Atsunobu Tsunoda

Corynebacterium ulcerans Diphtheria in Japan.

To the Editor: Corynebacterium ulcerans causes a zoonotic infection similar to diphtheria, which is caused by C. diphtheriae. Studies indicate that signs and symptoms of a diphtheria-like illness caused by C. ulcerans are milder than those caused by C. diphtheriae. However, some strains of C. ulcerans produce potent diphtheria toxin and may cause severe symptoms similar to those caused by C. diphtheriae (1). We report a case of a diphtheria-like illness caused by C. ulcerans infection. A previously healthy 52-year-old woman first noticed hoarseness approximately 3 days before admission to the hospital. On February 16, 2001, severe dyspnea and fever developed, and the patient was referred to the emergency room of the Asahi General Hospital by her private practitioner. Physical examination indicated a large stridor, which could be heard without using a stethoscope. Cyanosis was not observed. The endoscopic examination showed a thick white coat covering the nasopharynx and laryngeal vestibulum, and subglottic constriction was also observed. A chest x-ray showed diffuse infiltrates in both lungs. Pertinent laboratory findings on admission included leukocyte count of 16.8 x 103/μL and C-reactive protein of 20.0 mg/dL. The serum level of liver transaminase was normal, and both Wassermann reaction and anti-HIV antibody tests were negative. Pharyngolaryngitis and pneumonia was diagnosed in the patient. Because of severe dyspnea, intubation was performed, which caused sudden and unexpected exacerbation of the condition. Severe cyanosis subsequently developed. Extubation was immediately performed, and a thick white material was found to be filling the lumen of the endotracheal tube. Reintubation was performed, and dyspnea subsided. The patient was hospitalized in the intensive-care unit. Sulbactam sodium/ampicillin sodium (6 g per day) was intravenously administered for 4 days; however, the symptoms were not much improved. The symptoms were most consistent with those of diphtheria. Therefore, the patient was subsequently placed on erythromycin (1.0 g/day) and quickly responded to this treatment without administration of diphtheria antiserum. Erythromycin was intravenously administered at 1 g per day for 9 days, then orally administered at 1,200 mg per day for the next 14 days. Throughout the hospitalization, no complication occurred, and no abnormalities were noted in the electrocardiograms or in the patient’s neurologic status. The patient was discharged uneventfully, and no serious sequelae were noted for 20 months. History of immunization for diphtheria was not known. After the hospitalization for this acute illness, a laboratory report showed that C. ulcerans was cultured from the thick white coat of the throat. No other bacteria were found. The National Institute of Infectious Diseases in Tokyo later confirmed identification of the bacteria. By using Elek’s test, Vero cell toxicity, and polymerase chain reaction for toxigene, this strain of C. ulcerans was proven to produce diphtheria toxin identical to C. diphtheriae (2–4). Although administering appropriate antibiotics as well as antitoxin is a standard of care for patients with diphtheria, antitoxin was not given to this patient because of her rapid response to the erythromycin therapy. C. ulcerans infections in humans occur after drinking unpasteurized milk or coming in contact with dairy animals or their waste (5,6). However, person-to-person transmission of C. ulcerans has not been reported, and in some cases, the route of transmission is not clear (7). Recently, C. ulcerans-producing diphtheria toxin was isolated in the United Kingdom from cats with nasal discharge (8). Our patient did not have direct contact with dairy livestock or unpasteurized dairy products; however, more than 10 dairy farms are scattered around her home. Moreover, she kept nearly 20 cats in her house and had been scratched by a stray cat a week before illness developed. This stray cat, which had rhinorrhea and sneezing, had wandered into her house. The stray cat died before the patient became ill, and no further investigation could be made. Stray cats might well be one of the possible carriers of C. ulcerans and might have transmitted the bacteria to this patient. To our knowledge, a case of human infection caused by C. ulcerans has never been reported in Japan. On the basis of current experience, this bacterium does exist in Japan and can potentially cause a serious diphtheria-like illness in humans.

Nerve origin of the acoustic neuroma.

Two hundred and seventy-one Japanese patients who underwent surgical removal of neuroma from the cerebello-pontine angle using the translabyrinthine approach were retrospectively reviewed in order to investigate the nerve origin on an anatomical basis. In 269 out of the 271 cases, the origin of the neuromas was identified. Among these cases, 84.8 per cent of tumours originated from the inferior vestibular nerve (IVN), followed by the superior vestibular nerve (SVN) (8.9 per cent). Of the 5.6 per cent of tumours arising from the vestibular nerve, however, it could not be determined whether they originated from the SVN or IVN. Two cases of neuromas originating from the facial nerve were seen (0.7 per cent). No neuroma arose from the cochlear nerve. Currently, the diagnosis of acoustic neuromas is best made with Gd-enhanced magnetic resonance imaging (MRI). However, our data indicate that the development of a functional test of the individual IVN can be useful for screening most cases of acoustic neuroma and in facilitating their early diagnosis.

Two Japanese Corynebacterium ulcerans isolates from the same hospital: ribotype, toxigenicity and serum antitoxin titre

Two toxigenic Corynebacterium ulcerans isolates recovered from pharyngeal swabs of two patients from the same hospital in Japan during 2001-2002 were characterized by PFGE and ribotyping. Toxin production in different culture media was examined and serological analysis of patient sera was performed. The two isolates could not be distinguished by PFGE; however, their ribotypes were distinguishable. One of the isolates could represent a novel ribotype. Analysis of toxin production in different culture media demonstrated that the two isolates produced varying amounts of the diphtheria toxin. Serological analysis showed a greater than sevenfold increase in the serum antitoxin titre during the course of infection in one patient.

Anatomical feature of the middle cranial fossa in fetal periods: Possible etiology of superior canal dehiscence syndrome

Abstract Conclusion: Different from adults, the superior semicircular canal (SSC) protrudes into the cranium during the fetal period. This might cause adhesion of the membranous labyrinth to dura as the bony labyrinth develops much later than the membranous labyrinth. This adhesion interferes with ossification and leads to a bony defect in the SSC. Objectives: The purpose of this study was to investigate a possible etiology of superior canal dehiscence syndrome (SCDS) from a view point of ontogeny. Methods: Forty-two adult cadavers and 4 fetal cadavers were used for macroscopic observation of the middle cranial fossa (MCF). In addition, six fetuses underwent computed tomography (CT) examinations. The volume data of the CT obtained from four adults were also used for comparison. Using these CT data, we investigated the anatomic relationship between the MCF and SSC. Results: The SSC and the cochlea in fetuses protruded into the cranium in macroscopic anatomy and CT examination. On the other hand, the SSC of all adults was completely or mostly buried in the temporal bone.

Facial dismasking flap for removal of tumors in the craniofacial region.

Objective: This study was aimed at estimating the usefulness of the facial dismasking flap for craniofacial surgery.

Parapharyngeal space tumors: Anatomical and image analysis findings

OBJECTIVE The parapharyngeal space (PS) is defined as the deepest space in the neck and it consists of the pre- and post-styloid regions. PS tumors originating in these regions are thought to dislocate the carotid artery (CA) in either the posterior or anterior direction. To determine the precise anatomy of the PS and its relationship with the CA in diagnostic images, we conducted cadaveric and imagining analysis. MATERIALS AND METHODS We examined the posterior and lateral aspects of the PS in three cadavers. We also examined 17 patients who suffered from PS tumors, in which the carotid artery was dislocated (CA), then compared the results with surgical and pathological findings. RESULTS The anterior part of the PS was mainly composed of fatty tissue and is generally referred to as the pre-styloid region of the PS. In the posterior of this fatty region, blood vessels and nerves were tightly covered with muscles and adjacent fascias to form a compact musculo-fascial structure containing the CA, jugular vein, vagal, glossopharyngeal, accessory and sympathetic nerves, and a portion of the hypoglossal nerves. The hypoglossal nerves emerged from the hypoglossal canal posterior to this structure and coursed behind it, entering it at the upper third of the PS. These anatomical findings indicated that the PS was actually comprises of three regions. Image analysis showed that the CA was dislocated in the postero-lateral direction by a pleomorphic adenoma originating from the parotid gland and by a trigeminal schwannoma, both of which were pre-styloid tumors. On the other hand, the post-styloid tumors did not always dislocate the CA in the anterior direction. Tumors that developed within the musculo-fascial structure such as those of the carotid body tumor or sympathetic nerve schwannoma dislocated the CA from both the antero- to the postero-lateral directions. A hypoglossal nerve schwannoma originating from the most posterior part of the PS, which was behind the musculo-fascial structure dislocated the CA in the anterior direction. CONCLUSION The present findings indicated that the post-styloid region of the PS is considered to consist of two regions. As the CA is a component of this musculo-fascial structure, tumors originating from it that are defined as post-styloid did not always displace the CA in the anterior direction. Such anatomical recognition is helpful for diagnostic imaging of PS tumors.

Tumor volume measurements of acoustic neuromas with three-dimensional constructive interference in steady state and conventional spin-echo MR imaging.

The purpose was to compare three‐dimensional (3D) constructive interference in steady state (CISS) and conventional spin‐echo (SE) MR imaging in tumor volume measurements of acoustic neuromas. Twenty‐two patients with acoustic neuromas were examined using high‐resolution 3D‐CISS and SE imaging at a 1.5‐T system. Tumor volume determined by SE imaging with the ellipsoid formula was overestimated by 692 mm3(35%) on average as compared with that at 3D‐CISS with the voxel‐count method (the reference standard). Intra‐ and interobserver variations in SE imaging were poor as compared with 3D‐CISS imaging. However, tumor volume results with SE imaging showed a high correlation with those using 3D‐CISS imaging (P < .0001). On the basis of diameters shown on SE images, the tumor volume could be assessed using the following equation (P < .0001): (Tumor volume) = −26.407 + 0.387 × (maximum diameter along the pyramid) ×(maximum diameter perpendicular to the pyramid) × (maximum height). J. Magn. Reson. Imaging 2000;12:826–832.

The arcuate eminence is not a protrusion of the superior semi-circular canal but a trace of sulcus on the temporal lobe

Thirteen cadavers (26 temporal bones) were examined to show the arcuate eminence, especially its correspondence to the superior semicircular canal and inferior surface of the temporal lobe. Arc-like eminences on the petrous bone were observed in 92 per cent of specimens, however, they did not exactly correspond to the superior semi-circular canal. Some eminences corresponded to sulci of the temporal lobe of which most were traces of the occipitotemporal sulcus. On the other hand, a dull, smooth and even domed eminence existed in nine temporal bones independently of the arc-like eminence. Those eminences corresponded to each superior semi-circular canal in only three out of nine specimens. The arcuate eminence was listed as an important landmark in the middle cranial fossa approach. However, in order to drill out the internal auditory canal safety, surgeons should rely on other landmarks or apply other methods from our data.

Lipoma in the peri-tonsillar space

Lipomas in the head and neck region usually occur in the immediate subcutaneous tissue, and only rarely in the upper aerodigestive tract. We report here a case of a 58-year-old female with a lipoma in the peri-tonsillar space. The tumour originated from the left peri-tonsillar space over the palate tonsil and partly protruded into the oral cavity. MRI (magnetic resonance imaging) showed not only the accurate location of the tumour but also suggested its pathology. To our knowledge, a lipoma in the peri-tonsillar space is quite rare and MRI is useful in its diagnosis.

A full digital, high definition video system (1080i) for laryngoscopy and stroboscopy.

OBJECTIVE This study aimed to estimate the effectiveness of a full digital, high definition video system for laryngeal observations. METHODS A newly available, full digital, high definition video camera and high definition video monitor were used. With an endoscopic adaptor and rigid telescope, laryngoscopy and stroboscopy were performed on patients with various kinds of laryngeal lesions. RESULTS All laryngeal lesions were observed and recorded by the full digital, high definition video camera without incident. The image quality for laryngoscopy and stroboscopy was far superior to that of a conventional video system, including video-endoscopy. Even tiny structures or lesions could clearly be visualised on the monitor. The still image obtained from the full digital, high definition video camera was 1920 x 1080 pixels and was comparable to that obtained from a still camera. CONCLUSIONS Full digital, high definition video cameras are now commonplace products and can easily be applied to patients with laryngeal disorders. They provide superior laryngeal images, compared with conventional video systems. Furthermore, high definition video systems are cheaper than proprietary medical video systems. We consider our system to represent an accessible technique of gaining superior laryngeal observation in otolaryngological clinics.