Patterns of subregional cerebellar atrophy across epilepsy syndromes: An ENIGMA-Epilepsy study.

OBJECTIVE: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current corticocentric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural magnetic resonance imaging in 1602 adults with epilepsy and 1022 healthy controls across 22 sites from the global ENIGMA-Epilepsy working group. METHODS: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions. Linear mixed models compared total and regional cerebellar volume in (1) all epilepsies, (2) temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), (3) nonlesional temporal lobe epilepsy, (4) genetic generalized epilepsy, and (5) extratemporal focal epilepsy (ETLE). Relationships were examined for cerebellar volume versus age at seizure onset, duration of epilepsy, phenytoin treatment, and cerebral cortical thickness. RESULTS: Across all epilepsies, reduced total cerebellar volume was observed (d = .42). Maximum volume loss was observed in the corpus medullare (dmax = .49) and posterior lobe gray matter regions, including bilateral lobules VIIB (dmax = .47), crus I/II (dmax = .39), VIIIA (dmax = .45), and VIIIB (dmax = .40). Earlier age at seizure onset ( η ρ max 2 = .05) and longer epilepsy duration ( η ρ max 2 = .06) correlated with reduced volume in these regions. Findings were most pronounced in TLE-HS and ETLE, with distinct neuroanatomical profiles observed in the posterior lobe. Phenytoin treatment was associated with reduced posterior lobe volume. Cerebellum volume correlated with cerebral cortical thinning more strongly in the epilepsy cohort than in controls. SIGNIFICANCE: We provide robust evidence of deep cerebellar and posterior lobe subregional gray matter volume loss in patients with chronic epilepsy. Volume loss was maximal for posterior subregions implicated in nonmotor functions, relative to motor regions of both the anterior and posterior lobe. Associations between cerebral and cerebellar changes, and variability of neuroanatomical profiles across epilepsy syndromes argue for more precise incorporation of cerebellar subregional damage into neurobiological models of epilepsy.

Medication use in patients with functional seizures from a public and a private hospital.

PURPOSE: Currently, we have limited knowledge of any potential differences among patients with functional seizures (FS), otherwise known as psychogenic non-epileptic seizures (PNES), from different socioeconomic backgrounds. Investigating medication use among these patients may provide insight into the quality and intensity of medical care they receive. Thus, we aimed to assess and compare the frequency and quantity of antiseizure medications (ASMs), and psychiatric and other medications used among patients with FS from a private and public epilepsy monitoring units (EMUs) in Cape Town, South Africa. METHODS: Only video-electroencephalographically (video-EEG) confirmed patients with FS with no comorbid epilepsy were eligible for the study. For this retrospective case-control study we collected data on patients' medication-taking histories using digital patient records, starting with the earliest available digital patient record for each hospital. RESULTS: A total of 305 patients from a private hospital and 67 patients from a public hospital were included in the study (N = 372). Patients with FS attending the public hospital had lower odds of taking any ASMs at presentation (aOR=0.39, 95% CI [0.20, 0.75]) and ever taking psychiatric medications (aOR=0.41, 95% CI [0.22, 0.78]) compared to FS patients from the private hospital. They did, however, have higher odds of being discharged with an ASM (aOR=6.60, 95% CI [3.27, 13.35]) and ever taking cardiovascular medication (aOR=2.69, 95% CI [1.22, 5.90]) when compared to the private hospital patients. With every additional presenting ASM (aOR=0.63, 95% CI [0.45, 0.89]) and psychiatric medication (aOR=0.58, 95% CI [0.40, 0.84]) the odds of being from the public hospital decreased. However, they increased with every additional discharge ASM (aOR=3.63, 95% CI [2.30, 5.72]) and cardiovascular medication (aOR=1.26, 95% CI [1.02, 1.55]). CONCLUSION: Standard approaches to pharmacological treatment for patients with FS differed between the public and private hospitals and may indicate a gap in quality of care.

Patterns of subregional cerebellar atrophy across epilepsy syndromes: An ENIGMA-Epilepsy study.

Objective: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current cortico-centric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural MRI in 1,602 adults with epilepsy and 1,022 healthy controls across twenty-two sites from the global ENIGMA-Epilepsy working group. Methods: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions. Linear mixed models compared total and regional cerebellar volume in i) all epilepsies; ii) temporal lobe epilepsy with hippocampal sclerosis (TLE-HS); iii) non-lesional temporal lobe epilepsy (TLE-NL); iv) genetic generalised epilepsy; and (v) extra-temporal focal epilepsy (ETLE). Relationships were examined for cerebellar volume versus age at seizure onset, duration of epilepsy, phenytoin treatment, and cerebral cortical thickness. Results: Across all epilepsies, reduced total cerebellar volume was observed (d=0.42). Maximum volume loss was observed in the corpus medullare (dmax=0.49) and posterior lobe grey matter regions, including bilateral lobules VIIB (dmax= 0.47), Crus I/II (dmax= 0.39), VIIIA (dmax=0.45) and VIIIB (dmax=0.40). Earlier age at seizure onset (ηρ2max=0.05) and longer epilepsy duration (ηρ2max=0.06) correlated with reduced volume in these regions. Findings were most pronounced in TLE-HS and ETLE with distinct neuroanatomical profiles observed in the posterior lobe. Phenytoin treatment was associated with reduced posterior lobe volume. Cerebellum volume correlated with cerebral cortical thinning more strongly in the epilepsy cohort than in controls. Significance: We provide robust evidence of deep cerebellar and posterior lobe subregional grey matter volume loss in patients with chronic epilepsy. Volume loss was maximal for posterior subregions implicated in non-motor functions, relative to motor regions of both the anterior and posterior lobe. Associations between cerebral and cerebellar changes, and variability of neuroanatomical profiles across epilepsy syndromes argue for more precise incorporation of cerebellum subregions into neurobiological models of epilepsy.

Event-based modeling in temporal lobe epilepsy demonstrates progressive atrophy from cross-sectional data.

OBJECTIVE: Recent work has shown that people with common epilepsies have characteristic patterns of cortical thinning, and that these changes may be progressive over time. Leveraging a large multicenter cross-sectional cohort, we investigated whether regional morphometric changes occur in a sequential manner, and whether these changes in people with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS) correlate with clinical features. METHODS: We extracted regional measures of cortical thickness, surface area, and subcortical brain volumes from T1-weighted (T1W) magnetic resonance imaging (MRI) scans collected by the ENIGMA-Epilepsy consortium, comprising 804 people with MTLE-HS and 1625 healthy controls from 25 centers. Features with a moderate case-control effect size (Cohen d ≥ .5) were used to train an event-based model (EBM), which estimates a sequence of disease-specific biomarker changes from cross-sectional data and assigns a biomarker-based fine-grained disease stage to individual patients. We tested for associations between EBM disease stage and duration of epilepsy, age at onset, and antiseizure medicine (ASM) resistance. RESULTS: In MTLE-HS, decrease in ipsilateral hippocampal volume along with increased asymmetry in hippocampal volume was followed by reduced thickness in neocortical regions, reduction in ipsilateral thalamus volume, and finally, increase in ipsilateral lateral ventricle volume. EBM stage was correlated with duration of illness (Spearman ρ = .293, p = 7.03 × 10-16 ), age at onset (ρ = -.18, p = 9.82 × 10-7 ), and ASM resistance (area under the curve = .59, p = .043, Mann-Whitney U test). However, associations were driven by cases assigned to EBM Stage 0, which represents MTLE-HS with mild or nondetectable abnormality on T1W MRI. SIGNIFICANCE: From cross-sectional MRI, we reconstructed a disease progression model that highlights a sequence of MRI changes that aligns with previous longitudinal studies. This model could be used to stage MTLE-HS subjects in other cohorts and help establish connections between imaging-based progression staging and clinical features.

Mechanisms of cognitive impairment in temporal lobe epilepsy: A systematic review of resting-state functional connectivity studies.

Temporal lobe epilepsy is the most common form of focal epilepsy and related cognitive dysfunction impacts significantly on quality of life in patients. Identifying the mechanisms of such impairment would assist in the management and treatment of patients. The study of perturbations in resting-state networks could shed light on this subject. The aim of this systematic review was to synthesize findings on the relationship between aberrant resting-state functional connectivity and cognitive performance in patients with TLE. Literature searches were conducted on Scopus and PubMed electronic databases and 17 relevant articles were extracted, all of which studied the association between resting-state functional connectivity (RSFC) and cognition in adults with TLE. Study findings were synthesized according to methods used to analyze resting-state data, cognitive domains tested, and neuropsychology tasks administered. Results show that increased RSFC in the primary epileptogenic hippocampus, and reduced intra-hemispheric RSFC, are associated with weaker memory performance. In left TLE, memory impairment may be compensated for by bilateral hippocampal connectivity, which is also predictive of better postoperative memory outcomes. In right TLE, memory loss may be compensated for by increased connectivity between the contralateral hippocampus and inferior frontal gyrus. There is also tentative evidence that working memory dysfunction is related to reduced RSFC between the medial frontal-insular parietal network and the medial temporal network, executive dysfunction is related to reduced RSFC between frontal and parietal lobes, and between the frontal lobe and subcortical regions and that language dysfunction is related to reduced RSFC within the left fronto-temporal language network. Multicenter studies could refute or support these findings by enrolling large samples of patients and employing multivariate regression analysis to control for the effects of anatomical disruption, interictal discharges, seizure frequency, medication, and mood. Systematic review registration: PROSPERO: 191323.

The ENIGMA-Epilepsy working group: Mapping disease from large data sets.

Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller-scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now well-established by the ENIGMA Consortium, ENIGMA-Epilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and event-based modeling analysis. We explore age of onset- and duration-related features, as well as phenomena-specific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMA-Epilepsy.

Impaired Social Cognition in Epilepsy: A Review of What We Have Learnt From Neuroimaging Studies.

Background: Social cognition refers to specific mental processes that subserve social interaction. Impaired social cognition has been increasingly reported in patients with epilepsy and negatively affects overall quality of life (QOL). In this article, we will review neuroimaging studies of social cognition in people with epilepsy. Methods: An electronic search of the literature was conducted and 14 studies qualified for inclusion in the review. Results: Although the studies reviewed revealed a varied pattern of neural activations in response to emotion recognition and theory of mind tasks, consensual findings included altered pattern of signal activation in the social cognition network in patients with mesial temporal lobe epilepsy (MTLE) compared to healthy controls and significantly reduced signal activations and functional connectivity within this network in patients with right mesial temporal lobe pathology. Conclusion: This review contextualizes our current understanding of the pathophysiology of impaired social cognition in epilepsy and makes recommendations for further research.

Relationship Between EEG Electrode and Functional Cortex in the International 10 to 20 System.

INTRODUCTION: In this study, we attempted to define the variability in the anatomical relationship between scalp EEG electrodes and eloquent cortical function, as inferred from fMRI. METHODS: MRI-compatible fiducial markers were positioned at locations of CZ, C3 and C4, T3 and T4, and F7 and F8 in 10 healthy subjects. Well-validated fMRI paradigms were administered to activate primary motor cortex and language regions, and the distance between these brain regions and fiducial markers was measured. RESULTS: C3/C4, Cz, F8/F7, and T3/T4 were located 16 to 42 mm from the BOLD signal in the primary motor cortex for the contralateral hand and foot, and anterior and posterior language areas, 11 to 21 mm of which was the distance from the skin to the underlying cortex. CONCLUSIONS: There is considerable variation in the distance between the fMRI-defined primary motor and language cortex and the most contiguous electrode. This distance likely underestimates the true variability of electrode placement in relation to eloquent cortex in people with epilepsy or structural brain disorders. Because the evidence indicates that spikes on scalp EEG reflect discharges from the cortex that is of the order of 3 cm by 3 cm or greater in size, the demonstrated variability of electrode placement in relation to the cortex may be clinically and surgically important in individual patients.

Quality of life one year after epilepsy surgery.

BACKGROUND: The aim of surgery for medically intractable epilepsy was to achieve seizure freedom and improve overall quality of life (QOL) in patients. This investigation looked at changes in QOL one year after epilepsy surgery and the relationship of changes to mood, language, and seizure outcomes. METHOD: Depressive symptoms, QOL, and naming were measured in 25 patients with temporal lobe epilepsy before and one year after dominant temporal lobe resection. The Quality of Life in Epilepsy-89 (QOLIE-89), Beck Depression Inventory II (BDI-II), and Boston Naming Test (BNT) were used, respectively, and seizure outcome was reported according to the Engel classifications. Minimum clinically important differences (MCID) and reliable change indices (RCI) were used to assess the proportion of patients who achieved meaningful improvement or worsening in the respective areas of functioning, and the relationship between outcomes was evaluated. Changes on the 17 individual items of the QOLIE-89 were also assessed. RESULTS: Overall, there was a significant improvement in QOL, reduction in depressive symptoms, and decline in naming one year after surgery. Positive clinically important improvement in QOL was achieved in 76% of patients, meaningful reduction of depressive symptoms was achieved in 20%, and clinically important naming declines were observed in 48% of the cohort. Sixteen patients were seizure-free one year after surgery, but there was no significant correlation between changes in QOL and seizure outcome, depressive symptoms, or naming. CONCLUSION: The results in the reported cohort of patients showed that surgical treatment of temporal lobe epilepsy in the dominant hemisphere resulted in clinically meaningful improvement in overall QOL and declines in naming but no significant reduction of mood disturbance.

Left or right? Lateralizing temporal lobe epilepsy by dynamic amygdala fMRI.

OBJECTIVES: In this case series, the findings of 85 functional MRI studies employing a dynamic fearful face paradigm are reported. Previous findings have shown the paradigm to generate bilateral amygdala activations in healthy subjects and unilateral activations in patients with MTLE, in the contralateral hemisphere to seizure origin. Such findings suggest ipsilateral limbic pathology and offer collateral evidence in lateralizing MTLE. METHODS: The series includes 60 patients with TLE, 12 patients with extra-temporal lobe epilepsy, and 13 healthy controls. Functional MRI studies using a 1.5T scanner were conducted over a three-year period at a single epilepsy center and individual results were compared with EEG findings. RESULTS: In the cohort of unilateral TLE patients, lateralized activations of the amygdala were concordant with EEG findings in 76% of patients (77% lTLE, 74% rTLE). The differences in the mean lateralized indices of the lTLE, rTLE, and healthy control groups were all statistically significant. Lateralized amygdala activations were concordant with EEG findings in only 31% of the 12 patients with extra-temporal lobe epilepsy and bilateral amygdala activations were generated in all but one of the healthy control subjects. SIGNIFICANCE: This case series further endorses the utility of the dynamic fearful face functional MRI paradigm using the widely available 1.5T as an adjunctive investigation to lateralize TLE.

Functional Mapping in Pediatric Epilepsy Surgical Candidates: Functional Magnetic Resonance Imaging Under Sedation With Chloral Hydrate.

OBJECTIVES: Functional magnetic resonance imaging is a useful tool to lateralize and localize language in presurgical patients, as well as to localize other functionally salient cortex. The procedure is typically reserved for older children and adults, since it necessitates cooperation and participation in tasks. We have explored the applicability of functional magnetic resonance imaging for language and motor mapping at our epilepsy surgical center in younger children under sedation with chloral hydrate. METHODS: A series of 24 consecutive patients undergoing magnetic resonance imaging, between ages 16 months and 11 years, were scanned under sedation. Assisted finger-tapping and foot-tapping tasks were conducted for the purpose of motor mapping in nine patients, and a speech-based auditory task was conducted in 23 of the 24 patients for the purpose of lateralizing and localizing language. RESULTS: Significant blood oxygen level-dependent signal increases in hand and foot regions of the primary motor cortex were generated in all but one patient who underwent the motor mapping tasks. Signal increases in receptive language cortex were convincingly generated in 12 of the 23 (52%) patients who underwent the speech-based auditory task. CONCLUSIONS: These results suggest that functional magnetic resonance imaging can help to localize motor and/or somatosensory cortex and language cortex in young children under sedation with chloral hydrate. This procedure may be used to assist in presurgical planning. The findings also imply that a sedating agent may be used in pediatric neuroimaging as an alternative to general anesthesia.

Mindfulness based cognitive therapy may improve emotional processing in bipolar disorder: pilot ERP and HRV study.

Emotional processing in bipolar disorder (BD) is impaired. We aimed to measure the effects of mindfulness based cognitive-behavioral therapy (MBCT) in BD on emotional processing, as measured by event related potentials (ERP) and by heart rate variability (HRV). ERP and HRV were recorded during the completion of a visual matching task, which included object matching, affect matching, and affect labeling. Individuals with BD (n = 12) were compared with controls (n = 9) to obtain baseline data prior to the individuals with BD undergoing an 8-week MBCT intervention. ERP and HRV recording was repeated after the MBCT intervention in BD. Participants with BD had exaggerated ERP N170 amplitude and increased HRV HF peak compared to controls, particularly during the affect matching condition. After an 8-week MBCT intervention, participants with BD showed attenuation of ERP N170 amplitude and reduced HRV HF peak. Our findings support findings from the literature emphasizing that emotional processing in BD is altered, and suggesting that MBCT may improve emotional processing in BD.

Functional MRI language mapping in pre-surgical epilepsy patients: findings from a series of patients in the Epilepsy Unit at Mediclinic Constantiaberg.

BACKGROUND: Functional magnetic resonance imaging (fMRI) is commonly applied to study the neural substrates of language in clinical research and for neurosurgical planning. fMRI language mapping is used to assess language lateralisation, or determine hemispheric dominance, and to localise regions of the brain involved in language. Routine fMRI has been introduced in the Epilepsy Unit at Mediclinic Constantiaberg to contribute to the current functional mapping procedures used in pre-surgical planning. METHOD: In this paper we describe the language paradigms used in these routine studies as well as the results from 22 consecutive epilepsy patients. Multi-subject analyses were performed to assess the reliability of activation patterns generated by two language mapping paradigms, namely a verb generation task and passive listening task. Results from a finger-tapping task are also presented. RESULTS: The paradigms generate reliable and robust signal changes, enabling both the lateralisation of language and localisation of expressive and receptive language cortex. CONCLUSION: The fMRI results are meaningful at the group and individual level and can be recommended for language mapping in pre-surgical patients.

The effects of mindfulness-based cognitive therapy in patients with bipolar disorder: a controlled functional MRI investigation.

BACKGROUND: Preliminary research findings have shown that mindfulness-based cognitive therapy improves anxiety and depressive symptoms in bipolar disorder. In this study, we further investigated the effects of MBCT in bipolar disorder, in a controlled fMRI study. METHOD: Twenty three patients with bipolar disorder underwent neuropsychological testing and functional MRI. Sixteen of these patients were tested before and after an eight-week MBCT intervention, and seven were wait listed for training and tested at the same intervals. The results were compared with 10 healthy controls. RESULTS: Prior to MBCT, bipolar patients reported significantly higher levels of anxiety and symptoms of stress, scored significantly lower on a test of working memory, and showed significant BOLD signal decrease in the medial PFC during a mindfulness task, compared to healthy controls. Following MBCT, there were significant improvements in the bipolar treatment group, in measures of mindfulness, anxiety and emotion regulation, and in tests of working memory, spatial memory and verbal fluency compared to the bipolar wait list group. BOLD signal increases were noted in the medial PFC and posterior parietal lobe, in a repeat mindfulness task. A region of interest analysis revealed strong correlation between signal changes in medial PFC and increases in mindfulness. LIMITATIONS: The small control group is a limitation in the study. CONCLUSION: These data suggest that MBCT improves mindfulness and emotion regulation and reduces anxiety in bipolar disorder, corresponding to increased activations in the medial PFC, a region associated with cognitive flexibility and previously proposed as a key area of pathophysiology in the disorder.

Increased thalamic phospholipid concentration evident in bipolar I disorder.

BACKGROUND: Bipolar disorder is characterised by changes in brain metabolites, as measured by (1)H-MRS. However, there is no consistent metabolic profile for bipolar disorder, which includes changes in N-acetyl-aspartate (NAA), choline metabolites and myo-inositol. The aim of the present paper is to add to this literature of (1)H-MRS, the metabolite profiles in bipolar disorder. METHODOLOGY: Nineteen individuals with euthymic bipolar I disorder and eight control participants were recruited for the present study. (1)H-MRS chemical shift imaging (CSI) was used to measure NAA, choline metabolites and myo-inositol of several bilateral brain areas potentially involved in bipolar disorder: hippocampal complexes, brain stem including the locus coeruleus, and thalami. RESULTS: Compared with healthy controls, individuals with bipolar I disorder showed increased choline metabolites in bilateral thalami and increased NAA in left hippocampus. The (1)H-MRS data were not influenced by age, symptom severity, or medication status. CONCLUSIONS: Our present findings suggest that individuals with bipolar I disorder have increased phospholipid concentration in the thalami and increased NAA concentration in the left hippocampus. While MRS data on bipolar data remain somewhat inconsistent, the findings here are consistent with other evidence supporting the hypothesis that dysfunctional thalamocortical gating plays a role in bipolar disorder.

Naming outcomes of anterior temporal lobectomy in epilepsy patients: a systematic review of the literature.

Anterior temporal lobectomy (ATL) is the standard surgical treatment for medically intractable temporal lobe epilepsy (TLE). While seizure outcome is favorable, cognitive outcomes are a concern, particularly in respect of memory and naming. A systematic review of the literature on the naming outcomes of ATL is presented in this article. Searches were conducted on PubMed and PsycInfo, yielding a total of 93 articles, 21 of which met inclusion criteria. Declines in visual naming are common following ATL in the dominant hemisphere, and particularly, for naming living stimuli or famous faces. The Boston Naming Test (BNT) declines by a mean of 5.8 points, exceeding the Reliable Change Index (RCI). There are no reports of deficits in auditory naming following ATL, despite the fact that auditory naming has shown to be a more sensitive measure of dysnomia than the BNT in TLE patients. The absence of structural hippocampal pathology and late-onset epilepsy are the strongest predictors of naming decline. Recommendations are made for further study.

Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study.

BACKGROUND: Cognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients. METHODS: 12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated. RESULTS: (1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex. CONCLUSIONS: Individuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.

The neural substrates of mindfulness: an fMRI investigation.

"Mindfulness" is a capacity for heightened present-moment awareness that we all possess to a greater or lesser extent. Enhancing this capacity through training has been shown to alleviate stress and promote physical and mental well-being. As a consequence, interest in mindfulness is growing and so is the need to better understand it. This study employed functional magnetic resonance imaging (fMRI) to identify the brain regions involved in state mindfulness and to shed light on its mechanisms of action. Significant signal decreases were observed during mindfulness meditation in midline cortical structures associated with interoception, including bilateral anterior insula, left ventral anterior cingulate cortex, right medial prefrontal cortex, and bilateral precuneus. Significant signal increase was noted in the right posterior cingulate cortex. These findings lend support to the theory that mindfulness achieves its positive outcomes through a process of disidentification.