Current status of the cochlear prosthesis is overviewed. More than 190 patients underwent single channel implant at the House Ear Institute. Multichannel electrode system was also implanted in many patients in other institutes. Neither of single and multichannel system could have provided a sophisticated hearing for speech communication so far. However, many patients could discriminate simple words or environmental sounds. Other benefits of the current implant are reduction of tinnitus and improvement of lip reading. Postimplant rehabilitation still plays an important role in improvement of word discrimination. Problems to be solved lie in 2 major categories; 1) a method to evaluate functioning cochlear nerve for electrical stimulation. 2) improvement of a stimulator which produces an electronic signal for better frequency coding.
The diagnostic values of acoustic reflex (AR) and auditory brain stem responses (ABR) were investigated in 43 cases of unilateral acoustic neuromas and 7 cases (13 ears) of bilateral acoustic neuromas (von Recklinghausen disease). Using the contralateral stimulation with 500 Hz, 1kHz and 2kHz pure tones, the followings were used as AR parameters, 1) presence of AR, 2) threshold of AR, 3) reflex decay. Using 80 dB (HL) click stimulation, the followings were used as ABR parameters, 1) presence of each wave (I-V) 2) interpeak latencies between Wave I and Wave III and between Wave I and Wave V. The results were as follows: 1) The elevation of AR threshold by 500 Hz, 1 kHz and 2 kHz pure tones stimulation was a useful parameter of AR for the screening of acoustic neuromas. 2) Considering the hearing loss, absence of AR from 500 Hz to 2kHz stimulation suggested the existence of acoustic neuromas. 3) The accurate diagnostic rate of acoustic neuromas by AR was 81% and the false negative rate was 19%. 4) There were only a few cases in Recklinghausen disease patients who showed absence of AR. Therefore, the diagnostic value of AR in Recklinghausen disease seems to be much lower than in unilateral acoustic neuromas. 5) Compared with AR, the ABR findings seem to correlate better with the findings of other psychoacoustic tests. 6) Auditory brain stem responses showed abnormal findings in all cases of acoustic neuromas which showed false negative by AR. 7) In acoustic neuromas, the rate of presence of each wave in ABR decreased along with the increase of hearing loss at 4 kHz and 8 kHz. 8) There was a tendency of positive correlation between the prolonged interpeak latencies in ABR and the size of acoustic neuromas. However, it seems impossible to estimate the exact size of acoustic neuromas from the ABR latency. 9) The CT target imaging combined with air cisternography was very useful for the diagnosis of small-sized acoustic neuromas, especially for the diagnosis of intracanalicular tumors.
The authors report the case of a 6-year-old girl with familial facial palsy. Her family history showed many persons with facial palsy in her relatives. Peripheral facial palsy occurring in many members of a certian family was reported by Auerbach in 1912. A review revealed 22 such cases in foreign and 14 in Japanese literature.
Ten cases of mucocele of the ethmoidal sinus developing as a complication of surgery sinus are reported. Of the 10 cases, 3 showed visual disturbances. Operative findings of the 10 cases suggested three different modes in the development of the mucocele; 1) adhesions of the uncinate process to the lateral mucosa of the middle turbinate, 2) obliteration above the infundibulum due to imcomplete removal of the bullae ethmoidea, 3) obliteration around the third ground lamella due either to imcomplete removal of the lammella or to postoperative proliferation of granulation and/or bone regeneration. The authors suggested the following predisposing factors for the development of the mucocele; 1) operation in young patients, 2) combined intranasal and transantral procedure, 3) narrow ethmoidal sinus, 4) imcomplete procedure, 5) inadequate postoperative treatment and 6) postoperative distortion of the structure.
The case of a 57-year-old woman with a malignant schwannoma originating from the aural region is reported. Her symptoms were left otorrhea and hearing loss of five years duration associated with left facial paralysis. Histopathological examination from a previous operation done elsewhere under the diagnosis of cholesteatoma revealed malignant schwannoma. The patient was treated by irradiation (Lineac x-ray 5, 000 rad) and chemotherapy. However, her headache gradually increased, craniotomy was performed but the patient died from meningitis one month postoperatively. Postmortem microscopic examination revealed that spindle-shaped cells had the pattern of interlacing bundles, in part, with atypical nuclei. Electron microscopically, the tumor cells were spindle-shaped with atypical nuclei, rough chromatin and clear nucleolonema. In cytoplasm, rough ER and Golgi apparatus were seen to be moderately developed, and mitochondrias were not abundant. Discontinuous basement membrane was also observed. Malignant schwannoma in the head and neck region is comparatively rare. Its histological diagnosis is often difficult because of the absence of characteristic features.
A surgical technique for the closure of pharyngo-esophagostoma using the submentosubmandibular skin flap is described. This technique is applicable for the cases whose stoma is too large for simple closure and/or when neighboring skin is damaged by irradiation and/or surgery. The technique consists of the use of the rotating submento-submandibular skin flap for the external covering of the raw surface following the internal suturing. The tip of the flap can be extended to the level of tracheostoma if necessary. This technique was used satisfactorily for closure of seven pharyngo-esophagostomata.