Ryosei Minoda

Kumamoto University, Kumamoto, Kumamoto, Japan

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Publications (57)104.18 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the long-term efficacy of laryngeal reinnervation via refined nerve-muscle pedicle (NMP) flap implantation combined with arytenoid adduction to treat unilateral vocal fold paralysis (UVFP), employing laryngeal electromyography (LEMG), coronal imaging, and phonatory function assessment. Case series with chart review. University hospital. We retrospectively reviewed 12 UVFP patients who underwent refined NMP implantation with arytenoid adduction. Videostroboscopy, phonatory functional analysis, LEMG, and coronal imaging were performed before and 2 years after surgery. In LEMG analysis, a 4-point scale was employed to grade motor unit (MU) recruitment: 4+ reflected no recruitment, 3+ greatly decreased recruitment, 2+ moderately decreased recruitment, and 1+ mildly decreased activity, associated with less than the full interference pattern. Coronal images were assessed in terms of differences in thickness and the vertical positions of the vocal folds. Phonatory function improved significantly after operation in all patients. In terms of LEMG findings, the preoperative MU recruitment scores were 1+ in no patients, 2+ in 4 patients, 3+ in 1 patient, and 4+ in 7 patients. Postoperative MU recruitment results were 1+ in 6 patients, 2+ in 5 patients, 3+ in 1 patient, and 4+ in no patients. Thinning of the affected fold during phonation was evident preoperatively in 9 of 10 patients. The affected and healthy folds were equal in volume in 4 of 9 patients postoperatively. The LEMG findings and coronal imaging suggest that NMP implantation may have enabled successful reinnervation of the laryngeal muscles of UVFP patients. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.
    Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 02/2015;
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    ABSTRACT: The molecular mechanisms controlling the proliferation and differentiation of spiral ganglion cells (SGCs) in the inner ear are still largely unknown. TIS21 is a transcriptional cofactor that shows antiproliferative, antiapoptotic, and prodifferentiative effects on neural progenitor cells. To investigate the function of TIS21 during SGC development, we analyzed SGC neurogenesis from embryonic day 13.5 (E13.5) to postnatal day 4 (P4) in Tis21-GFP knock-in mice, in which the protein-encoding exon of the Tis21 gene was replaced by EGFP. Through E13.5 to P4, we found fewer SGCs in homozygous Tis21-GFP knock-in mice than in wild-type mice. Our results suggest that TIS21 is required for development of SGCs. Deleting Tis21 may affect progenitor cells or neuroblasts at the beginning of cochlear-vestibular ganglion formation and would consequently lead to a decrease in the number of SGCs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    Neuroscience Letters 10/2014; 584C:265-269. · 2.06 Impact Factor
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    ABSTRACT: Abstract Conclusions: Over-adduction of the unaffected vocal fold may not compensate vocal function in unilateral vocal fold paralysis (UVFP). Objective: To determine whether over-adduction of the unaffected vocal fold has any impact on vocal function in patients with UVFP. Methods: A total of 101 patients with UVFP who underwent three-dimensional computed tomographic (CT) examination of the larynx served as subjects. Three-dimensional endoscopic images together with coronal images during phonation were produced to evaluate over-adduction of the unaffected fold, posterior glottal gap, and differences in the vertical position and thickness between the vocal folds. Maximum phonation time (MPT) and mean airflow rate (MFR) were measured. Results: In all, 47 patients showed over-adduction. Their MPT and MFR were 4.9 ± 2.9 s and 653 ± 504 ml/s, respectively. The remaining 54 did not show over-adduction. Their MPT and MFR were 4.7 ± 2.7 s and 574 ± 384 ml/s, respectively. There were no significant differences in MPT or MFR between the two groups. Of the 47 patients with over-adduction, 9 showed no posterior glottal gap. However, their vocal function was not significantly different from that of 38 patients with posterior glottal gap or from that of 43 patients without over-adduction and having a posterior glottal gap.
    Acta Oto-Laryngologica 05/2014; · 0.99 Impact Factor
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    ABSTRACT: To assess laryngeal muscle activity in unilateral vocal fold paralysis (UVFP) patients using laryngeal electromyography (LEMG) and coronal images. Case series with chart review. University hospital. Twenty-one patients diagnosed with UVFP of at least 6 months in duration with paralytic dysphonia, underwent LEMG, phonatory function tests, and coronal imaging. A 4-point scale was used to grade motor unit (MU) recruitment: absent = 4+, greatly decreased = 3+, moderately decreased = 2+, and mildly decreased = 1+. Maximum phonation time (MPT) and mean flow rate (MFR) were employed. Coronal images were assessed for differences in thickness and vertical position of the vocal folds during phonation and inhalation. MU recruitment in thyroarytenoid/lateral cricoarytenoid (TA/LCA) muscle complex results were 1+ for 4 patients, 2+ for 5, 3+ for 6, and 4+ for 6. MPT was positively correlated with MU recruitment. Thinning of the affected fold was evident during phonation in 19 of the 21 subjects. The affected fold was at an equal level with the healthy fold in all 9 subjects with MU recruitment of 1+ and 2+. Eleven of 12 subjects with MU recruitments of 3+ and 4+ showed the affected fold at a higher level than the healthy fold. There was a significant difference between MU recruitment and the vertical position of the affected fold. Synkinetic reinnervation may occur in some cases with UVFP. MU recruitments of TA/LCA muscle complex in UVFP patients may be related to phonatory function and the vertical position of the affected fold.
    Otolaryngology Head and Neck Surgery 02/2014; 149(2 Suppl). · 1.72 Impact Factor
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    ABSTRACT: To determine the long-term functional outcomes of type II thyroplasty using titanium bridges for adductor spasmodic dysphonia (AdSD) by perceptual analysis using the Voice Handicap Index-10 (VHI-10) and by acoustic analysis. Fifteen patients with AdSD underwent type II thyroplasty using titanium brides between August 2006 and February 2011. VHI-10 scores, a patient-based survey that quantifies a patient's perception of his or her vocal handicap, were determined before and at least 2 years after surgery. Concurrent with theVHI-10 evaluation, acoustic parameters were assessed, including jitter, shimmer, harmonic-to-noise ratio (HNR), standard deviation of F0 (SDF0), and degree of voice breaks (DVB). The average follow-up interval was 30.1 months. No patient had strangulation of the voice, and all were satisfied with the voice postoperatively. In the perceptual analysis, the mean VHI-10 score improved significantly, from 26.7 to 4.1 two years after surgery. All patients had significantly improved each score of three different aspects of VHI-10, representing improved functional, physical, and emotional well-being. All acoustic parameters improved significantly 2 years after surgery. The treatment of AdSD with type II thyroplasty significantly improved the voice-related quality of life and acoustic parameters 2 years after surgery. The results of the study suggest that type II thyroplasty using titanium bridges provides long-term relief of vocal symptoms in patients with AdSD.
    Auris, nasus, larynx 12/2013; · 0.58 Impact Factor
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    ABSTRACT: Intubation laryngeal granulomas (ILGs) are a well-known complication of endotracheal intubation. Cases other than ILGs can be categorized as unspecified laryngeal granulomas (ULGs) since their etiologies are often difficult to confirm. We intended to clarify clinical features of both ILGs and ULGs and that anticoagulant medication could cause the formation and delayed healing of ILGs in terms of wound-healing delay. We compared the results of our treatment of ILGs (n = 16) and ULGs (n = 47) treated between 1998 and 2009 to characterize these patients. The clinical course, treatment (medical vs. surgical), indications for surgical resection, treatment outcome, and use of anticoagulants for preexisting disease were reviewed and compared between these two groups. The resolution rate was significantly better in ILGs (p < .05). Five ILGs and seven ULGs were surgically resected. The main reason for resection was airway obstruction and the need for histological assessment, respectively. The use of anticoagulants was significantly higher in ILGs than ULGs (8/16 vs. 4/47, p < .01). The resolution period was significantly longer in the ILGs patients with anticoagulant medication compared to that in the ILGs patients without anticoagulant medication (152 ± 101 days vs. 76 ± 44 days, p < .05). ILGs may have different clinical course from ULGs, especially in terms of the resolution period. Moreover, administration of anticoagulants may deter healing of small injury due to intubation. Patients taking anticoagulants should be managed carefully during the perioperative period to prevent the occurrence of ILGs.
    Archives of Oto-Rhino-Laryngology 10/2013; · 1.61 Impact Factor
  • Toru Miwa, Ryosei Minoda, Hidetake Matsuyoshi
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    ABSTRACT: BACKGROUND: Superficial siderosis (SS) is caused by repeated or continuous bleeding into the subarachnoid space that results in iron from hemoglobin (hemosiderin) being deposited on the surface of the brain. Clinically, the condition is characterized by sensorineural deafness, ataxia, and pyramidal signs. However the mechanism of peripheral vestibular disturbance was not revealed. We show the vestibular function of SS patients, and shed light on saccule-inferior vestibular nerve. METHODS: Over the past 9 years, 5 patients were definitively diagnosed with SS by MRI in our department. These patients were subjected to balance testing. RESULTS: Vestibular evoked myogenic potential (VEMP) was observed in patients who had suffered from SS for a short period but tended to be diminished or absent in patients who had suffered from the condition for a longer period. CONCLUSIONS: These findings in SS patients suggest that saccule-inferior vestibular function is maintained at early stages of the disorder. Our study may help to clarify the mechanism of SS.
    BMC Ear Nose and Throat Disorders 04/2013; 13(1):5.
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: Although numerous causative genes for hereditary hearing loss have been identified, there are no fundamental treatments for this condition. Herein, we describe a novel potential treatment for genetic hearing loss. Because mutations or deletions in the connexin (Cx) genes are common causes of profound congenital hearing loss in both humans and mice, we investigated whether gene supplementation therapy using the wild-type Cx gene could cure hearing loss. We first generated inner ear-specific connexin 30 (Cx30)-deficient mice via the transuterine transfer of Cx30-targeted short hairpin RNA (shRNA-Cx30) into otocysts. The inner ear-specific Cx30-deficient mice mimicked homozygous Cx30-deficient mice both histologically and physiologically. Subsequently, we cotransfected the shRNA-Cx30 and the wild-type Cx30 gene. The cotransfected mice exhibited Cx30 expression in the cochleae and displayed normal auditory functions. Next, we performed the transuterine transfer of the wild-type Cx30 gene into the otocysts of homozygous Cx30-deficient mice, thereby rescuing the lack of Cx30 expression in the cochleae and restoring auditory functioning. These results demonstrate that supplementation therapy with wild-type genes can restore postnatal auditory functioning. Moreover, this is the first report to show that Cx-related genetic hearing loss is treatable by in vivo gene therapy.Molecular Therapy (2013); doi:10.1038/mt.2013.62.
    Molecular Therapy 04/2013; · 6.43 Impact Factor
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    ABSTRACT: We established an animal model of recurrent laryngeal nerve reinnervation with persistent vocal fold immobility following recurrent laryngeal nerve injury. In 36 rats, the left recurrent laryngeal nerve was transected and the stumps were abutted in a silicone tube with a 1-mm interspace, facilitating regeneration. The mobility of the vocal folds was examined endoscopically 5, 10, and 15 weeks later. Electromyography of the thyroarytenoid muscle was performed. Reinnervation was assessed by means of a quantitative immunohistologic evaluation with anti-neurofilament antibody in the nerve both proximal and distal to the silicone tube. The atrophy of the thyroarytenoid muscle was assessed histologically. We observed that all animals had a fixed left vocal fold throughout the study. The average neurofilament expression in the nerve both distal and proximal to the silicone tube, the muscle area, and the amplitude of the compound muscle action potential recorded from the thyroarytenoid muscle on the treated side increased significantly (p < 0.05) over time, demonstrating regeneration through the silicone tube. Recurrent laryngeal nerve regeneration through a silicone tube produced reinnervation without vocal fold mobility in rats. The efficacy of new laryngeal reinnervation treatments can be assessed with this model.
    The Annals of otology, rhinology, and laryngology 01/2013; 122(1):49-53. · 1.05 Impact Factor
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    ABSTRACT: Intraorbital foreign bodies (IOFBs) are usually accompanied by notable skin wounds and/or ocular wounds, and often there is a clear history of a penetrating object. We report herein on a patient who had an asymptomatic IOFB for 30 years. To the best of our knowledge, there is only one other case of a patient with an IOFB for a longer asymptomatic period after the injury. IOFBs may be overlooked because a small penetrating wound may be accompanied by no signs of inflammation for many decades as in this patient's clinical course.
    Auris, nasus, larynx 11/2012; · 0.58 Impact Factor
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    ABSTRACT: Abstract Conclusions: Three different types of glottal configuration in unilaterally paralyzed larynx were proposed by utilizing three-dimensional computed tomographic (3DCT) images. This new classification might facilitate understanding of the behavior of the affected vocal fold in terms of vocal function. Objectives: To develop a classification of glottal configuration in unilateral vocal fold paralysis (UVFP) based on the thickness and location of the vocal folds utilizing 3DCT and to compare each type of configuration with vocal function. Methods: Thirty-seven consecutive patients with UVFP underwent CT during phonation and inhalation. 3D endoscopic and coronal images on two occasions were produced. Maximum phonation time and mean airflow rate were also measured. Results: Three types of glottal configuration were proposed. The thickness of the affected vocal fold during phonation was equal to or slightly thinner than the healthy fold in 10 patients (type A). The affected fold of the remaining 27 was thin during phonation; they were further classified into types B and C. In type B, the affected fold remained thin during phonation and inhalation (n = 12). Type C was allocated to those showing one or two paradoxical movements of the affected fold (n = 15). Those with type A showed significantly better vocal function.
    Acta oto-laryngologica 11/2012; · 0.98 Impact Factor
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    ABSTRACT: OBJECTIVES/HYPOTHESIS: To evaluate the impact of nimodipineon reinnervation of the long-term denervated rat thyroarytenoid (TA) muscle following nerve-muscle pedicle flap (NMP) implantation. STUDY DESIGN: Quantitative histologic and physiologic assessments. METHODS: Using 120 Wistar rats, we performed NMP implantation at different times after transection of the left recurrent laryngeal nerve (RLN). Sixty animals received nimodipine treatment (NIMO [+] group), and the remaining 60 animals received no nimodipine treatment (NIMO [-] group). As a control, an additional 28 animals were subjected only to transection of the left RLN (DNV group). Subgroups were assigned based on the period after RLN transection (0 [immediate], 8, 16, and 32 weeks). In the DNV group, we assessed histologically the muscle area, axons, neuromuscular junctions (NMJs), and myosin heavy chains (MyHC) type IIA and IIB in the TA muscle. In the NIMO (-) and NIMO (+) groups, histologic assessments and evoked electromyography were performed on the TA muscle at 10 weeks post-NMP implantation. RESULTS: In 8-week interval subgroups, the muscle fiber area and the number of NMJs in the NIMO (+) group were significantly greater than in the NIMO (-) group (P < 0.05, each). In the 0-week and 32-week interval subgroups, the muscle fiber subtype changed significantly, from IIA to IIB (P < 0.01 and P < 0.05, respectively); and, at all time-points the muscle fiber area, number of NMJs, and action potentials in the TA muscle tended to be greater in the NIMO (+) group than in the NIMO (-) group. CONCLUSIONS: Nimodipine expedited the effects of NMP implantation on reinnervation of the long-term denervated TA muscle. Laryngoscope, 2012.
    The Laryngoscope 09/2012; 123(4). · 2.03 Impact Factor
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    Toru Miwa, Ryosei Minoda
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    ABSTRACT: Cochlear implants (CIs) are associated with a potential risk for vestibular system insult or stimulation with resultant dysfunction. Twenty-six patients underwent equilibrium tests before undergoing CI surgery at our institute. As part of the equilibrium tests, a caloric test, static posturography, observation of nystagmus using an infrared CCD camera, and measurement of the vestibular-evoked myogenic potential (VEMP) were performed. Half of the patients (13 out of 26 patients) complained of vertigo or dizziness after the operation. In most patients (12 out of 13 patients), these symptoms occurred immediately after the operation and disappeared within one week. Patients who did not complain of vertigo or dizziness after the CI surgery had a statistically significant lower response for the caloric testing than the patients who experienced these symptoms. No significant differences in the static posturography, nystagmus and VEMP test results were seen between the group of patients who did not complain of vertigo or dizziness after the CI surgery and the group of patients who experienced these symptoms. This result suggests that the patients with normal peripheral vestibular functions preoperatively had a greater tendency to complain of vertigo or dizziness after the operation. The cause of postoperative vertigo or dizziness was judged to be due to the peripheral vestibular function before surgery. It is important for CI candidates to undergo equilibrium tests preoperatively as means of predicting postoperative vertigo or dizziness.
    Equilibrium Research 03/2012; 71(1):16-22.
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    ABSTRACT: To determine whether nimodipine, an L-type voltage-operated calcium channel antagonist that is an accelerator of axonal regeneration following peripheral nerve injury, can expedite reinnervation of denervated rat thyroarytenoid (TA) muscle following nerve-muscle pedicle (NMP) flap implantation. A quantitative histologic and physiologic assessment of the TA muscle following NMP flap implantation, with or without nimodipine treatment. Using 72 Wistar rats, we performed a transection on the left recurrent laryngeal nerve, followed by NMP flap implantation. Thirty-six animals received nimodipine treatment (NIMO [+] group), and the remaining 36 animals received no nimodipine treatment (NIMO [-] group). As a control, 18 animals were subjected only to transection of the left recurrent laryngeal nerve. We performed a histologic assessment for muscle area, axon, nerve terminals (NTs), and acetylcholine receptors (AchRs) in the TA muscle and electromyography at 2, 4, and 10 weeks after surgery. Muscle area, ratio of the number of NTs to that of AchRs (NT/AchR ratio), and evoked action potential in the TA muscle were significantly greater in the NIMO (+) group than in the NIMO (-) group (P < .05) at 4 weeks. At 10 weeks, the NT/AchR ratio was significantly greater in the NIMO (+) group than in the NIMO (-) group (P < .05). We found that nimodipine accelerated reinnervation of the denervated TA muscle following NMP flap implantation.
    The Laryngoscope 03/2012; 122(3):606-13. · 2.03 Impact Factor
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    ABSTRACT: X-linked agammaglobulinemia (XLA) is caused by a mutation in the Bruton tyrosine kinase, leading to an arrest in B cell development. Consequently, patients with XLA show significant decreases in gammaglobulin. Here, we describe a child with postmeningitic deafness and XLA who underwent a cochlear implantation. His psychomotor development had been normal and his congenital immunodeficiency was noticed only postoperatively. Immunoglobulin replacement treatment was started, but he still suffered repeated infections. Eventually, his cochlear implant was removed. A preoperative check of immunological status might be advisable in postmeningitic patients undergoing cochlear implantation to reduce the risk of postoperative infectious complications.
    Auris, nasus, larynx 02/2012; 39(6):638-40. · 0.58 Impact Factor
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    ABSTRACT: Regeneration of nerve fibers in the thyroarytenoid (TA) muscle occurred actively after damage on the recurrent laryngeal nerve (RLN) compared with the vagus nerve (VN). However, remyelination did not occur after damage on the RLN. To determine the regeneration process of nerve fibers in the TA muscle following transection and immediate anastomosis of the RLN or VN. Three types of animal model were prepared: an RLN anastomosis model (RLNa), a VN anastomosis model (VNa), and a peroneal nerve anastomosis model (PNa). Animals were sacrificed at five time points following the procedure. The modulation of axons, myelin sheaths, Schwann cells (SCs), nerve terminals (NTs), and acetylcholine receptors (AchRs) in the TA or tibialis anterior muscles was examined by immunohistochemical analysis. The ratios of the expression areas in axons, myelin sheaths, and SCs, and the number of NTs and AchRs in the treated (T) and untreated (U) sides (T/U) were evaluated. At 18 weeks, the T/U ratios of expression in RLNa, VNa, and PNa were 68.5, 0, and 100.4%, respectively, in axons; 0, 0, and 97.6% in myelin sheaths; 53.7, 0, and 93.6% in SCs; 61.0, 0, and 96.4% in NTs; and 99.4, 67.0, and 101.2% in AchRs.
    Acta oto-laryngologica 12/2011; 132(3):305-13. · 0.98 Impact Factor
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    ABSTRACT: Nerve-muscle pedicle (NMP) implantation was effective in the recovery of atrophic changes in the denervated thyroarytenoid (TA) muscle in aged rats. To evaluate the effects of NMP implantation on the denervated TA muscle in aged rats. Wistar rats aged 20 months and 8 weeks were respectively divided into two groups in which the left recurrent laryngeal nerve (RLN) was transected without (aged/young DNV group) or with (aged/young NMP group) NMP implantation. The aged DNV and NMP groups were further divided into two subgroups, based on the period after RLN transection (10 or 20 weeks). In the DNV groups, we assessed the area of muscle and the number of neuromuscular junctions (NMJs) histologically. In the NMP groups, we performed electromyography and histological assessments. For electromyography, we stimulated the transferred nerve and evaluated the muscle action potentials (MAPs) of the TA muscle. The muscle areas in the aged NMP groups were significantly larger than those in the aged DNV groups. More NMJs were found in aged NMP groups compared with aged DNV groups. MAPs were seen in all NMP animals. No significant differences were observed between the aged and young NMP groups in histological and physiological assessments.
    Acta oto-laryngologica 11/2011; 132(2):210-7. · 0.98 Impact Factor
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    ABSTRACT: The mouse otocyst, an anlage of the inner ear, is an attractive experimental target for developing treatment modalities for congenital inner ear diseases and for studying inner ear development. Poly-arginine (6-12 residues) is a cell-penetrating peptide and can be used to deliver cargo into cells. Here, we achieved transutero delivery of enhanced green fluorescent protein (EGFP) fused to a nine-arginine peptide into mouse embryonic otocysts. The EGFP signal was detected both in the lining cells of the otocysts and in their vicinity at 18 h post injection. Mice injected with EGFP fused to a nine-arginine peptide had normal auditory and vestibular functions. These data suggest that protein transduction using poly-arginine may be a useful alternative strategy to commonly used gene delivery methods for delivering therapeutically relevant molecules to the developing inner ear.
    Neuroreport 10/2011; 22(18):994-9. · 1.40 Impact Factor
  • Y. Toya, E. Yumoto, R. Minoda, Y. Kumai
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    ABSTRACT: Objective: Compare the modulation of nerve fibers, 1) between recurrent laryngeal nerve (RLN) and vagus nerve (VN) in the thryroarytenoid (TA) muscle, 2) between RLN in TA and peroneal nerve (PN) in tibialis anterior (TbA) muscle following nerve section and immediate anastomosis using rat model.
    Otolaryngology Head and Neck Surgery 09/2011; 145(2 Suppl):P195-P195. · 1.72 Impact Factor
  • Otolaryngology Head and Neck Surgery 04/2011; 145(5):874-5. · 1.72 Impact Factor

Publication Stats

867 Citations
104.18 Total Impact Points


  • 1998–2015
    • Kumamoto University
      • • Department of Otolaryngology-Head and Neck Surgery
      • • School of Medicine
      Kumamoto, Kumamoto, Japan
  • 2000–2013
    • The Australian Society of Otolaryngology Head & Neck Surgery
      Evans Head, New South Wales, Australia
  • 2003–2007
    • University of Michigan
      • Department of Otolaryngology - Head and Neck Surgery
      Ann Arbor, Michigan, United States
  • 2004
    • Kresge Eye Institute
      Detroit, Michigan, United States
    • Kansai Medical University
      • Department of Otolaryngology
      Moriguchi, Osaka-fu, Japan