Benign paroxysmal positional vertigo and its variants.

Benign paroxysmal positional vertigo is a common labyrinthine disorder caused by a mechanic stimulation of the vestibular receptors within the semicircular canals. It is characterized by positional vertigo and positional nystagmus, both provoked by changes in the position of the head with respect to gravity. The social impact of the disease and its direct and indirect costs to healthcare systems are significant owing to impairment of daily activities and increased risk of falls. The first description of a patient with benign paroxysmal positional vertigo is from Robert Bárány in 1921, but the features of the syndrome and the diagnostic maneuver were well described by Dix and Hallpike in 1952. Since then, the gradually increasing interest of otolaryngologists and neurologists has led to a progressive advance in the knowledge of this labyrinthine disorder with regard to its epidemiologic, pathophysiologic, clinical, and therapeutic aspects. Despite the often effective diagnosis and treatment of most cases of benign paroxysmal positional vertigo, the physiopathologic explanations of the disease are mainly speculative. In this chapter, we describe the epidemiologic, pathophysiologic, clinical, and therapeutic aspects of benign paroxysmal positional vertigo.