Caloric stimulation of the labyrinth and some forgotten pioneers

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.