Akemi Sugita-Kitajima

Evaluation of the otolith function using sinusoidal off-vertical axis rotation in patients with benign paroxysmal positional vertigo

The vestibulo-ocular reflex (VOR) was studied via sinusoidal off-vertical axis rotation (OVAR) to evaluate the otolith function in patients with benign paroxysmal positional vertigo (BPPV). Subjects were sinusoidally rotated with eyes open in complete darkness at frequencies of 0.4 and 0.8 Hz with a maximum angular velocity of 60 degrees s(-1) in earth-vertical axis rotation (EVAR) and OVAR. Twenty-three controls and 24 BPPV patients were investigated. Results showed that VOR gain during OVAR at 0.8 Hz in a 30 degrees nose-up position in BPPV patients was significantly less than the gain during EVAR, whereas the gain was not significantly different between EVAR and OVAR in the controls in each condition. In addition, to examine each type of BPPV, we also investigated whether there were any differences between the patients who suffered from dizziness and those who did not. VOR gain in OVAR of BPPV patients who were suffering from dizziness was significantly less than that of BPPV patients without dizziness. Not only cupulolithiasis or canalolithiasis, but also otolith dysfunction was considered to be the possible origin of BPPV. Because sinusoidal OVAR produced minimal nausea compared to constant velocity OVAR, the stimulation of 0.8 Hz nose-up in sinusoidal OVAR may be used to evaluate otolith function without discomfort for patients.

Does vertigo disappear only by rolling over? Rehabilitation for benign paroxysmal positional vertigo

Conclusion. We propose that the rolling-over maneuver (ROM) is as effective as the canalith repositioning maneuver (CRP) for the treatment of benign paroxysmal positional vertigo (BPPV). ROM involves easy movements, with only a small load. This therapy is suitable for most BPPV patients, even for those without an indication for CRP. Objectives. BPPV is a common vestibular disorder. CRP is known to be an effective therapy for the treatment of BPPV. Because of its various movements of the head and body, it is impossible to perform CRP in BPPV patients with orthopedic impairments or in the elderly. For these patients, we perform a maneuver called ROM, which involves easy movements. In this study, we compared the efficacy of ROM with that of CRP in patients with posterior semicircular canal-type BPPV. Patients and methods. The study included 22 patients with BPPV who were randomized and divided into the following 2 groups: 1) those treated by the modified Epley maneuver as CRP; and 2) those treated by ROM. Results. We found no significant difference between the two groups in the number of days from onset to remission of both nystagmus and vertigo.

Somatosensory input influences the vestibulo-ocular reflex

To evaluate the influence of somatosensory input on the vestibulo-ocular reflex (VOR), we used sinusoidal rotation tests in 19 young, healthy volunteers. For the control condition, subjects were sinusoidally rotated in complete darkness and with eyes opened at a frequency of 0.2 Hz with a maximum angular velocity of 30 degrees /s for 30s, and at frequencies of 0.4 and 0.8 Hz with a maximum angular velocity of 60 degrees /s for 30s. Sinusoidal tests were performed at earth vertical axis rotation (EVAR). For the experimental condition, we introduced somatosensory stimulation as subjects were sinusoidally rotated at the control parameters. Subjects were told to grasp an earth-fixed metallic bar with their right hands. Thus, their right arms continued to move as the rotating chair apparatus moved. We observed a significant increment (34%) in VOR gain change only at 0.2 Hz EVAR when subjects held the bar compared to that of the controls, who did not hold the bar. Gain change did not differ significantly across the other conditions. We hypothesize that arthrokinetic input (i.e., arm movement) had an additive effect on VOR in this study. This input might relate to a low-frequency component that strongly enhances the velocity storage system. Our findings have applications to types of vestibular rehabilitation regimens that implement somatosensory input.

Evaluation of the vestibulo-ocular reflex using sinusoidal off-vertical axis rotation in patients with acoustic neurinoma.

The vestibulo-ocular reflex (VOR) was studied to examine the utility of off-vertical axis rotation (OVAR) in the diagnosis of acoustic neurinoma. Subjects were sinusoidally rotated with eyes open in complete darkness at frequencies of 0.4 and 0.8 Hz with a maximum angular velocity of 60 degrees /s at either earth-vertical axis rotation (EVAR) or OVAR. Thirteen patients with acoustic neurinomas were investigated. Results showed that VOR gain during OVAR at 0.8 Hz and in a 30 degrees nose-up position in patients with internal auditory canal tumors was significantly less than the gain measured during EVAR. The VOR gain measured from all patients (including those with tumors extending to the cerebellopontine angle) was not significantly different when the patients were subjected to EVAR and OVAR. These observations were possibly due to superior vestibular nerve dysfunction. We concluded that certain stimulating parameters--patients nose tilted up 30 degrees; sinusoidal OVAR at 0.8 Hz and 60 degrees /s maximum angular head velocity--were useful for evaluating vestibular function in patients suffering from an acoustic neurinoma located within the internal auditory canal.

Evaluation of the vestibulo-ocular reflex using sinusoidal off-vertical axis rotation in patients with canal paresis.

OBJECTIVE The vestibulo-ocular reflex (VOR) was studied to determine the utility of off-vertical axis rotation (OVAR) in evaluating vestibular function in patients with canal paresis (CP). Our goal was to determine whether there is any correlation between caloric responses and sinusoidal rotatory responses. METHODS Subjects were rotated in a sinusoidal pattern with eyes open in complete darkness. Frequencies of 0.4 and 0.8Hz with a maximum angular velocity of 60°/s at either earth-vertical axis rotation (EVAR) or OVAR were used. RESULTS Twenty-three control subjects and 21 patients with CP were investigated. Results showed that (1) the VOR gain difference between EVAR and OVAR in the CP patients was not significant at 0.4Hz and at 0.8Hz; (2) the gain during 0.4Hz EVAR was less in the bilateral CP patients compared to controls; and (3) the VOR gain of the affected side at 0.8Hz was significantly less during OVAR than during EVAR. CONCLUSION We concluded that the absence or reduction of caloric responses does not indicate the absence of vestibular function. In addition, separation analysis of the VOR gain of affected and intact sides is useful for evaluating laterality of otolith function in patients with CP.

Neuro-Behçet's disease with dizziness

A 30-year-old man had complete-type Behçets disease since he was 23 years old. Disease signs and symptoms were well controlled. After experiencing no symptoms for some years, however, he experienced dizziness, headache, fever, dysarthria, right facial nerve palsy, and right tinnitus. He showed spontaneous horizontal-rotatory nystagmus directed toward the right side, and upbeat nystagmus. T2-weighted and fluid-attenuated inversion recovery MRI showed slight hyperintense signals in the medulla oblongata, pons, and left midbrain. Neurological involvement in Behçets disease was diagnosed.

A case of patulous Eustachian tube associated with dizziness induced by nasal respiration

OBJECTIVE To determine the relationship between Eustachian tube function and inner ear function in patulous Eustachian tube (pET). METHODS We encountered a patient with pET accompanied by dizziness that was induced by nasal respiration. Eye movements were recorded using video-oculography, and Eustachian tube function was assessed using a Eustachian tube function analyzer. Horizontal and vertical components of pupil position were assessed to test fixation, positional, and positioning nystagmus. Impedance testing with a Eustachian tube function analyzer was performed to confirm tympanometry results. We recorded these outcomes until the patients symptoms improved. RESULTS When pET improved, the patients symptoms were alleviated. CONCLUSION The present pET patient had mild vestibular symptoms. Therefore, pET patients with dizziness might be misdiagnosed with, for example, superior semicircular canal dehiscence, psychogenic vertigo, or Ménières disease. For patients with few clinical symptoms or laboratory findings, clinicians need to consider dizziness-induced pET as a possible diagnosis.