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J Kanzaki

Publications and source records attributed to J Kanzaki.

At least 19 recordsLinked to original sources
PubMed1992

Light and electron microscopic study of vestibular sensory epithelia in 17 cases with acoustic neurinoma.

Vestibular sensory epithelia were studied histologically and ultrastructurally in 17 cases with acoustic neurinoma (AN). The superior vestibular nerve (SVN) near the fundus was also histologically studied in 5 of these 17 cases. Histologically, severe fibrotic change of the vestibular sensory epithelia was found in 1 case, and severe fibrotic change of the SVN was also found in this case. Intra-epithelial cysts were found at the edge of the utricular sensory epithelia in 2 cases. The cysts consisted of the transitional epithelium and were filled with the darkly stained substances. Ultrastructurally, abnormal accumulation of darkly stained masses within the nerve ending and abnormal accumulation of the fibrillar material below the normal basal lamina were frequently observed. These morphological changes described above were regarded as the pathological changes due to AN. In addition, the relationship among the histologic changes, ultrastructural changes and clinical data were fully investigated, and some histologic and ultrastructural changes were regarded as artifacts or age-related changes.

Adult↗
PubMed1992

[Study in predictive posture control during the performance of actions].

In order to maintain an ordinary upright posture, the body's center of gravity must be predicted and controlled on the supporting surface based on synthesis of multiple-sensory inputs. In order to evaluate the accuracy of predictive (feedforward) posture control during the performance of actions, we measured maximal shifts in the body's center of gravity using a force platform in 6 normal adults under two visual conditions (with eyes open and closed) and four standing conditions (one-legged; heel to toe posture; and both legs together or apart). Subjects were asked to perform five kinds of voluntary actions (static standing; head tilting forward, backward and laterally; head turning; bending forward; and maximal inclinations to the anterior, posterior and lateral directions). The smaller the supporting surface, the more markedly displacement of the body's center of gravity was increased upon closing the eyes. This finding suggests that the accuracy of predictive posture control decreases as a result of the reduction in the number of multisensory inputs which determine spatial orientation. Assessing purposive shifts in center of gravity during voluntary actions, we can conclude that the body's center of gravity is accurately controlled even in the presence of head movements under ordinary standing conditions. To evaluate balance during the performance of routine actions, we must devise a better method of discriminating purposive shifts in center of gravity from control disorder errors as well as a method of quantifying the accuracy of feedforward regulation.

Adult↗
PubMed1992

Motion sickness and equilibrium ataxia.

In order to know the relationship between motion sickness and equilibrium ataxia, we performed Graybiel's ataxia test battery on 10 normal subjects: 1) before donning goggles which reversed the optical image horizontally and vertically; 2) while wearing the goggles and walking; and 3) after walking as long as possible up to 90 min. Horizontal reversal of vision resulted in a statistically significant decrease in the score for all the closed-eyes tests and one open-eyes test performed during walking and after walking, respectively. In contrast, walking while wearing vertical reversing goggles produced a significant but very small change for one of the closed-eyes tests alone. The present study indicates that failure to detect spatial orientation, which evokes autonomic nervous symptoms as an alarm sign, produces equilibrium ataxia by impairing the top-down regulation of body balance, and that vertically reversed vision does not impair spatial orientation needed to maintain upright posture or to execute locomotion.

Adult↗
PubMed1991

Psychological aspects of psychogenic deafness in children.

Twenty-nine children with psychogenic deafness were investigated from audiological and psychological aspects. ABR and Békésy audiometry were useful for diagnosing psychogenic deafness. The elapsed time from the start of treatment to audiometric recovery was significantly shorter in patients receiving psychological treatment, indicating that treatment by a team of otologists and counselors was able to hasten recovery in children with psychogenic deafness. The pattern of hearing recovery in the treated group was classified into 3 types and in the control group into 4 types. Counseling seemed to have a positive effect on patients with fluctuating improvement. In the patients in the treated group, the elapsed time to audiometric recovery from the beginning of psychological treatment was 7.5 months; however, in the control group recovery it took 17.1 months. Psychological treatment revealed that the clinical course of psychogenic deafness in children seemed to have some relation to the patient's personality and psychological stresses.

Adolescent↗
PubMed1991

Classification of the extended middle cranial fossa approach.

There are several possible operative approaches to acoustic neuroma surgery. Ideally, there should be no need to select among approaches according to tumor size or indications for hearing preservation. The ideal approach should also allow otologists and neurosurgeons to work as a team using the same operative field and achieve functional preservation (facial nerve function and hearing) in a high percentage of cases. In 1977, the authors first reported on the extended middle cranial fossa (EMCF) approach for AN surgery. Based on our 15-year experiences of this approach, we have classified it into 3 types and describe their indications and techniques in the present paper. In addition, we examine the advantages and disadvantages and emphasize its excellent applicability as a team approach for otologists and neurosurgeons.

Cerebellum↗
PubMed1991

Results of acoustic neuroma surgery by the extended middle cranial fossa approach.

The results of surgery in 160 cases of AN are reported. Surgery was carried out by the extended middle cranial fossa (EMCF) approach in 138 cases and by the middle cranial fossa (MCF) approach in 22 cases. The tumor extended an average of 28.9 mm into the posterior cranial fossa; 42% of the tumors extended 31 mm or more. Mortality was 1.9%. Of the 3 cases of death, two had large tumors of 45 mm and 52 mm each, and one was a case of recurrence. Total tumor removal was achieved in an average of 78.8% of the cases. When the cases were classified by date of operation, the total tumor removal rate in the 60 most recent cases was 93.3%. The rate of facial nerve presentation was 82.4% on average and 93% in the recent cases. Hypoglossal-facial nerve anastomosis was performed in 33% of the cases in which facial nerve function failed to recover for an extended period of time. Among recent cases, however, anastomosis has been carried out in 22% of the cases. Hearing was preserved in 20 cases. Useful hearing was preserved in 8 (38%) of 22 cases. Recurrence was confirmed through surgery in 3 cases. Recurrence was suspected but was unconfirmed in 3 cases.

Adolescent↗
PubMed1991

Hearing preservation in acoustic neuroma surgery by the extended middle cranial fossa method.

The results of attempted hearing preservation were investigated in 160 cases of acoustic neuroma surgery carried out by a team of otologists and neurosurgeons at Keio University Hospital during a 14-year period from 1976 to 1989. Surgery was carried out by the middle cranial fossa (MCF) approach in the earlier cases and by the extended middle cranial fossa (EMCF) approach in the more recent cases. Measurable postoperative hearing was preserved in 20 of the 160 cases. Preoperatively, 22 cases had tumors of 20 mm or smaller in diameter, hearing levels (HL) of 50 dB or lower, and speech discrimination scores (SDS) of 50% or higher; 8 (36%) met these conditions postoperatively. Among those cases with hearing preserved postoperatively, hearing was unchanged from the preoperative level in 9 cases and changed in 11 cases. Total tumor removal was achieved in 19 cases. In one case, part of the tumor was left in order to preserve hearing, but MRI and CT have revealed no change in hearing or tumor enlargement to date, at 4 1/2 years after surgery. Hearing was preserved but progressively deteriorated postoperatively in one case in which the tumor was believed to have been totally removed but there was recurrence and in another case of total resection of neurofibromatosis II. Postoperatively, there were increased incidences of absence of the stapedius reflex, Type V by Békésy audiometry, and prolongation of the IT5, disappearance of Wave V, and no response in measurements of the ABR.

Adolescent↗
PubMed1991

Preoperative findings and hearing preservation in acoustic neuroma surgery.

For the purpose of clarifying whether or not the possibility of hearing preservation can be predicted preoperatively, we compared clinical characteristics and preoperative test results between hearing preserved and hearing unpreserved patients. Based on an analysis of this study, we conclude that duration of symptoms, ABR findings and caloric test results, in addition to hearing level, speech discrimination score and tumor size should be considered as prognostic signs of hearing preservation. Although all factors do not suggest a definite possibility of hearing preservation, candidates for hearing preservation surgery should be selected according to these prognostic factors.

Adult↗
PubMed1991

Preservation of facial nerve function in acoustic neuroma surgery by the extended middle cranial fossa approach.

The anatomical preservation rates of the facial nerve and postoperative facial nerve function were investigated in cases of initial operation for acoustic neuroma by the middle cranial fossa or extended middle cranial fossa approach. The cases were divided chronologically into three groups according to the date of surgery. The rate of anatomical preservation was 93% in the most recent period, compared to 82.4% for the entire series. This was attributable to higher preservation rates being achieved in cases with medium or large tumors with increased experience. Also regarding postoperative facial nerve function, the number of cases with no paralysis or only partial paralysis increased and the number of cases requiring sacrifice of the facial nerve decreased as experience was accumulated in the series. Even when the facial nerve was preserved anatomically, however, facial-hypoglossal anastomosis was carried out actively if facial nerve function did not recover satisfactorily one year after surgery. For this reason, as many as 33% of the patients underwent anastomosis. This high percentage, however, is attributable to anastomosis ultimately being carried out in 47.7% of the patients in the early period; 22.2% of the patients in the most recent period underwent anastomosis.

Adolescent↗
PubMed1991

Surgical anatomy for the extended middle cranial fossa approach.

The surgical anatomy of the temporal bone and the cerebellopontine angle was studied in cadavers, by performing simulated surgery via the extended middle cranial fossa approach. This approach is classified into 3 types according to extension of the drilling area of the temporal bone. In this paper, the surgical anatomy visualized by the EMCF type II and type III is described. In the EMCF type II, mastoidectomy and labyrinthectomy are performed completely through the middle cranial fossa, and in the EMCF type III permitting hearing preservation surgery, sections of the middle cranial fossa dura and the cerebellar tentorium are added to House's middle cranial fossa approach. The comprehension of these anatomical structures is essential for surgeons in performing acoustic neuroma surgery. We believe that this study will serve to expand our knowledge of surgical anatomy, and that as a result the EMCF approach for acoustic neuroma surgery will become more popular.

Cerebellopontine Angle↗
PubMed1991

Landmark structures to approach the internal auditory canal: a dimensional study related to the middle cranial fossa approach.

For the purpose of assisting the accurate topological identification of the internal auditory canal (IAC) during surgery through the middle cranial fossa, we conducted a dimensional study around the IAC using histologically prepared temporal bones. The anterior margin of the porus acoustics, the posterior margin of the porus acousticus, and the center of the fundus were located 19.7 mm, 16.8 mm, and 8.2 mm from the center of the malleus head, respectively. The angles formed by lines connecting those three points of the IAC and the ossicles were also measured. These values could be of help to identify the accurate localization of the IAC using the ossicles as surgical landmarks, when available. The common crus, i.e. a critical inner ear structure for hearing preservation, was also studied. The distance from the medial side of the common crus to the posterior wall of the IAC was relatively constant. However, the distance from the medial side of the common crus to the surface of the posterior cranial fossa was variable. Measurements in the vertical sections showed that the thickness of the superior bony wall of the IAC was similar to that of the cochlear otic capsule which should be kept unexposed for hearing preservation.

Adolescent↗
PubMed1991

The course of the internal auditory artery and its branches. Computer-aided three-dimensional reconstructions.

The course and branches of the internal auditory artery (IAA) were studied in 7 vertically-sectioned normal adult human temporal bones, and three-dimensional reconstructions of the anatomical structures were made with the aid of a computer system. Single IAAs existed in 3 or 7 temporal bones whereas double IAAs existed in 4. The IAA ran either between the facial nerve and the VIIth nerve, or on the inferior-posterior surface of the VIIIth nerve at the porus. Branching and anastomosis of the IAA were highly variable in the middle to proximal portion of the internal auditory canal (IAC). The anterior vestibular artery ran on the anterior surface of the superior vestibular nerve, and the vestibulocochlear artery ran on the inferior surface of the inferior vestibular nerve. The main cochlear artery ran at the center of the cochlear nerve near the fundus. The course of the vessels was less variable at the distal portion of the IAC than at the proximal portion.

Adult↗
PubMed1991

Temporal bone pathology of acoustic neurinoma (unilateral and bilateral) in relation to the internal auditory canal surgery.

Temporal bone pathology of 3 cases with large unilateral acoustic neurinoma (AN) and 2 cases with large bilateral AN (neurofibromatosis 2; NF2) were studied. One case with unilateral AN was diagnosed as neurofibromatosis 1 (NF1). Unilateral AN had distinct borderlines at the fundus in 5 of 12 examination points between tumor tissues and nerve fibers, but only 1 of 12 was distinct around the porus acousticus. Bilateral AN showed no distinct borderlines at the fundus and around the porus acousticus. These findings suggest that clear separation of the VIIth or VIIIth nerve from large tumors is very difficult, especially in cases of bilateral AN. Geniculate ganglion cells of tumor origin on ears were fairly well preserved in 2 cases with unilateral AN and 1 case with bilateral AN. Well preserved geniculate ganglion cells could be dependent on blood supply not from the internal auditory artery.

Adolescent↗
PubMed1991

Ultrastructural localization of nerve growth factor receptor in acoustic neurinoma.

Light and electron microscopic immunohistochemical studies on nerve growth factor (NGF) receptors in acoustic neurinoma cases were made using a monoclonal antibody to human NGF receptor. Immunoreactivity of the NGF receptor was found exclusively on the cytoplasmic membrane of schwannoma cells. Reaction product was highly concentrated at the interdigitated distal end of the cell processes, but it was discontinuous in the perinuclear area of the cell body. Basal lamina was located outside the immunoreacted cytoplasmic membrane of the cell body, but it was not observed at the tip of the interdigitated cell processes. These findings suggest that NGF receptor expression has some relationship with the formation of interdigitated schwannoma cell processes. Other possibilities for the functional significance of the schwannoma NGF receptor are also discussed.

Antibodies, Monoclonal↗
PubMed1991

Postoperative complications in acoustic neuroma surgery by the extended middle cranial fossa approach.

The complications of acoustic neuroma (AN) surgery by the extended middle cranial fossa approach were studied in 160 cases. Death during surgery occurred in 3 cases (1.9%); 2 of these involved large tumors and the third was a case of recurrence. Transient temporal lobe symptoms were seen in 24 cases (15.3%); the average tumor diameter in these cases was 36.0 mm. Beside symptoms of 7th and 8th nerve disturbance, hemiparesis was seen 7.6%; 3rd, 4th, and 6th cranial nerve symptoms in 7.0%; and cerebellar symptoms in 7.6% of the patients. The incidence of these disturbances increased with tumor size. Cerebrospinal fluid (CSF) leakage occurred in 20.4% of the cases and this necessitated surgical treatment in 5% of the cases.

Cerebral Hemorrhage↗
PubMed1991

Questionnaire evaluation of balance in the performance of everyday activities after acoustic neuroma surgery.

We report the results of a questionnaire survey of balance during the performance of everyday activities in 57 patients who underwent acoustic neuroma surgery from one month to 13 years previously. Performance of everyday activities was temporarily impaired after surgery, but soon recovered to preoperative levels in most items. Unilateral labyrinthine loss impaired balance during actions involving head movement. However, there was no correlation between the results of rotation test VOR and the results of the questionnaire. Here we propose a new method of evaluating balance in everyday activities which takes into account the following five basic factors in assessing the difficulty of every day actions: 1) passivity, 2) involvement of head motion, 3) absence of vision, 4) shifting of center of gravity, 5) reduction of supporting foot area.

Activities of Daily Living↗
PubMed1991

Effect of alcohol on VOR compensation after unilateral labyrinthine loss.

It has been reported that alcohol ingestion reduces cerebellar control of the vestibulo-ocular reflex (VOR). To investigate the compensatory processes following labyrinthine loss, we examined gaze function and VOR before and after alcohol ingestion in 10 patients with unilateral lesion. The subjects were rotated sinusoidally in an electrically driven chair under two different visual conditions, i.e., mental arithmetic in the dark, and gaze fixation on a target on the wall. Whereas a control group (17 normal adults) showed no significant change after alcohol ingestion, patients showed a greater difference in gain between rotation to the intact side and affected side under the two conditions. The present study suggested significant cerebellar control of VOR and gaze function during recovery from unilateral labyrinthine dysfunction.

Adult↗