Diagnostic value of vestibular evoked myogenic potentials in benign paroxysmal positional vertigo.

OBJECTIVES: Vestibular evoked myogenic potentials (VEMPs) are useful for studying the disturbances along nerve pathways implicated in the transmission of neurological information from otolithic organs related to vestibular function. This study aims to determine the differences in VEMPs in patients affected with benign paroxysmal positional vertigo (BPPV). METHODS: We recruited 36 patients, 9 diagnosed with recurrent BPPV (rBPPV), 9 with only one episode of vertigo (iBPPV), and 18 as a control group. We performed cervical and ocular VEMPs (cVEMPs and oVEMPs). RESULTS: We observed differences in asymmetry ratio, which was 41.82% in cVEMPs in iBPPV and 68.27% in oVEMPs in rBPPV, while no asymmetry was found in control cases. Also, there was a lack of both VEMP responses in 22.2% of cases and an absence of cVEMP in 11.1% in iBPPV; in rBPPV, 11.1 % presented no responses in cVEMPs or oVEMPs, 22.2% showed no oVEMP, and 11.1% showed no cVEMP. These values were normal in the control group. CONCLUSION: The value of VEMPs in BPPV demonstrates the implication of vestibular damage, mainly utricle damage. For better sensitivity in detecting otolith abnormalities, we should perform oVEMPs and cVEMPs in recurrent BPPV and early stages of BPPV.

Otolithic functions in patients with residual dizziness after successful repositioning manoeuvres for unilateral posterior canal BPPV.

OBJECTIVE: To evaluate otolithic functions in patients with residual dizziness after successful canalith repositioning procedures (CRPs) for unilateral posterior canal benign paroxysmal positional vertigo (BPPV), and to investigate possible risk factors. METHODS: This case-control observational study included healthy controls and patients with residual dizziness after improvement following CRP for BPPV. All participants were subjected to full history taking, otoscopy, audiological basic evaluation, Dix-Hallpike test to search for posterior canal BPPV, residual dizziness screening, and vestibular evoked myogenic potential (VEMP) testing. Between-group differences were assessed and possible factors associated with residual dizziness were identified by univariate analysis. RESULTS: A total of 50 patients with residual dizziness (mean age, 56.53 ± 7.46 years [29 female: 21 male]) and 50 healthy controls (mean age, 58.13 ± 7.57 years [20 female: 30 male]) were included. A significant difference in VEMP latencies was found between the patient and control group (delayed in the patient group), with no significant between-group difference in amplitude in both ears. Aging, female sex, long duration of BPPV, number of CRPs, cervical VEMP and ocular VEMP abnormalities, and winter onset, were significantly associated with the risk of residual dizziness. CONCLUSIONS: Residual dizziness is a frequent sequel of BPPV that may relate to otolithic dysfunction. VEMP changes were revealed in the form of delayed latencies.

Subjective visual vertical after treatment of benign paroxysmal positional vertigo / Vertical visual subjetiva após tratamento da vertigem posicional paroxística benigna

Abstract Introduction: Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. Objective: To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. Methods: We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Results: Before repositioning maneuver, 9 patients (45.0%) had absolute values of the subjective visual vertical above the reference standard and 2 (10.0%) after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (p < 0.001). Conclusion: There is a reduction of the deviations of the subjective visual vertical, evaluated by the bucket test, immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo.

Resumo Introdução: A função do otólito pode ser estudada por meio de testes da vertical visual subjetiva, porque a inclinação da linha vertical além da faixa normal é um sinal de disfunção vestibular. A vertigem postural paroxística benigna é um distúrbio de um ou mais canais semicirculares labirínticos causado por frações de otólitos derivados da mácula utricular. Objetivo: Comparar a vertical visual subjetiva com o teste do balde antes e imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna. Método: Foram avaliados 20 pacientes. A posição estimada, onde uma linha de fluorescência dentro de um balde atingia a posição vertical, foi medida antes e imediatamente após a manobra de reposicionamento de partículas. Os dados foram tabulados e analisados estatisticamente. Resultados: Antes da manobra de reposicionamento, nove pacientes (45%) apresentaram valores absolutos de vertical visual subjetiva acima da referência padrão e dois (10%) depois da manobra; a média dos valores absolutos do desvio vertical foi significativamente mais baixa depois da intervenção (p < 0,001). Conclusão: Há uma redução dos desvios da vertical visual subjetiva, avaliada pelo teste do balde, imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna.

Quantas manobras são necessárias para abolir o nistagmo na vertigem posicional paroxística benigna? / The number of procedures required to eliminate positioning nystagmus in benign paroxysmal positional vertigo

OBJETIVO: Avaliar o número de manobras necessárias para abolir o nistagmo posicional em pacientes com Vertigem Posicional Paroxística Benigna e verificar possíveis influências do substrato fisiopatológico e/ou canal semicircular acometido. FORMA DE ESTUDO: clínico prospectivo com coorte transversal. MATERIAL E MÉTODO: Sessenta pacientes com Vertigem Posicional Paroxística Benigna foram tratados por meio das manobras de reposicionamento de estatocônios, repetidas semanalmente até a abolição do nistagmo. A Análise de Variância foi aplicada para verificar diferenças entre as variáveis dos fatores "substrato fisiopatológico" e "canal semicircular acometido". RESULTADOS: Foram necessárias de 1 a 8 manobras, em média 2,13 para abolir o nistagmo posicional. A cupulolitíase necessitou de um número maior de manobras que a ductolitíase (p=0,0002*) e não houve diferença entre os canais semicirculares (p=0,5213). Nos canais anterior e posterior, a ductolitíase precisou em média de uma a duas manobras e a cupulolitíase precisou em média de três manobras. No canal lateral, tanto a ductolitíase quanto a cupulolitíase precisaram de duas manobras, em média. CONCLUSÕES: São necessárias de uma a oito manobras semanais de reposicionamento de estatocônios, em média duas, para eliminar o nistagmo posicional na Vertigem Posicional Paroxística Benigna. A cupulolitíase necessita de maior número de manobras que a ductolitíase. O canal semicircular acometido não influencia o número de manobras terapêuticas.

AIM: To evaluate the number of weekly canalith repositioning procedures needed to eliminate positioning nystagmus in patients with benign paroxysmal positional vertigo and to verify influences of canalithiasis or cupulolithiasis and/or semicircular canal involvement. STUDY DESIGN: clinical prospective with transversal cohort. MATERIAL AND METHOD: Sixty patients with benign paroxysmal positional vertigo were consecutively selected according to each combination of canalithiasis or cupulolithiasis with semicircular canal involvement. Patients were treated by means of canalith repositioning procedures repeated weekly until the elimination of the positioning nystagmus. Analysis of Variance was used to verify differences between the variables. RESULTS: An average of 2.13 procedures (from 1 to 8) was needed to eliminate the positioning nystagmus. Canalithiasis required an average of 1.53 procedures, while cupulolithiasis needed 2.92 procedures (p=0.0002). An average of two procedures was needed to eliminate the positioning nystagmus in cases with posterior canal involvement, 2.39 procedures in cases with anterior canal involvement and 2.07 procedures in cases with lateral canal involvement (p=0.5213). CONCLUSIONS: From one to eight weekly canalith repositioning procedures were needed, with an average of two, to eliminate positioning nystagmus in benign paroxysmal positional vertigo. Cupulolithiasis requires a greater number of procedures than canalithiasis to eliminate positioning nystagmus. Semicircular canal involvement didn't influence the number of therapeutic maneuvers.