Hideo Shojaku

Epidemiological Studies on Benign Paroxysmal Positional Vertigo in Japan

In 1980, the Research Committee of Peripheral Vestibular Disorders in Japan, which is supported by the Ministry of Health and Welfare, was founded by 24 members, from several districts in Japan. The Committees first task was to draft the diagnostic criteria for several peripheral vestibular disorders, such as benign paroxysmal positional vertigo (BPPV), and vestibular neuronitis. For the national epidemiological survey, they then collected the data on 101 cases of BPPV out of some 783 vestibular disorder patients. In addition, data on 103 patients of BPPV out of 559 vestibular disorder patients were also collected from the Neuro-otological Clinic of the Toyama Medical and Pharmaceutical University Hospital. From these epidemiological surveys, the incidence of BPPV in Japan was estimated at 10.7 per 100,000 population, while that of BPPV in Toyama was estimated at 17.3 per 100,000 population. The ratio of BPPV was higher in female than male patients in both surveys. The age at the onset of BPPV peaked in the fourth decade in both males and females. Compared with the other epidemiological features of Menieres disease and sudden deafness with vertigo in the same surveys, it appeared that the characteristic features of BPPV are epidemiologically similar to those of Menieres disease, but different from those of sudden deafness.

Epidemiological and Clinical Characteristics of Meniere's Disease in Japan

From 1975 to 1990, nationwide surveys on Menières disease were performed three times by the Research Committee of Menières disease (1975-76) and the Research Committee of Peripheral Vestibular Disorders (1982-84 and 1990) in Japan. Nine hundred and fifty-eight definite Menière cases, 520 in the 1st, 230 in the 2nd and 148 in the 3rd survey, were sampled by the members of the Committees. The epidemiological and clinical characteristics of Menières disease were analyzed and compared with such control cases as other vertiginous patients, ENT patients without vertigo, and healthy subjects. In Menières disease, the male to female ratio has changed from even to female predominance over the 15 years the study ran. The age distribution at onset peaked in the forties for males and thirties for females. Significant epidemiological results are summarized as follows: Definite Menières disease has a higher incidence in married persons and in people with a nervous and precise character, whereas the incidence is lower in obese people. Physical and mental fatigue induced the onset of attacks. Menières disease happened in day time in many cases, especially during the afternoon. As these epidemiological findings were commonly observed in all the surveys, the results are considered to be universal epidemiological characteristics of Menières disease in Japan. In the same period, regional investigations were performed by Toyama Medical Association and our University. The male to female ratio in Toyama indicated a more significant female predominance than in the nationwide surveys. The prevalence of Menières disease in Toyama Prefecture has been almost constant in all surveys, about 17/100,000 since 1974.(ABSTRACT TRUNCATED AT 250 WORDS)

Topographical distribution of Purkinje cells in the uvula and the nodulus projecting to the vestibular nuclei in cats

The localization of the Purkinje cells in the uvula and nodulus projecting to the vestibular nuclei and the prepositus hypoglossal nucleus (PH) was studied by means of retrograde axonal transport of horseradish peroxidase in cats. Findings indicate a zonal organization in the uvula and nodulus projecting to the vestibular nuclei as follows; the Purkinje cells located in the medial half of the uvula except for the area along the posterolateral fissure project to the middle part of the inferior vestibular nucleus (IV) (middle IV zone); those in the lateral half of the uvula other than the laterocaudal part project to the caudal part of the IV (caudal IV zone); those in the mediorostral part of the nodulus and the middle part of the nodulus project to the middle part of the medial vestibular nucleus (MV) (middle MV zone); those in the lateral part of the nodulus project to the caudal part of the MV (caudal MV zone); those in the medial part of the uvula and nodulus along the posterolateral fissure project to the dorsal peripheral part of the superior vestibular nucleus (SV) (SV zone). There is no specific projection zone in the uvula and nodulus projecting to the lateral vestibular nucleus, the ventral peripheral and the central part of the SV, the rostral part of the MV, the rostral part and the caudal pole of the IV, the caudal one-third of the group f, the group x and the PH.

Clinical Usefulness of Glycerol Vestibular-evoked Myogenic Potentials: Preliminary Report

The detection of intense sound-induced vestibular-evoked myogenic potentials (VEMPs) on the sternocleidomastoid muscle comprises the basis of the saccular function test. In order to evaluate the endolymphatic hydrops (EH) of the saccule of the inner ear, a glycerol VEMP (GVEMP) test was performed in 15 patients with unilateral typical Ménières disease (UMD) and 7 with delayed endolymphatic hydrops (DEH). Using the GVEMP test, 8 of the 15 patients (53%) with UMD were evaluated as being abnormal. In addition, a greater number of patients (67%) were judged to be abnormal when the results of the GVEMP test were combined with those from a glycerol dehydration test, trans-tympanic electrocochleography (ECochG) or furosemide vestibulo-ocular reflex test (FVOR). Four of the 7 patients with DEH (57%) showed abnormal results in the GVEMP test. In particular, in patients with the ipsilateral type of DEH, only the GVEMP test was able to detect the affected side. These findings suggest that the GVEMP test is a new and useful test for EH, and that a test battery comprising the GVEMP test together with one of the other three tests is useful for diagnosing EH of the inner ear.The detection of intense sound-induced vestibular-evoked myogenic potentials (VEMPs) on the sternocleidomastoid muscle comprises the basis of the saccular function test. In order to evaluate the endolymphatic hydrops (EH) of the saccule of the inner ear, a glycerol VEMP (GVEMP) test was performed in 15 patients with unilateral typical Ménières disease (UMD) and 7 with delayed endolymphatic hydrops (DEH). Using the GVEMP test, 8 of the 15 patients (53%) with UMD were evaluated as being abnormal. In addition, a greater number of patients (67%) were judged to be abnormal when the results of the GVEMP test were combined with those from a glycerol dehydration test, trans-tympanic electrocochleography (ECochG) or furosemide vestibulo-ocular reflex test (FVOR). Four of the 7 patients with DEH (57%) showed abnormal results in the GVEMP test. In particular, in patients with the ipsilateral type of DEH, only the GVEMP test was able to detect the affected side. These findings suggest that the GVEMP test is a new and useful test for EH, and that a test battery comprising the GVEMP test together with one of the other three tests is useful for diagnosing EH of the inner ear.

Epidemiologic characteristics of definite Ménière's disease in Japan : A long-term survey of toyama and niigata prefectures

To identify epidemiologic characteristics of definite cases of Ménière’s disease (DMD), we conducted retrospective surveys of the period 1990–2004 of the Nishikubiki district and of the period 1980–2004 of Toyama Medical and Pharmaceutical University. Three hundred and seventy-five patients (50 from Nishikubiki, 325 from Toyama) were diagnosed with DMD according to the diagnostic criteria proposed by the Japanese Society for Equilibrium Research. There was a slight increase in the prevalence of DMD during the period 1990–2004. However, incidence did not change significantly over time. The average annual prevalence and incidence were 34.5 and 5.0, respectively, per 100,000 population. Incidence and prevalence predominated in females. With respect to age at disease, the incidence in elderly patients was increased when we corrected for age distribution in the overall population.

Facial nerve palsy as a complication of parotid gland surgery and its prevention

The incidence of postoperative facial palsy in 73 patients who had under-gone surgery for parotid gland tumor is reported. Slight facial palsy occurred in 9 (14%) of 66 benign tumors but recovered completely within 3 months following surgery. However, in 7 patients with malignant tumors, 3 (43%) developed permanent palsy and 1 (14%) temporary palsy. The incidence of benign tumors depends on the tumor size and localization. However, the incidence decreased considerably in the last 6 years compared to the first 6 years. This is considered to be due to routine use of computed tomography with sialography and microsurgery during parotidectomy.

Positron emission tomography for predicting malignancy of sinonasal inverted papilloma.

Background: Sinonasal inverted papilloma (IP) is an uncommon nasal tumor. It is known for being locally invasive and recurrent, with a high probability of malignant transformation. Accurate initial staging and close surveillance are critical in the management of the disease. Methods and Results: Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) was performed in 5 patients with IP. High FDG uptake (maximum standardized uptake (SUVmax) value >3.0) was observed in all patients, and 2 patients with IP associated with squamous cell carcinoma (SCC) exhibited higher SUVmax values. Conclusion: The SUVmax value of a sinonasal tumor can warn the surgeon of the probability of an associated malignancy, even when preoperative biopsy demonstrates a purely benign papilloma.

Nasal septal neurinoma.

A case of nasal septal neurinoma is presented. The patient was a 71-year-old male who complained of nasal obstruction and epistaxis. Results of the physical examination showed a giant mass filling the nasal cavity and the nasopharynx. A biopsy taken from its tissue surface showed histological features of neurofibroma. The lesion was completely resected with the patient under general anesthesia. The tumor completely occupied the right nasal cavity and the nasopharynx, partially penetrated the nasal septum and extended to the left nasal cavity. After the operation, the final pathological diagnosis was not neurofibroma but neurinoma in which Antoni type A and type B cells were mixed. The postoperative course was uneventful, and no recurrence has been observed to date.

Prognosis of inner ear function in pneumolabyrinth: case report and literature review

Pneumolabyrinth, the presence of air within the labyrinth, is a rare radiologic finding associated with a well-known perilymphatic fistula (PLF). As there are only 24 published case reports in medical literature, multiple treatment options for the pneumolabyrinth are available. We report a case of a 20-year-old man with a pneumolabyrinth secondary to tympanic membrane and ossicular trauma. Despite conservative treatment, sensorineural hearing loss (SNHL) had progressed rapidly, and his profound deafness had not recovered after surgical exploration with closure of the PLF. Functional prognostic factors of SNHL are revised and compared with this case.

Ménière's disease and delayed endolymphatic hydrops in children.

In order to study the characteristics of pediatric patients (≤ 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménières disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising ≈ 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.In order to study the characteristics of pediatric patients (< or = 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménières disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising approximately 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.