Nervous System & Special Senses

{"ops":[{"insert":"Nystagmus"},{"insert":"\n","attributes":{"header":1}},{"insert":"Nystagmus refers to rapid uncoordinated eye movements. Depending on the direction of movement, this can be classified as either horizontal (side to side), vertical (up and down) or circular (rotational).\n"},{"insert":"Benign paroxysmal positional vertigo (BPPV)"},{"insert":"\n","attributes":{"header":1}},{"insert":"BPPV is a clinical disorder where short episodes of vertigo are induced by bending over, looking up, standing up from a supine position, or turning over in bed. These episodes typically last less than a minute.\r\n\r\nBPPV occurs due to disease of the semicircular canals, with the posterior canal being the one most frequently affected. There are two competing theories to explain the underlying pathogenesis.\r\n\r\nThe canalithiasis theory is more popular; this postulates that free-floating debris in the endolymph becomes impacted in one of the semicircular canals. This stimulates the ampulla of that canal, thereby causing vertigo.\r\n\r\nThe cupulolithiasis theory stipulates that particles termed \u0022otoconia\u0022 come into existence following trauma, ischemi"}]}

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