Cortical involvement in a gait-related imagery task: comparison between Parkinson's disease and normal aging.

PURPOSE: We employed imaginary tasks to investigate the neurophysiology of gait in patients with Parkinson's disease (PD) using functional magnetic resonance imaging (fMRI). METHODS: Cortical activation of gait-related imagery was explored in 13 PD patients, 13 age-matched controls (Old), and 14 young volunteers (Young) using fMRI. The tasks included gait initiation, stepping over an obstacle and gait termination using an event-related design. Subjects watched a video clip showing an actor walking and imagined the walking process. RESULTS: At gait initiation, no significant difference could be found between PD and the Old controls. Activation in the visual related areas in the Old subjects was increased compared to the Young subjects. While imagining stepping over obstacles, the right dorsal premotor area (PMd), precentral, right inferior parietal lobule, and bilateral precuneus were more activated in PD compared to the Old. An extensive network of bilateral SMA, PMd, posterior parietal lobe and visual association areas was activated in the Old versus the Young subjects. At gait termination, visual related areas were noted when PD was compared to the Old. In contrast, increased activation in bilateral pre-SMA, PMd, ventral premotor area, precentral, posterior parietal lobes and visual association areas were activated in the Old when compared to the Young. CONCLUSIONS: Our study provides image based evidence for gait disturbance in PD patients and during normal aging. The compensatory cortical mechanism in the findings could be a background resource for further therapeutic interventions.

Parkinson disease: diagnostic utility of diffusion kurtosis imaging.

PURPOSE: To examine the usefulness of diffusion kurtosis imaging for the diagnosis of Parkinson disease (PD). MATERIALS AND METHODS: Examinations were performed with the understanding and written consent of each subject, with local ethics committee approval, and in compliance with national legislation and Declaration of Helsinki guidelines. Diffusion-weighted magnetic resonance imaging was performed in 30 patients with idiopathic PD (mean age, 64.5 years ± 3.4 [standard deviation]) and 30 healthy subjects (mean age, 65.0 years ± 5.1). Mean kurtosis, fractional anisotropy, and mean, axial, and radial diffusivity of the basal ganglia were compared between the groups. Disease severity was assessed by using Hoehn and Yahr staging and the motor section of the Unified Parkinson's Disease Rating Scale (mean scores, 2.0 and 33.6, respectively). Receiver operating characteristic (ROC) analysis was used to compare the diagnostic accuracies of the indexes of interest. Pearson correlation coefficient analysis was used to correlate imaging findings with disease severity. RESULTS: Mean kurtosis in the putamen was higher in the PD group (0.93 ± 0.15) than in the control group (0.71 ± 0.09) (P < .000416). The area under the ROC curve (AUC) was 0.95 for both the ipsilateral putamen and the ipsilateral substantia nigra. The mean kurtosis for the ipsilateral substantia nigra had the best diagnostic performance (mean cutoff, 1.10; sensitivity, 0.92; specificity, 0.87). In contrast, AUCs for the tensor-derived indexes ranged between 0.43 (axial and radial diffusivity in substantia nigra) and 0.65 (fractional anisotropy in substantia nigra). CONCLUSION: Diffusion kurtosis imaging in the basal ganglia, as compared with conventional diffusion-tensor imaging, can improve the diagnosis of PD.

Detection of nighttime melatonin level in Chinese Original Quiet Sitting.

BACKGROUND/PURPOSE: Some research has shown that melatonin levels increase after meditation practices, but other research has shown that they do not. In our previous functional magnetic resonance imaging study, we found positive activation of the pineal body during Chinese Original Quiet Sitting (COQS). To find other supporting evidence for pineal activation, the aim of this study was to evaluate the effect of COQS on nighttime melatonin levels. METHODS: Twenty subjects (11 women and 9 men, aged 29-64 years) who had regularly practiced daily meditation for 5-24 years participated in this study. All subjects served alternately as participants in the mediation and control groups. COQS was adopted in this study. Tests were performed during two nighttime sessions. Saliva was sampled at 0, 10, 20, 30, 45, 60 and 90 minutes after COQS and tested for level of melatonin. Time period effect analysis and mixed effect model analysis were preceded by paired t test analysis. RESULTS: In the meditation group (n = 20), the mean level of melatonin was significantly higher than the baseline level at various times post-meditation (p < 0.001). Within the control group (n = 20), the mean level of melatonin at various times was not significantly different compared with baseline (p>0.05). These results suggested that the melatonin level was statistically elevated in the meditation group and almost unchanged in the control group after nighttime meditation. The urine serotonin levels detected by measuring 5-hydroxy-indole-3-acetic acid levels were also studied, but no detectable difference between the groups was found. CONCLUSION: Our results support the hypothesis that meditation might elevate the nighttime salivary melatonin levels. It suggests that COQS can be used as a psychophysiological stimulus to increase endogenous secretion of melatonin, which in turn, might contribute to an improved sense of well-being.

Microstructural changes in patients with progressive supranuclear palsy: a diffusion tensor imaging study.

PURPOSE: To determine whether progressive supranuclear palsy (PSP) is associated with specific diffusion tensor imaging (DTI) patterns of diffusivity, anisotropy, and coherence in functionally relevant brain areas. MATERIALS AND METHODS: In all, 17 PSP patients and 17 controls were scanned using a 3 T magnetic resonance imaging (MRI) scanner. Patients were assessed in the off-medication condition using the Hoehn and Yahr staging and the United Parkinson's Disease Rating Scale, motor subscale (UPDRS-III). Diffusion information were analyzed in relation to disease severity and subtypes. RESULTS: Numerous changes in diffusion properties were identified in the subcortical areas. In the midbrain, fractional anisotropy (FA) decreased and MD (mean diffusivity) increased with disease progression. UPDRS-III scores correlated positively with both FA in the caudate and MD in the pons. DTI analysis of disease subtypes demonstrated significant differences between PSP-Parkinsonism and Steele-Richardson-Olszewski syndrome in axial diffusivity values in the putamen and globus pallidus, as well as in intervoxel diffusion coherence values in the middle cerebellar peduncle. CONCLUSION: Our findings, cautiously interpreted, demonstrate the advantage of using a functional imaging technique to aid in the specificity of defining more precisely the pathological processes taking place in white and gray matter regions in PSP.

EEG-based emotion recognition in music listening.

Ongoing brain activity can be recorded as electroencephalograph (EEG) to discover the links between emotional states and brain activity. This study applied machine-learning algorithms to categorize EEG dynamics according to subject self-reported emotional states during music listening. A framework was proposed to optimize EEG-based emotion recognition by systematically 1) seeking emotion-specific EEG features and 2) exploring the efficacy of the classifiers. Support vector machine was employed to classify four emotional states (joy, anger, sadness, and pleasure) and obtained an averaged classification accuracy of 82.29% +/- 3.06% across 26 subjects. Further, this study identified 30 subject-independent features that were most relevant to emotional processing across subjects and explored the feasibility of using fewer electrodes to characterize the EEG dynamics during music listening. The identified features were primarily derived from electrodes placed near the frontal and the parietal lobes, consistent with many of the findings in the literature. This study might lead to a practical system for noninvasive assessment of the emotional states in practical or clinical applications.

Diagnosis and development of screening items for migraine in neurological practice in Taiwan.

BACKGROUND/PURPOSE: The objectives of this study were to: (1) survey migraine diagnoses among neurological outpatients in Taiwan; (2) compare neurologists' migraine diagnoses with the International Classification of Headache Disorders 2nd Edition (ICHD-2) criteria; and (3) evaluate the diagnostic ability of screening items on a patient migraine questionnaire. METHODS: This prospective study surveyed patients who consulted neurologists for the first time with a chief complaint of headache, excluding those experiencing headaches for > or = 15 days/month. Each neurologist interviewed a maximum of 10 patients. Patients were asked to complete a self-administered questionnaire and their physicians completed another questionnaire. The physicians were asked if patients could be diagnosed with migraine. In addition, a diagnosis of ICHD-2 migraine was made by the physician's questionnaire through a computer-generated algorithm. In this study, migraine without aura (code 1.1) or migraine with aura (code 1.2) were designated as "strict migraine", and the combination of strict migraine and ICHD-2 probable migraine (code 1.6) as "any migraine". RESULTS: Among 755 patients who were eligible for analysis, 537 (71%) were diagnosed as having "any migraine", 363 (48%) with "strict migraine", and 451 (60%) with physician-diagnosed migraine. Among the 537 patients diagnosed as having "any migraine", 308 patients (57%) had not been diagnosed by any physician before. A moderate agreement (kappa statistic around 0.5) was found between the physicians' diagnoses and ICHD-2 "strict migraine" or "any migraine". In patients with ICHD-2 probable migraine (n = 174), only 52% were diagnosed with migraine by our physicians. Nausea was the best single item for predicting migraine diagnosis, while any combination of two items among nausea/vomiting, moderate or severe pain and photophobia, provided the optimum screening tool. CONCLUSION: Migraine was the most common headache diagnosis in the neurologists' clinics. Probable migraine was not completely adopted as a migraine spectrum among neurologists. In contrast to ID Migraine(TM), moderate or severe headache intensity replaced headache-related disability as one screening item for migraine in Taiwan.

Comparison of fMRI BOLD Effect and Arterial Pulsation Harmonic Distribution among Different Breathing Rate.

The phenomenon of respiratory sinus arrhythmia (RSA) had been studied since 1733. Most researches were focused on the heart rates or blood pressure variability. It was well known that heart rate variability (HRV) induced by respiration decreased progressively with age. In general, it is caused by the function of the autonomic nervous system (ANS). Seldom researches studied the relationship of this phenomenon with cerebral circulation. In our previous research, we found that different breathing rate could redistribute the proportion of systemic circulation, and also observed that the slower the breathing rate the more proportion of cerebral circulation appeared on head. In this paper, we further examined the BOLD (Blood Oxygenation Level Dependent) signal fluctuations in brain stem among different breathing rate by the technique of functional magnetic resonance imaging (fMRI). We found that the BOLD signal changes were hinged on the breathing rate, and the variability was consistent with the pulsatile pressure study.

Comparison of fMRI BOLD Effect and Arterial Pulsation Harmonic Distribution among Different Breathing Rate.

The phenomenon of respiratory sinus arrhythmia (RSA) had been studied since 1733. Most researches were focused on the heart rates or blood pressure variability. It was well known that heart rate variability (HRV) induced by respiration decreased progressively with age. In general, it is caused by the function of the autonomic nervous system (ANS). Seldom researches studied the relationship of this phenomenon with cerebral circulation. In our previous research, we found that different breathing rate could redistribute the proportion of systemic circulation, and also observed that the slower the breathing rate the more proportion of cerebral circulation appeared on head. In this paper, we further examined the BOLD (Blood Oxygenation Level Dependent) signal fluctuations in brain stem among different breathing rate by the technique of functional magnetic resonance imaging (fMRI). We found that the BOLD signal changes were hinged on the breathing rate, and the variability was consistent with the pulsatile pressure study.

Studies of chinese original quiet sitting by using functional magnetic resonance imaging.

Since different meditations may activate different regions in brain, we can use functional magnetic resonance imaging (fMRI) to investigate it. Chinese original quiet sitting is mainly one kind of traditional Chinese meditation. It contains two different parts: a short period of keeping phrase and intake spiritual energy, and a long period of relaxation with no further action. In this paper, both those two stages were studied by fMRI. We performed two different paradigms and found the accurate positions in the brain. The pineal gland and the hypothalamus showed positive activation during the first and second stages of this meditation. The BOLD (Blood Oxygenation Level Dependent) signal changes had also been found.