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.
Distinguishing central and peripheral causes of dizziness is vital. A case is presented where a 42-year-old man with a history of posterior circulation ischemic stroke developed acute unilateral vestibulopathy with hearing loss. Clinical examination revealed signs of vestibular dysfunction on the left side. Audiometry confirmed deafness on the left, but imaging ruled out new central issues. The patient was diagnosed with audiovestibulopathy and treated with steroids, antiviral agents, intratympanic injections, and hyperbaric oxygen therapy. Hearing loss persisted, but dizziness improved with vestibular rehabilitation. Poststroke patients should be closely monitored for peripheral complications. Further research should explore the benefits of antiplatelet therapy in vascular-related conditions, even without clear central lesions.
Objectives Benign paroxysmal positional vertigo (BPPV) is one of the most common causes of dizziness. Even though the etiology of BPPV has been widely studied, the exact mechanism remains still unclear. One of the possible factors explaining the pathophysiology of BPPV is ischemia of vestibule. In the present study, we have focused on the platelet indices including mean platelet volume (MPV), platelet distribution width (PDW), and platelet crit (PCT) to assess a risk of vestibule ischemia causing BPPV.
Methods From January 2021 to March 2021, a retrospective review was performed on 39 patients diagnosed with BPPV through vestibular nystagmography. For each platelet indices, a comparative analysis was conducted between the patient group and control group.
Results There were no significant differences when the platelet, MPV, PDW, and PCT values were compared between the study and control group. Rather, the control group showed higher PDW value than the study group.
Conclusions Ischemia of vestibule is one of the well-known causes of BPPV, but the current study showed that BPPV cannot be explained by the vestibule ischemia itself. Further studies are needed to identify the potential of ischemia regarding BPPV by approaching with other methods with a large study group.
Autoimmune inner ear disease (AIED) is a rare disease, accounting for <1% of all cases of hearing impairment or dizziness. It is characterized by sensorineural hearing loss (SNHL) or vestibular dysfunction that results from an immunemediated process. Clinical features of AIED is SNHL that progresses over weeks to month with fluctuating hearing symptoms. Because there are no diagnostic laboratory and clinical feature, response to immunosuppressive therapy were important for diagnosis of AIED. Many diseases such as sudden SNHL and Meniere disease may also mimic AIED, a broad differential must be maintained in patients suspected of having AIED. We report a case of a 46-year-old female who presented with sudden hearing loss and vertigo. We could diagnose her as AIED with systemic lupus erythematous. The symptoms were improved treated with steroids.
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Sensorineural Hearing Loss of Suspected Autoimmune Etiology: Two Cases of Cogan’s Syndrome Jungmin Ahn, Brian Kim, Kyoung Rai Cho, Young-Soo Chang Korean Journal of Otorhinolaryngology-Head and Nec.2021; 64(12): 943. CrossRef
A Case of Autoimmune Sensorineural Hearing Loss Responding to Cytotoxic Agent Yong Woo Lee, Jin Lee, Min-Beom Kim, Sun O Chang Korean Journal of Otorhinolaryngology-Head and Nec.2019; 62(8): 470. CrossRef
Ménièreʼs disease is a poorly understood disorder of the inner ear characterized by intermittent episodic vertigo, fluctuating hearing loss, ear fullness and tinnitus. In this paper, we present a review of the histopathology, cytochemistry, gene, blood-labyrinthine barrier and imaging of Ménièreʼs disease. Histopathology is significant for neuroepithelial damage with hair cell loss, basement membrane thickening, perivascular damage and microvascular damage. Cytochemical alterations are significant for altered AQP4 and AQP6 expression in the supporting cell, and altered cochlin and mitochondrial protein expression. Since the discovery of aquaporin water channels (AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7 and AQP9), it has become clear that these channels play a crucial role in inner ear fluid homeostasis. Several gene studies related to Ménièreʼs disease have been published, but there is no clear evidence that Ménièreʼs disease is associated with a special gene. Currently, imaging techniques to determine the extent and presence of endolymphatic hydrops are being studied, and further studies are needed to correlate the visualization of the endolymphatic hydrops with clinical symptoms.
We describe a case of meningeal carcinomatosis of the internal auditory meatus
presenting as sudden deafness accompanied by dizziness. A 54-year-old woman
complained of acute right-side hearing loss in October 2014. The pure tone
audiometry test revealed right-side hearing loss of 47.5 dB. She was treated with
oral steroids. Her hearing as well as her symptoms of dizziness worsened and
she was admitted for further examination. Her right and left-side hearing had
worsened to 105.0 dB and 47.5 dB, respectively. A magnetic resonance imaging
scan of the head revealed bilateral enhancement of the internal auditory canal
and multiple brain metastases. The chest radiograph revealed a mass in the left
lung. Adenocarcinoma of the lung was diagnosed. Lumbar puncture yielded no
evidence of carcinoma cells in the cerebrospinal fluid, but an increased number
of lymphocytes was confirmed. A diagnosis of multiple brain metastases and
leptomeningeal metastasis from the adenocarcinoma of the lung was considered.
Whole-brain radiation therapy (30 Gr/10 fractions) was administered. Progressive
bilateral hearing loss is a rare first manifestation of meningeal carcinomatosis.
It is quite important to consider the possibility of this condition when patients
present with sudden deafness.
Congenital inner ear malformations are frequently found in patients with sensorineural hearing loss, but isolated vestibular anomalies with normal cochlear development have been rarely reported. We report a 20-year-old man with recurrent dizziness and disequlibrium without hearing impairment. Neuro-otological evaluations showed a left peripheral vestibulopathy with normal hearing function. Three dimensional volume rendering image using magnetic resonance constructive interference in steady state sequence demonstrated isolated vestibular anomalies involving bilateral horizontal semicircular canals. Isolated vestibular anomalies might not be as rare as previously thought among patients with recurrent dizziness, and should be carefully evaluated through various imaging techniques
Background and Objectives : Nowdays, numbers of patient who suffers from inner ear disease are increased and we need to completely understand about inner ear anatomy and embryology. But we have many problems to use human itself as a model, so it is difficult for us to study. Instead of using human as a model, recent days, many doctors use mammalians and birds. In this study, we used chicken embryo as a model whose inner ear was thought to be similar with human's inner ear and we made effort to get inner ear images by light microscope.
Materials and Method : We incubated Gallus domesticus in auto-incubator for 12days. In each embryonic day (4th to 12th days), we got the chicken embryo and made paraffin block. Next, with micro-tomb, we made slice section and fixed to slide. Using micro-digital camera system, we took the picture of the inner ear of chicken embryo.
Results : We observed the structures of inner ear of chicken embryo from 4th embryonic day to 12th embryonic day. In 4th day and 5th day, we could not get the definite clear image. But from 6th to 12th day, we got the clear images of utricle, saccule, semicircular canals, etc. In several micro-section methods, making oblique coronal section was showed the best images of inner ear.
Conclusion : This study was the start point of chicken inner ear embryology and anatomy. Hereafter, we should make the deeper study about chicken inner ear with these results and investigate the genetic and extrinsic factors which influence to inner ear disease. So we should solve the fundamental problem of inner ear disease based on this study.
Background and objectives : Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery (AICA) is known to be associated with vertigo, nystagmus, facial weakness, and gait ataxia. There have been few reports on deafness associated with the AICA infarction. Furthermore, previous neurological reports have not emphasized the inner ear as a localization of sudden deafness. The aim of this study was to investigate the incidence of deafness associated with the AICA infarction and the sites predominantly involved in deafness.
Materials and method : During two years we prospectively identified 12 consecutive patients with unilateral AICA infarction diagnosed by brain MRI. Pure tone audiogram, speech discrimination testing, stapedial reflex testing, and auditory brainstem responses were performed to localize the site of lesion in the auditory pathways. Electronystagmography was also performed to evaluate the function of the vestibular system.
Results : The most common affected site on brain MRI was the middle cerebellar peduncle (11). Four patients had vertigo and/or acute auditory symptoms such as hearing loss or tinnitus as an isolated manifestation from 1day to 2months prior to infarction. Audiological testings confirmed sensorineural hearing loss in 11 (92%) patients, predominantly involved the cochlea in 6 and retrocochlear in 1. The other 4 patients had a severe to profound hearing loss most likely of cochlear origin. Electronystagmography demonstrated no response to caloric stimulation in 10(83%) patients.
Conclusions : In our series, sudden deafness was an important sign for the diagnosis of the AICA infarction. Audiological examinations suggest that sudden deafness in AICA infarction is usually due to dysfunction of the cochlea, resulting from ischemia to the inner ear.