Raising a building: raising Neurotology
Things do not create themselves, a book does not write itself and a building does not construct itself. Medicine, science, knowledge and society itself are the byproduct of several contributors and various situations, just as the building of a building.
The history of vestibular research is a story of many people, from many countries, with different backgrounds, that contributed to build Neuro-otology.
Probably, when the Italian anatomist Gabriele Falloppio (ca. 1523-1526) published his thorough descriptions of the semicircular canals in Observationes anatomicae (1561), was far from realizing the physiological importance of these structures. Just as those excavating the foundations of a cathedral could never contemplate the results centuries later.
A similar naivety was probably experienced by the French anatomist Guichard Joseph DuVerney (1948-1730) when publishing Traite de L'Organe de L'Ouie (1683), the Italian anatomist Antonio Maria Valsalva (1666-1723) with De Aura Humana Tractarus (1704) or the Italian anatomist Antonio Scarpa (1752-1832) when reporting Anatomiae Disquisitiones de Auditu et Olfatu (1789). All these authors contributed to a full-knowledge of the incredible inner ear anatomy.
Those who in the early 19th century attempted, within the medical knowledge of that time, to understand the functions of inner ear, relied on exhaustive anatomical descriptions of the labyrinth. However, there were some misconceptions related to inner ear function, such as that it was only responsible for hearing. Moreover, semicircular canals were only amenable for detecting basic tones and noise, sound intensity and its localization in space.
The 19th century was fundamental in attaining current knowledge cohesion regarding Anatomy, Histology and Physiology, similarly to other fields of science and, in particular, Medicine. The Italian marquis Alfonso Giacomo Gaspare Corti (1822-1876), the Swedish anatomist Magnus Gustaf Retzius (1842-1919) and later in the early 20th century the Spanish Santiago Ramón y Cajal (1852-1934) and Rafael Lorente de Nó (1902-1990) would contribute to a better understanding of the microscopic anatomy and histology of the inner ear and its innervation.
As the stonecutters who painstakingly carve stones to a perfect fit in the columns of a cathedral, the French anatomist and physiologist Marie Jean Pierre Flourens (1794-1867) was the first to fully understand the role of the posterior labyrinth, along with its cerebellar connections, in balance and gait maintenance. This conception was greatly due to his interesting studies with pigeons, published between 1824 - 1861.
Another “master stonecutter” of the Neuro-otology was the Czech physiologist Jan Evangelista Purkinje, who described several types of nystagmus triggered by rotational stimuli and associated, for the first time, the sensation of vertigo with cerebellum.
Flourens experiments laid the foundations for the clinical studies of the French physician Prosper Meniere (1799-1862), who succeeded Jean Marc Gaspard Itard as the head of the Deaf-Mute institute of Paris, gaining a great deal of experience on the management of patients with ear-related diseases.
The importance of Meniere in Neuro-otology surpasses the thorough description of the disease that bears his name. He was the first author to report a possible association between vertiginous episodes and a labyrinth impairment, rather than a primary brain problem. A series of anatomo-clinical cases published by Meniere in 1861 supported this theory. Meniere’s finding was initially unnoticed, until Armand Trousseau and, mostly Gelle and Jean-Martin Charcot upholded this concept. Charcot was the first to propose the eponym Meniere´s disease for the association of recurrent vertigo, hearing loss and tinnitus.
The second half of the 19th century was the one to see the flourishment of the “sculptors” and “painters” of the great construction of the neuro-otology building.
In 1870, the German physiologist Friedrich Leopold Goltz (1834-1902) already perceived the labyrinth as the one responsible for head positioning. He proposed that the stimulation of the ampullary crest of the semicircular canals was elicited by endolymph hydrostatic pressure changes during head movements.
Independently, albeit almost simultaneously, the German physicist Ernst Mach (1838-1916), the Viennese physician Josef Breuer (1842-1925) and the Scottish chemist Alexander Crum-Brown (1838-1922) presented the hydrodynamics theory of the semicircular canals function between November 1873 and January 1874. They pointed out these structures as the sensors of rotatory head movements, eliciting an effector reflex in the eye and spinal musculature. Additionally, Breuer is regarded as the first to acknowledge the vestibular origin of nystagmus… and he also formulated many of the key concepts that laid the foundation for modern psychotherapy.
The German physiologist Ernst Julius Richard Ewald (1855-1921), successor of Goltz as chair of Physiology in Strasburg, developed a series of experiments in animal models that underwent labyrinthectomies, studying labyrinth tone and its consequences in gait and posture. Likewise, he introduced the concept of “compensation” after vestibular damage. However, Ewald is primarily remembered for the experiments that allowed him to stablish his two famous rules for endolymphatic currents.
The Russian-French physiologist Elie de Cyon (1842-1912) in Paris, and Endre Högyes (1847-1906) in Hungary started the study of the vestibular central pathways. Hoegyes was the first to perform an electronystagmography registry in an animal model, in 1881. Nonetheless, the first electrooculography in humans was not performed until 1922, by E. Schott.
The Austrian otolaryngologists Gustav Alexander (1873 ? 1932), Robert Bárány (1876 ?1936) and Heinrich Neumann (1873-1939) studied Otology in Vienna alongside Adam Politzer, the true father of Otology. Their clinical research achievements contributed greatly to current vestibular physiology knowledge. Bárány´s concept of caloric nystagmus is still regarded as the basis for contemporary caloric and rotatory testing. Likewise, the majority of otoneurological physical examination deeply relies in the signs described by these authors.
Excellence minds summation ensure success. The history of Neuro-otology is a history of success.
ANGEL BATUECAS-CALETRIO MD, PHD
JUAN MANUEL ESPINOSA SÁNCHEZ MD
History Comitee for the XXXI Barany Society meeting