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ObjectiveThe pathogenesis of Ménière's disease is still largely unknown; however, it is known to be strongly associated with stress. Excessive stress can cause hyperactivity of the sympathetic autonomic nervous system. With the aim of understanding changes in sympathetic hyperactivity before and after Ménière's disease, we compared autonomic nervous function in patients in a stable phase of Ménière's disease and that in healthy adults. We also gathered data over about 10 years on autonomic nervous function immediately before a Ménière's attack.Study DesignProspective study.PatientsAutonomic nervous function was analyzed in 129 patients in a stable phase of Ménière's disease 31 healthy adult volunteers. In nine patients, autonomic nervous function was also measured immediately before and after treatment of a vertigo attack.Main Outcome MeasurePower spectrum analysis of heart rate variability (HRV) of EEG/ECG and an infrared electronic pupillometer were used. Sympathetic and parasympathetic nervous function was measured.ResultsThere were no statistically significant differences in autonomic nervous function determined by HRV and electronic pupillometry between patients in a stable phase of Ménière's disease and healthy adults. Sympathetic function as measured by electronic pupillometry parameters VD and T5 showed no difference between the affected and unaffected sides in the baseline data measured in the stable phase (VD: affected side is 31.02 ± 6.16 mm/sec, unaffected side is 29.25 ± 5.73 mm/sec; T5: affected side is 3.37 ± 0.43 msec, unaffected side is 3.25 ± 0.39 msec). In contrast, all nine patients whose HRV data had been obtained just before an attack showed marked suppression of the parasympathetic nervous system and activation of the sympathetic nervous system. Electronic pupillometry also revealed an overactivation of the sympathetic nervous system on the affected side, just before the attacks. Analysis of sequential changes after the onset of an attack revealed that overactivation on the affected side was reduced after treatment, and no difference between affected and unaffected sides was observed 3 days after treatment.ConclusionDetailed analysis of autonomic nervous function showed that immediately before an attack of Ménière's disease, the sympathetic nervous system on the affected side was strongly overactivated.

The aim of this study was to classify unilateral vestibular neuritis (VN) with caloric testing, cervical vestibular evoked myogenic potentials (C-VEMPs) , ocular vestibular evoked myogenic potentials (O-VEMPs), and the video head impulse test (vHIT). Eight Patients (3 males and 5 females, mean age 55.6 years) with VN were studied. cVEMP and oVEMP (105 dBSPL 500 Hz short tone burst stimulation) were recorded. The caloric test and vHIT for the 3 semicircular canal were performed. The caloric test, cVEMP and oVEMP in combination with vHIT were able to allow the classification of 4 types of VN: entire VN, superior VN, inferior VN, and ampullary VN. In our case, 75 of the cases were entire VN, 12.5 were superior VN, and 12.5 were inferior VN. Three patients had only deficits of the horizontal and/or inferior semicircular canals or their ampullary nerves. One of eight VN patients had symptoms similar to benign paroxysmal positional vertigo after three weeks onset of VN. The results lead us to believe that clinical VN comprises vestibular neuritis and vestibular labyrinthitis. Currently, in Japan it would be essential that there is canal paresis in caloric test for VN diagnosis. We hope to include inferior VN within the diagnosis criteria of VN in the near future. video Head Impulse Test VEMP Evaluation of vestibular function using video Head Impulse Test, caloric test and VEMP in patients with vestibular neuritis

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Rotation testing was performed to evaluate the functions of the vestibular system by applying a rotational stimulation to a subject and observing the eye movements caused by the vestibulo-ocular reflexes (VORs). VORs comprise the semicircular-ocular reflex (ScOR) and the otolith-ocular reflex (OOR). When the subject's lateral semicircular canal is positioned horizontal to the ground and earth vertical axis rotation (EVAR) is applied, the lateral semicircular canal is stimulated by rotational acceleration, resulting in eye movements caused by the ScOR. In contrast, with off-vertical axis rotation (OVAR), the direction of gravitational acceleration changes continuously during rotation, which simultaneously stimulates the otolith organ. The resultant eye movements are caused by both the ScOR and the OOR. In previous studies, the application of conflicting visual vestibular stimulation using a flat screen under EVAR conditions did not show a significant change in the VOR gain after stimulation. In the present study, we applied conflicting visual vestibular stimulation (1 stimulation, 2 stimulation) using a flat screen under OVAR conditions and compared the VOR gain before and after stimulation. No significant change in the VOR gain was observed before and after 2 stimulation; however, a significant decrease in the VOR gain was observed after 1 stimulation. These results were obtained due to the effects of tilt suppression and because the conflicting visual vestibular stimulation we used was an appropriate form of stimulation to elicit the OOR. While various methods of vestibular rehabilitation have been reported for equilibrium disturbances, the effects of tilt suppression and whether the stimulation used for vestibular rehabilitation is an appropriate form of stimulation need to be considered. off-vertical axis rotation OVAR Effects of visual stimulation using a flat screen under off-vertical axis rotation conditions on the semicircular ocular reflex