A century of eighth nerve surgery

A scholarly review of over 70 original papers from the late 19th and early 20th centuries.

Although many neurotologists consider vestibular nerve section to be a recent innovation, eighth nerve division dates back to the dawn of intracranial surgery. Although surgery of peripheral nerves (e.g., repair after injury) is ancient, intracranial nerve surgery began in the latter part of the 19th century with fifth nerve division for tic douloureux. By analogy, it was reasoned that hyperactivity of the eighth nerve (initially tinnitus and later vertigo) could be relieved by dividing this nerve. In 1898, Fedor Krause (1856-1937) of Berlin attempted the first eighth nerve section. This patient, as did many during this era, died shortly after the operation. Most of the survivors had facial palsy. These innovative early surgeons used a variety of approaches, including the suboccipital, middle fossa, and transtemporal routes. After an initial burst of excitement during the first decade of the century, poor results led to few procedures being performed through the second and third decades. Throughout this era, there was much debate about the relative merits of labyrinthectomy (introduced by Milligan and Lake in 1904) as opposed to eighth nerve division. In the late 1920s, the prolific Walter E. Dandy (1886-1946) of Baltimore repopularized eighth nerve section and ultimately performed 607 procedures between 1927 and 1946. Although Dandy achieved a high vertigo control rate and reduced the mortality rate to <1%, he had a high rate of facial nerve weakness (9.1% transient, 4.2% permanent). Remarkably, the latter outcome was never published in his numerous papers on the subject, but was first revealed in a 1951 retrospective survey, which appeared some 5 years after his death. Selective division of the vestibular fibers was introduced by Kenneth G. McKenzie (1892-1963) of Toronto in 1931. At least 11 sizable series appeared in the literature before the introduction of microsurgical vestibular nerve section by William F. House (b. 1923) of Los Angeles in 1960.

The introduction and progressive refinement of eighth nerve section played a central role in the evolution of operative neurotology. Many of the most vigorous debates of recent years (e.g., the choice of operative route, the optimal site of division, and the relative role of inner ear surgery vs. nerve surgery) have antecedents in the controversies of the distant past.