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Aim Neuronal degeneration in the locus coeruleus occurs in the early phase of Alzheimer's disease, similar to mild cognitive impairment. The locus coeruleus produces norepinephrine, a deficiency of which causes both memory disturbance and psychological symptoms. Thus, we evaluated signal alterations in the locus coeruleus of patients with Alzheimer's disease and mild cognitive impairment using a high-resolution fast spin-echo T1-weighted imaging. Methods A total of 22 patients with Alzheimer's disease, 47 patients with mild cognitive impairment and 26 healthy controls were prospectively examined by high-resolution fast spin-echo T1-weighted imaging at 3 Tesla. Signal intensities in the locus coeruleus were manually measured and expressed relative to those in the adjacent white matter structures as contrast ratios. Results Locus coeruleus contrast ratios were significantly reduced in patient groups with Alzheimer's disease, mild cognitive impairment that converted to Alzheimer's disease and mild cognitive impairment that did not convert to Alzheimer's disease (1.80-16.09% [median, 9.30%], 3.45-14.84% [median 6.87%] and 3.01-19.19% [median 7.72%], respectively) compared with the healthy control group (6.24-20.94% [median 14.35%]; P < 0.0001). The sensitivity and specificity for discriminating these diseases were 85.0% and 69.2%, respectively, which suggests that this measurement can be carried out reliably. There was no significant difference in the locus coeruleus contrast ratios among the Alzheimer's disease, mild cognitive impairment-converted and mild cognitive impairment-non-converted groups. Conclusions High-resolution fast spin-echo T1-weighted imaging can show signal attenuation in the locus coeruleus of patients with Alzheimer's disease or with mild cognitive impairment whose pathology may or may not eventually convert to Alzheimer's disease. Geriatr Gerontol Int 2015; 15: 334-340. [ABSTRACT FROM AUTHOR]

Objectives. It has been reported that disturbance in sensory and motor function may induce sensorimotor incongruence and produce pain, discomfort and other sensations in healthy volunteers. One study suggested that sensorimotor incongruent information to healthy subjects results in increased neuronal activity in the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex; however, this study did not take into consideration the discomfort induced by sensorimotor incongruence. The present study attempted to characterize intracortical electrical activities for sensorimotor incongruence in the frequency domain. In our study, electroencephalogram (EEG) cortical sources were compared between sensorimotor congruence and sensorimotor incongruence. In addition, high and no discomfort subgroups were compared during sensorimotor incongruence.Methods. Eighteen healthy female subjects participated in this study. Subjects were then asked to flex/extend both arms in a congruent/incongruent manner while viewing a whiteboard/mirror. EEG was performed to determine the cortical activation during sensorimotor congruence and incongruence.Results. Alpha band activity in the right posterior parietal cortex during sensorimotor incongruence was significantly lower than that of sensorimotor congruence. The source activities induced in the anterior cingulate cortex (ACC) beta band activity and the posterior cingulate cortex (PCC) alpha band activity significantly decreased in the high-discomfort vs the no-discomfort subgroup.Conclusion. The present findings suggest that the ACC and PCC are more activated in the high-discomfort subgroup than in the no-discomfort subgroup during sensorimotor incongruence. This method may evaluate the effectiveness of new medication therapy and/or rehabilitation by assessing the difference in the neuronal activity of chronic patients before and after treatment. [ABSTRACT FROM PUBLISHER]

Background. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is one of the standard surgical treatments for advanced Parkinson's disease. However, it has been difficult to accurately localize the stimulated contact area of the electrode in the subthalamic nucleus and its adjacent structures using a two-dimensional atlas. The goal of this study is to verify the real and detailed localization of stimulated contact of the DBS electrode therapeutically inserted into the STN and its adjacent structures using a novel computed three-dimensional atlas built by a personal computer. Method. A three-dimensional atlas of the STN and its adjacent structures (3D-Subthalamus atlas) was elaborated on the basis of sagittal slices from the Schaltenbrand and Wahren stereotactic atlas on a personal computer utilizing a commercial software. The electrode inserted into the STN and its adjacent structures was superimposed on our 3D-Subthalamus atlas based on intraoperative third ventriculography in 11 cases. Findings. Accurate localization of the DBS electrode was identified using the 3D-Subthalamus atlas, and its clinical efficacy of the electrode stimulation was investigated in all 11 cases. Conclusion. This study demonstrates that the 3D-Subthalamus atlas is a useful tool for understanding the morphology of deep brain structures and for the precise anatomical position findings of the stimulated contact of a DBS electrode. The clinical analysis using the 3D atlas supports the contention that the stimulation of structures adjacent to the STN, particularly the zona incerta or the field of Forel H, is as effective as the stimulation of the STN itself for the treatment of advanced Parkinson's disease. [ABSTRACT FROM AUTHOR]