Cortical spectral dynamics of vibrotactile frequency processing

Using neuroimaging to individualize TMS treatment for depression: Toward a new paradigm for imaging-guided intervention

Feasibility, safety, and effectiveness of transcranial direct current stimulation for decreasing post-ERCP pain: a randomized, sham-controlled, pilot study

Functional neuroimaging studies on patients with depression have found abnormal activity in the left prefrontal and anterior cingulate cortex compared with healthy controls. Other studies have shown that these regions become active in healthy subjects during verbal fluency tasks, while patients with depression show impaired performance on such tasks. We used functional magnetic resonance imaging to investigate changes in cerebral blood oxygenation associated with a verbal fluency task in depressed patients and healthy volunteers. In contrast to 10 age- and sex-matched healthy control subjects who activated the left prefrontal cortex and the anterior cingulate cortex during word generation, 10 depressed subjects showed attenuated activation in the left prefrontal cortex and did not show significant activation in the anterior cingulate cortex. These findings suggest that impaired performance during verbal fluency task in depressed patients is associated with abnormal neural responses within these regions.

Cortical excitatory and inhibitory correlates of the fronto-limbic circuit in major depression and differential effects of left frontal brain stimulation in a randomized sham-controlled trial

Neuronal signatures of a random-dot motion comparison task

PURPOSE: Physical activity (PA) benefits people with chronic low back pain (cLBP), yet objective data on PA and pain experience are limited. This study aims to (1) characterize 24-hour PA patterns via accelerometry-derived step counts in individuals with cLBP, (2) examine associations between PA patterns and patient-reported outcomes (PROs), and (3) cluster individuals by PA patterns to identify potential cLBP phenotypes. METHODS: We analyzed data from the ongoing comeBACK study (NIH Back Pain Consortium-BACPAC, 1 U19AR076737-01), including 283 participants (mean age 56.8 years, 57.0% female). Participants wore an Actigraph GT3X+ sensor on the right hip for 7+ days. Step count data and 24-hour PA patterns were analyzed. Further individual clusters were identified using K-means clustering based on activity pattern distribution. Nonparametric comparisons of PA and PROs (PROMIS-29 Physical Function and Pain Interference) across clusters were performed, and Spearman correlation analysis examined associations between PA pattern distribution and PROs. RESULTS: Eight distinct 24-hour activity patterns were identified: Inactive (17.3%), Low PA (25.3%), Morning (9.8%), Mid-Day (20.5%), Evening (5.6%), All Day (6.4%), Bi-Phase (14.5%), and High PA (0.6%). Based on the distribution of these patterns, participants were grouped into five clusters: Mainly Inactive (N = 53), Mainly Low PA (N = 65), Mainly Bi-Phase (N = 38), Mainly Mid-Day (N = 68), and Various PA Patterns (N = 59). The Inactive cluster exhibited the lowest step count, poorest physical function, and highest pain interference compared to other clusters. In contrast, the Mid-Day and Various PA Pattern clusters showed above-average step counts, higher physical function, and lower pain interference. Correlation analysis indicated that the percentages of Inactive and Mid-Day patterns were consistently associated with various pain-related PROs. CONCLUSIONS: We identified distinct 24-hour physical activity patterns among individuals with cLBP and explored their relationship with patient-reported physical function and pain interference. These findings suggest that clustering based on PA patterns could help identify potential cLBP phenotypes, supporting future tailored physical activity interventions for cLBP management. Supported by: National Institute Of Arthritis And Musculoskeletal And Skin Diseases of the National Institutes of Health under Award Number U19AR076737, The Back Pain Consortium (BACPAC) Research Program

Reliability of conditioned pain modulation in healthy individuals and chronic pain patients: a systematic review and meta-analysis.

P206 Cross-hemispheric frontoparietal desynchronization impairs the visual-spatial working memory in humans

BackgroundCortical activation patterns in patients with Parkinson's disease (PD) may be influenced by postural strategies, but the underlying neural mechanisms remain unclear. Our aim is to examine the role of the fronto-parietal lobes in patients with PD adopting different postural strategies and the effect of dual task (DT) on fronto-parietal activation.MethodsTwo groups of patients with PD adopting either the posture first strategy (PD-PF) or the posture second strategy (PD-PS) were examined respectively when in the “OFF” state while single-walking task (SW) and DT. Frontal and parietal lobe activity was assessed by functional near infrared spectroscopy (fNIRS) and measuring gait parameters. Linear mixed models were used for analyses.ResultsPatients with PD who adopted PS had greater cortical activation than those who adopted PF, and there was no difference between PF and PS in the behavioral parameters. For oxyhemoglobin levels, the task condition (SW vs. DT) had a main effect in fronto-parietal lobes. Postural strategy (PD-PF vs. PD-PS) a main effect in the left prefrontal cortex (LPFC), left parietal lobe (LPL), and right parietal lobe (RPL) regions. In the task of walking with and without the cognitive task, patients with PD adopting PS had higher activation in the LPL than those adopting PF. In DT, only PD patients who adopted PS had elevated oxyhemoglobin levels in the LPFC, right prefrontal cortex (RPFC), and LPL compared with the SW, whereas patients with PD who adopted PF showed no differences in any region.ConclusionDifferent patterns of fronto-parietal activation exist between PD-PF and PD-PS. This may be because PD-PS require greater cortical functional compensation than those adopting PF.

BackgroundThe ability to abstain from drinking, despite incentives to imbibe, is essential to recovery from alcoholism.MethodsWe used an incentive conflict task to investigate ability to abstain from responding during presentations of incentive cues. Both alcoholic (n = 23) and healthy subjects (n = 22) were required to withhold responding during the simultaneous presentation of two visual stimuli in which the individual presentation allowed responding for monetary reward. Brain structures activated during performance of the task were studied using functional magnetic resonance imaging in healthy volunteers (n = 8), and changes in gray matter volume were studied in a separate group of patients (n = 29) compared with control subjects (n = 31) in regions of interest identified on functional magnetic resonance imaging.ResultsAbstinent alcoholic patients were severely impaired on the incentive conflict task. The impairment was greater in patients with experience of several versus a single detoxification. Healthy volunteers, during the same incentive conflict task, showed distinct patterns of brain activation (including gyrus rectus, ventromedial prefrontal cortex, and superior frontal gyrus). Reduction of gray matter volume in ventromedial prefrontal cortex and superior frontal gyrus of patients was more extensive in those with multiple detoxifications.ConclusionsPerformance deficits in alcoholics are associated with withdrawal-induced impairments in prefrontal subfields, which are exacerbated following repeated episodes of detoxification. Detoxification thus compromises functional and structural integrity of prefrontal cortex and may thus impair the ability to control future drinking. Performance in the incentive conflict task is a sensitive biomarker for such deficits.

Effects of proprioceptive neuromuscular facilitation (PNF) and yoga postures on the hemodynamics of the prefrontal cortex.

Early identification of adolescent depression requires objective biomarkers. This study investigated the functional near-infrared spectroscopy (fNIRS) activation patterns and mismatch negativity (MMN) characteristics in adolescents with first-episode mild-to-moderate depression. We enrolled 33 patients and 33 matched healthy controls, measuring oxyhemoglobin (Oxy-Hb) concentration in the frontal cortex during verbal fluency tasks via fNIRS, and recording MMN latency/amplitude at Fz/Cz electrodes using event-related potentials (ERP). Compared with healthy controls, the depression group showed significantly prolonged MMN latency [Fz: (227.88 ± 31.08) ms vs. (208.70 ± 25.35) ms, P < 0.01; Cz: (223.73 ± 29.03) ms vs. (204.18 ± 22.43) ms, P < 0.01], and obviously reduced Fz amplitude [(2.42 ± 2.18) μV vs. (5.65 ± 5.59) μV, P = 0.03]. A significant positive correlation was observed between MMN latencies at Fz and Cz electrodes ( P < 0.01). Oxy-Hb in left frontopolar prefrontal channels (CH15/17) was significantly decreased in patient group ( P < 0.05). Our findings suggest that adolescents with depression exhibit hypofunction in the left prefrontal cortex and impaired automatic sensory processing. The combined application of fNIRS and ERP techniques may provide an objective basis for early clinical identification.

We present a new functional magnetic resonance imaging (fMRI) analysis method that incorporates both spatial and temporal dynamics of blood-oxygen-level dependent (BOLD) signals within a region of interest (ROI). 3D moment descriptors are used to characterize the spatial changes in BOLD signals over time. The method is tested on fMRI data collected from eight healthy subjects performing a bulb-squeezing motor task with their right-hand at various frequencies. Multiple brain regions including the left cerebellum, both primary motor cortices (MI), both supplementary motor areas (SMA), left prefrontal cortex (PFC), and left anterior cingulate cortex (ACC) demonstrate significant task-related changes. Furthermore, our method is able to discriminate differences in activation patterns at the various task frequencies, whereas using a traditional intensity based method, no significant activation difference is detected. This suggests that temporal dynamics of the spatial distribution of BOLD signal provide additional information regarding task-related activation thus complementing conventional intensity-based approaches.

Working memory (WM) deficit represents the most common cognitive impairment in psychiatric and neurodevelopmental disorders, making the identification of its neural substrates a crucial step towards the conceptualization of restorative interventions. We present a meta-analysis focusing on neural activations associated with the most commonly used task to measure WM, the N-back task, in patients with schizophrenia, depressive disorder, bipolar disorder, and attention-deficit/hyperactivity disorder. Showing qualitative similarities and differences in WM processing between patients and healthy controls, we propose possible targets for cognitive enhancement approaches. Selected studies, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, were analyzed through the activation likelihood estimate statistical framework, with subsequent generation of disorder-specific N-back activation maps. Despite similar WM deficits shared across all disorders, results highlighted different brain activation patterns for each disorder compared with healthy controls. In general, results showed brain activity in frontal, parietal, subcortical, and cerebellar regions; however, reduced engagement of specific nodes of the fronto-parietal network emerged in patients compared with healthy controls. In particular, neither bipolar nor depressive disorders showed detectable activations in the dorsolateral prefrontal cortices, while their parietal activation patterns were lateralized to the left and right hemispheres, respectively. On the other hand, patients with attention-deficit/hyperactivity disorder showed a lack of activation in the left parietal lobe, whereas patients with schizophrenia showed lower activity over the left prefrontal cortex. These results, together with biophysical modeling, were then used to discuss the design of future disorder-specific cognitive enhancement interventions based on noninvasive brain stimulation.

Physical fitness and chronic low back pain: A case-control study including 517 individuals