Against vivisection: Charcot and Pitres’ discovery of the human motor cortex and the birth of modern neurosurgery and of the surgical treatment of epilepsy

ABSTRACT

This article addresses the discrepancy between Edouard Hitzig’s and David Ferrier’s findings on the cortical localization of movements in animals and Jean-Martin Charcot’s findings in humans. The results of Hitzig’s and Ferrier’s vivisections were criticized by experimentalists in England and France as discordant, irreproducible, and inconclusive, and they were rejected by clinicians as irrelevant. Charcot addressed the gap between animal and human motor function by correlating motor deficits and focal epileptic seizures in patients to their autopsy findings. By this method he discovered the functional organization of the human motor cortex and produced the first accurate human motor brain map. Ferrier, William Osler, and Hughlings Jackson acknowledged Charcot’s findings, and his findings guided the first neurosurgeons in localizing and resecting intracranial mass lesions presenting with focal epileptic seizures. Although his contributions in these fields have been neglected by modern historians, Charcot made significant contributions to the neurobiology of the human motor system, to epileptology, and to the birth of modern neurosurgery.

KEYWORDS:

• Charcot
• cortex
• Ferrier
• Fritsch
• Hitzig
• motor strip
• movement
• Pitres

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

¹ Parts of this article have been addressed in abridged form in Leblanc R. Charcot’s motor brain map and nineteenth-century neurosurgery (Journal of Neurosurgery 2021, 135, 1843–1848).

² The corpus striatum, or the striate body, is composed of the caudate and lentiform nuclei. With the thalamus, they constitute the basal ganglia within the deep, subcortical white matter.

³ For a seventeenth-century discussion of movement see Duncan (1678), Lamy (1678), Pourfour du Petit (1710), Thompson (1992), and Walusinski (2018).

⁴ Opisthotonus is extreme spastic curving of the body caused by compression of the brainstem from a cerebellar mass lesion. It is sometimes referred to as a cerebellar fit, although it is not an epileptic phenomenon.

⁵ Volta’s battery was composed of a layer of silver and a layer of zinc, with a layer of salt water between them.

⁶ For a discussion of Volta and Galvani, see Brazier (1988); on animal electricity, see J. P. Johnson (2011).

⁷ This was an astute observation, as damage to the lateral aspect of the cerebellum in humans causes ataxia of the limbs. Midline damage causes truncal ataxia characterized by unsteadiness, swaying to one side or the other, or front to back, and falling in one of those directions.

⁸ Foville was referring to the thalamus and corpus striatum.

⁹ Flourens thought that the will to move originated in the cortex, and that motility was a function of the spinal cord.

¹⁰ Bouillaud also mentioned Foville, but only in passing, and to chastise him for not citing Saucerotte in his treatise.

¹¹ The thalamus and corpus striatum.

¹² The thalamus and corpus striatum.

¹³ Pitres had studied histology with Louis-Antoine Ranvier (1835–1922), the discoverer of the gap within the myelin sheet of peripheral nerves.

¹⁴ Fritsch lost interest in cortical localization, but Hitzig continued animal experimentation and expanded greatly on their initial observations.

¹⁵ The paramedial lobe is mainly a medial extension of the primary motor cortex, with which it shares the same architectonic structure. A small portion of the paracentral lobule is a medial extension of the primary sensory cortex.

¹⁶ Hitzig’s work was discussed and partially translated into French by Carville and Duret (1875), who reproduced Hitzig’s simian brain map.

¹⁷ Charcot referred to the precentral gyrus as the ascending frontal convolution, and to the postcentral gyrus as the ascending parietal convolution.

¹⁸ Unremitting focal motor seizures.

¹⁹ Bourneville also mentioned atrophy of the superior third of the postcentral gyrus (1876, 173).

²⁰ A small number of fibers do not decussate. They constitute the anterior corticospinal tract.

²¹ The centrum semiovale, the white matter between the cortex and subcortical gray nuclei.

²² Papilledema, a sign of intracranial hypertension.

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Funding

The author reported there is no funding associated with the work featured in this article.