Review of the pathology underlying benign paroxysmal positional vertigo

The pathophysiological mechanism underlying benign paroxysmal positional vertigo (BPPV) is related to free-floating debris/otoliths in the semicircular canal (canalolithiasis) or debris/otoliths attached to the cupula (cupulolithiasis). These debris/otoliths are considered to originally accumulate after detachment from the neuroepithelium of the utricular macula secondary to a type of degeneration. An idiopathic form, which is assumed to occur spontaneously, is diagnosed when the causative pathology is obscure. However, an association between various other systemic or inner ear conditions and BPPV has been reported, indicating the existence of secondary BPPV. This study was performed to present the first review of the pathology underlying BPPV following a complete PubMed/Medline search. In total, 1932 articles published from 1975 to 2018 were reviewed. The articles were classified according to 17 potentially causative factors (aging; migraine; Meniere's disease; infection; trauma; idiopathic sudden sensorineural hearing loss; sleeping habits; osteoporosis and vitamin D insufficiency; hyperglycemia and diabetes mellitus; chronic head and neck pain; vestibule or semicircular canal pathology; pigmentation disorders; estrogen deficiency; neurological disorders; autoimmune, inflammatory, or rheumatologic disorders; familial or genetic predisposition; and allergy). A discussion of the underlying cause of BPPV for each factor is presented.