Analysis of the alpha activity envelope in electroencephalography in relation to the ratio of excitatory to inhibitory neural activity.

Alpha waves, one of the major components of resting and awake cortical activity in human electroencephalography (EEG), are known to show waxing and waning, but this phenomenon has rarely been analyzed. In the present study, we analyzed this phenomenon from the viewpoint of excitation and inhibition. The alpha wave envelope was subjected to secondary differentiation. This gave the positive (acceleration positive, Ap) and negative (acceleration negative, An) values of acceleration and their ratio (Ap-An ratio) at each sampling point of the envelope signals for 60 seconds. This analysis was performed on 36 participants with Alzheimer's disease (AD), 23 with frontotemporal dementia (FTD) and 29 age-matched healthy participants (NC) whose data were provided as open datasets. The mean values of the Ap-An ratio for 60 seconds at each EEG electrode were compared between the NC and AD/FTD groups. The AD (1.41 ±0.01 (SD)) and FTD (1.40 ±0.02) groups showed a larger Ap-An ratio than the NC group (1.38 ±0.02, p<0.05). A significant correlation between the envelope amplitude of alpha activity and the Ap-An ratio was observed at most electrodes in the NC group (Pearson's correlation coefficient, r = -0.92 ±0.15, mean for all electrodes), whereas the correlation was disrupted in AD (-0.09 ±0.21, p<0.05) and disrupted in the frontal region in the FTD group. The present method analyzed the envelope of alpha waves from a new perspective, that of excitation and inhibition, and it could detect properties of the EEG, Ap-An ratio, that have not been revealed by existing methods. The present study proposed a new method to analyze the alpha activity envelope in electroencephalography, which could be related to excitatory and inhibitory neural activity.

Pandemic-Induced Occupational Disruption and Association With Health in Japanese Community-Dwelling Older Adults.

The COVID-19 pandemic caused occupational disruption and adverse health outcomes in community-dwelling older adults. This study aimed to investigate the extent of occupational disruption in older adults and its relationship to health-related quality of life (QOL), depression, and frailty. In this cross-sectional study, retention rates in four activity domains and relationships with health outcomes were examined in Japanese older adults aged ≥65 years (n=163) using canonical correlation analysis (CCA) and mixed linear models. More than 25% of activities were restricted compared with the pre-pandemic period. CCA demonstrated correlations between four retention rates and health outcomes (canonical correlation = .42, p = .0003). Retention in instrumental and social activities independently predicted QOL and depression (p < .05). This study highlights that different activities may have different effects on health outcomes and can provide community occupational therapy practitioners with a perspective to assess occupational disruption and identify activities for intervention.

Pandemic-Induced Changes of Daily Routine and Its Association with Health for Japanese Older AdultsWe investigated the changes in daily activity due to the COVID-19 pandemic among community-dwelling older adults in Japan and examined their association with health outcomes. The results showed that more than 25% of activity was reduced due to the pandemic. There was a moderate association between changes in activity and physical, mental, and subjective health. Especially, instrumental and social activities were strongly associated with mental and subjective health. This study highlights the possibility that different types of activities may have different effects on health. Our study can provide occupational therapy practitioners supporting community-dwelling older adults with a perspective to assess changes in daily activities due to the pandemic and identify activities to target for future intervention. As this study was conducted at a single point in time, future studies should be conducted at multiple points in time.

Changes in Community-Dwelling Elderly's Activity and Participation Affecting Depression during COVID-19 Pandemic: A Cross-Sectional Study.

We determined the changes in the activity or participation of the community-dwelling elderly in Japan during the COVID-19 pandemic and identified the activities leading to depression. This will allow us to evaluate rehabilitation interventions that can be used to minimize or eliminate the negative impact of COVID-19 on today's community-dwelling elderly. Herein, demographics, activity or participation (Activity Card Sort-Japan version: ACS-JPN), the number of social networks (Lubben Social Network Scale: LSNS), and depression (Geriatric Depression Scale: GDS) were examined in 74 community-dwelling elderly in Japan from August to October 2020. A statistical analysis was conducted to determine the effect of demographics on GDS, LSNS, and ACS-JPN, to compare the activity retention rates of the four domains using ACS-JPN, and to extract the activities that might affect depression using a generalized linear model. The results show that the retention of leisure activity with a high physical demand (H-leisure) and sociocultural activities was significantly lower than instrumental activities of daily living and leisure activity with a low physical demand (L-leisure). L-leisure and the number of social networks were possible risk factors for depression during the pandemic. This study highlighted the importance of maintaining the number of L-leisure and social networks at home to prevent depression in community-dwelling elderly when they could not perform outdoor activities and direct interpersonal interaction.

Reappraisal of Malignant Risk Assessment for Small (≤20 mm) Non-functioning Pancreatic Neuroendocrine Tumors.

BACKGROUND: Optimal management of non-functioning pancreatic neuroendocrine tumors (PanNETs) ≤20 mm is controversial. The biological heterogeneity of these tumors poses challenges when deciding between resection and observation. METHODS: In this multicenter, retrospective cohort study, we analyzed all patients (n = 78) who underwent resection of non-functioning PanNETs ≤20 mm at three tertiary medical centers from 2004 to 2020 to assess the utility of preoperatively available radiological features and serological biomarkers of non-functioning PanNETs in choosing an optimal surgical indication. The radiological features included non-hyper-attenuation pattern on enhancement computed tomography (CT; hetero/hypo-attenuation) and main pancreatic duct (MPD) involvement, and serological biomarkers included elevation of serum elastase 1 and plasma chromogranin A (CgA) levels. RESULTS: Of all small non-functioning PanNETs, 5/78 (6%) had lymph node metastasis, 11/76 (14%) were WHO grade II, and 9/66 (14%) had microvascular invasion; 20/78 (26%) had at least one of these high-risk pathological factors. In the preoperative assessment, hetero/hypo-attenuation and MPD involvement were observed in 25/69 (36%) and 8/76 (11%), respectively. Elevated serum elastase 1 and plasma CgA levels were observed in 1/33 (3%) and 0/11 (0%) patients, respectively. On multivariate logistic regression analysis, hetero/hypo-attenuation (odds ratio [OR] 6.1, 95% confidence interval [CI] 1.7-22.2) and MPD involvement (OR 16.8, 95% CI 1.6-174.3) were significantly associated with the high-risk pathological factors. The combination of the two radiological worrisome features correctly predicted non-functioning PanNETs with high-risk pathological factors, with about 75% sensitivity, 79% specificity, and 78% accuracy. CONCLUSIONS: This combination of radiological worrisome features can accurately predict non-functioning PanNETs that may require resection.

Identification of Subgroups of Activity Participation in Group of Community-Dwelling Older Adults.

Occupational therapy in public health is advancing for groups of older adults, but few studies have focused on measuring population-based activity engagement. This study aimed to identify subgroups based on the daily activity pattern of community-dwelling older adults. Japanese older adults aged ≥65 years responded to a 128-activity-item questionnaire. Sparse principal component analysis was applied to summarize the activities, and k-means clustering was used to identify subgroups. Respondents were divided into three subgroups (subgroup 1: n = 39, high instrumental/leisure and social/cognitive activity; subgroup 2: n = 51, high instrumental/leisure and low social/cognitive activity; subgroup 3: n = 44, low instrumental/leisure and social/cognitive activity). The three subgroups were associated with sociodemographics (sex, area, education, and activity level) (p < .05). This study highlighted the activity-based subgroups of older adults and provided a novel viewpoint regarding occupation-based community assessments in addition to previous community occupational therapy practice.

Gender differences in psychosocial factors related to severe stress in a construction company in Japan.

BACKGROUND: In Japan, women's participation in the workforce has been increasing. However, there are few studies about gender differences in stress factors in the workplace. OBJECTIVES: We aimed to clarify gender differences in psychosocial factors in the workplace related to severe stress. METHODS: In total, 930 male and 339 female employees working in a construction company in Japan participated in this study. We used individual responses to the Brief Job Stress Questionnaire (BJSQ) conducted by their company for the most recent year between 2016 and 2019. Data were categorized by gender, and we extracted the factors contributing to severe stress using logistic regression. RESULTS: We identified 142 men and 32 women who had severe stress. Logistic regression analysis showed that six factors ("Qualitative job overload", "Job control", "Interpersonal conflict", "Poor physical environment", "Supervisor's support", and "Job satisfaction and life satisfaction") were significantly associated with the presence of severe stress in men. In women, five factors ("Qualitative job overload", "Job control", "Interpersonal conflict", "Suitable work", and "Job satisfaction and life satisfaction") showed a significant association with severe stress. CONCLUSION: Factors associated with severe stress were "Poor physical environment" and "Supervisor's support" in men, and "Suitable work" in women.

Constrictive pericarditis caused by pericardial metastasis from esophageal squamous cell carcinoma: a case report.

Constrictive pericarditis is a rare condition characterized by clinical signs of right heart failure subsequent to the loss of pericardial compliance. We report a case of constrictive pericarditis due to pericardial metastasis in a patient with a history of esophageal squamous cell carcinoma that had a pathological complete response (pCR) to preoperative chemoradiotherapy. A 66-year-old woman was referred to our division for the treatment of advanced esophageal cancer. Video-assisted thoracoscopic surgery esophagectomy (VATSE) with 3-field lymphadenectomy was performed after neoadjuvant chemoradiotherapy (NAC-CRT). Pathological examination revealed no residual tumor, lymph node metastasis, lymphatic invasion, or vessel invasion. The histological treatment effect of the chemoradiotherapy was pathological complete response (pCR). Five months after surgery, the patient was admitted to a nearby hospital for the treatment of acute pericarditis. However, a month after admission, acute pericarditis progressed to constrictive pericarditis, and she was referred to our hospital for further management. Subsequently, urgent pericardiectomy was performed through a lower half sternotomy incision. After surgery, heart failure improved for a while but worsened again. The patient died 7 days after the surgery. Pathological examination of the resected pericardium revealed evidence of metastasis from squamous cell carcinoma of the esophagus. An autopsy revealed the spread of esophageal cancer to the bilateral pleura, right lung, pericardium, diaphragm, soft tissue surrounding the tracheal bifurcation, and bilateral hilar lymph nodes. Similarly, tumor cells were found in the lymphatic vessels of the pericardium and pleura. Even if pCR is achieved with NAC-CRT, as in our case, esophageal cancer may metastasize and present as constrictive pericarditis within a short period; therefore, careful patient follow-up is essential.

Pre-stimulus alpha oscillation and post-stimulus cortical activity differ in localization between consciously perceived and missed near-threshold somatosensory stimuli.

Conscious perception of a near-threshold (NT) stimulus is characterized by the pre- and post-stimulus brain state. However, the power of pre-stimulus neural oscillations and strength of post-stimulus cortical activity that lead to conscious perception have rarely been examined in individual cortical areas. This is because most previous electro- and magnetoencephalography (EEG and MEG, respectively) studies involved scalp- and sensor-level analyses. Therefore, we recorded MEG during a continuous NT somatosensory stimulus detection task and applied the reconstructed source data in order to identify cortical areas where the post-stimulus cortical activity and pre-stimulus alpha oscillation predict the conscious perception of NT somatosensory stimuli. We found that the somatosensory hierarchical processing areas, prefrontal areas and cortical areas belonging to the default mode network showed stronger cortical activity for consciously perceived trials in the post-stimulus period, but the cortical activity in primary somatosensory area (SI) is independent of conscious perception during the early stage of NT stimulus processing. In addition, we revealed that the pre-stimulus alpha oscillation only in SI is predictive of conscious perception. These findings suggest that the bottom-up stream of somatosensory information flow following SI and pre-stimulus alpha activity fluctuation in SI as a top-down modulation are crucial constituents of conscious perception.

Chronic pain-related cortical neural activity in patients with complex regional pain syndrome.

Quantitative objective measurement of chronic pain is important. We elucidated chronic pain-related cortical neural activity and neural connectivity among pain-related brain regions in complex regional pain syndrome (CRPS). Resting-state magnetoencephalography recordings were performed. Cortical current density and neural connectivity, revealed by amplitude envelope correlation (AEC), were estimated on standardized brain magnetic resonance imaging. Intra-experiment pain was assessed subjectively using a visual analogue scale (VAS). The correlation between current density and VAS scores was calculated for the occipital areas and pain-related cortices. Current density in the primary (SI) and secondary (SII) somatosensory cortex and precuneus in both hemispheres was negatively correlated with the pain VAS score. The AEC and VAS values were significantly correlated for the SII and the precuneus and for the SII and insular cortex in the alpha frequency band in the right hemisphere. In the theta frequency band, the AEC and VAS values correlated for the SII and posterior cingulate cortex in the right hemisphere. Our results suggested that disruption of pain processes and functions in the default mode network occurs in CRPS. Our method targeting the neural mechanism of pain has the potential to offer a clinically objective means of evaluating it.

Early gastric cancer with an Adachi type VI (group 26) vascular anomaly diagnosed preoperatively and treated by laparoscopic surgery: a case report.

BACKGROUND: It is important to understand the branching pattern of the celiac artery for a safe surgery. Various branching anomalies of the celiac artery were classified by Adachi in 1928. In Adachi's classification, type VI (group 26) is a rare anatomical anomaly (0.4%) that requires care when carrying out a surgery in gastric cancer patients with this anomaly. Herein, we reported a case treated successfully with laparoscopic distal gastrectomy with D1+ lymph node dissection for early gastric cancer. CASE PRESENTATION: An 84-year-old female was referred to our division for an additional surgical treatment for early gastric cancer that was resected by endoscopic submucosal dissection. A three-dimensional computed tomography angiography revealed an angioplany of the common hepatic artery branching from the left gastric artery. According to Adachi's classification, the anomaly of this patient corresponded to type VI (group 26). Preoperative anatomical information of this rare anomaly helped us to safely perform a laparoscopic distal gastrectomy and lymph node dissection with common hepatic artery preservation. The patient had an uneventful postoperative course and was discharged on postoperative day 11. CONCLUSIONS: We consider that Group 26 anomalies require the most precise anatomical understanding among Adachi classification type VIs, since it affects hepatic blood flow and can cause serious complications. In this time, we reported a successful case to perform laparoscopic distal gastrectomy with safety and accuracy by preoperative understanding of the precise vascular anatomy.

Laparoscopic hand-sewn esophagojejunal anastomosis in laparoscopic proximal gastrectomy for early gastric cancer.

PURPOSE: In Asian countries, proximal gastrectomy is a standard treatment option for early primary gastric cancer located in the upper third of the stomach. However, laparoscopic proximal gastrectomy (LPG) is not widely employed due to the technical difficulty of laparoscopic esophagojejunal anastomosis. Therefore, we began performing laparoscopic hand-sewn esophagojejunal anastomosis. In this report, we describe the technique of this method and the short-term surgical outcomes. METHODS: Between February 2016 and June 2020, 18 patients underwent LPG with double-tract reconstruction at our institution. Laparoscopic hand-sewn esophagojejunal anastomosis was attempted for all patients. RESULTS: The median operative time for the 18 patients was 431 min (range: 301-549 min), and the estimated blood loss was 100 mL (range: 0-1524 mL). The median time for the hand-sewn esophagojejunostomy was 42 min (range: 26-81 min). Only one case was converted to open surgery after the reconstruction due to bleeding from an artery of the lesser curvature. No anastomotic leakage was observed in any patients (0/18, 0 %); however, two patients developed anastomotic stenosis (2/18, 11%). The mean length of postoperative hospital stay was 10 days (range: 8-28 days). CONCLUSION: The laparoscopic hand-sewn esophagojejunal anastomosis in LPG is a simple, cost-effective, and safe procedure. We believe that our method is a feasible choice. However, careful and longer follow-up of more patients is necessary to determine the advantages of our method.

Immunohistochemically Detected Expression of ATRX, TSC2, and PTEN Predicts Clinical Outcomes in Patients With Grade 1 and 2 Pancreatic Neuroendocrine Tumors.

OBJECTIVE: The goal of this retrospective study was to clarify the clinical implications of immunohistochemically detected protein expression for genes that are frequently mutated in pancreatic neuroendocrine tumors (PNETs). BACKGROUND: The clinical management of PNETs is hindered by their heterogenous biological behavior. Whole-exome sequencing recently showed that 5 genes (DAXX/ATRX, MEN1, TSC2, and PTEN) are frequently mutated in PNETs. However, the clinical implications of the associated alterations in protein expression remain unclear. METHODS: We collected Grade 1 and 2 (World Health Organization 2017 Classification) primary PNETs samples from 100 patients who underwent surgical resection. ATRX, DAXX, MEN1, TSC2, and PTEN expression were determined immunohistochemically to clarify their relationships with prognosis and clinicopathological findings. RESULTS: Kaplan-Meier analysis indicated that loss of TSC2 (n = 58) or PTEN (n = 37) was associated with significantly shorter overall survival, and that loss of TSC2 or ATRX (n = 41) was associated with significantly shorter recurrence-free survival. Additionally, loss of ATRX or TSC2 was significantly associated with nodal metastasis. In a multivariate analysis, combined loss of TSC2 and ATRX (n = 31) was an independent prognostic factor for shorter recurrence-free survival (hazard ratio 10.1, 95% confidence interval 2.1-66.9, P = 0.003) in G2 PNETs. CONCLUSIONS: Loss of ATRX, TSC2, and PTEN expression might be useful as a method of clarifying the behavior and clinical outcomes of Grade 1 and 2 PNETs in routine clinical practice. Combined loss of TSC2 and ATRX had an especially strong, independent association with shorter recurrence-free survival in patients with G2 PNETs. Loss of pairs in ATRX, TSC2, or PTEN would be useful for selecting the candidate for postoperative adjuvant therapy.

Four cases of laparoscopic colectomy for sigmoid colon and rectal cancer with persistent descending mesocolon.

BACKGROUND: Persistent descending mesocolon (PDM) is a congenital anomaly associated with the failure of fixation of the descending colon to the lateral abdominal wall. In the laparoscopic colectomy for colorectal cancer, it has been noticed that there are extensive adhesions and a distinctive anatomy of colonic vessels in cases with PDM. Therefore, it is necessary to have sufficient knowledge about PDM so that it can be appropriately treated during surgery. CASE PRESENTATION: Case 1-a 79-year-old man underwent laparoscopic intersphincteric resection for rectal cancer. Preoperative barium enema (BE) revealed that the sigmoid colon was located at the right side of the abdomen. An enhanced computed tomography (CT) showed that the common trunk of the left colic artery (LCA) and the first sigmoid colonic artery (S1) branched from the inferior mesenteric artery (IMA). Case 2-a 68-year-old man underwent laparoscopic sigmoidectomy for sigmoid colon cancer and laparoscopic distal gastrectomy for gastric cancer synchronously. BE showed that the descending colon ran from the splenic flexure to medial caudal side. An enhanced CT showed that the distance from the LCA to the marginal artery was 1.0 cm. Case 3-a 68-year-old man underwent laparoscopic low anterior resection for rectal cancer. BE showed that the descending colon ran to the medial caudal side. An enhanced CT showed that the mesentery of the descending colon was comparatively shortened. Case 4-a 60-year-old man underwent laparoscopic sigmoidectomy for sigmoid colon cancer. An enhanced CT showed that the descending colon ran to the medial caudal side and predicted that the LCA and S1 formed a common trunk and branched radially from the IMA. We reported four cases with PDM recognized preoperatively as above. Three cases had a shortening of the mesocolon. While dissecting the vessels, although special attention was required to maintain the blood flow to the intestine, none of these cases developed any complications during the postoperative course. CONCLUSIONS: We considered that it is important to have positional awareness of the LCA and the marginal artery to perform the laparoscopic surgery safely when a colorectal cancer with PDM is diagnosed preoperatively using imaging methods.

Items Selection for the Japanese Version of the Preschool Activity Card Sort.

Preschool Activity Card Sort (PACS) is a valid measure of preschoolers' participation and is a useful and unique tool for focusing on the extent and frequency of their participation. However, given the cultural differences between Japan and other countries, researchers should consider these differences when adapting the PACS for use with children in Japan. The purpose of this study was to select culturally suitable activity items to develop the Japanese version of PACS (PACS-JPN). A two-round survey of parents (who had typically developing children aged between 3 and 6 years) was conducted. The final version of the PACS-JPN included 98 activity items. The PACS-JPN reflects Japanese sociocultural background and allows occupational therapists to assess preschoolers' actual participation by assessing multiple aspects of children's community life. The psychometric properties, including the validity and reliability of the PACS-JPN should be examined in future research.

A case of Schloffer tumor with rapid growth and FDG-PET positivity at the port site of laparoscopic sigmoidectomy for colon cancer.

BACKGROUND: Schloffer tumor is a foreign body granuloma in the abdominal subcutaneous layer that develops due to a foreign body such as suture from several months to years postoperatively. Herein, we report a case of a rapidly growing Schloffer tumor with F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) positivity at the port site of laparoscopic sigmoidectomy for colon cancer. CASE PRESENTATION: An 85-year-old man, who underwent laparoscopic sigmoidectomy for stage IIIa sigmoid colon cancer 10 months ago, was referred to our hospital with complaints of a growing mass in the abdominal wall. The tumor was palpable at the right-sided abdominal wall corresponding to the port site of laparoscopic sigmoidectomy. The tumor rapidly grew for 2 months. Computed tomography showed a ring-enhanced mass at the right-sided abdominal wall. PET examination revealed high accumulation of FDG in the tumor. Tumor resection was performed due to suspected port site recurrence. The pathological diagnosis was inflammatory granuloma, so-called Schloffer tumor. CONCLUSION: In the era of laparoscopic surgery, Schloffer tumor may be one of the differential diagnoses for rapidly growing tumor with FDG-PET positivity at the port site in postoperative patients with advanced colorectal cancer.

A solitary fibrous tumor in the pelvic cavity of a patient with Doege-Potter syndrome: a case report.

BACKGROUND: A solitary fibrous tumor (SFT) is a mesenchymal lesion, which commonly develops in the thorax. Non-islet cell hypoglycemia is a rare paraneoplastic phenomenon caused by an extra-pancreatic tumor. We report a rare case of a pelvic SFT with severe hypoglycemia, which was considered to be Doege-Potter syndrome. CASE PRESENTATION: A 72-year-old man was referred to our hospital for treatment of hypoglycemia and a large pelvic tumor. His blood glucose level was 52 mg/dl; serum insulin level, 1.0 µIU/ml; C-peptide level, 0.2 ng/ml; and insulin-like growth factor-I (IGF-I) level, 31 ng/ml. Contrast-enhanced computed tomography (CT) showed a 13-cm mass in the pelvic cavity. Magnetic resonance imaging (MRI) revealed a lobulated tumor with iso- and high-intensity areas combined in T2-weighted images. No clear invasion to any adjacent organs was identified. The tumor was resected, and hypoglycemic symptoms disappeared immediately. Pathological diagnosis was an SFT with malignant potential that secreted IGF-II and caused hypoglycemia. There has been no tumor recurrence during the 1 year of follow-up. CONCLUSION: Non-islet cell tumor hypoglycemia should be considered in the differential diagnosis of patients presenting with tumors and hypoglycemia.

Selection of Activity Items for Development of the Activity Card Sort-Japan Version.

The Activity Card Sort (ACS) can both record the clients' participation and any changes, which is a useful tool for practitioners to establish tailored occupation-focused goals. However, there is a limitation to apply the ACS to Japanese older adults as it consists of culturally relevant activities in the United States. The aim of this study was to select activity items reflecting Japanese older adults' lifestyles and opinions to develop the Activity Card Sort-Japan Version (ACS-JPN). In the item selection process, a two-round questionnaire survey was conducted for community-dwelling Japanese older adults (Round 1: n = 177, M age = 69.9 years; Round 2: n = 178, M age = 74.9 years). Seventy-two activity items were finally included in the ACS-JPN and were classified into four domains. The ACS-JPN has some unique features compared with other ACS versions. This study only selected activity items. Further work on psychometric properties is needed.

Association between changes in visual evoked magnetic fields and non-motor features in Parkinson's disease.

Visual dysfunction can be caused by several abnormalities, including dysfunctions in the visual cortex and retina. Our aim was to investigate changes in visual evoked brain responses in the primary visual cortex associated with Parkinson's disease (PD). Sixteen healthy control subjects and ten patients with PD participated in this study. We assessed the visual evoked magnetic field (VEF) using magnetoencephalography (MEG). Checkerboard pattern reversal (CPR) and monotonous grating pattern (MGP) stimulations were used. Magnetic resonance imaging (MRI) was performed to analyze brain volume and generate a tractogram. Cognitive and olfactory function, and Unified Parkinson's Disease Rating Scale (UPDRS) scores were evaluated in patients with PD. Four components of the VEF (1M, 2M, 3M, 4M) were observed following stimulation. For both stimuli, results from the 1M and 2M components were significantly greater and the latency of the 1M component was increased markedly in the PD group compared with the healthy control group. In the PD group, 1M latency correlated with the UPDRS score of 1 for both stimuli, and a correlation was observed between olfactory function and the UPDRS score of 3 for the CPR stimulation alone. We suggest that the conduction delay observed following visual stimulation occurs peripherally rather than in the primary visual cortex. Degeneration of selective elements of the visual system in the retina, possibly midget cells, may be involved.

The temporal stability and variability across frequency bands in neural synchrony between primary and secondary somatosensory areas following somatosensory stimulation.

OBJECTIVES: To examine the temporal stability and variability of neuronal synchronization among the contralateral primary somatosensory cortex (cSI) and contralateral (cSII) and ipsilateral secondary somatosensory cortex (iSII) in response to median nerve stimulation. METHODS: Both the spontaneous magnetoencephalography (MEG) signals as the pre-stimulus condition and somatosensory evoked magnetic-fields (SEF) were recorded in eleven healthy subjects. We calculated a phase-locking value (PLV) between two areas among cSI, cSII, and iSII in five frequency bands (theta: 5-7 Hz, alpha: 8-12 Hz, beta: 15-29 Hz, gamma-1: 30-59 Hz, and gamma-2: 60-90 Hz), and compared the PLV among in pre-stimulus and stimulus conditions. RESULTS: The PLV between cSI and cSII for the theta band activity varied within 2 s from the stimulus onset. On the other hand, the PLV between cSI and iSII for the alpha band did not vary within 2 s. CONCLUSION: The fluctuation of neuronal synchrony among sensory-related cortices in response to median nerve stimulation depends on the induced frequency band and inter-region. SIGNIFICANCE: This study is the first to report the temporal characteristic of stimulus-driven neural synchrony following somatosensory stimulation.