Objectives Vertigo is a common condition. Definitive treatment is to induce vestibular compensation. Currently, no medications have been discovered that enhance vestibular functional restoration. The current study was conducted to evaluate the ability of ordinary Korean red ginseng (KRG) to induce vestibular compensation.
Methods Twelve Sprague-Dawley rats were divided into two groups. Five rats (KRG group) were fed KRG extract (100 mg/kg) for 2 weeks before undergoing unilateral labyrinthectomy (ULx). The remaining seven rats (control group) were untreated before ULx. After surgery, all animals were housed in the same environment without being fed additional extract. To evaluate vestibular function, gain of the horizontal nystagmus to 0.2 Hz with a peak velocity of 100°/second sinusoidal rotation was compared and analyzed before ULx as well as 3 and 7 days after surgery.
Results Before the operation, gain of the control and KRG group were 0.81±0.05 and 0.88±0.08, respectively, with 0.2-Hz stimulation. This value decreased to 0.43±0.08 and 0.53±0.08, respectively on 3 days after operation (p=0.047), and it was 0.40±0.06 and 0.68±0.11, respectively on 7 days after surgery. The difference of gain between the two groups was statistically significant at each 3 and 7 days (p<0.05). By confirming c-Fos protein expression in medial vestibular nuclei, the functional effect of KRG causing vestibular modulation was confirmed.
Conclusions Rats treated with KRG showed more rapid and complete recovery after acute vestibular loss compared to untreated animals. Therefore, KRG could be one of candidate for the useful medication of vestibular diseases.
Objectives We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure.
Methods Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure.
Results The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO2 laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group.
Conclusions This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.
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Galvanic Vestibular Stimulation Improves Spatial Cognition After Unilateral Labyrinthectomy in Mice Thanh Tin Nguyen, Gi-Sung Nam, Jin-Ju Kang, Gyu Cheol Han, Ji-Soo Kim, Marianne Dieterich, Sun-Young Oh Frontiers in Neurology.2021;[Epub] CrossRef
The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice Thanh Tin Nguyen, Gi-Sung Nam, Jin-Ju Kang, Gyu Cheol Han, Ji-Soo Kim, Marianne Dieterich, Sun-Young Oh Frontiers in Neurology.2021;[Epub] CrossRef
Objectives : We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, SCC occlusion and 4G hypergravity exposure.
Methods : ICR mice(n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery and the last group was exposed to 4G hypergravity for two weeks. The movement of mice were recorded using camera in Y maze which had 3 radial arms. We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure.
Results : The bilateral labyrinthectomy group which semicircular canal & otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO2 laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group.
Conclusion : This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.
Objective: Mèniére's disease is one of the most common causes of episodic vestibular syndrome that shows symptom complexes of recurrent vertigo, hearing loss, tinnitus and ear fullness. Isosorbide (Isobide) is a osmotic diuretics which has been used for Meniere's disease to reduce the endolymphatic pressure. The purpose of this study was to evaluate the efficacy of isosorbide in the treatment of Mèniére's disease by comparing the combined therapy of isosorbide and betahistine (Meniace) to betahistine only.
Methods Among 220 patients enrolled with Mèniére's disease from 9 centers, 187 patients completed this clinical study. Patients were randomly subjected either to betahistine alone therapy at dose of 6 mg three times a day (n=97) or to combined therapy with isosorbide (dose of 30 mL three times a day) and betahistine (n=90) for 12 weeks. Two groups were compared at 4 and 12 weeks after treatment on frequency of vertigo, hearing level (pure tone audiometry, speech audiometry), electocochleography (ECoG), tinnitus (Tinnitus Handicap Inventory, THI) and quality of life (Korean functional level scale, Korean dizziness handicap inventory).
Results During first 4 weeks after treatment, the frequency of vertigo was not reduced in either betahistine alone therapy group or combined therapy group. However, between 8 and 12 weeks, the frequency of vertigo was significantly reduced in either group, and in the combined group frequency of vertigo was more significantly reduced than in the betahistine alone therapy group (p=0.041). The hearing level, ECoG, tinnitus and quality of life was not significantly different between two groups.
Conclusion Isosorbide and betahistine combined therapy were more effective for vertigo control than betahistine alone therapy. Isosorbide is an effective diuretic in vertigo control in definite Mèniére's disease.
Benign paroxysmal positional vertigo (BPPV) is diagnosed when vertigo and typical nystagmus are elicited by the positional maneuvers. Otherwise, the others unexplainable nystagmus beyond the typical form was called “atypical form” BPPV. The reports of atypical form in BPPV have been decreased according to expansion of knowledge or experience about various BPPV. Atypical BPPV include the switch or transitional, bilateral, and multi-canal type BPPV. Recently those complicated BPPV have been investigated by 3D video nystagmography and high resolution magnetic resonance image. Although we could not fully understand the etiology and pathophysiology of BPPV, These efforts to define the atypical BPPV should be helpful to grow up background knowledge of physician.
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.
Therefore, by establishing method that enables to track and observe quantified VSR, the reliability of experiment is attempted to be increased. Materials and Methods:On five SD Rats to measure electromyogram (EMG), electrodes, in the form of stranded cables composed of seven wires, are chronically implanted on both sides of the soleus muscles. Pre and post operative condition of sitting still, standing, and ladder step walking was compared before, and six and twenty four hours after a unilateral labyrinthectomy with quantified muscle activity in maximal voluntary activity. Simultaneously by using multi modality electric potential plus package, the muscle activity between the two legs was tracked and compared. Results: In the sitting still position, the left/right soleus muscle activities were 25.7/26.0 μV before a unilateral labyrinthectomy which was changed after the surgery with the value of 23.1/8.1 μV and 23.4/14.3 μV when six and twenty four hours passed respectively. In the standing position, 92.8/124.0 μV of preoperative value was changed to 89.6/37.3 μV six hours after the unilateral labyrinthectomy, and it was 97.0/54.7 μV 24 hours after. The preoperative value in ladder step walking test was 56.2/86.0 μV, and postoperative ones were 54.9/21.2 μV and 55.7/38.0 μV after six and twenty four hours respectively. Conclusion: VSR assessment method by using quantitative EMG well reflects the process of vestibular compensation, and to maintain the tension of extensor muscles, ladder step walking test is shown to be useful.
Background and Objectives: A typical side effect of super high magnetic field is dizziness and it is expected that 7 Tesla (T) super high magnetic field will have temporary influence on vestibular nucleus. Prevalence rate of dizziness generally increases with advancing years, so this study discusses whether the influence of 7 T super high magnetic field differs depending on the age.
Materials and Methods: C57BL/6 mice weighting from 10-40 g were categorized into 4-week-old and 16-week-old groups. They were exposed to 7 T magnetic field and immunohistochemical staining was done to observe expression of c-fos protein in vestibular nucleus of mice.
Results: Control group with normal vestibular system did not show c-fos protein. However, mice exposed to 7 T magnetic field showed c-fos expression selectively on medial and lateral parts of vestibular nucleus and there was no significant difference of c-fos expression between both sides (p<0.05). There was statistically significant difference between the different age group: 16-week-old mice group showed higher number of cells expressing c-fos protein than 4-week-old mice group did (p<0.05).
Conclusion: It is statistically significant that 7 T super high magnetic field is more influential to older age group.
Background and Objectives: In this research, movements of mouse after labyrinthectomy were analyzed to determine the degree of vestibular dysfunction and compensation. Materials and Methods: By using an infrared lamp, mouse movements were recorded for 100 seconds in a dark room. The experimental area was manufactured as a circular space with a diameter of 60 cm. The movements of five mice labyrinthectomized on right side were observed and recorded at 3 hours, 9 hours and 120 hours after the operation, and also the ten mice of control group. Results: The differences between the total moving distances and the rotating angle from the origin that set the center of round field between groups were analyzed with pictures of 1 frame per second. It is concluded that all 4 groups show significant differences between its mean rotation angle and total moving distances statistically. At 9 hours after right labyrinthectomy, mice tended to turn clockwise; but at 120 hours, there was no significant difference between clockwise and counter-clockwise rotation. Conclusion: Measuring the movement of mouse in round free field can be the proper method to determine the degree of vestibular dysfunction and vestibular compensation. This test was time-saving and cost-effective method.
This controversial diagnosis centers around the phenomenon of perilymph leaking from the inner ear into the middle ear cleft through the oval window, round window or other fissures in the bony labyrinth that may be abnormally patent. A perilymph fistula may develop after stapedectomy surgery, penetrating middle ear trauma, head trauma, barotrauma, or possibly spontaneously. Uncertainty regarding the clinical criteria for the diagnosis and the inability to document the presence of a microfistula at surgery contribute to the problematic nature of this diagnosis. However, this condition should be seriously considered in the patient with vertigo after head trauma, barotrauma injury, or previous middle ear surgery. It is particularly likely in patients with penetrating middle ear trauma with vertigo. Most authors agree that perilymph fistulas generally heal spontaneously, therefore a few days of bed rest is appropriate in acute cases. Cases suspected after penetrating trauma should be explored early if symptoms persist. Here, authors report a case of multiple perilymph fistula possibly caused by tympanostomy tube insertion in a 48-year-old man with a review of the literature.
Endolymphatic hydrops is believed to be underlying pathophysiology of Meniere’s disease. The degree of endolymphatic hydrops observed by MRI (magnetic resonance imaging) in patients with Meniere’s disease offers a new method to study the progression of Meniere’s disease. There have been multiple attempts to diagnose Meniere’s disease with the help of radiologic tests including MRI in Korea. We describe a case report of a patient with Meniere’s who showed changes of endolymphatic sac in MRI after endolymphatic sac decompression.
Multicanal BPPV (benign paroxysmal positional vertigo), especially BPPV affecting both labyrinths, is uncommon. A review of the literature revealed that the majority of reported cases of multiple BPPV either involved a combination of two different canals limited to one labyrinth or two different canals in both labyrinths, although one case of multicanal BPPV was reported to involve three canals bilaterally. Here, the authors report a case of bilateral posterior canalolithiasis and unilateral horizontal canal cupulolithiasis in a 54-year-old man, and include a review of the literature.
Sung Kwang Hong, Eui Kyung Koh, Kyu Sung Kim, Kyoung Ho Park, Hong Ju Park, Seong Ki Ahn, Joong Ho Ahn, Won Sang Lee, Gi Jung Im, Jae Yun Jung, Won Ho Chung, Gyu Cheol Han, Sung Won Chae, Ja Won Koo
Background and Objectives: It is hard to determine the efficacy of several treatment options of Ménière’s disease since dynamic course of the disease and diverse rate of recurrence. Few modalities are regarded as ‘effective’ in the viewpoint of evidence based medicine. Study was conducted to know the current status of treatment options for Ménière’s disease.
Materials and Methods: A multicenter survey was conducted using questionnaires to collect information on current status of treatment patterns in Ménière’s disease. The questionnaire answered by neurotologic surgeons working at 12 institutes in Korea was analyzed.
Results: Low salt diet was always instructed to their patients, but 8 out of 12 responders (67%) did not emphasis on the amount of dietary salt. Duration of pharmacotherapy was ranged from 3 to 12 months. Intratympanic steroid injection was performed in 8 institutes (67%). Every institute agreed on the role of intratympanic gentamicin application. Treatment options for intractable patients were asked. Endolymphatic sac surgery, intratympanic steroid, Meniette device and intratympanic aminoglycoside injection were answered in patients who hope to preserve residual hearing. On the contrary, in patients without serviceable hearing, intratympanic jnjection of aminoglycosides (9/12, 75%) dominated as the next treatment option.
Conclusions: Most institutes provide similar patterns of practice in medical treatment. The application of intratympanic aminoglycoside is also agreed in intractable patients without serviceable hearing. However, thoughts about the role and detailed methods of the surgical and adjunctive treatment options were not agreed, especially in intractable patients with good hearing. Further clinical studies and discussions would be necessary to provide consensus for the best treatment of Ménière’s disease in Korea.
Key words : Ménière’s disease, Pharmacotherapy, Surgery, Aminoglycosides
Background and Objectives: The acute unilateral vestibular neuritis is fairly a common disease and the precise diagnostic tool is needed for the selection of effective treatments. Therefore, we studied the clinical usefulness of the rotatory chair test and caloric test which have been commonly used in patient of acute unilateral vestibular neuritis.
Materials and Methods: One hundred and sixty four patients who were diagnosed with acute unilateral vestibular neuritis from August of 2004 to June of 2007 were included. Their medical records of the rotating chair test and caloric test were reviewed retrospectively to study the correlation of the two tests.
Results: Of 164 patients, 101 patients (61.6%) and 88 patients (53.7%) showed significant canal paresis (CP) and directional preponderance (DP) on the caloric tests that corresponded with the physical exam. 130 patients (79.3%) and 84 patients (51.2%) showed significant asymmetry and time constant (Tc) on the rotating chair test that corresponded with the predictive direction with spontaneous nystagmus.
Conclusions: For acute unilateral vestibular neuritis patients, the asymmetry of the rotatory chair test showed the highest correlation with clinical findings. But physical exam should be preceded because neither rotator chair test nor caloric test yields a specific correlation with the physical exam. Especially, single test only may too many false negative results. For these tests can reduce false positive cases of the physical exam and raise the specificity of the diagnosis, the planning of proper treatments should be followed thereafter.