Quantitative sensory testing in a magnetic resonance environment: considerations for thermal sensitivity and patient safety.

Introduction: Quantitative sensory testing (QST) is often used to understand the perceptual basis of acute and chronic conditions, including pain. As the need grows for developing a mechanistic understanding of neurological pathways underlying perception in the basic and clinical sciences, there is a greater need to adapt techniques such as QST to the magnetic resonance (MR) environment. No studies have yet evaluated the impact of the MR environment on the perception of thermal stimuli.

Towards a deeper understanding of pain: How machine learning and deep learning algorithms are needed to provide the next generation of pain medicine for use in the clinic.

As our definition of pain evolves, the factors implicit in defining and predicting pain status grow. These factors each have unique data characteristics and their outcomes each have unique target attributes. The clinical characterization of pain does not, as defined in the most recent IASP definition, require any tissue pathology, suggesting that the experience of pain can be uniquely psychological in nature.

Evidence of Chronic Complement Activation in Asymptomatic Pediatric Brain Injury Patients: A Pilot Study.

Physical insult from a mild Traumatic Brain Injury (mTBI) leads to changes in blood flow in the brain and measurable changes in white matter, suggesting a physiological basis for chronic symptom presentation. Post-traumatic headache (PTH) is frequently reported by persons after an mTBI that may persist beyond the acute period (>3 months). It remains unclear whether ongoing inflammation may contribute to the clinical trajectory of PTH.

Sensorimotor Integration and Pain Perception: Mechanisms Integrating Nociceptive Processing. A Systematic Review and ALE-Meta Analysis.

Pain treatment services and clinical indicators of pain chronicity focus on afferent nociceptive projections and psychological markers of pain perception with little focus on motor processes. Research supports a strong role for the motor system both in terms of pain related disability and in descending pain modulation. However, there is little understanding of the neurological regions implicated in pain-motor interactions and how the motor and sensory systems interact under conditions of pain.

Alterations in the structure and function of the brain in adolescents with new daily persistent headache: A pilot MRI study.

Objective: The purpose of this study was to explore brain morphological and functional connectivity alterations in adolescents with new daily persistent headache (NDPH) compared to pain-free, healthy controls.

Background: NDPH is one of the most disabling and least understood primary headache conditions. To date, no studies have considered the role of brain function and structure in pediatric patients with NDPH.

Biological laterality and peripheral nerve DTI metrics.

Background And Purpose: Clinical comparisons do not usually take laterality into account and thus may report erroneous or misleading data. The concept of laterality, well evaluated in brain and motor systems, may also apply at the level of peripheral nerves. Therefore, we sought to evaluate the extent to which we could observe an effect of laterality in MRI-collected white matter indices of the sciatic nerve and its two branches (tibial and fibular).

DTI and MTR Measures of Nerve Fiber Integrity in Pediatric Patients With Ankle Injury.

Acute peripheral nerve injury can lead to chronic neuropathic pain. Having a standardized, non-invasive method to evaluate pathological changes in a nerve following nerve injury would help with diagnostic and therapeutic assessments or interventions. The accurate evaluation of nerve fiber integrity after injury may provide insight into the extent of pathology and a patient's level of self-reported pain.

A lateralized model of the pain-depression dyad.

Chronic pain and depression are two frequently co-occurring and debilitating conditions. Even though the former is treated as a physical affliction, and the latter as a mental illness, both disorders closely share neural substrates. Here, we review the association of pain with depression, especially when symptoms are lateralized on either side of the body.

Commentary: Novel Use of Offset Analgesia to Assess Adolescents and Adults with Treatment Resistant Endometriosis-Associated Pain.

Background And Objective: Endometriosis, affecting approximately 176 million adults and adolescents worldwide, is a debilitating condition in which uterine tissue grows outside the uterus. The condition costs the US economy approximately $78 billion annually in pain-related disability. By understanding the neural underpinnings of endometriosis-associated pain (EAP) and risk factors for chronification, translational research methods could lessen diagnostic delays and maximize successful pain remediation.

Clinical features and sex differences in pediatric post-traumatic headache: A retrospective chart review at a Boston area concussion clinic.

Background: Often concussion/mTBI triggers a chronic headache syndrome called persistent post-traumatic headache (P-PTH) that can last from months to years post-injury, and produce significant disruption of childhood education, social interaction and development. Although prevalent and highly disabling, P-PTH is underrepresented in headache and pain research and lacks clear definition and pathophysiology. Clinical presentation of P-PTH frequently resembles that of other headache disorders, like migraine, yet the pathophysiological mechanisms are distinct and not fully understood, making the disorder difficult to treat in the clinical setting.

Delineating conditions and subtypes in chronic pain using neuroimaging.

Differentiating subtypes of chronic pain still remains a challenge-both from a subjective and objective point of view. Personalized medicine is the current goal of modern medical care and is limited by the subjective nature of patient self-reporting of symptoms and behavioral evaluation. Physiology-focused techniques such as genome and epigenetic analyses inform the delineation of pain groups; however, except under rare circumstances, they have diluted effects that again, share a common reliance on behavioral evaluation.

Evaluating task-based brain network activity in pediatric subjects with an mTBI: mechanisms of functional compensation are symptom-level dependent.

The diagnosis of a mild traumatic brain injury (mTBI) places large emphasis on patient-reported symptoms which has restricted our ability to evaluate patients. Task-based functional magnetic resonance imaging has the potential to act as an objective measurement of abnormal brain activity and inform clinical decision-making; however, there is little research evaluating pediatric subjects as a function of mTBI-related symptoms. The objective of this study was to evaluate the extent to which brain activity during a spatial navigation task is different between children with mTBI and a group of healthy controls (HCs) based on symptom reporting.

GABA and glutamate levels correlate with MTR and clinical disability: Insights from multiple sclerosis.

Converging areas of research have implicated glutamate and γ-aminobutyric acid (GABA) as key players in neuronal signalling and other central functions. Further research is needed, however, to identify microstructural and behavioral links to regional variability in levels of these neurometabolites, particularly in the presence of demyelinating disease. Thus, we sought to investigate the extent to which regional glutamate and GABA levels are related to a neuroimaging marker of microstructural damage and to motor and cognitive performance.

Abnormal functional connectivity and cortical integrity influence dominant hand motor disability in multiple sclerosis: a multimodal analysis.

Functional reorganization and structural damage occur in the brains of people with multiple sclerosis (MS) throughout the disease course. However, the relationship between resting-state functional connectivity (FC) reorganization in the sensorimotor network and motor disability in MS is not well understood. This study used resting-state fMRI, T1-weighted and T2-weighted, and magnetization transfer (MT) imaging to investigate the relationship between abnormal FC in the sensorimotor network and upper limb motor disability in people with MS, as well as the impact of disease-related structural abnormalities within this network.

Combined structural and functional patterns discriminating upper limb motor disability in multiple sclerosis using multivariate approaches.

A structural or functional pattern of neuroplasticity that could systematically discriminate between people with impaired and preserved motor performance could help us to understand the brain networks contributing to preservation or compensation of behavior in multiple sclerosis (MS). This study aimed to (1) investigate whether a machine learning-based technique could accurately classify MS participants into groups defined by upper extremity function (i.e.

Cortical Damage and Disability in Multiple Sclerosis: Relation to Intracortical Inhibition and Facilitation.

Background: Multimodal research combining biomarkers of intracortical activity and cortical damage could shed light on pathophysiological and adaptive neural processes related to the clinical severity of neurological conditions such as multiple sclerosis (MS).

Objective: Among people with relapsing-remitting and progressive forms of MS, we assessed the extent to which transcranial magnetic stimulation (TMS)-based biomarkers of excitatory and inhibitory cortical activity are related to cortical damage and clinical impairment.

Methods: Participants included 18 healthy individuals and 36 people with MS who had a relapsing-remitting or progressive clinical course.

Intracortical inhibition abnormality during the remission phase of multiple sclerosis is related to upper limb dexterity and lesions.

Objective: The impact of inhibitory cortical activity on motor impairment of people with relapsing-remitting multiple sclerosis (RRMS) has not been fully elucidated despite its relevance to neurorehabilitation. The present study assessed the extent to which transcranial magnetic stimulation (TMS)-based metrics of intracortical inhibition are related to motor disability and brain damage.

Methods: Participants included forty-three persons with RRMS in the remitting phase and twenty-nine healthy controls.

Distinct visual cues mediate aperture shaping for grasping and pantomime-grasping tasks.

The authors examined whether the top-down requirements of dissociating the spatial relations between stimulus and response in a goal-directed grasping task renders the mediation of aperture trajectories via relative visual information. To address that issue, participants grasped differently sized target objects (i.e.

Goal-directed grasping: the dimensional properties of an object influence the nature of the visual information mediating aperture shaping.

An issue of continued debate in the visuomotor control literature surrounds whether a 2D object serves as a representative proxy for a 3D object in understanding the nature of the visual information supporting grasping control. In an effort to reconcile this issue, we examined the extent to which aperture profiles for grasping 2D and 3D objects adheres to, or violates, the psychophysical properties of Weber's law. Specifically, participants grasped differently sized 2D and 3D objects (20, 30, 40, and 50mm of width) and we computed the just-noticeable-difference scores associated with aperture profiles at decile increments of normalized grasping time.

Assessing aggression following traumatic brain injury: a systematic review of validated aggression scales.

Background: Every year, millions of people worldwide suffer traumatic brain injuries (TBIs). Aggressive behavior, a known psychological symptom following TBI, has been regarded as an obstacle toward rehabilitation. Having measures that accurately assess aggression during rehabilitation is critical toward proper evaluation.

Grasping time does not influence the early adherence of aperture shaping to Weber's law.

The "just noticeable difference" (JND) represents the minimum amount by which a stimulus must change to produce a noticeable variation in one's perceptual experience (i.e., Weber's law).

Pro- and antisaccades: dissociating stimulus and response influences the online control of saccade trajectories.

The authors examined whether the diminished online control of antisaccades is related to a trade-off between movement planning and control or the remapping of target properties to a mirror-symmetrical location (i.e., vector inversion).