Audiology & neuro-otology
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Audiology & neuro-otology · Jan 2012
Comprehensive analysis of head-shaking nystagmus in patients with vestibular neuritis.
Although biphasic head-shaking nystagmus (HSN) is a basic response to head shaking in patients with unilateral vestibular loss, monophasic HSN is commonly seen in patients with dizziness of undetermined etiology. Since the clinical significance of HSN remains unclear, we sought to characterize different types of HSN in patients with vestibular neuritis (VN) during the acute stage (within 7 days after the onset of vertigo) and at follow-up (about 2 months after the onset of vertigo), and to compare HSN and caloric responses. We analyzed HSN, spontaneous nystagmus and caloric tests in 66 patients with VN. ⋯ The two tests utilize different mechanisms to assess vestibular hypofunction and are complementary. Biphasic paretic HSN is the most common pattern at follow-up and occurs when the initial SPVs induced by head rotation are large enough to induce the adaptation of primary vestibular afferent activity. Monophasic HSN, which is commonly found in dizzy patients, indicates less severe vestibular hypofunction than biphasic HSN in the 2-Hz frequency range, and the caloric tests can provide further information about the side and presence of vestibular hypofunction at lower frequencies.
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Audiology & neuro-otology · Jan 2012
ReviewAnalysis of hearing preservation and facial nerve function for patients undergoing vestibular schwannoma surgery: the middle cranial fossa approach versus the retrosigmoid approach--personal experience and literature review.
To compare hearing preservation and facial nerve function outcomes in patients undergoing vestibular schwannoma surgery performed using either the middle cranial fossa approach (MCFA) or the retrosigmoid approach (RSA). ⋯ No statistically significant difference in hearing preservation was identified when comparing tumors operated upon via the MCFA versus the RSA. However, our results indicate that a higher risk of facial nerve function impairment exists if the surgery is performed via the MCFA under circumstances where the tumor extends to the cerebellopontine angle.