Caloric stimulation of the labyrinth and some forgotten pioneers

Abstract

Introduction Understanding the physiology of the caloric stimulation of the vestibular end organ was a seminal discovery in the history of neurotology. Robert Barany has been traditionally credited with this (1906). However, well before Barany, three scientists observed, qualified and quantified a similar phenomenon with different explanations. They were Charles Edouard Brown Sequard (1858), A Bornhardt (1876) and Benno Baginsky (1881). Materials and methods Articles with key words containing ‘caloric test’ and the ‘vestibular system’ were searched and studied from a historical perspective in scientific research repositories and journals on the history of medicine. Contemporaneous articles of the three scientists were analysed and inferences drawn. Results and discussion Charles Edouard Brown Sequard noticed the caloric effect on the ear causing giddiness in 1853, A Bornhardt observed nystagmus on application of ice cold water/hot iron rod to the semicircular canals in 1876 and Benno Baginsky in 1881 identified the correct pressure/temperature on the external/middle ear to elicit a caloric response. They also stumbled across key observations of vestibular physiology which were later confirmed in the 20th century. Conclusions This paper resurrects the works of these three forgotten pioneers and their contributions to our understanding of the physiology of the vestibular system.