. Secondary Literature. Works on Brown-Séquard are M. Berthelot, Notice sur la vie et les travaux de M. Brown-Séquard (Paris, 1904); E. Dupuy, “Notice sur M. le Pr. Brown Séquard, ancien président de la Société de biologie,” in Mémoires de la Société de biologie, 46 (1894), 759–770; E. Gley, “C.-E. Brown-Séquard,” in Archives de physiologie normale et pathologique, 5th ser., 6 (1894), 501–516; J. M. D. Olmsted, Charles-Edouard Brown-Séquard. A Nineteenth Century Neurologist and Endocrinologist (Baltimore, 1946); and F. A. Rouget, Brown-Séquard et son oeuvre (Port Louis, Mauritius, 1930). An interesting set of letters between Brown-Séquard and his assistant d’Arsonval is in L. Delhoume, De Claude Bernard à d’Arsonval (Paris, 1939).

M. D. Grmek