Masatsugu Asai

Influence of visually induced self-motion on postural stability.

Conclusion Our results indicate that the illusion of self-motion is a significant factor leading to spatial disorientation. Objective Under normal circumstances, self-motion is perceived in response to motion of the head and body. However, under certain conditions, such as virtual reality environments, visually induced self-motion can be perceived even though the subject is not actually moving, a phenomenon known as “vection”. The aim of this study was to examine the possible influence of illusory self-rotation (circular vection) on postural adjustments. Material and methods The subjects were 10 young females with no history of ocular or vestibular disease. Video-motion analysis was applied to measure postural movements during vertical optokinetic stimulation. Results For most subjects, movement of the visual surroundings induced head and body displacements in the same direction as that of the visual stimulus, regardless of the onset of self-motion perception. However, there was a significant increase in postural instability after the subjects began to perceive false self-motion in the opposite direction to that of the visual stimulus.

Foreign body aspiration in children: A nationwide survey in Japan

BACKGROUND Foreign body aspiration (FBA) is a common cause for a respiratory emergency in young children and can be a life-threatening event. We, therefore, conducted the first nationwide survey in Japan. METHODS We asked doctors of 261 tertiary hospitals across the nation to fill out a case card of FBA-diagnosed cases they had experienced for the past 2 years. In the case card, age and gender of the patients, elapsed time until being referred to the hospital, presenting symptoms, previous diagnosis, suspected aspiration episode, type and location of aspirated foreign body, and consequences were inquired. This retrospective survey was carried out during 21 months, since January 2005 through September 2006. RESULTS Replies from 169 hospitals (64.8%) revealed that 163 cases of FBA had been treated in 114 hospitals during the past 2 years. Median age of cases was 1 year (2 months to 15 years), and 66.5% were male. Only 50.9% of the cases were referred to hospitals within 24h. Comparing these early-diagnosed cases, children with delayed diagnosis had similar age and sex distribution. In respect of presenting symptoms, characteristic ones such as choking or dyspnea were observed significantly more often in the early-diagnosed cases, whereas significantly predominant symptoms in children with delayed diagnosis were non-specific ones like coughing and wheezing (both, p<0.05). Although significantly more cases with early diagnosis reported suspected aspiration episodes (p<0.05), even in the delayed diagnosis group more than half cases (65%) had suspected episodes as well. Severe consequences occurred in seven cases (4.3%): four cases of irreversible hypoxic brain damage and one death due to multiorgan failure in the early diagnosis group; one bronchiectasis and one recurrent pneumonia in the delayed diagnosis group. CONCLUSIONS Characteristics of FBA among children in Japan were not substantially different from the reports from other countries. Suspected episodes were important, and there were some differences in presenting symptoms between early and delayed diagnosis cases. However, there are still no key sings to make a prompt diagnosis. In order to prevent FBA and make a timely diagnosis, continuous and extensive educational programs should be provided.

Mumps virus infection in adults : Three cases of supraglottic edema

Mumps virus infections primarily involve the parotid glands and most frequently affect school‐aged children. We present three unusual adult cases of mumps with dyspnea secondary to severe swelling of the salivary glands and review previously reported cases in the literature. Dyspnea developed progressively after the onset of salivary gland swelling. Laryngoscopy revealed an advanced edematous change in the supraglottis obstructing the airway. In two cases, tracheotomy was needed because of rapid worsening of the supraglottic edema. Questioning regarding breathing problems and laryngoscopic examination is therefore recommended when one encounters a mumps case with combined parotid and salivary gland swelling.

Influence of a Cold Front upon the Onset of Meniere's Disease in Toyama, Japan

In order to clarify the influence of a cold front (CF) upon the onset of Meniéres disease (MD), major CFs were defined by meteorological observations, and the influence of CFs on MD was evaluated by using the time n method. From our preliminary study it was seen that the onset of MD had its highest incidence exactly on days where a CF passed by. Out of the patients with MD, sudden deafness (SD) and Bells palsy (BP) who visited our neurotological clinic of the Toyama Medical and Pharmaceutical University from 1987 to 1992, 67 MD patients, 70 SD patients and 70 BP patients could clearly define the date of the onset of their disease, and were therefore selected for this epidemiological study. Thirty-six our of the 67 MD patients had the first attack on the day when a CF passed by or on the next day. The results obtained from these studies were as follows. i) The onset of MD was influenced by the passing of a CF, and this influence was more specific in MD than in SD or BP. ii) In the 36 CF influence MD patients, the majority were over the forty years, and their hearing level was worse than that of the other 31 MD patients during the observation periods.

Large Tonsillolith Mimicking Peritonsillar Abscess: A Case Report

A case of large tonsillolith is described. A 26-year-old male presented with a history of recurrent throat infections. A diagnosis of peritonsillar abscess was made. A tonsillolith was spontaneously expelled on admission. A tonsillectomy was subsequently performed. The tonsillolith was yellowish-gray, measured 30 x 26 x 16 mm, and weighed 8.5 g, which was the largest reported case in Japan. Chemical analysis revealed the stone to consist of calcium phosphate.

Classification, diagnostic criteria and management of benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vertigo and the posterior and/or lateral semicircular canals are usually affected. BPPV is characterized by brief attacks of rotatory vertigo associated with positional and/or positioning nystagmus, which are elicited by specific head positions or changes in head position relative to gravity. In patients with the posterior-canal-type of BPPV, torsional nystagmus is induced by the Dix-Hallpike maneuver. In patients with the lateral-canal-type of BPPV, horizontal geotropic or apogeotropic nystagmus is induced by the supine roll test. The pathophysiology of BPPV is canalolithiasis comprising free-floating otoconial debris within the endolymph of a semicircular canal, or cupulolithiasis comprising otoconial debris adherent to the cupula. The observation of positional and/or positioning nystagmus is essential for the diagnosis of BPPV. BPPV is treated with the canalith repositioning procedure (CRP). Through a series of head position changes, the CRP moves otoconial debris from the affected semicircular canal to the utricle. In this review, we provide the classification, diagnostic criteria, and examinations for the diagnosis, and specific and non-specific treatments of BPPV in accordance with the Japanese practical guidelines on BPPV published by the Japan Society for Equilibrium Research.

Intermittent pressure therapy of intractable Meniere's disease and delayed endolymphatic hydrops using the transtympanic membrane massage device: a preliminary report.

Abstract Conclusion. Middle ear pressure treatment by the tympanic membrane massage (TMM) device as well as the Meniett device is effective and provides minimally invasive options for intractable vertigo in patients with Menieres disease (MD) and delayed endolymphatic hydrops (DEH). Objective: The effects of the TMM device were evaluated according to the criteria of the Japan Society for Equilibrium Research (1995) in patients with MD and DEH and compared to those in patients treated with the Meniett device. Methods: Twelve ears of 10 patients (MD 8; DEH 2) were treated with the TMM device, while 16 ears of 15 patients (MD 11; DEH 4) were treated with the Meniett device. All the patients had failed to respond to medical treatment including diuretics before each pressure treatment, and were followed up for more than 12 months after treatment. Tympanotomy is necessary before treatment for the Meniett device, not but for the TMM device. Results: With both devices, the frequency of vertigo after treatment was significantly lower than before treatment (p < 0.05). The time course of vestibular symptoms with the TMM device was not significantly different from that with the Meniett device (p > 0.05). No complications were directly attributable to treatment with the TMM device.

Head and body sway in response to vertical visual stimulation

Conclusions. Postural responses differed according to the stimulus direction, i.e. vertical visual stimulation induced head rather than trunk displacements. Accordingly, it could be that center of foot pressure (COP) responses tended to underestimate the postural sway during visual stimulation. Objectives. To investigate head and body sway in response to vertical visual surround motion, and to examine the correlation between the displacements of head and body segments derived from video-motion analysis and COP measurements. Material and methods. Postural sway was assessed in 10 young female subjects by video-motion analysis of four different head and body segments, and by use of force-plate posturography. Head and body sway in the pitch plane was induced by rotating a random pattern of dots about the subjects inter-aural axis at a constant acceleration of 1°/s2 or a constant velocity of 60°/s in darkness. Results. Generally, head displacement was greater than that of other body parts during vertical optokinetic stimulation (OKS). In most subjects, maximum head displacements were induced in the same direction as the visual motion. Downward OKS induced a forward head and body sway. The COP trajectory correlated well with the displacements of each head and body segment during downward OKS. In contrast, postural responses to upward OKS were complicated in terms of their time course. The correlation coefficient between each head and body segment and the COP varied among individuals for upward OKS.

Magnetic Resonance Imaging of an Inhaled Peanut

A foreign body aspirated in the tracheobronchial tree is one of the high-risk accidents of childhood. Cohen et all reported that a peanut is the most commonly inhaled foreign body. However, its inhalation is sometimes difficult to diagnose without typical symptoms. Previous radiologic methods, including chest radiography, fluoroscopy, computed tomography (CT), and radioisotope imaging, cannot clearly visualize radiolucent foreign bodies such as peanuts.

Contribution of Vision to the Stabilization of Body Sway in Patients with Spinocerebellar Degeneration

Body sway was recorded with closed eyes, open eyes and visual feedback for 30 s each. Thirteen patients with spinocerebellar degeneration and 17 age-matched normal controls underwent the examination. Four parameters (area, length, sums of frequency spectrum in the anterior-posterior and lateral directions) were computed. Furthermore, Romberg ratios between closed and open eye conditions [Romberg c/o] and Romberg ratios between closed eyes and visual feedback conditions [Romberg c/f] were computed. Four parameters were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. However, three of eight Romberg ratios were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. The results implied that the proprioceptive-posture loop was mainly disordered while the visuo-postural loop was intact in patients with spinocerebellar degeneration.