Benign paroxysmal positioning vertigo: Classic descriptions, origins of the provocative positioning technique, and conceptual developments

The original description of benign paroxysmal positioning vertigo (BPPV) has been variously attributed to Barany, Adler, and others. In addition, the proper eponymic designation for the provocative positioning test used to diagnose BPPV has been unclear, because authors use a variety of different terms, including Barany, Nylen-Barany, Nylen, Hallpike, Hallpike-Dix, and Dix-Hallpike to refer to the procedure in current use. Based on a review of the extant medical literature, Barany was the first to describe the condition in detail, and Dir and Hallpike were the first to clearly describe both the currently used provocative positioning technique and the essential clinical manifestations of benign paroxysmal positioning vertigo elicited by that technique. Nevertheless, despite their important contributions, neither Barany nor Dir and Hallpike understood the pathophysiology of BPPV nor did they appreciate that the positioning techniques they used actually demonstrated pathology in the semicircular canals rather than the utricle. The modern understanding of the pathophysiology of BPPV began with Schuknecht's proposal that the dysfunction resulted from the gravity-dependent movement of loose or fixed dense material within the posterior semicircular canal (''cupulolithiasis''). Although Schuknecht's formulations were not consistent with all clinical features of thedisease, they led to the modern ''canalolithiasis theory'' and highly effective canalith repositioning or ''liberatory'' maneuvers for BPPV.