Tadashi Kitahara

Dr. Tadashi Kitahara


Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 January 2015 in Health and Quality of Life Outcomes
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Journal Article
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MKMasaki Kondo
Masaki Kondo
KKKensuke Kiyomizu
Kensuke Kiyomizu
FGFumiyuki Goto
Fumiyuki Goto
TKTadashi Kitahara
Tadashi Kitahara
TITakao Imai
Takao Imai
TATatsuo Akechi
Tatsuo Akechi
Dizziness or vertigo is associated with both vestibular-balance and psychological factors. A common assessment tool is the Vertigo Symptom Scale (VSS) -short form, which has two subscales: vestibular-balance and autonomic-anxiety. Despite frequent use, the factor structure of the VSS-short form has yet to be confirmed. Here, we clarified the factor structure of the VSS-short form, and assessed the validity and reliability of the Japanese version of this tool. We conducted a cross-sectional, multicenter, psychometric evaluation of patients with non-central dizziness or vertigo persisting for longer than 1 month. Participants completed the VSS-short form, the Dizziness Handicap Inventory, and the Hospital Anxiety and Depression Scale. They also completed the VSS-short form a second time 1–3 days later. The questionnaire was translated into Japanese and cross-culturally adapted. We conducted a confirmatory factor analysis followed by an exploratory factor analysis. Convergent and discriminant validity, internal consistency, and test-retest reliability were evaluated. The total sample and retest sample consisted of 159 and 79 participants, respectively. Model-fitting for a two-subscale structure in a confirmatory factor analysis was poor. An exploratory factor analysis produced a three-factor structure: long-duration vestibular-balance symptoms, short-duration vestibular-balance symptoms, and autonomic-anxiety symptoms. Regarding convergent and discriminant validity, all hypotheses were clearly supported. We obtained high Cronbach’s α coefficients for the total score and subscales, ranging from 0.758 to 0.866. Total score and subscale interclass correlation coefficients for test-retest reliability were acceptable, ranging from 0.867 to 0.897. The VSS-short form has a three-factor structure that was cross-culturally well-matched with previous data from the VSS-long version. Thus, it was suggested that vestibular-balance symptoms can be analyzed separately according to symptom duration, which may reflect pathophysiological factors. The VSS-short form can be used to evaluate vestibular-balance symptoms and autonomic-anxiety symptoms, as well as the duration of vestibular-balance symptoms. Further research using the VSS-short form should be required in other languages and populations.

7 November 2019 in Laryngoscope Investigative Otolaryngology
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Journal Article
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TITaeko Ito
Taeko Ito
HIHiroshi Inui
Hiroshi Inui
TMToshiteru Miyasaka
Toshiteru Miyasaka
TSTomoyuki Shiozaki
Tomoyuki Shiozaki
AHAkihito Hasukawa
Akihito Hasukawa
TKTadashi Kitahara
Tadashi Kitahara
Objective: Recently, 3‐Tesla magnetic resonance imaging (MRI) with intravenous gadolinium injection has been used to reveal endolymphatic hydrops (EH). In the present study, we aimed to evaluate EH in patients with Meniere's disease (MD) objectively and quantitatively, and compared the endolymphatic space (ELS) in individuals with MD and healthy controls, to gain understanding of the characteristics of MD.Methods: Eighty‐two patients with unilateral MD (uMD), 16 patients with bilateral MD (bMD), and 47 healthy volunteers were enrolled. All participants underwent 3‐T MRI at 4 hours after intravenous gadolinium injection. The volumes of the total fluid space (TFS) and ELS were measured semiautomatically using our workstation, and the percentage of ELS to TFS (ELS percentage) was calculated.Results: The ELS percentage was 13.9 in the ears of controls, 18.2 in the contralateral ear of individuals with uMD, 26.1 in the affected ears of these individuals, and 23.0 in both ears of individuals with bMD. The ELS percentages in the affected ear of uMD and the ears of bMD individuals were significantly higher than that in the ears of control individuals (P < .01, one‐way analysis of variance (ANOVA), Tukey's test).Conclusion: The ELS is significantly larger in the affected ears of uMD and in both ears of bMD individuals. Accurate diagnosis of MD can be facilitated by using 3‐T MRI 4 hours after intravenous gadolinium injection and performing volumetric measurements of the ELS.Level of Evidence: 2b

30 June 2016 in PLOS ONE
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Journal Article
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TKTadashi Kitahara
Tadashi Kitahara
HOHidehiko Okamoto
Hidehiko Okamoto
MFMunehisa Fukushima
Munehisa Fukushima
MSMasaharu Sakagami
Masaharu Sakagami
TITaeko Ito
Taeko Ito
TYToshiaki Yamanaka
Toshiaki Yamanaka
Meniere's disease, a common inner ear condition, has an incidence of 15–50 per 100,000. Because mental/physical stress and subsequent increase in the stress hormone vasopressin supposedly trigger Meniere's disease, we set a pilot study to seek new therapeutic interventions, namely management of vasopressin secretion, to treat this disease. We enrolled 297 definite Meniere's patients from 2010 to 2012 in a randomized-controlled and open-label trial, assigning Group-I (control) traditional oral medication, Group-II abundant water intake, Group-III tympanic ventilation tubes and Group-IV sleeping in darkness. Two hundred sixty-three patients completed the planned 2-year-follow-up, which included assessment of vertigo, hearing, plasma vasopressin concentrations and changes in stress/psychological factors. At 2 years, vertigo was completely controlled in 54.3% of patients in Group-I, 81.4% in Group-II, 84.1% in Group-III, and 80.0% in Group-IV (statistically I < II = III = IV). Hearing was improved in 7.1% of patients in Group-I, 35.7% in Group-II, 34.9% in Group-III, and 31.7% in Group-IV (statistically I < II = III = IV). Plasma vasopressin concentrations decreased more in Groups-II, -III, and -IV than in Groups-I (statistically I < II = III = IV), although patients’ stress/psychological factors had not changed. Physicians have focused on stress management for Meniere’s disease. However, avoidance of stress is unrealistic for patients who live in demanding social environments. Our findings in this pilot study suggest that interventions to decrease vasopressin secretion by abundant water intake, tympanic ventilation tubes and sleeping in darkness is feasible in treating Meniere’s disease, even though these therapies did not alter reported mental/physical stress levels. Trial Registration: ClinicalTrials.gov NCT01099046

1 June 2018 in Auris Nasus Larynx
Verified
Journal Article
Closed access
TKTadashi Kitahara
Tadashi Kitahara

1 April 2013 in Auris Nasus Larynx
Verified
Journal Article
Closed access
TMTakahiro Michiba
Takahiro Michiba
TKTadashi Kitahara
Tadashi Kitahara
NHNoriko Hikita-Watanabe
Noriko Hikita-Watanabe
MFMunehisa Fukushima
Munehisa Fukushima
YOYoshiyuki Ozono
Yoshiyuki Ozono
HIHidenori Inohara
Hidenori Inohara

27 October 2004 in Journal of Neurochemistry
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Journal Article
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AHArata Horii
Arata Horii
CMChisako Masumura
Chisako Masumura
Paul SmithPaul Smith
Paul Smith
CDCynthia L. Darlington
Cynthia L. Darlington
TKTadashi Kitahara
Tadashi Kitahara
TKTakeshi Kubo
Takeshi Kubo
To investigate the molecular background of vestibular compensation, a model of lesion‐induced plasticity, we used a microarray analysis to examine genes that show asymmetrical expression between the bilateral vestibular nucleus complexes (VNCs) 6 h following unilateral vestibular deafferentation (UVD). Asymmetrical gene expression was then validated by a real‐time quantitative PCR. Among the 88 genes for which the ipsilateral (ipsi) : contralateral (contra) was > 1.35, the number of known genes was 33 (38%), and the number of expressed sequence tag (EST) sequences was 55 (62%). Among the 130 genes for which the contra : ipsi was > 1.35, the number of known genes was 55 (42%), and the number of EST sequences was 75 (58%). Changes in some of the genes were consistent with previous studies; however, we found several new genes which could be functionally related to the molecular basis of the electrophysiological asymmetry between the VNCs following UVD. Ipsi > contra genes included the GABAA receptor rho subunit, regulatory proteins of G protein signaling, calcium signaling related molecules such as the voltage‐dependent calcium channel α2/δ subunit 1, calcineurin subunit Aβ and Ca2+ pump. Contra > ipsi genes included the neuronal high affinity glutamate transporter, 5‐hydroxytryptamine receptor 1D, mitogen‐activated protein kinase 12 and ubiquitin carboxy‐terminal hydrolase L1.