Two great anatomists led audiologists and otolaryngologists to their fundamental knowledge of the auditory mechanism, both were famous for their own middle ear equalization maneuvers: the Valsalva and Toynbee maneuvers. The maneuvers were created over a century apart, but both researchers’ contributions provided major increases in knowledge of the auditory system, its anatomy, physiology and diseases. Hearing International reviews these individuals and their contributions to the field, as well as the somewhat mysterious demise of Toynbee.
The first in this famous duo of researchers was Antonio Maria Valsalva (January 17, 1666 – February 2, 1723), an Italian anatomist born in Imola (close to Bologna). His research focused on the anatomy of the ears. He coined the term Eustachian tube. He also described the aortic sinuses in his writings, which were published posthumously in 1740. His name is associated with the Valsalva antrum of the ear (sometimes called the Mastoid Antrum) and, probably his most famous invention, the Valsalva maneuver, for equalizing the pressure between the atmosphere and the middle ear.
The Valsalva maneuver is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one’s mouth, pinching one’s nose shut while pressing out as if blowing up a balloon. Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to “clear” the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in diving, hyperbaric oxygen therapy, or aviation. In Valsalva’s time, his maneuver was used to remove suppuration and foreign bodies from the ear and, interestingly, the method had been used by Arab physicians as far back as the 11th century.
A contemporary of Isaac Newton, Bach and Molière, Valsalva was initially educated in the humanities, mathematics, and natural sciences. After studying liberal arts, Valsalva then studied medicine and philosophy in Bologna. He was taught by Marcello Malpighi, who is known as the founder of microscopic anatomy. Valsalva graduated from the Bologna medical school in 1687 and in 1705, he was appointed professor of anatomy at Bologna. He was later chosen as president of the Academy of the Sciences. Valsalva taught Giovanni Battista Morgagni, who worked for Valsalva at Bologna and assisted him in his famous publication Anatomy and Diseases of the Ear in 1704.
Valsalva both studied and taught in the fields of science, surgery, anatomy, physiology, and psychiatry. He opposed cauterization in the treatment of wounds, and recommended humanitarian treatment of mentally ill patients. His main interest was the middle and internal ear, including the muscles of the external ear and the pharyngeal muscles. Valsalva named the Eustachian tube and described its function and that of its muscle. He showed the connection between the mastoid cells and the tympanic cavity, and made observations on physiologic and pathologic processes of the ear. De aure humana tractatus published in 1704 contains a description of the Valsalva maneuver and patency test of the auditory tubes.
A skilled anatomist, Valsalva conducted many autopsies on deceased patients. During the 17th century, lacking chemical tests and knowledge of disease transmission mechanisms, he sometimes tasted the fluids he encountered in cadavers in an effort to better characterize them. “Gangrenous pus does not taste good“, he wrote, “leaving the tongue tingling unpleasantly for the better part of the day.”
Although Valsalva will best be remembered for the maneuver that bears his name, his most substantial contribution to the field of medicine was his detailed illustrative work of the anatomy, physiology, and pathology of the ear titled, De aure humana tractatus and published in 1704. As he lost his health, he lost his sense of smell, but he recognized the prodromal symptoms, in the form of dyslalia, of the disease that would eventually cause his death from stroke at Bologna in 1723.
Morgagni published a biography on Valsalva in 1740 and in 1741 he published second edition (sometimes called the “Morgagni” version) of Valsalva’s Treatise on the Human Ear ( De aure humana tractatus). The 1741 publication is the work of Valsalva through the pen of Morgagni and was considered the scientific pinnacle of his time, having a great influence on the development of modern otology. Morgagni wrote “. . . there is nobody of those times who goes ahead of him, very few who are his equal”.
Valsalva Continues to be famous even in the US Space program! On 25 May 2011, NASA reported that during the second spacewalk of Space Shuttle mission STS-134, astronaut Drew Feustel used a part of his Extravehicular Mobility Unit (spacesuit) to make use of “a spongy device called a Valsalva that is typically used to block the nose in case a pressure readjustment is needed.”
Next week Hearing International will explore Toynbee, his contributions and the mysterious circumstances surrounding his death.