We compare motion patterns of the hearing organ in the apical turn of the guinea pig cochlea, as monitoredby confocal imaging, with motion predicted by a cochlear model including finite element details. Weadjust the model to the angle of view of the images and to the anatomical variability of the organ, by use of aleast-squares method assuming a priori knowledge of the organ's geometry. This approach allows us to fitalso the model's mechanical parameters, based on the motion of the cochlear partition measured under quasistaticchanges of pressure or during sound stimulation. A number of stiffness parameters of the hearingorgan can thus be inferred without placing a physical probe inside the cochlea. This will be useful in buildingcochlear models and in confronting these models with experiments.
Nonlinear capacitance (NLC) is used as an indicator of prestin's function. It is well known that a numberof factors might directly affect the NLC, suggesting that those factors also modify the hearing level in vivo. However, we do not have sufficient data to explain the relationship between NLC in vitro and hearing in vivo. To date, elegant mutation works have demonstrated the functions of a motor protein on a molecular level. Prestin transgenic mouse will not only show the physiological role of prestin, but also facilitate the gradualrecognition of possible manifestations of prestin-induced hearing loss.
Since the discovery of prestin, putative motor protein, attention has been paid to prestin with lesserattention to the surrounding lipids in the investigation of the outer hair cell (OHC) electromotility. Recentstudies opened the possibility that not only modification of prestin, but also of the surrounding lipids in themembrane can affect cochlear amplification and hearing acuity.
We discuss the shape of actin based cilia using generic arguments involving solely the polymerizationand depolymerization rates of actin bundles and membrane properties such as tension, curvature modulusand adhesion. We obtain the typical shapes of stereocilia and microvili and we show that in an appropriateparameter range, the length of a stereocilium is proportional to its treadmilling velocity as found experimentallyby Rzadzinska et al.
Morphological aberration of the Eustachian tube is a significant factor of various middle ear diseases. Traditionally, cadaveric specimens have been used for studies on the morphology of Eustachian tubes.However, this approach was not too efficient, as samples were limited in number as they were difficult to obtain, and biological conditions were not reflected due to rigor mortis and atrophy during specimen preparation. We thus decided to use Multi-Slice CT (MSCT) to perform 3-D anatomic measurements of the Eustachiantube. MSCT has benefits of isotropy and high resolution, and it is useful in preparing images of any plane. Forty-eight adults were studied. For the purpose of measurement, various anatomic indices were carefullyand precisely defined to identify each area on the image. Calculations based on each coordinate value enabledthe measurement of length, diameter and angle of the Eustachian tube of normal adults. Therefore, measurements of the Eustachian tube, which were traditionally difficult as it is located in the deeppart of the cranium, were simplified in many specimens. Mean value of total length was 39. 2±3. 2 mm, cartilage part length of the tube 30.0±2.7mm and bony part9.2±1.6mm. Mean values of diameter of tympanic orifice were 5.2×3.2mm, and pharyngeal orifice 9.7×4.4mm. Mean value of angle between bony part and cartilage part was 160.9-13.6 degrees. This approach to anatomic measurement is expected to contribute greatly to investigation on various middleear diseases.
Consideration on psychosomatic factors is important in treating the patients with patulous eustachian tube (ET) condition. In this study, two psychological tests: Yatabe Guilford personality test (YG) and Maudsley personalityinventory (MPI) were performed to examine personality and neuroticism, in twenty-two patients withpatulous ET and in 83 patients with the other diseases as controls who consulted our outpatients clinics since September 2006. In patients with patulous ET, N score was significantly higher than in control group (23. 05 vs.14.725; p<0.005). Patients with patulous ET were also found to have tendency lacking in agreeableness andmild lower thinking extraversion and high neurotic tendency as their personality. Theses personal charactersmay be related to the strong and persistent complaints of symptoms in the patients, and it seemed important toconsider such a psychic aspect when managing patients with patulous ET.
Treatment outcome of acute otitis media (AOM) in children was assessed when treated with the newlyreleased clinical guideline in Japan. Our goal of this study is to clarify how appropriate this guideline is andwhether it has any difficulties in use for daily clinical practice. Twelve hospitals in Hokkaido, Japan participatedin this study between May and September 2006. Patients were diagnosed and treated according to the guideline. Swab samples were obtained from nasopharynx at their first visits to detect pathogens. Patients wererequested to visit the clinic 3 days, a week, 2 weeks, and 4 weeks after their first visit. A hundred forty-six patients'records were analyzed on the initial stages, initial scores of the tympanicmembranes (TMs), isolated bacteria, and treatment information including antibiotics and myringotomy theyunderwent. Twenty-five patients dropped out of the study, therefore 121 patients were followed until their TMscores reached zero. A hundred ninety-eight bacteria were isolated from 133 patients. Fifty-seven percent of S. pneumoniae were penicillin resistant and 59% of H. influenzae were β-lactamase non-producing ampicillin resistantstrains. A hundred twenty-two of 146 patients (84%) underwent antibiotic therapy recommended in the guideline.Sixty-three of 76 recommended cases (83%) underwent myringotomy. Eleven cases (9%) still hadinflammatory changes in their TMs even a week after their first visit. However, 8 of these 11 cases achievedTM score 0 in 2 weeks, and so did the others in 4 weeks after their first visit. Moreover, their symptom scoresreached zero in a week for all patients. Improvement of symptoms and TM findings was satisfactory when patients with AOM in children weretreated with the guideline. This guideline would be expected to play an important role to spread the appropriateuse of antibiotics in this country.
We evaluated the outcome of 133 ears with a perforation of TM underwent myringoplasty at Niigata University hospital between January 1999 and December 2003. The patients' mean age was 45 years, with arange of 9-79 years. The diagnosis consisted of dry-state chronic otitis media in 82 ears (61%), wet-statechronic otitis media in 9 ears (7%), otitis media sequelae in 23 ears (17%), residual perforations after theinsertion of tympanostomy tube in 13 ears (10%), and traumatic TM perforations in 6 ears (5%). Classificationof the perforation size of TM showed grade I (25% perforation of TM) in 42 ears (32%), grade II (50% perforationof TM) in 61 ears (46%), and grade (subtotal perforation of TM) and grade IV (total perforationof TM) in 15 ears (11%). The postoperative closure rate was 88% of all cases in 6 months and 77% of all cases in 12 months. Therewas no significant difference between diagnosis and perforation size related to the rate of closure. Of the earswith recurrent TM perforation, perforation recurred within 6 months after surgery in some ears, whereas itrecurred despite closure of TM perforation after epithelization in the other ears. There was no enlargement ofthe TM perforation size or reduction of hearing level in any patients in comparison to the preoperative state.
The incidence of the external and middle ear squamous cell carcinoma (SCC) is extremely rare in thehead and neck cancer with less than 1%. Therefore, the correlation between the staging classification and theprognosis has not been clear. Prognostic factors for patients with the external and middle ear SCC wereassessed in the initial clinical symptoms and radiographic imaging. 13 patients with the external and middle ear SCC (5 male and 8 female) that had been treated at the Department of Otorhinolaryngology, Kanazawa University hospital from 2000 to 2006 were selected for this study. The radiation therapy followed surgery inten patients. One patient received the radical cure irradiation before surgery. Two patients received a surgicalexcision alone. The temporal bone involvement and the parotid gland involvement in the radiographic image (computedtomography imaging and/or magnetic resonance imaging) were assessed. Clinical symptoms (otalgia, hearingdisturbance, tinnitus, vertigo and facial nerve palsy) before treatment were reviewed based on the medicalrecord. The correlation of those clinical factors and T staging in the Pittsburgh classification with overall survivalwas statistically assessed. The temporal bone involvement significantly correlated with worse prognosis. However, parotid gland involvement did not influence the prognosis. Moreover, statistically significant differencein T staging of the Pittsburgh classification (Tl·T2vs. T3·T4) was not found. The temporal boneinvolvement in the radiographic image was a prognostic factor for patients with the external and middle ear SCC. Pittsburgh classification needs to be modified because the bony part of the external auditory canalinvolvement is considered as T2 stage and the soft tissue involvement is defined as T4 stage.
Two patients were admitted to our hospital with a suspicion of labyrinthine vertigo. The first case, a 61-year-old male with a history of hypertension and diabetes mellitus, was suffered from rotatory vertigo. CT ofthe head region revealed no abnormalities. With a diagnosis of horizontal dextro-rotary mixed vertigo, he wasadmitted to our department. MRI revealed the presence of an infarction at the posterior inferior cerebellarartery (PICA); but ENG findings showed a left labyrinthine disorder. Case 2, a 56-year-old male, also had ahistory of hypertension and diabetes mellitus. He experienced rotary vertigo one week earlier. Meanwhile hedeveloped rotatory vertigo and right tinnitus, in addition to horizontal levo-rotatory mixed nystagmus. MRIindicated the presence of an infarction at the right PICA region. Those patients suffering from vertigo withbackground conditions such as hypertension are likely to suffer from cerebellar infarction.
The management of postoperative defects in petrous bone cholesteatomas should be considered regardingthe anatomical characteristics, but the lesion that are repaired by surgery should be appropriately taken carefor postoperative follow-up. We experienced a case with a petrous bone cholesteatoma where the matrix, whichseverely adhered to the dura mater, was removed using the middle cranial fossa approach. After surgery, postoperativechanges in the exposed dura mater were observed. The epithelial layer gradually covered theexposed dura mater and the surface of the exposed layer became smooth by three and half months after theoperation. Although an obliteration method using fatty tissue may be the procedure of first choice for themanagement of postoperative defects in petrous bone cholesteatomas, an open method combined with the middlecranial fossa approach, which preserves the residual tegmen tympani, may also be appropriate as alternativechoice.
Squamous cell carcinoma (SCC) of the external auditory canal is an extremely rare lesion with an incidenceof approximately 1.4 cases per million. To date there is no accepted staging system or treatment guidelinefor SCC. A 76-year-old man had experienced an obstructive sensation of the right ear for 6 months. There was aswollen lesion from his eardrum to the deep auditory canal. The pathological diagnosis was SCC by biopsy fromthe deep extemal auditory canal. CT scan demonstrated no bony erosion or soft issue involvement, likelybecause this tumor was in the early stage (T2NOMO). This patient was treated for SCC of the extemal auditorycanal with tympanoplasty and canaloplasty. Two years post-operatively, there has been no recurrent tumoror stenosis at his extemal auditory canal. In limited lesions it may be possible to preserve the ossicles andreconstruct the conducting mechanism of the ear. However, on appraisal of this case, we must consider the indicationsand strict observation on the patient postoperatively.