Apogeotropic – elicits horizontal nystagmus that beats toward the uppermost ear.When the patient head is rolled to the healthy side, again elicits horizontal nystagmus beating toward the earth (undermost ear), but the direction of nystagmus has changed. Geotropic – elicits horizontal nystagmus that beats toward the earth when the patient head is rolled to the pathologic side.The 2 types of lateral semicircular canal BPPV have different nystagmus findings: Ĭompared to posterior semicircular BPPV, horizontal semicircular BPPV may have no latency, responses do not fatigue and the duration may be greater than 60 seconds. Horizontal BPPV can be evaluated using the supine roll test (also called the Pagnini-McClure maneuver). Horizontal or lateral semicircular canal BPPV should be considered when the patient has a history compatible with BPPV and the Dix-Hallpike test elicits horizontal or no nystagmus. Horizontal/Lateral semicircular canal BPPV Upon repeated testing, the nystagmus is likely fatigue, although repeating the maneuver multiple times is not recommended due to patient discomfort. The nystagmus can reverse directions when the patient is returned to the upright position. The latency of onset between the start of Dix-Hallpike and the start of vertigo or nystagmus can vary between 2-20 seconds, and the nystagmus intensity typically increases and then resolves within 1 minute from the onset of the nystagmus. Activation of both the ipsilateral inferior oblique and contralateral superior rectus leads to an upbeat-torsional nystagmus during the maneuver where the patient is brought from the upright to supine position with the head turned 45° towards the affected ear. Posterior SCC BPPV is the most common type of BPPV and can be tested by the Dix-Hallpike test. Nystagmus features Posterior semicircular BPPV Nystagmus must be observed during a provoking maneuver as described below to confirm BPPV. These vertigo spells may be associated with nausea and vomiting but patients do not complain of hearing loss or other neurologic symptoms. Patients with BPPV present with recurrent episodes of vertigo that last less than 1 minute and are provoked by changes in head movements relative to gravity. ![]() Resulting alterations in cupular deflection lead to pathological perceptions of motion.
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