Ken Kitamura

Tsuchiura Kyodo General Hospital, Tsukuba, Ibaraki, Japan

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Publications (182)188.86 Total impact

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    ABSTRACT: Factitious disorders are characterized by intentionally abnormal physical and/or psychological behavior, and affected patients often make up their symptoms and clinical histories. The most serious and chronic type of factitious disorder is Munchausen syndrome. We report the case of a 24-year-old woman with a 2-year history of sensorineural hearing loss (SNHL) who later confessed to feigning her hearing loss. She was eventually diagnosed with a factitious disorder. During those 2 years, she was able to induce her SNHL by exposing herself to excessive noise or high doses of aspirin. To the best of our knowledge, this is the first report describing an association between a factitious disorder and SNHL.
    No preview · Article · Dec 2015 · Ear, nose, & throat journal
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    ABSTRACT: The objective of the present study was to clarify the features of otological complications for hyperbaric oxygen therapy (HBOT) and the risk factors for these complications. We enrolled 1115 patients (776 males and 339 females; age 5–89 years) who underwent HBOT. All otological symptoms experienced during HBOT sessions were evaluated, and risk factors were analysed using multivariate logistic regression analysis. Otoscopic findings and interventions for otological complications were assessed in 58 symptomatic patients who visited the Otolaryngology Department. Otological symptoms were experienced by 165 (14.8 %) of the 1115 patients. The multivariate logistic regression analysis identified ages of >60 years and female sex as independent risk factors, whereas patients with sports injuries were at lower risk than those with other primary diseases, except for severe infectious disease. Eighty-two patients (49.7 %) suffered from symptoms at the first HBOT session. The most prevalent symptoms were otalgia (157/165), followed by ear fullness (13/165), hearing loss (12/165) and tinnitus (3/165). One patient experienced vertigo and deterioration of the bone-conduction pure-tone thresholds, suggesting inner ear barotrauma. In 116 ears of the 58 symptomatic patients, abnormal otoscopic findings were recognized in 58 ears (50.0 %). Twenty-seven of the 58 ears required myringotomy or tube insertion, and HBOT was stopped in eight ears in four patients. Of the remaining 58 ears with normal otoscopic findings, 51 received no treatment. Physicians should be aware of both middle and inner ear barotrauma as potential complications of HBOT.
    No preview · Article · Dec 2015 · Archiv für Klinische und Experimentelle Ohren- Nasen- und Kehlkopfheilkunde
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    ABSTRACT: Objective: To assess possible delayed recovery of the maximum speech discrimination score (SDS) when the audiometric threshold ceases to change. Methods: We retrospectively examined 20 patients with idiopathic sudden sensorineural hearing loss (ISSNHL) (gender: 9 males and 11 females, age: 24-71 years). The findings of pure-tone average (PTA), maximum SDS, auditory brainstem responses (ABRs), and tinnitus handicap inventory (THI) were compared among the three periods of 1-3 months, 6-8 months, and 11-13 months after ISSNHL onset. Results: No significant differences were noted in PTA, whereas an increase of greater than or equal to 10% in maximum SDS was recognized in 9 patients (45%) from the period of 1-3 months to the period of 11-13 months. Four of the 9 patients showed 20% or more recovery of maximum SDS. No significant differences were observed in the interpeak latency difference between waves I and V and the interaural latency difference of wave V in ABRs, whereas an improvement in the THI grade was recognized in 11 patients (55%) from the period of 1-3 months to the period of 11-13 months. Conclusion: The present study suggested the incidence of maximum SDS restoration over 1 year after ISSNHL onset. These findings may be because of the effects of auditory plasticity via the central auditory pathway.
    No preview · Article · Dec 2015 · Auris, nasus, larynx
  • Yurika Kimura · Nao Makino · Hitome Kobayashi · Ken Kitamura
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    ABSTRACT: We report the case of an 84-year-old female presenting with an aberrant ICA with cerebral air embolization caused by Eustachian tube air inflation (ETAI). High pressure of air inflation developed because of an aberrant ICA blocking the tympanic orifice of the Eustachian tube, with release of the high-pressure air into the aberrant ICA. It must be kept in mind that complications may occur not only during transtympanic treatment, but also in any treatment, such as ETAI, in aberrant ICA cases.
    No preview · Article · Nov 2015 · Auris, nasus, larynx
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    ABSTRACT: Objective: To characterize the long-term outcomes of meatoplasty using our new technique, inferiorly based retroauricular island pedicle flap for external auditory canal (EAC) stenosis. Methods: A long-term clinical analysis of meatoplasty for nine patients (mean age, 33 years; age range, 8-64 years) with stenotic EAC was performed. The follow-up period after meatoplasty ranged from 5 years to 14 years, with a mean duration of 8.4 years. We compared preoperative and postoperative otoscopic findings, high-resolution computed tomographic (CT) images of the EAC, and hearing levels. Results: Otoscopic examinations demonstrated widened EAC in eight of the nine patients. There was a significant increase in the size of the EAC on postoperative CT examinations when compared with the preoperative state. The hearing outcome in all patients was variable. The postoperative air-bone gap (ABG) was closed to 10dB or less in two cases, while the other seven cases showed ABG ranging from 15.0dB to 57.5dB. Conclusions: We performed meatoplasty using inferiorly based retroauricular island pedicle flap for nine patients with EAC stenosis and eight of the nine patients demonstrated satisfactory patent EAC during a mean follow-up of 8.4 years.
    No preview · Article · Oct 2015 · Auris, nasus, larynx
  • Yurika Kimura · Nao Makino · Motoji Sawabe · Ken Kitamura
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    ABSTRACT: An aberrant internal carotid artery (ICA) in the middle ear is a rare vascular malformation. This study describes an aberrant ICA with a fatal complication caused by Eustachian tube air inflation (ETAI). Temporal bone histopathology findings, which have not been previously reported for a symptomatic aberrant ICA, are shown.
    No preview · Article · Jul 2015 · Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology
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    Preview · Article · Jan 2015
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    ABSTRACT: In Japan, patients with peritonsillar abscess are usually hospitalized. In contrast, ambulatory management has been performed in other countries. Patients seek safe, inexpensive, convenient, and shorter periods of treatment. We compared the therapeutic effects between ambulatory and hospitalized care in patients with peritonsillar abscess of a moderate degree.The subjects, recruited between January 2009 and October 2012, comprised 125 patients with peritonsillar abscess (95 men and 30 women) consisting of 70 hospitalized patients and 55 ambulatory care patients with ages varying from 17 to 89 years old. Of the 125 patients, 74 were affected on the right side and 51 on the left. The ratio of smokers was 63% in men and 20% in women. All patients were treated with antibiotics and aspiration for drainage of abscess. Both SBT/ABPC and CLDM were most frequently administered. The average number of aspiration treatments was 3.04. Peritonsillar abscess recurred in 19 cases (19%), while 14 cases (14%) had recurrence within one month after discharge.The therapeutic effect was compared regarding the recovery period, inflammatory parameters, and the number of aspiration treatments. The clinical outcome showed no statistically significant difference between the ambulatory and hospitalized care groups. We concluded that ambulatory therapy is as effective as and less expensive than hospitalized care in moderate and mild cases of peritonsillar abscesses.
    No preview · Article · Jan 2015 · Practica Otologica, Supplement
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    ABSTRACT: Croup is an acute respiratory tract inflammation characterized by swelling of the subglottic tissue caused by an infection with respiratory viruses such as parainfluenza virus, influenza virus, adenovirus and respiratory syncytial virus. Its symptoms include fever, barking cough, stridor and hoarseness. It is a relatively common condition in childhood, especially at younger than three years of age. Since it rarely occurs in adulthood, the clinical features of adult croup are mostly unknown. We report herein on three cases of adult croup and review another 17 cases of adult croup described in the literatures written in English or Japanese. The clinical features of adult croup were compared to that of croup in children. The patients with adult croup present with symptoms such as sore throat and dysphagia in addition to the symptoms that are common for croup in children. A coronal neck X-ray revealed a characteristic narrowing of the subglottic trachea, the steeple sign, in all cases. Although flexible laryngoscopy also has a high diagnostic value, it is necessary to pay careful attention to the clinical findings of possible airway obstruction. Two of our three cases and eight of 17 reported cases required airway management, indicating a much more severe condition in adults compared to that in children. Another clinical characteristics of adult cases include that only very severe cases have been diagnosed as croup. A rise of antigen titer against parainfluenza virus type 3 was detected in one case, while influenza virus antigen was detected in the other two cases.
    Full-text · Article · Jan 2015 · Practica Otologica, Supplement
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    ABSTRACT: Drawing illustrates the distribution of kainate receptor subunits, GluK1,2,4,5, and the AMPA receptor subunit, GluA2, at synapses on inner (IHC) and outer (OHC) hair cells in the adult rat, as described in this study. At IHC afferent (a) synapses, GluA2, GluK2 and GluK5 are postsynaptic and GluK2 is presynaptic. OHC afferent synapses bearing ribbons (usually one or two; colored green in drawing) have GluK2 and GluK5, while those lacking ribbons have small amounts of GluK5 only; efferent (e) synapses have GluK1, GluK2, and GluK5.
    No preview · Article · Aug 2014 · Hearing Research
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    ABSTRACT: Conclusion: Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) is considered to be a distinct entity in Japan. The combination of both HPV-DNA sequencing analysis and immunohistochemistry (IHC) for p16(INK4A) is useful to discriminate the OPSCC patients with a better prognosis from other cases, especially in the advanced stage. Surgical treatment is recommended for HPV-negative advanced cancer. Objective: The number of HPV-related OPSCCs has been increasing worldwide. However, the incidence and prognostic significance of this cancer in Japan have not yet been fully elucidated. Methods: Seventy-seven Japanese patients with OPSCC were enrolled in this study. The prevalence of HPV-DNA was assessed by PCR and sequencing. The expression of p16(INK4A) and p53 was examined by IHC. The clinicopathological parameters and disease-specific survival were analyzed for HPV-positive and -negative patients. Results: HPV-DNA was detected in 32 patients. Thirty-four patients were p16(INK4A)-positive by IHC. The patients who were positive for HPV infection were significantly younger. Furthermore, in the stage III or IV cases, the 3-year disease-specific survival of the HPV infection-positive group was significantly better than that of the HPV-negative group. Surgical treatment was demonstrated to lead to a good prognosis for the patients with HPV-negative advanced cancer.
    No preview · Article · Jul 2014 · Acta Oto-Laryngologica
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    Ayako Maruyama · Takao Tokumaru · Ken Kitamura
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    ABSTRACT: Introduction Pleomorphic adenoma accounts for 65 percent of all salivary gland tumors. It has been identified in several anatomical regions, but pleomorphic adenoma arising in the ear canal, first described in 1951, is extremely rare. Case presentation A 40-year-old Japanese man’s left ear canal was obstructed by a pleomorphic adenoma that caused mild conductive hearing loss. The tumor was resected and he remains disease-free two years after surgery. Conclusions Pleomorphic adenoma usually arises from a major and minor salivary gland, but pleomorphic adenoma of the ear canal is derived from the ceruminous gland. We discuss the present case and 37 other case reports in our effort to clarify the clinical features and the course of pleomorphic adenoma in the ear canal.
    Preview · Article · Jun 2014 · Journal of Medical Case Reports
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    ABSTRACT: Hypothesis: Micro-computed tomography (micro-CT) is useful for assessing the 3-dimensional (3D) morphology and age-related changes of the otoconial layer. Background: Wriggle mouse Sagami (WMS) is a mutant of the plasma membrane Ca2+ ATPase type2 gene (Atp2b2) with deficits in the saccular otoconia. We examined the effectiveness of micro-CT in evaluating the otoconial layer of WMS and C57BL/6J mice. Methods: Otic capsules of C57BL/6J mice at different fixation time were examined using micro-CT to evaluate the effects of the fixation time on the otoconial layer. Otic capsules of Atp2b2wri/wri, Atp2b2wri/+, and Atp2b2+/+ mice at P14, P21, and the age of 3 months were used to analyze age-related changes in the otoconial layer. A series of cross-section and 3D reconstructed images of the otoconial layer were obtained. The micro-CT findings were compared with the otic capsule findings cleared in methyl salicylate using stereomicroscopy. Results: Micro-CT produced high-resolution images of the otoconial layer, thereby providing information regarding the spatial configuration and 3D curvature. There were no changes between the different fixation times. In the Atp2b2wri/+ and Atp2b2+/+ mice, the saccular and utricular otoconial layers were normal among all age groups. In the Atp2b2wri/wri mice, the saccular otoconial layer decreased on P14 and was absent on P21, whereas the utricular otoconial layer disappeared at 3 months of age. Conclusion: We obtained precise information regarding the mouse otoconial layer with minimum artifacts. This method is expected to improve our understanding of the physiologic function and age-related changes in otolith organs.
    Full-text · Article · Jun 2014 · Otology & Neurotology
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    ABSTRACT: Conclusion: The long-term follow-up study revealed a good audiovestibular prognosis in our patients with Vogt-Koyanagi-Harada disease (VKH) after adequate treatment. Objectives: To evaluate the audiovestibular findings and long-term prognosis of patients with VKH. Methods: A total of 82 ears in 41 patients (9 males and 32 females, aged 18-78 years) with VKH were examined in the audiovestibular study. Of the 41 patients, 16 patients with follow-up periods of more than 12 months (13-158 months) were included in the long-term follow-up study. Audiovestibular examinations included pure-tone audiometry; positional, positioning, and spontaneous nystagmus tests; and a caloric test. Results: Among the 41 patients, 28 (68%) complained of auditory symptoms at the initial visit and 28 (68%) showed sensorineural hearing loss (SNHL). Of the 24 patients who underwent nystagmus tests, only 3 (13%) presented with vestibular symptoms whereas 11 (46%) had nystagmus. Among 32 ears in 16 patients enrolled in the long-term follow-up study, 19 ears showed SNHL at the initial visit. The SNHL returned to normal in 14 ears (74%) and remained minimal in severity in the other 5 ears (26%) at the last visit. None of the patients showed persistent or repetitive vestibular symptoms.
    No preview · Article · Apr 2014 · Acta oto-laryngologica
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    ABSTRACT: Mutations in DFNA5 lead to autosomal dominant nonsyndromic hereditary hearing loss (NSHHL). To date, four different mutations in DFNA5 have been reported to cause hearing loss. A 3 bp deletion mutation (c.991-15_991-13del) was identified in Chinese and Korean families with autosomal dominant NSHHL, which suggested that the 3 bp deletion mutation was derived from a single origin. In the present study, we performed genetic screening of mutations in the interval between intron 6 and exon 9 of DFNA5 in 65 Japanese patients with autosomal dominant NSHHL and identified the c.991-15_991-13del mutation in two patients. Furthermore, we compared the DFNA5-linked haplotypes consisting of intragenic SNPs between the reported Chinese and Korean families and found that the Japanese patients showed a shared region spanning 41,874 bp. This is the first report of DFNA5 mutations in Japanese patients with autosomal dominant NSHHL, supporting the suggestion that the 3 bp deletion mutation occurred in their ancestors.
    No preview · Article · Feb 2014 · Annals of Human Genetics
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    ABSTRACT: It has been reported that fatal complications associated with influenza include unexpected cardiopulmonary arrest as well as pneumonia, encephalitis and myocarditis. Here we report three cases with life-threatening epiglottic abscess that developed shortly after diagnosis of influenza. Case 1: A 45-year-old male visited a primary-care physician with a sore throat and was diagnosed with influenza B using a throat swab. A few hours later, breathing became difficult and he called for an ambulance. An emergency medical team found him in cardiopulmonary arrest at home. Case 2: A 62-year-old male with fever and dysphagia was diagnosed as influenza A and administered the neuraminidase inhibitor zanamivir. Breathing difficulties appeared several hours later, during the night. Case 3: A 53-year-old female with a sore throat was diagnosed as influenza B and administered the inhaled neuraminidase inhibitor laninamivir octanoate. The sore throat was resolved after several days but dyspnea reappeared four days after the diagnosis of influenza. In all three cases, flexible fiberscopy revealed a swollen epiglottis with an abscess that had almost completely closed the upper respiratory tract. We believe that acute epiglottitis can be a fatal complication in patients infected with influenza virus. It is recommended to assess the presence or absence of signs and symptoms of airway constriction in physical examination of patients with influenza. It is also important to give instruction to patients to return to the clinic if respiratory distress develops.
    No preview · Article · Jan 2014 · Nihon Kikan Shokudoka Gakkai Kaiho

  • No preview · Article · Jan 2014
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    ABSTRACT: Objective: Molecular analysis using archival human inner ear specimens is challenging because of the anatomical complexity, long-term fixation, and decalcification. However, this method may provide great benefit for elucidation of otological diseases. Here, we extracted mRNA for RT-PCR from tissues dissected from archival FFPE human inner ears by laser microdissection. Methods: Three human temporal bones obtained at autopsy were fixed in formalin, decalcified by EDTA, and embedded in paraffin. The samples were isolated into spiral ligaments, outer hair cells, spiral ganglion cells, and stria vascularis by laser microdissection. RNA was extracted and heat-treated in 10 mM citrate buffer to remove the formalin-derived modification. To identify the sites where COCH and SLC26A5 mRNA were expressed, semi-nested RT-PCR was performed. We also examined how long COCH mRNA could be amplified by semi-nested RT-PCR in archival temporal bone. Results: COCH was expressed in the spiral ligament and stria vascularis. However, SLC26A5 was expressed only in outer hair cells. The maximum base length of COCH mRNA amplified by RT-PCR was 98 bp in 1 case and 123 bp in 2 cases. Conclusion: We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases.
    No preview · Article · May 2013 · Hearing research
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    ABSTRACT: Hearing loss (HL) is the most common sensory disorder in humans. Many patients with mitochondrial diseases have sensorineural HL (SNHL). The HL of these patients manifests as a consequence of either syndromic or nonsyndromic mitochondrial diseases. Furthermore, the phenotypes vary among patients even if they are carrying the same mutation. Therefore, these features make it necessary to analyze every presumed mutation in patients with hereditary HL, but the extensive analysis of various mutations is laborious. We analyzed 373 patients with suspected hereditary HL by using an extended suspension-array screening system for major mitochondrial DNA (mtDNA) mutations, which can detect 32 other mtDNA mutations in addition to the previously analyzed 29 mutations. In the present study, we detected 2 different mtDNA mutations among these 373 patients; m.7444G>A in the MT-CO1 gene and m.7472insC in the MT-TS1 gene in 1 patient (0.3%) for each. As these two patients had no clinical features other than HL, they had not been suspected of having mtDNA mutations. This extended screening system together with the previous one is useful for the genetic diagnosis and epidemiological study of both syndromic and nonsyndromic HL.Journal of Human Genetics advance online publication, 13 September 2012; doi:10.1038/jhg.2012.109.
    No preview · Article · Sep 2012 · Journal of Human Genetics
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    ABSTRACT: When we assess anatomical problems and the safety and effectiveness for performing a difficult surgical procedure or planning novel surgical approaches, preoperative human dissections are very helpful. However, embalming with the conventional formaldehyde method makes the soft tissue of the cadaver harder than that of a living body. Therefore, the cadaver embalmed with conventional formaldehyde is not appropriate for dissections when assess surgical approaches. Thiel's method is a novel embalming technique, first reported by W. Theil in 1992. This method can preserve color and softness of the cadaver without risk of infections. We have used cadavers embalmed with Thiel's method for preoperative assessments and have confirmed the usefulness of this method especially for the prevention of complications or in assessing surgical approaches. The cadaver embalmed with this method has several advantages over other embalming methods and it might be also useful for the developments of new surgical devices or evaluation of a surgeon's skill.
    No preview · Article · Aug 2012 · Nippon Jibiinkoka Gakkai Kaiho

Publication Stats

2k Citations
188.86 Total Impact Points


  • 2015
    • Tsuchiura Kyodo General Hospital
      Tsukuba, Ibaraki, Japan
  • 1999-2014
    • Tokyo Medical and Dental University
      • • Department of Otolaryngology
      • • Department of Otorhinolaryngology
      • • Department of Head and Neck Surgery
      • • Department of Neurosurgery
      • • Department of Medicine
      Edo, Tokyo, Japan
  • 2004
    • Teikyo University
      • Department of Medicine
      Edo, Tōkyō, Japan
  • 1992-2004
    • Jichi Medical University
      • • Department of Genetic Therapeutics
      • • Department of Otolaryngology
      Totigi, Tochigi, Japan
  • 1990-2004
    • The University of Tokyo
      Tōkyō, Japan
  • 2003
    • Tokyo Dental College
      Edo, Tōkyō, Japan
  • 2000
    • Harvard Medical School
      • Department of Radiology
      Boston, Massachusetts, United States
    • Iwate Medical University
      • Department of Otorhinolaryngology
      Morioka, Iwate, Japan