Biomedical subjects

Hidetaka Kumagami

Publications and source records attributed to Hidetaka Kumagami.

8 recordsLinked to original sources

PubMed2006

Cochlear implantations in visually impaired patients.

We retrospectively review the cases to evaluate the outcome of cochlear implantation (CI) in patients with severe-to-profound hearing loss and visual impairment (VI). Six adults with severe or profound hearing loss and significant VI underwent multichannel CI. Follow-up period ranged from 17 months to 7 years. Case history, etiology of visual and hearing loss, and benefit from CI were evaluated. To measure the outcomes, we selected the pure-tone thresholds with CI, the speech discrimination scores (SDS) using the Japanese video SDS system, the speech perception rates using the Japanese CD SDS system by monosyllable and word, and the open-set and closed sentence score using live voice. All the patients live happily after CI. There was no significant difference between the present six patients and the patients with profound hearing loss without VI in evaluations of hearing and quality of life. CI can play a significant rehabilitative role in patients with severe hearing loss and VI.

Adult↗

PubMed2006

Ligation of eustachian tube for intractable patulous eustachian tube: a preliminary report.

Pharyngeal orifice of the eustachian tube was ligated on ten patients, 15 ears with intractable patulous eustachian tube. While the eustachian tube orifice was observed by an endoscope inserted through the contralateral nostril, the orifice was ligated transnasally and/or transorally using instruments usually used in the endoscopic nasal surgery. Now 13-27 months after the surgery, the outcome was excellent (both symptoms and sonotubometry were normalized) in two ears, good (either symptoms or sonotubometry was improved) in seven ears, and unchanged in the remaining six ears. In one of the ears with an outcome of unchanged, the ligation was found to be spontaneously released soon after surgery, but the symptom was improved after the second operation 2.5 months after the first operation. Temporary otitis media with effusion was seen in one ear, mild inflammation around the ligated site also in one ear, but no other serious complication has been observed. Although further improvement in the surgical procedure and further discussion about its long-term outcome should be required, this procedure appeared to be one of the therapeutic options for intractable patulous eustachian tube.

Adult↗

PubMed2006

The influence of Er. YAG laser application in fenestration to the inner ear.

OBJECTIVE: Erbium (Er.) YAG laser may be usable for middle ear surgery because of its ability to ablate bony tissue. We investigated the inner ear damage caused by the fenestration to the inner ear with Er. YAG laser. DESIGN: We investigated the influence of Er. YAG laser on the inner ear using electrophysiological technique. RESULTS: Several cases had a decrease in endocochlear potential (EP) and cochlear microphonics (CM) after the fenestration to the inner ear. CONCLUSIONS: Er. YAG laser is safe if it is used for the small and superficial fenestration to the stapes footplate. However, a few extra pulses after fenestration are dangerous.

Acoustic Stimulation↗

PubMed2006

Does topical application of 5-fluorouracil ointment influence inner ear function?

OBJECTIVE: To investigate the effect of 5-fluorouracil (5-FU) ointment on the inner ear of guinea pigs. STUDY DESIGN AND SETTING: In group A (n = 7), 5-FU ointment was applied into the left external auditory canal. In group B (n = 10), 5-FU ointment was applied to the left middle ear through myringotomy. In both groups, the right ear served as a control. One week later the endocochlear DC potential (EP) was measured and morphology of the cochleae was examined using scanning electron microscopy (SEM) and light microscopy. RESULTS: In group A, there was no significant difference between the EP values of the experimental side and the control side. In group B, there was a statistically significant difference between them (P < 0.05). Morphologic findings showed no damage. CONCLUSION: 5-FU ointment application to the external ear seems to be safe but its application to the middle ear may pose some risk of ototoxicity.

Administration, Topical↗

PubMed2005

Differentiating imaging findings in primary and secondary tumors of the jugular foramen.

The preoperative diagnosis of a jugular foramen tumor may be challenging, since a large variety of unusual lesions may be located in this region. These tumors may be classified as primary lesions (which are located in the jugular foramen or extend from the jugular foramen into the surrounding structures) and as secondary lesions (that extend from the surrounding structures into the jugular foramen). Primary tumors include glomus jugulare tumors, schwannomas, meningiomas and peripheral primitive neuroectodermal tumors, while secondary tumors comprise chordomas, chondrosarcomas, chondroblastomas, giant-cell tumors, cholesterol granulomas, giant cholesterol cyst, endolymphatic sac tumors, reactive myofibroblastic tumors, temporal bone carcinomas and metastases. Accurate preoperative radiological suspicion is of great value for preoperative patient counseling and has a direct impact on the surgical planning in these cases. The present study describes and discusses the main differentiating imaging features of lesions involving the jugular foramen, whose accurate preoperative radiological evaluation is essential for proper surgical planning.

Brain Neoplasms↗

PubMed2005

Clinical efficacy of 5-fluorouracil (5-FU) topical cream for treatment of cholesteatoma.

OBJECTIVE: In order to clarify clinical efficacy of commercially available 5-fluorouracil (5-FU) topical cream, a clinical study was conducted. METHODS: Two to three cubic millimetres of 5-FU topical cream (Kyowa, Roche) was applied on 50 cases of various types of cholesteatoma (50 patients) two to five times with the interval of 2 weeks, and its clinical efficacy was evaluated by the criteria we developed. RESULTS: In total, 59% of the cholesteatomas showed good effect, 29% of them showed fair effect, and the effect was poor in the remaining 12%. It was particularly effective in cholesteatomas in the EAC, attic cholesteatomas with an aerated mastoid, and in recurrent-type cholesteatomas. CONCLUSION: 5-FU topical cream appeared effective for the treatment of cholesteatomas.

Administration, Topical↗

PubMed2004

Measurement of the endolymphatic sac potential in human.

In this study, we measured human endolymphatic sac potential (ESP) in 8 patients with vestibular schwannoma and in five patients with Ménière's disease during surgery. ESP was measured with a glass electrode filled with 154 mM NaCl and with an outside tip diameter ranging from 2 to 3 microm. The mean value of human ESP in patients with vestibular schwannoma was +13.3+/-1.9 mV. Since electron microscopy showed that the endolymphatic sacs of the eight patients with vestibular schwannoma were normal in the ultrastructures the value can be close to normal human ESP. While in Ménière's disease, three cases showed low potentials and two cases showed almost the same values observed as in the eight patients with vestibular schwannoma. In the two cases with Ménière's disease, the epithelial cells of the endolymphatic sac were preserved. Our study can be considered as the first successful measurement of human ESP and revealed the existence of Ménière's disease having normal endolymphatic sac in function as well as morphology.

Adult↗

PubMed2003

Otolith dysfunction during vertiginous attacks in Ménière's disease.

OBJECTIVE: Vertiginous attacks of Ménière's disease (MD) are characterized by various types of vertigo, namely rotatory vertigo, dizziness and drop attack. When a patient complains of dizziness without spontaneous nystagmus, otolith dysfunction cannot be ruled out. The purpose of this study was to evaluate otolith dysfunction during vertiginous attacks of MD or delayed endolymphatic hydrops. MATERIAL AND METHODS: Vestibular function tests were carried out daily for several days in 11 patients (MD, n = 9; delayed endolymphatic hydrops, n = 2) during vertiginous attacks. Otolith function was evaluated by means of the static torsional position of both eyes [static ocular torsion (OT)] whilst in an upright position. We defined otolith dysfunction as an abnormal change (range) in OT without spontaneous nystagmus or as an abnormal change in OT without a change in spontaneous nystagmus. RESULTS: Four patients had an abnormal change (range) in OT without spontaneous nystagmus or an abnormal change in OT without a change in spontaneous nystagmus during vertiginous attacks of MD. CONCLUSIONS: Otolith dysfunction occurs in patients during vertiginous attacks of MD. In cases of ataxia without spontaneous nystagmus, otolith dysfunction most likely causes atypical attacks of MD.

Adolescent↗