Shigeru Higami

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OBJECTIVES To determine the relation between severity of obstructive sleep apnoea (OSA) and degree of cerebral metabolic impairment. METHODS Fifty five patients with habitual snoring and excessive daytime sleepiness underwent standard overnight polysomnography and magnetic resonance spectroscopy separately. Proton MR spectra were measured with two(More)
Thirty-one patients, aged 22-71 years, with nocturnal apneic episodes and/or habitual snoring were studied with magnetic resonance spectroscopy (MRS) and diagnostic polysomnography separately to determine whether accumulation of lactate caused by cerebral hypoxia during sleep is associated with sleep-disordered breathing (SDB), aging and co-morbidities(More)
In this study we investigated the non-linear properties of respiratory movement in patients with obstructive sleep apnoea syndrome (OSAS) during sleep without and with nasal continuous positive airway pressure (nCPAP). To calculate the correlation dimension (D2) in respiratory movement we applied an algorithm proposed by Grassberger and Procaccia.(More)
In order to examine the pathology in patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS), the nonlinear properties of respiratory movement and breath-to-breath variations during resting wakefulness with eyes closed was investigated. Recording of the respiratory movement using inductive plethysmography was performed on 14 patients with OSAHS(More)
Both the influence of comorbid obstructive sleep apnea-hypopnea syndrome (OSAHS) on daytime sleepiness and its pathological mechanism in 10 narcoleptic patients was studied. Mild elevation of esophageal negative pressure and obstruction in the velopharyngeal area, as observed by upper airway magnetic resonance imaging, during apneic episodes was observed in(More)
To assess whether hypersomnia in Prader-Willi syndrome (PWS) patients is related to the respiratory disorder during sleep (RDDS), we made a systematic evaluation regarding the relationship between the two disorders in three patients. All patients showed hypersomnia manifested as the long duration of night sleep and shortened sleep latencies of multiple(More)
Twenty-one patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) were classified into three categories according to their pharyngeal stenosis patterns during sleep, as determined from endoscopic findings: (i) a falling type (n = 6); (ii) an all-round type (n = 11); and (iii) a bilateral type (n = 4). In all patients with the bilateral type, the(More)
The authors investigated the relationship between esophageal pressure fluctuation (DPes) during sleep and the following parameters: respiratory disorder variables and daytime sleepiness manifested as the Epworth sleepiness scale (ESS). In the younger patient group under 60 years of age (n=33), DPes was correlative to both the apnea-hypopnea index and ESS.(More)
In order to clarify the efficacy and indication of prosthetic mandibular advancement (PMA) on obstructive sleep apnea syndrome (OSAS), we made a comparison of both the polysomnographic findings and the upper airway configuration between before and during PMA on 19 OSAS patients. During PMA, there was a significant decreased apnea hypopnea index compared to(More)