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Biomedical subjects

E Sakata

Publications and source records attributed to E Sakata.

At least 19 recordsLinked to original sources
PubMed2006

Number of positive lymph nodes independently affects long-term survival after resection in patients with ampullary carcinoma.

AIM: The nodal status is an established prognostic factor in ampullary carcinoma. The aim of this study was to compare the prognostic power of the anatomic location of positive nodes with that of the number of positive nodes. METHODS: Of 73 consecutive patients treated for ampullary carcinoma, 62 underwent pancreaticoduodenectomy with regional lymphadenectomy. A survival analysis of these 62 patients by nodal status was conducted retrospectively. A total of 1942 lymph nodes taken from the patients were examined histologically for metastasis. The location of positive regional nodes was classified into 4 categories, according to the Japanese staging system. The number of positive regional nodes was recorded for each patient. The median follow-up period was 124 months. RESULTS: Nodal disease was found in 31 patients, of whom 23 had 1-3 positive regional nodes and 8 had >or=4 positive regional nodes. Univariate analysis revealed that both the location (p<0.0001) and the number (p<0.0001) of positive nodes were significant prognostic factors. Multivariate analysis revealed that the number of positive nodes was an independent prognostic factor (p=0.007), while the location failed to remain as an independent variable. The median survival time was 59 months with a 5-year survival rate of 48% in patients with 1-3 positive nodes, whereas all patients with >or=4 positive nodes died of the disease within 29 months of resection (p=0.0001). CONCLUSION: The number, not the location, of positive regional lymph nodes independently affects long-term survival after resection in patients with ampullary carcinoma.

Adult↗
PubMed2001

Special features of old age vertigo.

In daily clinical practice, it is seen that elderly patients complain most frequently of dizziness, tinnitus, and hearing loss. Listening to those complaints, do we not tend just to attribute them to age? Against this background, we review vertigo in elderly patients briefly and consider the key points of its treatment. In comparison to younger people, what is first noticeable about elderly people is that they have a lot of fat in the body and a markedly low level of intracellular water. In other words, elderly people are always at risk of dehydration and liable to enter a shock state. The dorsal root in the elderly is also degenerated, and this explains such diverse complaints as dizziness, tinnitus, ringing in the head, headache, neck and shoulder stiffness, and lumbago. However, these complaints cannot be dismissed simply as "an unidentified syndrome." Behind these complaints is invariably one or another organic disorder. This is the conclusion we have reached from our day-to-day clinical practice.

Aged↗
PubMed2001

Treatment of cochlear tinnitus with transtympanic infusion of 4% lidocaine into the tympanic cavity.

Tinnitus is an otological symptom that is encountered often, yet its treatment is difficult. If tinnitus is of cochlear origin, a reasonable assumption is that a total depression of the cochlear function will abolish cochlear tinnitus. To achieve this depression, transtympanic infusion of a local anesthetic (4% lidocaine) to anesthetize the inner ear was conducted in a patient suffering from tinnitus. Transtympanic infusion of 4% lidocaine was performed as a treatment for cochlear tinnitus, and its efficacy was investigated. The overall efficacy rate for the 292 patients with 369 affected ears was 81%. In the investigation of the treatment results in cases of different underlying ear diseases, the efficacy rate was high for tinnitus accompanying sudden deafness and labyrinthine vertigo. However, vestibular symptoms, such as vertigo and nausea, developed after lidocaine infusion. No permanent side effects were noted. Lidocaine infusion is thought to be a useful treatment option for tinnitus and should be considered before surgical treatment. Inner ear anesthesia into the tympanic cavity has been carried out in patients who had cochlear tinnitus and in whom conservative methods of therapy, such as oral medication, had proved unsuccessful. This treatment method is useful as a local therapy for cochlear tinnitus.

Anesthetics, Local↗
PubMed2000

Caloric eye-tracking pattern test: visual suppression and the possibility of simplified differential diagnosis between peripheral and central vertigo.

During the examination of patients who complain of vertigo or who have equilibrium disorders, often identifying the etiology of the disorders is difficult (i.e., determining whether it is dependent on a peripheral or a central vestibular disorder). To attempt to determine the etiology in these cases, we devised a new method: the caloric eye-tracking pattern test. In normal subjects and in patients with peripheral disorders, as is well-known, caloric nystagmus has little influence on the eye-tracking pattern. In contrast, in patients with central vestibular disorders, caloric nystagmus evoked abnormalities in the eye-tracking pattern, either superimposed or as saccades, despite the fact that the eye-tracking pattern before caloric stimulation was normal. These findings result from the visual suppression mechanism to vestibular nystagmus. We can conclude that the visual suppression to vestibular nystagmus is evoked more strongly by pursuing a moving visual stimulus than by gazing at a stationary target. These results are interesting, not only from the physiological viewpoint but from the clinical viewpoint. The differential diagnosis should include both peripheral and central vertigo.

Adult↗
PubMed1997

Postural sway frequency analysis in workers exposed to n-hexane, xylene, and toluene: assessment of subclinical cerebellar dysfunction.

To clarify the effects of organic solvents on the postural balance system, 29 male sandal, shoe, and leather factory workers exposed to n-hexane, xylene, and toluene (solvent workers) were examined by computerized static posturography with sway frequency analysis. Concentrations of metabolites of solvents in urine samples taken from the workers in the morning before work ranged from 0.41 to 3.06 (mean, 1.20) mg/g creatinine (Cn) for 2,5-hexanedione, from 0.10 to 0.43 (mean, 0.19) g/g Cn for methylhippuric acid, and from 0.05 to 2.53 (mean, 0.37) g/g Cn for hippuric acid; estimated concentrations of n-hexane in workplace air ranged from 13 to 100 (mean, 40) ppm. Control subjects were 22 healthy males without exposure to solvents. With eyes open, postural sway with a frequency of 2-4 Hz in solvent workers was significantly larger than that in controls in the anteroposterior direction. With eyes closed, sway with a frequency of 0-1 Hz was significantly larger in solvent workers in the mediolateral and anteroposterior directions. Results of multiple regression analysis showed that with eyes open the 1- to 2-Hz and 2- to 4-Hz sways were related positively to 2,5-hexanedione and inversely with methylhippuric acid. The pattern of changes suggests that the vestibulocerebellar and spinocerebellar afferent systems are asymptomatically affected by n-hexane; the effect of n-hexane on the vestibulocerebellar system is possibly inhibited by xylene.

Cerebellum↗
PubMed1997

Clinical Experiences of Steroid Targeting Therapy to Inner Ear for Control of Tinnitus.

We summarize our long-term clinical experiences with an inner-ear drug delivery system (DDS) for control of tinnitus. The inner-ear DDS consist of transtympanic perfusion of 2 or 4 mg dexamethasone to the round window via the middle ear. Therapeutic results of steroid targeting therapy to the inner ear were evaluated in 3,978 ears of 3,041 patients. Tinnitus improved in 75% of these patients immediately after treatment and in 68% after 6 months. The effects of such therapy on tinnitus varied depending on the underlying diseases. The improvement of tinnitus in the presence of labyrinthine hydrops was good, whereas the effects on noise- or drug-induced tinnitus were poor. Our results indicate that in high-tone tinnitus, the effects were poor, but they were good for low-pitched tinnitus. No correlation existed between the efficacy of management and loudness of the tinnitus. The dangers of perforating the eardrum and of inciting the discomfort of vertigo as a result of the transtympanic injection of dexamethasone are minimal. We believe that the transtympanic infusion technique is an effective DDS for control of inner-ear diseases and symptoms. This technique may be performed by any neurootologist in an outpatient clinic.

Journal Article↗
PubMed1997

Subclinical vestibulo-cerebellar, anterior cerebellar lobe and spinocerebellar effects in lead workers in relation to concurrent and past exposure.

By computerized static posturography, the subclinical effects of past and concurrent lead absorption on the vestibulo-cerebellum (lower vermis), anterior cerebellar lobe and spinocerebellar afferent pathway were examined in 49 male chemical factory workers exposed to lead stearate (lead workers). Their concurrent blood lead (BPb) concentrations ranged from 7 to 36 (mean 18.0) microgram/100 g. In the past, their maximum BPb ranged from 11 to 113 (mean 47.7) micrograms/100 g; mean BPb was 7-52 (mean 23.5) micrograms/100 g; and cumulative BPb, defined as mean BPb x years of exposure, was 15-1268 (mean 390.6) micrograms.year/100 g. Control subjects were 23 healthy male workers who had never been occupationally exposed to lead. The postural sway of high (2-4 Hz) and low (1 Hz or less) frequencies with eyes open for lead workers was significantly greater than that for controls in the medio-lateral (right-left) and anterior-posterior directions. Similarly, the sway of high and low frequencies with eyes closed was significantly larger in lead workers than in controls in the medio-lateral direction. Results of stepwise multiple regression analysis indicated that the sway with frequencies of 0.5-2 Hz with eyes open was related to concurrent BPb in the anterior-posterior direction. With eyes closed the sway of high frequency was significantly related to mean BPb in the past in the medio-lateral direction. The pattern of the changes suggests that the vestibulo-cerebellum, anterior cerebellar lobe and spinocerebellar pathway are asymptomatically affected by lead. It appears that the change in the vestibulo-cerebellum reflects concurrent lead absorption, while on the other hand, that in the anterior cerebellar lobe reflects past lead absorption.

Adult↗
PubMed1996

[Neurotological examination of patients with alcohol dependency].

This study was performed in 37 patients with alcohol dependency. The mean age was 46.3 years and mean duration of heavy drinking was 23.8 years. The mean duration of temperance to the initial examination was 21.4 days and that to the second examination was 82.0 days. The results of the test on body sway in patients with alcohol dependency may summarized as follows. In patients with alcohol dependency the length of and the area covered by the body sway were significantly larger than in the normal group (p < 0.05). This significant difference from the normal group disappeared open eyes, but remained with eyes closed (p < 0.05). The Romberg quotients of both the length and the environmental area tended to be larger than the normal group mean (p < 0.05). The oscillation power spectrum obtained with eyes open and that obtained with eyes closed tended to be low at levels below 0.2Hz and high at range of 0.2Hz to 0.5Hz in the right left direction. The power spectrum in the anterior-posterior direction obtained with eyes closed was lower than that in the normal group at levels less than 0.2Hz, and higher than that in the normal group at range of 2.0Hz to 3.0Hz on the first examination. After temperance on the second examination, these significant differences had disappeared at all levels. The results of the present study on ocular movements in patients with alcohol dependency may be summarized as follows. Using the oculomotor test, abnormalities appeared in more than 40% of the test subjects for ETT, OKN, OKAN, VS and lateral gaze nystagmus test. According to the report of Matsuoka in 1979, some head positional nystagmus was noted in about 30% of patients with alcohol dependency. In the present study, the rate of appearance was as low as 8%. Ataxic pursuit, vertical positioning nystagmus, decrease of VS, disturbance of OKN and abnormalities of OKAN were found. These results suggested lesions between the brain stem and cerebellum, especially around the upper and lower vermis of cerebellum. After about 3 months of temperance, each test revealed a tendency towards some improvement, but the disturbance appeared to be fixed in some cases. It was important that some improvement in the oculomotor and the central vestibular system was found after about 3 months temperance. These results are quite promising for treatment and recovery in patients with alcohol dependency.

Adult↗
PubMed1996

Treatment of Cochlear-Tinnitus with Dexamethasone Infusion into the Tympanic Cavity.

Intratympanic dexamethasone infusion was performed as a treatment for cochlear-tinnitus and its efficacy was investigated. This is a Steroid Targeting Therapy (STT) for cochlear-tinnitus. The overall effective rate for the 1214 patients with 1466 affected ears was 71%. In this study, cochlear tinnitus was seen frequently in the age group of 50 - 60 years old, a relatively older population. The results of the treatment for tinnitus in different age groups did not show a correlation between age and efficacy rate of treatment. In the investigation of the treatment results with different underlying ear diseases, the efficacy rate was high for tinnitus accompanying chronic otitis media, Ménière's disease, and labyrinth syphilis. The efficacy rate tended to decrease more with longer disease duration. When the mean hearing level and treatment results were evaluated, a high effective rate was found in patients who had mild deafness. The efficacy rate was high in tinnitus of low tone pitch, and low tinnitus with high tone pitch. On the other hand, different degreees of loudness of tinnitus did not correlate with treatment effects. This treatment method is useful as a local therapy for cochlear-tinnitus in an outpatient setting.

Journal Article↗
PubMed1994

Use of the visual suppression test using post-rotatory nystagmus to determine skill in ballet dancers.

Twelve ballet dancers with various levels of dancing experience and skill were examined with the visual suppression test using post-rotatory nystagmus (PRVST) and caloric stimulation (CVST). The PRVST results showed a suppression rate that was higher than in untrained subjects. The CVST results showed a suppression rate similar to that in untrained subjects. A correlation between the PRVST and CVST suppression rates and the length of dancing experience showed that the suppression rate increased as the level of experience and skill rose. These results indicate that the PRVST and CVST can aid in the clinical and quantitative assessment of the function of the central nervous system in visual-vestibular interactions in ballet dancers. Additionally, testing may have determined function of vestibulo-cerebellar pathways through habituation of visual-vestibular interactions. Findings indicate that it may be possible to use suppression rates of PRVST and CVST to determine the approximate level of a dancer's experience and skill.

Adult↗
PubMed1991

Early diagnosis of acoustic neuroma (1989) after experience of 37 cases.

Although the diagnosis of acoustic neuroma as classically described is generally thought to be easy, this is not always true for this so-called "ear tumor" which is localized within the internal auditory meatus. Recently, remarkable progress has been made in the diagnostic instrumentation and operative techniques used to treat acoustic neuroma, emphasizing the need for early diagnosis so that treatment can take place earlier than before. Through early diagnosis, some cases of total resection of acoustic neuroma have recently become possible, with preservation of not only facial nerve function, but preservation of auditory function as well. In the present report, we outline the early diagnosis of acoustic neuroma by summarizing 37 cases of acoustic neuroma experienced at our institution. We discuss historical presentations, and laboratory tests used in diagnosis including pure tone audiometry, speech audiometry, auditory brainstem evoked response (ABR), vestibular caloric stimulation, and computed tomography (CT) enhanced by introduction of air into the posterior fossa. Two representative cases are also presented. It should be emphasized that no clinical test is 100% sensitive or specific, and attention must be paid to chronological discrepancies in the patient's presentation and "cookbook"-type approaches to evaluation should be avoided.

Adult↗
PubMed1991

Positional nystagmus of benign paroxysmal type (BPPN) due to cerebellar vermis lesions. Pseudo-BPPN.

Positioning nystagmus accompanied by severe vertigo has been reported in patients with partial lesions of the inner ear, especially otolith lesions. Typically, this type of nystagmus shows a latent period and subsequent fatiguability. We concur with this finding and have constantly emphasized the significance of this phenomenon in clinical diagnosis. Since we started using CT-scanning, this type of nystagmus has been noted in 47 patients, all of whom had cerebellar vermis lesions. Attention should be focused on this association; if such a combination were seen in only 1 or 2 patients, it could simply be attributed to coincidence. But its occurrence in as many as 47 patients indicates a causal role of cerebellar vermis lesions. Its mechanism may be explained by incomplete inhibition of the vestibulo-oculomotor system including the cerebellar flocculonodular lobe or vestibulo-cerebellum.

Cerebellar Diseases↗
PubMed1991

Visual suppression test using post-rotatory nystagmus. Clinical course in patients with motion sickness.

With the results of VS test (%) we were able to classify patients into three groups as follows: Group I, hyper range of visual suppression, VS (%) = 100-90; Group II, normal range of VS (%) = 89-45; Group III, reduced or abolished range of VS (%) = less than 44. The results with VS test using post-rotatory nystagmus (PRN) were in Group I 58 cases, in Group II 28 cases and in Group III 1 case, and using caloric nystagmus (CN) the results in Group I were 39 cases, Group II 29 cases, and Group III 1 case. With the correlation of VS test between PRN and CN we were able to classify patients into four types as follows: Type I, hyper range of VS in both PRN and CN; Type II, hyper range of VS in PRN; however, normal range of VS in CN; Type III, normal range of VS in both PRN and CN; Type IV reduced or abolished range of VS in both PRN and CN. It was very interesting in the clinical course of motion sickness that patients under 11 years of age (18 cases) of Type I (31 cases) showed marked improvement to Type III (11 cases) at the time of disappearance of symptoms; however, patients over 12 years of age (13 cases) of Type I remained stationary Type I (9 cases) at the time of disappearance of symptoms.

Cerebellum↗
PubMed1991

Treatment of vestibular disorders.

At our department, we generally perform inner ear anesthesia with lidocaine and intratympanic dexamethasone injection for treatment of patients with Menière's disease or labyrinthine vertigo due to circulatory disturbances of the inner ear, having failed other conservative treatments. These treatments were performed in 322 patients who consulted us during the past 7 years, including 136 patients with Menière's disease and 186 patients with labyrinthine vertigo. The criteria for evaluation of the therapeutic effect included the AAOO (1972), the AAO-HNS (1985) and Sakata's (1987) method. Both therapeutic methods were effective not only for the inhibition of vertiginous attacks, but also for the treatment of tinnitus. In the overall evaluation of therapeutic effect, dexamethasone injection was more effective than inner ear anesthesia in cases of Menière's disease whereas inner ear anesthesia was more effective than dexamethasone injection in cases of labyrinthine vertigo. When the three methods of evaluation were compared, the rate of positive effect increased in this order: the AAOO method showed fewer positive effects than the AAO-HNS method, and fewer than or equal to Sakata's method. For example in cases of Menière's disease that are resistant to drug therapy, these two therapeutic methods appear to be worthwhile before attempting surgical treatment for refractory vertigo.

Anesthesia↗
PubMed1989

Acquired pendular oscillation after brain-stem hemorrhage.

Six patients who manifested acquired pendular oscillation (APO) after brain-stem hemorrhage were examined with electro-oculograph. The characteristics of APO in these 6 cases were compatible with those reported in the literature as the syndrome of so-called 'rhythmic palato-ocular myoclonus'. The characteristics of APO of our cases did not differ by the presence or absence or rhythmic involuntary oscillation of the palate. In comparison with APO with multiple sclerosis (MS), our cases had slower frequency, and their amplitudes were not stable like APO with MS. Moreover, they did not disappear by lid-closure like APO with MS. Although it has been believed that the APO will continue for life, we have met with some cases which are abating gradually. It was considered that APO might be attributed to the injury of the eye position integrator that is under the influence of the rhythm generator around the reticular formation. It was found that vertical pendular oscillation (VPO) existed in 3 cases out of 6. It was concluded that the impairment of the bilateral PPRF was closely associated with the appearance of the VPO.

Adult↗
PubMed1987

Positional nystagmus of benign paroxysmal type (BPPN) due to cerebellar vermis lesions. Pseudo-BPPN.

Positioning nystagmus accompanied by severe vertigo had been reported in patients with partial lesions of the inner ear, especially otolith lesions. Typically this type of nystagmus represents a latent period and subsequent fatiguability. We concur with this finding and have constantly emphasized the significance of this phenomenon in clinical diagnosis. Since we started to use CT-scanning, this type of nystagmus has been noted in 20 patients, all of whom had cerebellar vermis lesions. Attention should be focused on this association. A simple coincidence could not be excluded if such a combination were seen in only 1 or 2 patients, it could be attributed to simple coincidence. But its occurrence in as many as 20 patients a causal role of cerebellar vermis lesions. Its mechanism may be explained by incomplete inhibition of the vestibulo-oculomotor system including the cerebellar flocculonodular lobe or vestiburo-cerebellum.

Arachnoid↗