Research in Vestibular Science

Vestibular Rehabilitation for Patient with Bilateral Peripheral Vestibular Deficit: Hyun Woo Park, Seong Ki Ahn; Res Vestib Sci. 2016;15(1):1-4.

Abstract PDF: Bilateral vestibular deficit affects far fewer patients than unilateral deficit, and thus has been understudied. When bilateral vestibular organs are injured, loss of input of vestibulo-ocular and vestibulo-spinal reflex that normally stabilize the eyes and body, affected patients suffer blurred vision during head movement, postural instability, and disequilibrium. Vestibular rehabilitation therapy is an exercise-based treatment program designed to promote vestibular adaptation and substitution. The rationale for the exercises, which originated from the observation that patients who were active recovered faster, was based on the supposition that the head movements that provoke the patient’s dizziness play an important role in hastening the recovery process. Here the author reviews the clinical manifestation and treatment of bilateral vestibular deficit that include vestibular rehabilitation therapy and vestibular device that studied today.

Functional Neuroimaging in Neuro-Otology: Jae Jin Song; Res Vestib Sci. 2016;15(1):5-10.

Abstract PDF: Neuro-otologic symptoms such as dizziness, hearing loss, or tinnitus give rise to peripheral change-induced neuroplasticity or central pathology-induced structural or functional changes. In this regard, functional neuroimaging modalities such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), quantitative electroencephalography (qEEG), or functional near infrared spectroscopy have provided researchers with possibility to observe neuro-otologic disease-induced central functional changes. Among these methods, PET and fMRI are advantageous over qEEG or MEG with regard to spatial resolution, while qEEG and MEG are advantageous over PET or fMRI with regard to temporal resolution. Also, fMRI or MEG is not suitable for patients with implanted devices, whereas PET is not ideal for repetitive measures due to radiation hazard. In other words, as these modalities are complementary to one another, researchers should choose optimum imaging modality on a case by case basis. Hereinafter, representative functional neuroimaging modalities and their application to neuro-otologic research will be summarized.

Vestibulo-Ocular Reflex Recordings of Small Rodents using a Novel Marker Array: Mi Joo Kim, Jiyeon Lee, Eui Jae Hong, Eun Ji Lee, Yu Jin Min, Dong Ju Lee, Nam Beom Kim, Gyu Cheol Han; Res Vestib Sci. 2016;15(1):11-16.

Abstract PDF: Objective: Recording the nystagmus of small experimental rodents is an integral technique in vestibular research. Theoretically, the size and the shape of markers strongly affect the analysis of 3 dimensional nystagmus.
Methods
The nystagmus of 6 healthy ICR mice were recorded and their gain values were compared using 200 μm, 300 μm, 400 μm, and 600 μm isosceles triangle markers at the peak velocity of 60o/sec and 100o/sec with the rotational stimulations of 0.1 Hz, 0.2 Hz, and 0.5 Hz.
Results
The gain values of 3 different sizes of the markers showed no significant differences in horizontal- vertical-torsional component. However, it was unable to record the nystagmus with 200 μm markers since the markers were too small to be placed and stayed on the center of the pupils.
Conclusion
Technicians can decide the size of the markers from 200 to 600 ?m to record the nystagmus of mice, depending on the technicians’ skills.

Long-Term Outcomes of Canalith Repositioning for Benign Paroxysmal Positional Vertigo: Kaplan-Meier Estimate: Gu Il Rhim; Res Vestib Sci. 2016;15(1):17-21.

Abstract PDF: Objective: The objective of this study is to determine the long-term recurrence rate of benign paroxysmal positional vertigo (BPPV) and the factors associated to such recurrence.
Methods
Retrospective review was performed for 295 patients diagnosed as idiopathic BPPV. After successful resolution by particle repositioning maneuver, all patients were followed up by visiting clinic or telephone. A study period was 1?56 months and average follow up period for study population after the initial treatment was 26 months. The rate of recurrence was estimated according to the
method
of Kaplan-Meier and compared by the log-rank test.
Results
Overall recurrence rate by Kaplan-Meier estimate was 50% at 30 months. Kaplan-Meier estimate suggests the effect of patient age, sex and visit of treatment sessions in initial episode on BPPV recurrence over 3 year follow-up period. Recurrent rate was significantly higher in patients aged 40 years or older (p＜0.013) and in patients with three or more visit of treatment sessions (p＜0.015). However, there was no significant association between recurrence rate and sex.
Conclusion
The long-term recurrence of BPPV was associated with age above 40 years and the number of visit for treatment sessions. This finding suggests that the recurrence of BPPV may be related with aging process.

A Case of Dolichoectasia of Vertebrobasilar Artery Presenting Simultaneous Bilateral Sudden Sensorineural Hearing Loss with Vertigo: Bum Ki Cho, Oh Joon Kwon, Dong Hyun Kim, Chang Woo Kim; Res Vestib Sci. 2016;15(1):22-26.

Abstract PDF: Sudden sensorineural hearing loss (SNHL) develops usually in unilateral ear without known etiology. In contrast, bilateral sudden SNHL is mostly related to serious systemic diseases and have a severe hearing loss and poor prognosis compared than unilateral one. We describe here a 59-year-old man presented with a bilateral sudden SNHL and vertigo possibly attributed to dolichoectasia in vertebrobasilar artery, and discuss the possible mechanism.

Periodic Alternating Nystagmus in Patients with Cerebellar Abscess: Hyung Lee, Hyun Ah Kim; Res Vestib Sci. 2016;15(1):27-29.

Abstract PDF: Periodic alternating nystagmus (PAN) is characterized by a periodical reversal in the direction of the nystagmus. Acquired PAN is caused by lesions of the inferior cerebellar vermis, causing disinhibition of the velocity storage mechanism, which is mediated by the vestibular nuclei. An eighty-year-old woman with abscess in midline cerebellum experienced dizziness and imbalance. We observed short period PAN with 7?8 seconds.

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