Tsunetaka Yoshida

Diffusion tensor magnetic resonance imaging of disruption of regional white matter in schizophrenia.

Diffusion tensor imaging provides a new approach for quantifying anisotropic diffusion of white matter in vivo. We used this technique to investigate subtle disruption of regional white matter in schizophrenia. Twelve patients with schizophrenia were compared with 11 healthy controls. Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale. A significant fractional anisotropy (FA) reduction was found in all white matter regions bilaterally in schizophrenic patients. Higher FA of left frontal white matter correlated significantly with higher dosage of antipsychotic medication. These findings support the view that the pathological process is a distortion of the central nervous system myelination affecting the whole white matter. Our findings also show the effects of antipsychotics on the white matter in the left frontal region in schizophrenia.

Effects of Electroconvulsive Therapy on Frontal White Matter in Late-Life Depression: A Diffusion Tensor Imaging Study

This study was conducted to elucidate the effects of electroconvulsive therapy (ECT) on frontal white matter in late-life depressed patients. Diffusion tensor imaging was performed on 8 late-life depressed patients and 12 healthy age-matched controls. The patients were scanned before and after a course of ECT. Fractional anisotropy (FA) was determined in the frontal and temporal regions and the corpus callosum. A significant white matter FA reduction was found in widespread frontal and temporal brain regions in patients with depression before ECT treatment compared with controls. A significant increase in frontal white matter FA was seen following ECT treatment. A course of bilateral ECT ameliorated white matter integrity in frontal brain regions. This suggests a strong relationship with the antidepressant action of ECT.

Differences in quantitative EEG between frontotemporal dementia and Alzheimer’s disease as revealed by LORETA

OBJECTIVE To determine the electrophysiological characteristics of frontotemporal dementia (FTD) and the distinction with Alzheimers disease (AD). METHODS We performed analyses of global field power (GFP) which is a measure of whole brain electric field strength, and EEG neuroimaging analyses with sLORETA (standardized low resolution electromagnetic tomography), in the mild stages of FTD (n = 19; mean age = 68.11 ± 7.77) and AD (n = 19; mean age = 69.42 ± 9.57) patients, and normal control (NC) subjects (n = 22; mean age = 66.13 ± 6.02). RESULTS In the GFP analysis, significant group effects were observed in the delta (1.5-6.0 Hz), alpha1 (8.5-10.0 Hz), and beta1 (12.5-18.0 Hz) bands. In sLORETA analysis, differences in activity were observed in the alpha1 band (NC > FTD) in the orbital frontal and temporal lobe, in the delta band (AD>NC) in widespread areas including the frontal lobe, and in the beta1 band (FTD > AD) in the parietal lobe and sensorimotor area. CONCLUSIONS Differential patterns of brain regions and EEG frequency bands were observed between the FTD and AD groups in terms of pathological activity. SIGNIFICANCE FTD and AD patients in the early stages displayed different patterns in the cortical localization of oscillatory activity across different frequency bands.

Global Approach to Multichannel Electroencephalogram Analysis for Diagnosis and Clinical Evaluation in Mild Alzheimer’s Disease

To establish an early diagnosis of Alzheimer’s disease (AD), we evaluated brain spatial dynamics and cognitive function in mild AD. Seventeen patients with the diagnosis of mild AD and 17 age-matched controls were examined for Ω (global complexity), Σ (total power) and Φ (generalized frequency) by 19-channel electroencephalography (EEG). As a result, the mild AD group showed significantly higher Ω values than the control group. The Φ values were highly correlated with the Mini-Mental State Examination scores and the full IQ and performance IQ scores of the Japanese Wechsler Adult Intelligence Scale Revised. These results indicate an increase in spatial complexity of the brain electric field in mild AD, as well as a close relationship between slowing of the global frequency of field changes and the cognitive decline in mild AD.

Inter- and intraoperator reliability of brain tissue measures using magnetic resonance imaging

Abstract.Grey matter, white matter and cerebrospinal volume in the human brain were measured using magnetic resonance image analysis software BRAINS. Ten volunteers were scanned in the MR sequence (3D-SPGR; 1.5-mm slice thickness and T2 images; 3mm slice thickness). Two operators obtained ten volume measures of grey matter,white matter and cerebrospinal fluid (CSF) in the intracranial box, frontal box, temporal box, parietal box and occipital box. The same data set of ten scans was segmented and the volumes measured on a second occasion by one operator using the same procedure. The interoperator and intraoperator reliabilities for measures of the three brain tissues were very good, with reliability coefficients (intraclass correlation coefficients) ranging between 0.971 and 0.999. The segmentation and measurement are useful for volumetric studies in the human brain using BRAINS.

Acupuncture-induced cerebral blood flow responses in dystonia

ObjectiveThe effect of acupuncture (ACP) on regional cerebral blood flow (rCBF) is unclear. Single-photon emission computed tomography studies on three patients with dystonia were performed before and after ACP treatment to test the contention that ACP affects rCBF.Methods Pre-ACP and post-ACP CBF study were performed on the same day; 99m Tc ethyl cysteinate dimer was injected for each study. rCBF images were analyzed using a three-dimensional stereotaxic ROI template (3DSRT) to objectively measure rCBF. We evaluated rCBF bilaterally in five segments related to the pathophysiology of dystonia (1, superior frontal; 2, middle and inferior frontal; 3, primary sensorimotor; 4, lenticular nucleus; and 5, thalamus). More than 10% left-right asymmetry in rCBF over three continuous slices was defined as significant laterality. Post-ACP rCBF and laterality were evaluated with the pre-ACP rCBF study acting as a control in each subject.ResultsThe clinical effect of ACP was remarkable in all patients and rCBF increased in most segments. PreACP rCBF exhibited significant laterality in eight segments of the three patients. Laterality reversed in seven of these segments and resolved in the remaining segment after ACP. Pre-ACP rCBF laterality was not preserved in any segment after ACP. The remaining five segments exhibited laterality only after ACP. In total, after ACP, 13 of 15 segments demonstrated a change in CBF that was greater unilaterally.ConclusionsACP results in an increase in CBF that is greater unilaterally. We think that unilateral change in CBF may be correlated with the action of ACP on the central nervous system in patients with dystonia.

Extravasation of Tc-99m sodium pertechnetate detected on Meckel's cine scintigraphy in hemorrhagic diverticulum.

Meckels diverticulum scintigraphy using Tc-99m sodium pertechnetate usually shows persistent focal uptake in the midabdomen. The authors describe a patient with a hemorrhagic diverticulum demonstrating active, intermittent intraluminal tracer extravasation on Meckels scintigraphy, a pattern mimicking gastrointestinal bleeding scintigraphy using Tc-99m red blood cells or Tc-99m human serum albumin. Cine scintigraphy was helpful in the evaluation of the intraluminal hemorrhage.

Brain perfusional spect in early Alzheimer's disease related to efficacy of donepezil

Abstract The purpose of this study was to investigate the relation between the clinical efficacy and the change of regional Cerebral Blood Flow (rCBF) in the early stage of Alzheimers Disease (AD) patients after treatment of Donepezil Hydrochloride (DH). The subjects were four outpatients. They were diagnosed to have AD on criteria of DSM-IV, ICD-10, and NINCDS-ADRDA. We estimated the cognitive functions by ADAS-Jcog. SPECT examination was performed after i.v. injection of [ 123 I]-IMP. The ARG method was used for calculation of rCBF. In three of four patients (the responders to DH) the scores of ADAS-Jcog were improved within three months after treatment of DH therapy. On the other hand, the one patient (the non-responder to DH) had no significant changes. Two of three responders showed a marked increase of rCBF in all brain regions after one month. The non-responder showed decreases of rCBF in many regions after one month. In the present study the consistent relation between the clinical efficacy and the changes of rCBF were not observed. Further evaluation, including the larger samples and longer observation period, will be needed to obtain the consistent relation of the changes between clinical evaluation and rCBF.

Global field power and low resolution electromagnetic tomography solutions in Alzheimer's disease

Abstract Brain electrophysiological characteristics of Alzheimers disease (AD) were investigated by global field power (GFP) and low-resolution electromagnetic tomography (LORETA). GFP measures the energy of the brain electric field. LORETA computes for the smoothest of all possible source configurations throughout the brain volume by minimizing the total source strengths. The study population included a total of 29 AD patients and 15 age-matched controls. Clinical stages were based on the functional assessment staging (FAST). Mild-AD consists of 18 patients with a diagnosis of moderate cognitive decline (Stage 4). Advanced-AD consists of 11 patients with a diagnosis of severe cognitive decline (Stages 5, 6 and 7). Nineteen-channel eye-closed EEG was recorded using Cz reference and artifact-free 20 s were picked up and recomputed vs. average reference. Mild-AD showed lower power at Beta-2 and Beta-3 bands than control, and remarkably, advanced-AD showed lower power at the higher band of Alpha-1 than control. The t-scores of the current density of mild-AD were more reduced in the right frontal and temporal areas than the control at the beta bands, and of advanced-AD, reduced in low temporal area at alpha bands and reduced in temporal and parietal area at beta bands. This result clearly demonstrates the physiological characteristics of the clinical stages in Alzheimers disease.