Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° m...Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° maneuver for lateral semicircular canal type, we noticed that no nystagmus occurred in the sitting position just after treatment. Despite direct excitation to the utricle by the pathological debris, none of the subjects complained of dizziness. Thus, we hypothesized that nystagmus and dizziness do not occur by stimulation of the otolith organs. Objective: The aim of the study was to observe and record the eye movements induced by the otolith organs to confirm our hypothesis. Materials and Methods: Twelve healthy humans were tested. In the sitting position, the head was tilted to the right ear by 45° and vice versa. Afterward, the head was bent forward by 90° (nose-down), and the subject’s seat was reclined to the head-hanging position. Each position was kept for five seconds. We interviewed the subjects to assess their dizziness. Results: None of the subjects showed nystagmus and complained of dizziness in every position. Conclusions: Nystagmus does not occur by the stimulation to the otolith organs;therefore, ocular counter-rolling is a semicircular canal ocular reflex.展开更多
Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. ...Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Now-adays, two kinds of VEMP, cervical VEMP （cVEMP） and ocular VEMP （oVEMP） are clinically used. cVEMP is a test of sacculo-collic refex while oVEMP is a test of utri-culo-ocular refex. Absence of responses, large interau-ral asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior ves-tibular neuritis was established. A prominent feature of VEMP in Meniere’s disease is a shift of a preferred fre-quency in cVEMP. The whole aspects of VEMP fndings in patients with benign paroxysmal positional vertigo are not clarifed yet. Sensitivity of cVEMP to vestibular schwannoma was 80.0%, while specifcity was 52.7%. Concerning diagnosis of superior canal dehiscence syn-drome （SCDS）, oVEMP to air-conducted sound is the most helpful. Augmentation of oVEMP responses is a prominent feature in SCDS. I also presented “idiopathic otolithic vertigo”, which I proposed as a new clinical en-tity based on VEMP fndings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rota-tory vertigo. Majority of patients with these symptoms had absent or decreased responses of oVEMP and/or cVEMP. I proposed that these patients could be diag-nosed as having “idiopathic otolithic vertigo”.展开更多
文摘Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° maneuver for lateral semicircular canal type, we noticed that no nystagmus occurred in the sitting position just after treatment. Despite direct excitation to the utricle by the pathological debris, none of the subjects complained of dizziness. Thus, we hypothesized that nystagmus and dizziness do not occur by stimulation of the otolith organs. Objective: The aim of the study was to observe and record the eye movements induced by the otolith organs to confirm our hypothesis. Materials and Methods: Twelve healthy humans were tested. In the sitting position, the head was tilted to the right ear by 45° and vice versa. Afterward, the head was bent forward by 90° (nose-down), and the subject’s seat was reclined to the head-hanging position. Each position was kept for five seconds. We interviewed the subjects to assess their dizziness. Results: None of the subjects showed nystagmus and complained of dizziness in every position. Conclusions: Nystagmus does not occur by the stimulation to the otolith organs;therefore, ocular counter-rolling is a semicircular canal ocular reflex.
文摘Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Now-adays, two kinds of VEMP, cervical VEMP （cVEMP） and ocular VEMP （oVEMP） are clinically used. cVEMP is a test of sacculo-collic refex while oVEMP is a test of utri-culo-ocular refex. Absence of responses, large interau-ral asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior ves-tibular neuritis was established. A prominent feature of VEMP in Meniere’s disease is a shift of a preferred fre-quency in cVEMP. The whole aspects of VEMP fndings in patients with benign paroxysmal positional vertigo are not clarifed yet. Sensitivity of cVEMP to vestibular schwannoma was 80.0%, while specifcity was 52.7%. Concerning diagnosis of superior canal dehiscence syn-drome （SCDS）, oVEMP to air-conducted sound is the most helpful. Augmentation of oVEMP responses is a prominent feature in SCDS. I also presented “idiopathic otolithic vertigo”, which I proposed as a new clinical en-tity based on VEMP fndings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rota-tory vertigo. Majority of patients with these symptoms had absent or decreased responses of oVEMP and/or cVEMP. I proposed that these patients could be diag-nosed as having “idiopathic otolithic vertigo”.
