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Original Articles
- Unilateral Vestibulopathy Mimicking Inner Ear Ischemia Modeling Using Photothrombosis and Behavioral Assessment Using EthoVision
- Min Seok Song, Min Young Lee, Ji Eun Choi, So-Young Chang, Jae-Hun Lee, John Patrick Cuenca, Nathaniel T. Carpena, Jae Yun Jung
- Res Vestib Sci. 2023;22(4):112-119. Published online December 15, 2023
- DOI: https://doi.org/10.21790/rvs.2023.22.4.112
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Abstract
PDF - Objectives
Inner ear ischemic animal models using photochemical reactions have been devised in various ways. Localized vascular ischemia occurs with 532-nm laser irradiation after systemic rose bengal injection, a known photothrombotic mechanism. The aim of this study is to evaluate a photothrombosis-induced vestibulopathy mimicking behavioral changes in the inner ear ischemia model.
Methods
Seven-week-old male Spraque-Dawley rats were used. Animals were divided into three groups: control group (n=6), sham laser group (n=9), and laser group (n=9). To induce the photothrombosis, animals were injected with rose bengal into the femoral vein and then were irradiated with a 532-nm laser (175 mW for 900 seconds) via transtympanic membrane. To investigate the vestibulopathy after photothrombosis, the behavior tests (tail lift reflex test, air righting reflex test, rotarod test) were performed on the 1st, 3rd, and 7th days after surgery. Additionally, an open field test was conducted and analyzed using EthoVision XT (Noldus).
Results
The laser group exhibited significant behavioral change to mimic vestibulopathy in all assessments. Inducing photothrombosis with rose bengal caused severe gait instability, which precluded rotarod testing. In the tail lift reflex test, the laser group displayed vestibular dysfunction with a lower angle formation compared to the control rats. During the open field test, the laser group exhibited reduced mobility, a condition that persisted in the laser groups for 7 days.
Conclusions
Noninvasive laser irradiation using rose bengal and a 532-nm laser induces photothrombosis in the inner ear of animals, leading to the development of vestibulopathy mimicking imbalanced behavior.
- Sleep and Vestibular Neuritis
- Hyun Ah Kim, Hyung Lee
- J Korean Bal Soc. 2006;5(1):44-48.
- 3,304 View
- 21 Download
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Abstract
PDF
- Background
and Objectives: While it is known that sleep have influence on emergence of rapid eye movements(REMs), namely saccades including fast component of nystagmus, whether spontaneous nystagmus due to vestibular imbalance presents during sleep is still unclear. The purpose of our study was to investigate whether tonic vestibular imbalance appeared as spontaneous nystagmus during the wakeful state could present during REM sleep. Materials and Method: Overnight polysomnography (PSG) was performed in 7 patients with spontaneous nystagmus due to vestibular neuritis (VN) and 7 control patients without dizziness or any nystagmus. The numbers of horizontal saccades were counted, during 3 minutes samples of the alert state before and after the PSG and the first and last REM sleep.
Results
All patients with VN showed significantly more saccades (fast phases of spontaneous nystagmus) towards the side contralateral to their vestibular lesion in the awake state before and after the PSG compared with control group. By contrast, during REM sleep the patients with VN showed no preponderance in saccade direction (p<0.05). Some brief nystagmoid jerks showed during REM sleep in both patients and controls equally and also had no preponderance in direction.
Conclusion
The tonic vestibular imbalance at peripheral level observed during alert state does not appear at the brainstem level during REM sleep. It is suggested that a de-afferentation of the peripheral vestibular input to the REM sleep generating areas may explain an absence of nystagmus during REM sleep in patients with VN. Key Words : Vestibular imbalance, Nystagmus, REM sleep
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