Takuro Sumi

Audiovestibular findings in patients with mitochondrial A1555G mutation.

Objective: The aims of this study were to explore the prevalence of the A1555G mutation among a group of Japanese patients and to assess the pathophysiology of the hearing impairment associated with the mutation.

The effect of 3,4-diaminopyridine on the patients with hereditary pure cerebellar ataxia

BACKGROUND Downbeat nystagmus (DBN) is often seen in patients with pure cerebellar type of spinocerebellar ataxia (SCA) like spinocerebellar ataxia type 6 (SCA6). DBN frequently presents with other cerebellar symptoms such as postural imbalance or ataxia. A potassium channel blocker 3,4-diaminopyridine (3,4-DAP) has been reported to reduce DBN by increasing the excitability of Purkinje cells. OBJECTIVE The objective of this study is to determine whether 3,4-DAP has a beneficial effect on DBN along with postural imbalance and ataxic symptoms in 10 patients with SCA6 and five patients with chromosome 16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA). RESULTS The patients took 20mg of 3,4-DAP twice a day for a week. DBN was observed in seven patients with SCA6 and two with 16q-ADCA. Although 3,4-DAP significantly reduced DBN (P<0.05), other ataxic symptoms did not improved. However, 3,4-DAP showed benefit in two patients with oscillopsia. CONCLUSION 3,4-DAP may be effective on DBN and oscillopsia, although it was not proved to be effective on other symptoms of ataxia in SCA patients.

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.

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.

Longitudinal study of 29 patients with Meniere's disease with follow-up of 10 years or more (In commemoration of Professor Emeritus Isamu Watanabe).

Abstract Conclusions: A final incidence of bilateral involvement was 20.7%. Episodic spells of vertigo were completely controlled in 23 of 29 patients, while 11 of 29 patients demonstrated over 70 dB hearing loss. Objective: To analyze the clinical course of 29 patients with Menieres disease during follow-up of 10 years or more. Methods: The subjects were 29 patients with a mean follow-up of 18.3 years. The hearing level was measured by the pure tone average (PTA) of four frequencies at the initial and the final examination, and it was classified into four categories according to the American Academy of Otolaryngology-Head and Neck Society (AAO-HNS) criteria. The control of vertigo was evaluated by the modified AAO-HNS criteria. Results: At enrolment two patients had bilateral involvement. In the period of follow-up, bilateral involvement emerged in four more patients. The hearing levels at the final examinations were as follows: 3 patients, <25 dB; 6 patients, 26–40 dB; 9 patients, 41–70 dB; and 11 patients, >70 dB. The control of vertigo according to the modified AAO-HNS guideline was class A in 23 patients, class B in 2 patients, and class C in 1 patient; the remaining 3 patients could not be evaluated.

Improving the Quality of Life of Patients With Severe Dysphagia by Surgically Closing the Larynx

Objectives: The aim of this study was to elucidate the utility of the Kano method with surgical closure of the larynx by cricoid cartilage removal in improving quality of life in patients with severe dysphagia and their caregivers. Methods: Nine patients with severe dysphagia who underwent the Kano method were evaluated for oral intake and activities of daily living using the functional oral intake scale and the Barthel index, respectively, as indices of quality of life. Additionally, nutritional status, inflammation, and postoperative complications were assessed. Furthermore, 7 family caregivers were queried regarding frequency of sputum suction, mood of family caregivers, and postoperative satisfaction. Results: Functional oral intake scale and Barthel index scores as well as inflammation improved significantly after surgery (P < .05). There were no severe complications or other complications requiring surgical intervention. The frequency of sputum suction was reduced postoperatively (P < .05). The mood of family caregivers was significantly improved and satisfaction level was high postoperatively. Conclusions: Surgical closure of the larynx is an appropriate choice for patients with irreversible severe dysphagia and impaired articulation or vocal function because quality of life is improved for both patients and family caregivers and the satisfaction of family caregivers is sufficient.

Right dominance in the incidence of external auditory canal squamous cell carcinoma in the Japanese population: Does handedness affect carcinogenesis?: SCC in the EAC and Handedness

To investigate the relationship between handedness and the incidence of squamous cell carcinoma in the external auditory canal (EACSCC).

High-Resolution ENT Video Endoscope with Superior Image Quality Equivalent to that of Gastric Video Endoscopes

Background and study aims: To assess the usability of high resolution fiberscope which has equivalent image quality to that of the esophageal and gastric video endoscopes Patients and methods: Image resolution of this endoscope was estimated by the United States Air Force (USAF) resolution test chart. Clinical application was done between January and December 2010 and transnasal observation of the larynx and hypopharynx were performed during this period. These examinations were done for screening and follow-up for patients with hypopharyngeal and laryngeal disorders. Results: This endoscope could distinguish features on a scale of nearly 20 μm, and abnormal vascular patterns on the mucosal surface characteristic of carcinomas were clearly observed under a conventional light source. In addition, these changes on the mucosal surface became more apparent with use of the i-SCAN®. Nevertheless, the handling of this video endoscope was similar to that of popular ENT video endoscopes, and all patients tolerated its use well. Conclusion: This new device may dramatically improve pharyngolaryngeal examination in ENT clinics.

A novel permanent tracheostomy technique for prevention of stomal stenosis (triangular tracheostomy).

OBJECTIVE Stenosis of a permanent tracheostoma after total laryngectomy lowers postoperative quality of life (QOL), and its prevention is clinically important. METHODS From April 2003 to March 2009, the authors performed 87 permanent tracheostomies. For the purpose of prevention of tracheostomal stenosis, we had applied new technique from October 2005. RESULTS The incidence of the tracheostomal stenosis was retrospectively reviewed. Until September 2005, conventional permanent tracheostomy was applied for 33 cases and tracheostomal stenosis developed in 6 cases (18.2%). On the other hand, stenosis did not develop in any of the 54 cases in which the new technique was used. The triangular method was significantly superior to the conventional method in preventing stenosis. Stomal recurrence did not develop in either technique. CONCLUSION The key point of the new technique is as follows: at the upper end of trachea, the posterior part of tracheal cartilage is preserved and the anterior edge of the tracheostoma is made much lower. The shape of the tracheostoma approximates a triangle, and the area is greater than with other methods. From our experience, this technique is safe and effective for the prevention of tracheostomal stenosis.