Takuya Ohmichi

Superficial siderosis of the central nervous system: a case with an unruptured intracranial aneurysm

We present a case of superficial siderosis (SS) of the central nervous system (CNS) with an unruptured intracranial aneurysm to illustrate that the commonly encountered unexplainable progressive sensorineural hearing loss (SNHL) can be an important sign for the early awareness of this rare disorder. The literature on SS is reviewed and the pathogenesis of SS is discussed.

Bilateral congenital cholesteatoma

We report a case of bilateral congenital cholesteatoma in a 6-year-old boy. Cholesteatoma was present in both ears around the tympanic isthmus (the only open passage from the tympanic cavity to the attic), extending to behind the horizontal portion of the facial nerve. This patient underwent a total of three canal wall up operations on each side to remove the cholesteatoma completely and improve hearing. This case fulfills the criteria proposed by Derlacki and Clemis in 1965. Bilateral congenital cholesteatoma is a rare condition, but the incidence of congenital cholesteatoma in children has increased recently for the following reasons: Reassessment of the criteria, the introduction of computed tomography, and increased awareness of congenital cholesteatoma. When operating on patients with bilateral cholesteatoma, the best method for preservation of hearing should be chosen. We discuss these problems in the present report.

Immunohistochemical localization of manganese superoxide dismutase in the rat cochlea

There has been recent increasing interest in the involvement of superoxide radicals (O2−) and their scavenging enzymes, the superoxide dismutases, in the pathophysiology of certain diseases. Since mitochondria are significant intracellular sources of O2− and important targets of oxidant injury, determining the intracochlear localization of mitochondrial O2− scavenging enzyme may provide important insight into the pathogenesis of injury due to cochlear oxidants. In order to locate the mitochondrial O2− scavenging enzyme, manganese superoxide dismutase (MnSOD), the authors used a modified immunoglobulin peroxidase bridge sequence method to detect MnSOD in paraffin-embedded, formalin-fixed rat cochleas. Site-specific immunolocalization of MnSOD could be demonstrated in the cochlear labyrinth, suggesting that the generation of intracochlear O2− was possibly implicated in the metabolically active sites and sites rich in vascularity. This study also provided a useful probe for detecting MnSOD immunohistochemically from ethylenediamine tetraacetic acid-treated materials without requiring an antigen retrieval procedure.

Immunohistochemical Localization of Manganese Superoxide Dismutase in Rat Vestibular Dark Cell Regions

A modified immunoglobulin peroxidase bridge sequence method was used to detect the localization of manganese superoxide dismutase (MnSOD), a superoxide radical (O2−) scavenging enzyme locating in mitochondrial matrix, in the vestibular labyrinth of pigmented rats. Strong positive MnSOD immunostaining was demonstrated in the dark cell regions of the ampullae, utricle, and common crus. The result provides for the first time direct evidence demonstrating the existence of mitochondrial O2− scavengers in the vestibular labyrinth and illustrates that the specific sites for vestibular MnSOD immunolocalization are the dark cell regions. This site specificity of MnSOD immunolocalization suggests that dark cell regions may possess high metabolic activity and may encounter constant threat from O2−. We assume MnSOD is needed in protecting some physiologic functions of the dark cell regions. Cell types showing negative MnSOD immunostaining may conceivably be relatively vulnerable to acute O2− damage.

Visualization of Human Vestibular Aqueduct with Computeraided Serial Section Reconstruction System

The computer-aided serial section reconstruction system (SERSERS) was employed to elucidate the entire configuration of the vestibular aqueduct in the human temporal bone. The advantages and the disadvantages of this system are discussed in comparison with several conventional methods such as X-ray visualization, plastic casting and graphic reconstruction. In spite of some limitations encountered, such as difficulty in placing a marker on each section or time consumption in data input, SERSERS can be useful in the study of the vestibular aqueduct, since a three-dimensional structure which can be observed from multidirectional aspects is reconstructed.

Electron Spin Resonance Spin Trapping Assay and Immunohistochemical Localization of Superoxide Dismutases in the Rat Nasal Mucosa

The immunohistochemical method and electron spin resonance (ESR) spin trapping assay were employed to detect the localization and biochemical activity of superoxide dismutases (SODs) in the rat nasal mucosa. Manganese SOD and copper-zinc SOD were immunohistochemically illustrated to be richly expressed in the epithelial cells and the subepithelial glands of nasal mucosa. The olfactory vesicles also showed positive immunostaining for manganese SOD and copper-zinc SOD. ESR spin trapping assay revealed that SOD activity in the mucosa of olfactory areas was significantly higher than in the mucosa of respiratory areas; however, the ratio of SOD activity in the mitochondrial fraction to SOD activity in the cytosolic fraction was similar, approximating 17:83 in the mucosa of both the olfactory and respiratory areas. The predominant localization of SODs in epithelial cells of nasal mucosa suggests the importance of mucosal epithelium in protecting nasal mucosa against cytotoxic superoxide (O2-) radicals. Epithelial goblet cells and the connective tissue of lamina propria, which showed no positive immunostaining for SODs, are considered to be vulnerable to oxidative insults implicated in the generation of O2- radicals. The higher SODs activity in the mucosa of olfactory areas implies that there is a different requirement of SOD in mucosa of the respiratory and olfactory areas on scavenging microenvironmental O2- radicals.

Unilateral Sudden Deafness with Jumbling Phenomenon; A Case Report.

A 45-year-old woman with hypertension developed tinnitus and a feeling of obstruction in her right ear after taking a new antihypertension drug. The next morning she complained of vertigo and hearing loss in her right ear. After ten days, the vertigo disappeared but Jumbling phenomenon was occurred. The patient could not walk without holding on to a handrail. Otoneurologic testing revealed unilateral hearing loss and bilateral vestibular disorder. We explained the importance of rehabilitation to the patient and gave instructions for exercising. After a few weeks she could walk alone.Although her equilibrium disorder was reduced, in otoneurologic test showed little improvement. Plasticity of the central nervous system seemed to have compensated for her disorder.A few cases of bilateral sudden hearing loss and bilateral vestibular neuronitis have been reported. They were thought to have been caused by virus infection, vascular disorder of the inner ear, syphilis, diabetes, cancer metastasis to the temporal bone, etc.We felt that the etiology in our patient was a vascular disorder of the inner ear due to an excessive reduction in blood pressure. This case emphasizes the importance of rehabilitation in nonacute vestibular disorders.

A Case of Pemphigus Vulgaris Associated with an Abnormal Sensation on the Laryngopharynx

A 59-year-old man complained of an abnormal sensation in the laryngopharynx. The patient had received an early-stage gastrectomy on February 6, 1989. The present illness, consisting of an abnormal sensation in the laryngopharynx, mild pain on swallowing, and dysphagia, began around July 1990. Because of these symptoms, the patient visited our clinic on October 22, 1990, and was diagnosed by esophageal endoscopy as having a geographical erosion and ulcer in a region beginning approximately 35 cmfrom the incisor teeth and continuing to the inlet to the esophagus. Biopsy was performed and a diagnosis of pemphigus vulgaris was made. The patient is being treated at the outpatient service with 5 mg predonine, and the clinical course is being monitored. We conclude that patients who present with intractable stomatitis or an abnormal sensation in the laryngopharynx should receive endoscopy for early histological diagnosis and treatment.