Fixel-Based Analysis Reveals Whole-Brain White Matter Abnormalities in Cervical Dystonia.

Background: Cervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.

Objectives: We investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.

Memory functioning after hippocampal removal: Does side matter?

To address the memory functioning after medial temporal lobe (MTL) surgery for refractory epilepsy and relationships with the side of the hippocampal removal, 22 patients with pharmaco-resistant epilepsy who had undergone MTL resection (10 right/12 left) at the Salpêtrière Hospital were compared with 21 matched healthy controls. We designed a specific neuropsychological binding memory test that specifically addressed hippocampal cortex functioning, and left-right material-specific lateralization. Our results showed that both left and right mesial temporal lobe removal cause a severe memory impairment, for both verbal and visual material.

Long-term deep intracerebral microelectrode recordings in patients with drug-resistant epilepsy: Proposed guidelines based on 10-year experience.

Purpose: Human neuronal activity, recorded in vivo from microelectrodes, may offer valuable insights into physiological mechanisms underlying human cognition and pathophysiological mechanisms of brain diseases, in particular epilepsy. Continuous and long-term recordings are necessary to monitor non predictable pathological and physiological activities like seizures or sleep. Because of their high impedance, microelectrodes are more sensitive to noise than macroelectrodes.

Clinical Characteristics, Angioarchitecture and Management of Tectum Mesencephali Arteriovenous Malformations : A Retrospective Case Series.

Purpose: Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located close to eloquent structures making them challenging to treat. We aimed to present clinical presentation, angiographic features and treatment strategies of TM-AVMs through a single center retrospective case series.

Methods: A TM-AVMs is defined as a nidus located in the parenchyma or on the pia mater of the posterior midbrain.

Conscious and unconscious expectancy effects: A behavioral, scalp and intracranial electroencephalography study.

Objective: The scope of unconscious cognition stretched its limits dramatically during the last 40 years, yet most unconscious processes and representations that have been described so far are fleeting and very short-lived, whereas conscious representations can be actively maintained in working memory for a virtually unlimited period. In the present work we aimed at exploring conscious and unconscious lasting (>1 second) expectancy effects.

Methods: In a series of four experiments we engaged participants in the foreperiod paradigm while using both unmasked and masked cues that were informative about the presence/absence of an upcoming target.

Intracranial Recordings and Computational Modeling of Music Reveal the Time Course of Prediction Error Signaling in Frontal and Temporal Cortices.

Prediction is held to be a fundamental process underpinning perception, action, and cognition. To examine the time course of prediction error signaling, we recorded intracranial EEG activity from nine presurgical epileptic patients while they listened to melodies whose information theoretical predictability had been characterized using a computational model. We examined oscillatory activity in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the pars orbitalis of the inferior frontal gyrus, lateral cortical areas previously implicated in auditory predictive processing.

Resting-State Neural Firing Rate Is Linked to Cardiac-Cycle Duration in the Human Cingulate and Parahippocampal Cortices.

Stimulation and functional imaging studies have revealed the existence of a large network of cortical regions involved in the regulation of heart rate. However, very little is known about the link between cortical neural firing and cardiac-cycle duration (CCD). Here, we analyze single-unit and multiunit data obtained in humans at rest, and show that firing rate covaries with CCD in 16.

Practical contouring guidelines with an MR-based atlas of brainstem structures involved in radiation-induced nausea and vomiting.

Background And Purpose: The objective of this project was to define consensus guidelines for delineating brainstem substructures (dorsal vagal complex, including the area postrema) involved in radiation-induced nausea and vomiting (RINV). The three parts of the brainstem are rarely delineated, so this study was also an opportunity to find a consensus on this subject.

Materials And Methods: The dorsal vagal complex (DVC) was identified on autopsy sections and endoscopic descriptions.

Single-unit activities during the transition to seizures in deep mesial structures.

Focal seizures are assumed to arise from a hypersynchronous activity affecting a circumscribed brain region. Using microelectrodes in seizure-generating deep mesial regions of 9 patients, we investigated the firing of hundreds of single neurons before, during, and after ictal electroencephalogram (EEG) discharges. Neuronal spiking activity at seizure initiation was highly heterogeneous and not hypersynchronous.

Cognitive dissonance resolution depends on episodic memory.

The notion that past choices affect preferences is one of the most influential concepts of social psychology since its first report in the 50 s, and its theorization within the cognitive dissonance framework. In the free-choice paradigm (FCP) after choosing between two similarly rated items, subjects reevaluate chosen items as more attractive and rejected items as less attractive. However the relations prevailing between episodic memory and choice-induced preference change (CIPC) remain highly debated: is this phenomenon dependent or independent from memory of past choices? We solve this theoretical debate by demonstrating that CIPC occurs exclusively for items which were correctly remembered as chosen or rejected during the choice stage.

Is the cardiac monitoring function related to the self in both the default network and right anterior insula?

The self has been proposed to be rooted in the neural monitoring of internal bodily signals and might thus involve interoceptive areas, notably the right anterior insula (rAI). However, studies on the self consistently showed the involvement of midline default network (DN) nodes, without referring to visceral monitoring. Here, we investigate this apparent discrepancy.

Voluntary control of intracortical oscillations for reconfiguration of network activity.

Voluntary control of oscillatory activity represents a key target in the self-regulation of brain function. Using a real-time closed-loop paradigm and simultaneous macro- and micro-electrode recordings, we studied the effects of self-induced intracortical oscillatory activity (4-8 Hz) in seven neurosurgical patients. Subjects learned to robustly and specifically induce oscillations in the target frequency, confirmed by increased oscillatory event density.

Incomplete Hippocampal Inversion: A Comprehensive MRI Study of Over 2000 Subjects.

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes.

Safety profile of intracranial electrode implantation for video-EEG recordings in drug-resistant focal epilepsy.

Invasive electroencephalography recordings with depth or subdural electrodes are necessary to identify the ictogenic area in some drug-resistant focal epilepsies. We aimed to analyze the safety profile of intracranial electrode implantation in a tertiary center and the factors associated with its complications. We retrospectively examined complications in 163 intracranial procedures performed in adult patients.

Intracranial markers of emotional valence processing and judgments in music.

The involvement of the amygdala and orbitofrontal cortex in the processing of valenced stimuli is well established. However, less is known about the extent to which activity in these regions reflects a stimulus' physical properties, the individual subjective experience it evokes, or both. We recorded cortical electrical activity from five epileptic patients implanted with depth electrodes for presurgical evaluation while they rated "consonant" and "dissonant" musical chords using a "pleasantness" scale.

Detection of volume loss in hippocampal layers in Alzheimer's disease using 7 T MRI: a feasibility study.

In Alzheimer's disease (AD), the hippocampus is an early site of tau pathology and neurodegeneration. Histological studies have shown that lesions are not uniformly distributed within the hippocampus. Moreover, alterations of different hippocampal layers may reflect distinct pathological processes.

Event-Related Potential, Time-frequency, and Functional Connectivity Facets of Local and Global Auditory Novelty Processing: An Intracranial Study in Humans.

Auditory novelty detection has been associated with different cognitive processes. Bekinschtein et al. (2009) developed an experimental paradigm to dissociate these processes, using local and global novelty, which were associated, respectively, with automatic versus strategic perceptual processing.

An Intracranial EEG Study of the Neural Dynamics of Musical Valence Processing.

The processing of valence is known to recruit the amygdala, orbitofrontal cortex, and relevant sensory areas. However, how these regions interact remains unclear. We recorded cortical electrical activity from 7 epileptic patients implanted with depth electrodes for presurgical evaluation while they listened to positively and negatively valenced musical chords.

Resting state networks' corticotopy: the dual intertwined rings architecture.

How does the brain integrate multiple sources of information to support normal sensorimotor and cognitive functions? To investigate this question we present an overall brain architecture (called "the dual intertwined rings architecture") that relates the functional specialization of cortical networks to their spatial distribution over the cerebral cortex (or "corticotopy"). Recent results suggest that the resting state networks (RSNs) are organized into two large families: 1) a sensorimotor family that includes visual, somatic, and auditory areas and 2) a large association family that comprises parietal, temporal, and frontal regions and also includes the default mode network. We used two large databases of resting state fMRI data, from which we extracted 32 robust RSNs.

Human gamma oscillations during slow wave sleep.

Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS). At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS.

Impaired recognition of musical emotions and facial expressions following anteromedial temporal lobe excision.

We have shown that an anteromedial temporal lobe resection can impair the recognition of scary music in a prior study (Gosselin et al., 2005). In other studies (Adolphs et al.

Neuropathology of sleep disorders: a review.

Sleep disorders are important manifestations of neurodegenerativediseases and sometimes are clinically evident well before the onset of other neurological manifestations. This review addresses theneuroanatomical basis and the mechanisms of sleep regulation in humans in relation to the neuropathology of entities associated with sleep disturbances in selected diseases, including Alzheimer disease, progressive supranuclear palsy, Lewy body disorders, multiple-system atrophy, and fatal familial insomnia. This includes abnormalities of circadian rhythm, insomnia, narcolepsy, rapid eye movements sleep behavior disorders, and excessive daytime sleepiness.