Mechanical pain sensitivity is associated with hippocampal structural integrity.

Rodents and human studies indicate that the hippocampus, a brain region necessary for memory processing, responds to noxious stimuli. However, the hippocampus has yet to be considered a key brain region directly involved in the human pain experience. One approach to answer this question is to perform quantitative sensory testing on patients with hippocampal damage-ie, medial temporal lobe epilepsy.

Hippocampal-cortical interactions during event boundaries support retention of complex narrative events.

According to most memory theories, encoding involves continuous communication between the hippocampus and neocortex, but recent work has shown that key moments at the end of an event, called event boundaries, may be especially critical for memory formation. We sought to determine how communication between the hippocampus and neocortical regions during the encoding of naturalistic events related to subsequent retrieval of those events and whether this was particularly important at event boundaries. Participants encoded and recalled two cartoon movies during fMRI scanning.

A Novel Orthoplastic Reconstruction of Relapsed Clubfoot With Total Ankle Arthroplasty.

Congenital clubfoot is addressed in infancy and rarely persists into adulthood. Ankle arthroplasty is an increasingly popular surgical intervention for patients with ankle arthritis since it allows a natural ankle range of motion and completely replaces a degenerative hindfoot. Here, we describe the first successful total ankle arthroplasty (TAA) for a patient with previously treated congenital clubfoot that reverted later in life.

Leveraging the resting brain to predict memory decline after temporal lobectomy.

Objective: Predicting memory morbidity after temporal lobectomy in patients with temporal lobe epilepsy (TLE) relies on indices of preoperative temporal lobe structural and functional integrity. However, epilepsy is increasingly considered a network disorder, and memory a network phenomenon. We assessed the utility of functional network measures to predict postoperative memory changes.

Long-term, multi-event surprise correlates with enhanced autobiographical memory.

Neurobiological and psychological models of learning emphasize the importance of prediction errors (surprises) for memory formation. This relationship has been shown for individual momentary surprising events; however, it is less clear whether surprise that unfolds across multiple events and timescales is also linked with better memory of those events. We asked basketball fans about their most positive and negative autobiographical memories of individual plays, games and seasons, allowing surprise measurements spanning seconds, hours and months.

The effects of acute dopamine depletion on resting-state functional connectivity in healthy humans.

Alpha-methyl-para-tyrosine (AMPT), a competitive inhibitor of tyrosine hydroxylase, can be used to deplete endogenous dopamine in humans. We examined how AMPT-induced dopamine depletion alters resting-state functional connectivity of the basal ganglia, and canonical resting-state networks, in healthy humans. Fourteen healthy participants (8 females; age [mean ± SD] = 27.

The hippocampus constructs narrative memories across distant events.

Life's events are scattered throughout time, yet we often recall different events in the context of an integrated narrative. Prior research suggests that the hippocampus, which supports memory for past events, can support the integration of overlapping associations or separate events in memory. However, the conditions that lead to hippocampus-dependent memory integration are unclear.

Baseline resting-state functional connectivity determines subsequent pain ratings to a tonic ecologically valid experimental model of orofacial pain.

Pain is a subjective experience with significant individual differences. Laboratory studies investigating pain thresholds and experimental acute pain have identified structural and functional neural correlates. However, these types of pain stimuli have limited ecological validity to real-life pain experiences.

Intrinsic connectivity reveals functionally distinct cortico-hippocampal networks in the human brain.

Episodic memory depends on interactions between the hippocampus and interconnected neocortical regions. Here, using data-driven analyses of resting-state functional magnetic resonance imaging (fMRI) data, we identified the networks that interact with the hippocampus-the default mode network (DMN) and a "medial temporal network" (MTN) that included regions in the medial temporal lobe (MTL) and precuneus. We observed that the MTN plays a critical role in connecting the visual network to the DMN and hippocampus.

Parcellation of the Hippocampus Using Resting Functional Connectivity in Temporal Lobe Epilepsy.

We have previously shown that the connectivity of the hippocampus to other regions of the default mode network (DMN) is a strong indicator of memory ability in people with temporal lobe epilepsy (TLE). Recent work in the cognitive neuroscience literature has suggested that the anterior and posterior aspects of the hippocampus have distinct connections to the rest of the DMN and may support different memory operations. Further, structural analysis of epileptogenic hippocampi has found greater atrophy, characterized by mesial temporal sclerosis, in the anterior region of the hippocampus.

A multivariate neuroimaging biomarker of individual outcome to transcranial magnetic stimulation in depression.

The neurobiology of major depressive disorder (MDD) remains incompletely understood, and many individuals fail to respond to standard treatments. Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) has emerged as a promising antidepressant therapy. However, the heterogeneity of response underscores a pressing need for biomarkers of treatment outcome.

Increased Cortical Thickness in Attentional Networks in Parkinson's Disease with Minor Hallucinations.

Hallucinations are common in Parkinson's disease (PD). Based on functional brain MRI data, hallucinations are proposed to result from alterations in the dorsal attention network (DAN), ventral attention network (VAN), and default mode network. Using structural MRI data from Parkinson's Progression Markers Initiative (PPMI), we examined cortical thickness in these networks in PD patients with (=30) and without (=30) minor hallucinations who were matched on multiple clinical characteristics (e.

The medial temporal lobe in nociception: a meta-analytic and functional connectivity study.

Recent neuroimaging studies implicate the medial temporal lobe (MTL) in nociception and pain modulation. Here, we aim to identify which subregions of the MTL are involved in human pain and to test its connectivity in a cohort of chronic low-back pain patients (CBP). We conducted 2 coordinate-based meta-analyses to determine which regions within the MTL showed consistent spatial patterns of functional activation (1) in response to experimental pain in healthy participants and (2) in chronic pain compared with healthy participants.

Language network measures at rest indicate individual differences in naming decline after anterior temporal lobe resection.

While anterior temporal lobe (ATL) resection is an effective treatment for temporal lobe epilepsy, surgery on the dominant hemisphere is associated with variable decline in confrontation naming. Accurate prediction of naming impairment is critical to inform clinical decision making, and while there has been some degree of success using task-based functional MRI (fMRI) paradigms, there remains a growing interest in the predictive utility of resting-state connectivity as it allows for relatively shorter scans with low task demands. Our objective was to assess the relationship between measures of preoperative resting-state connectivity and postoperative naming change in patients following left ATL resection.

Applications of Resting-State Functional MR Imaging to Epilepsy.

We discuss the value of resting-state functional MR imaging (rsfMR imaging) as an emerging technique to address questions about memory and language that are central in surgery for temporal-lobe epilepsy, namely the identification and characterization of eloquent cortex to avoid surgical morbidity. The emergence of a robust set of data using rsfMR imaging has opened new avenues for exploring more direct relationships between neural networks and current cognitive function and prediction of postoperative change. These techniques are also being explored for their potential to characterize epilepsy subtypes, identify epileptic foci, and monitor treatment effects.

Distinct hippocampal functional networks revealed by tractography-based parcellation.

Recent research suggests the anterior and posterior hippocampus form part of two distinct functional neural networks. Here we investigate the structural underpinnings of this functional connectivity difference using diffusion-weighted imaging-based parcellation. Using this technique, we substantiated that the hippocampus can be parcellated into distinct anterior and posterior segments.

Functional and structural correlates of memory in patients with mesial temporal lobe epilepsy.

Individuals with medial temporal lobe epilepsy (mTLE) often show material-specific memory impairment (verbal for left, visuospatial for right hemisphere), which can be exacerbated following surgery aimed at the epileptogenic regions of medial and anterolateral temporal cortex. There is a growing body of evidence suggesting that characterization of structural and functional integrity of these regions using MRI can aid in prediction of post-surgical risk of further memory decline. We investigated the nature of the relationship between structural and functional indices of hippocampal integrity with pre-operative memory performance in a group of 26 patients with unilateral mTLE.

The human hippocampus is sensitive to the durations of events and intervals within a sequence.

Temporal details are an important facet of our memories for events. Consistent with this, it has been demonstrated that the hippocampus, a key structure in learning and memory, is sensitive to the temporal aspects of event sequences, including temporal order, context, recency and distance. One unexplored issue is whether the hippocampus also responds to the temporal duration characteristics of an event sequence, for example, how long each event lasted for or how much time elapsed between events.

Linking DMN connectivity to episodic memory capacity: what can we learn from patients with medial temporal lobe damage?

Computational models predict that focal damage to the Default Mode Network (DMN) causes widespread decreases and increases of functional DMN connectivity. How such alterations impact functioning in a specific cognitive domain such as episodic memory remains relatively unexplored. Here, we show in patients with unilateral medial temporal lobe epilepsy (mTLE) that focal structural damage leads indeed to specific patterns of DMN functional connectivity alterations, specifically decreased connectivity between both medial temporal lobes (MTLs) and the posterior part of the DMN and increased intrahemispheric anterior-posterior connectivity.

Social inference deficits in temporal lobe epilepsy and lobectomy: risk factors and neural substrates.

In temporal lobe epilepsy and lobectomy, deficits in emotion identification have been found consistently, but there is limited evidence for complex social inference skills such as theory of mind. Furthermore, risk factors and the specific neural underpinnings of these deficits in this population are unclear. We investigated these issues using a comprehensive range of social inference tasks (emotion identification and comprehension of sincere, deceitful and sarcastic social exchanges) in individuals with temporal lobe epilepsy or lobectomy (n = 87).

Advantages of sentence-level fMRI language tasks in presurgical language mapping for temporal lobe epilepsy.

fMRI language mapping has become increasingly utilized for determining language dominance before surgical intervention for temporal lobe epilepsy (TLE). This study aimed to examine the differences between two classes of fMRI word generation tasks used in our clinic: tasks using a single word cue, referred to as simple generative tasks (SGTs), and tasks also involving sentence-level processing, referred to as sentence-level language tasks (SLTs). Specifically, we aimed to investigate the extent and laterality of activation and frontal-temporal connectivity during these language tasks and their relationship to clinical language measures.