Comparison of alterations in cerebral hemoglobin oxygenation in late life depression ans Alzheimer's disease as assessed by near-infrared spectroscopy

BACKGROUND: Patients with Alzheimer's disease (AD) often present with apathy symptoms resembling the decreased motivation observed in depressed patients. Therefore, differentiating the initial phase of AD from late life depression may be difficult in some cases. Near-infrared spectroscopy (NIRS) is a functional neuroimaging modality that uses near-infrared light to measure changes in hemoglobin concentration on the cortical surface during activation tasks. The objective of this study was to investigate differences in brain activation associated with late life depression and with AD by means of NIRS. METHODS: NIRS was performed in 30 patients with depression, 28 patients with AD, and 33 healthy controls, all aged 60 years or older. During two tasks, a verbal fluency task and a visuospatial task, changes in oxygenated hemoglobin concentration in the frontal and parietal cortices were investigated. RESULTS: In the visuospatial task, cortical activation was lower in the depressed group than in the AD group, and significant differences were observed in the parietal cortex. CONCLUSIONS: NIRS can detect differences in brain activation between patients with late life depression and those with AD. NIRS is a promising tool for the differential diagnosis of late life depression and AD.ArticleBEHAVIORAL AND BRAIN FUNCTIONS. 10:8 (2014)journal articl

顔面皮膚温を指標とした画像色表現の客観的評価法に関する研究

目次 / p1 第1章 序論 / p1 　1.1 本研究の目的と従来研究 / p1 　1.2 論文の構成 / p4 第2章 フラクタルブロック符号化による画像の正確な色表現 / p8 　2.1 まえがき / p8 　2.2 カラーコピーシステムの概要 / p8 　2.3 フラクタルブロック符号化による画像圧縮 / p9 　2.4 まとめ / p20 第3章 ファジィ推論を用いた画像色彩の感性表現 / p21 　3.1 まえがき / p21 　3.2 色彩感性の定量表現 / p21 　3.3 ファジィ推論を用いた色変換 / p25 　3.4 まとめ / p32 第4章 顔面皮膚温の非接触計測 / p33 　4.1 まえがき / p33 　4.2 システム構成と原理 / p33 　4.3 人物の抽出手法 / p35 　4.4 顔面内特定部位の皮膚温計測手法 / p42 　4.5 まとめ / p47 第5章 顔面皮膚温の物理的及び生理的基本変動特性 / p48 　5.1 まえがき / p48 　5.2 温熱刺激に伴う皮膚温変動 / p49 　5.3 温熱刺激とストレスに伴う顔面皮膚温変動 / p58 　5.4 まとめ / p76 第6章 顔面皮膚温による感覚の客観的評価 / p77 　6.1 まえがき / p77 　6.2 顔面皮膚温によるストレス推定 / p77 　6.3 顔面皮膚温による疲労推定 / p85 　6.4 まとめ / p93 第7章 顔面皮膚温による画像色表現の客観的評価 / p94 　7.1 まえがき / p94 　7.2 画像刺激実験 / p94 　7.3 画像の好ましさの評価 / p96 　7.4 まとめ / p98 第8章 結言 / p100 謝辞 / p103 参考文献 / p104 学術研究論文等研究業績一覧 / p108広島大学(Hiroshima University)博士(工学)Engineeringdoctora

Principal component analysis for ataxic gait using a triaxial accelerometer

Abstract Background It is quite difficult to evaluate ataxic gait quantitatively in clinical practice. The aim of this study was to analyze the characteristics of ataxic gait using a triaxial accelerometer and to develop a novel biomarker of integrated gate parameters for ataxic gait. Methods Sixty-one patients with spinocerebellar ataxia (SCA) or multiple system atrophy with predominant cerebellar ataxia (MSA-C) and 57 healthy control subjects were enrolled. The subjects were instructed to walk 10 m for a total of 12 times on a flat floor at their usual walking speed with a triaxial accelerometer attached to their back. Gait velocity, cadence, step length, step regularity, step symmetry, and degree of body sway were evaluated. Principal component analysis (PCA) was used to analyze the multivariate gait parameters. The Scale for the Assessment and Rating of Ataxia (SARA) was evaluated on the same day of the 10-m walk trial. Results PCA divided the gait parameters into four principal components in the controls and into two principal components in the patients. The four principal components in the controls were similar to those found in earlier studies. The second principal component in the patients had relevant factor loading values for gait velocity, step length, regularity, and symmetry in addition to the degree of body sway in the medio-lateral direction. The second principal component score (PCS) in the patients was significantly correlated with disease duration and the SARA score of gait (ρ = −0.363, p = 0.004; ρ = −0.574, p < 0.001, respectively). Conclusions PCA revealed the main component of ataxic gait. The PCS of the main component was significantly different between the patients and controls, and it was well correlated with disease duration and the SARA score of gait in the patients. We propose that this score provides a novel method to assess the severity of ataxic gait quantitatively using a triaxial accelerometer