I. Definition Benign positional paroxysmal vertigo (BPPV) is a common self-limiting disease of the inner ear associated with changes in head or body posture,
BPPV is a common self-limiting disease of the inner ear. 50-70% are primary, also called idiopathic, with no obvious cause; 30-50% are secondary, often secondary to or complicated by vaginitis, vestibular neuritis, head trauma, migraine, Meniere’s disease, sudden deafness, ear and ear neurosurgery, and other pathological conditions. Clinical types of BPPV: posterior semicircular canal BPPV, horizontal semicircular canal BPPV, and anterior semicircular canal BPPV. all of the above three types can develop bilaterally. (1) Dix-Hallpike test: also known as Barany test or Nylen-Barany test, is a common test to determine posterior or superior semicircular canal BPPV. (2) Roll maneuver: It is the most common test to determine the horizontal hemianopia. The nystagmus of BPPV has the following common features: short latency (generally 1~5 seconds); repeatedly placed in the evoked position with a weakened response (nystagmus is fatiguing). (1) Nystagmus characteristics of posterior semicircular canal BPPV: vertical upward twisting nystagmus to the downward ear occurs when the affected semicircular canal is the downward ear, and the nystagmus changes to vertical upward twisting nystagmus to the contralateral ear when it returns to the sitting position. The duration of nystagmus in tubular calculi is <1min; in crestal cap calculi, the duration is >1min. (2) Characteristics of nystagmus in external semicircular canal BPPV: horizontal nystagmus to the downward ear occurs bilaterally, but is more severe to the affected side (tubular calculi); horizontal nystagmus to the upward ear occurs bilaterally, but is more severe to the affected side (crestal cap calculi). The duration of horizontal semicircular canal BPPV nystagmus varies from a few seconds to a few minutes. (3) Nystagmus characteristics of anterior hemianopia BPPV: vertical downward torsional nystagmus to the downward ear occurs when the affected hemianopia is the downward ear, and the nystagmus changes to vertical downward torsional nystagmus to the contralateral ear when it returns to the sitting position. The nystagmus of canal stenosis lasts <1min; the duration of crestal cap stenosis lasts >1min. V. Efficacy assessment Grade I The vertigo disappears completely Grade II The vertigo or positional nystagmus is reduced but does not disappear Grade III The vertigo positional nystagmus does not change, intensifies or turns into other types of BPPV.