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Neurobiology of Disease Apr 2023Neuromodulation (neurostimulation) is a relatively new and rapidly growing treatment for refractory epilepsy. Three varieties are approved in the US: vagus nerve... (Review)
Review
Neuromodulation (neurostimulation) is a relatively new and rapidly growing treatment for refractory epilepsy. Three varieties are approved in the US: vagus nerve stimulation (VNS), deep brain stimulation (DBS) and responsive neurostimulation (RNS). This article reviews thalamic DBS for epilepsy. Among many thalamic sub-nuclei, DBS for epilepsy has been targeted to the anterior nucleus (ANT), centromedian nucleus (CM), dorsomedial nucleus (DM) and pulvinar (PULV). Only ANT is FDA-approved, based upon a controlled clinical trial. Bilateral stimulation of ANT reduced seizures by 40.5% at three months in the controlled phase (p = .038) and 75% by 5 years in the uncontrolled phase. Side effects related to paresthesias, acute hemorrhage, infection, occasional increased seizures, and usually transient effects on mood and memory. Efficacy was best documented for focal onset seizures in temporal or frontal lobe. CM stimulation may be useful for generalized or multifocal seizures and PULV for posterior limbic seizures. Mechanisms of DBS for epilepsy are largely unknown, but animal work points to changes in receptors, channels, neurotransmitters, synapses, network connectivity and neurogenesis. Personalization of therapies, in terms of connectivity of the seizure onset zone to the thalamic sub- nucleus and individual characteristics of the seizures, might lead to improved efficacy. Many questions remain about DBS, including the best candidates for different types of neuromodulation, the best targets, the best stimulation parameters, how to minimize side effects and how to deliver current noninvasively. Despite the questions, neuromodulation provides useful new opportunities to treat people with refractory seizures not responding to medicines and not amenable to resective surgery.
Topics: Animals; Deep Brain Stimulation; Epilepsy; Thalamus; Seizures; Drug Resistant Epilepsy
PubMed: 36809846
DOI: 10.1016/j.nbd.2023.106045 -
Neuron Jan 2016While the function of the pulvinar remains one of the least explored among the thalamic nuclei despite occupying the most thalamic volume in primates, it has long been...
While the function of the pulvinar remains one of the least explored among the thalamic nuclei despite occupying the most thalamic volume in primates, it has long been suspected to play a crucial role in attentive stimulus processing. In this issue of Neuron, Zhou et al. (2016) use simultaneous pulvinar-visual cortex recordings and pulvinar inactivation to provide evidence that the pulvinar is essential for intact stimulus processing, maintenance of neuronal oscillatory dynamics, and mediating the effects of attention.
Topics: Animals; Attention; Male; Pulvinar; Vision, Ocular; Visual Cortex; Visual Pathways
PubMed: 26748085
DOI: 10.1016/j.neuron.2015.12.022 -
Current Opinion in Neurology Apr 2023Neurostimulation is a quickly growing treatment approach for epilepsy patients. We summarize recent approaches to provide a perspective on the future of neurostimulation. (Review)
Review
PURPOSE OF REVIEW
Neurostimulation is a quickly growing treatment approach for epilepsy patients. We summarize recent approaches to provide a perspective on the future of neurostimulation.
RECENT FINDINGS
Invasive stimulation for treatment of focal epilepsy includes vagus nerve stimulation, responsive neurostimulation of the cortex and deep brain stimulation of the anterior nucleus of the thalamus. A wide range of other targets have been considered, including centromedian, central lateral and pulvinar thalamic nuclei; medial septum, nucleus accumbens, subthalamic nucleus, cerebellum, fornicodorsocommissure and piriform cortex. Stimulation for generalized onset seizures and mixed epilepsies as well as increased efforts focusing on paediatric populations have emerged. Hardware with more permanently implanted lead options and sensing capabilities is emerging. A wider variety of programming approaches than typically used may improve patient outcomes. Finally, noninvasive brain stimulation with its favourable risk profile offers the potential to treat increasingly diverse epilepsy patients.
SUMMARY
Neurostimulation for the treatment of epilepsy is surprisingly varied. Flexibility and reversibility of neurostimulation allows for rapid innovation. There remains a continued need for excitability biomarkers to guide treatment and innovation. Neurostimulation, a part of bioelectronic medicine, offers distinctive benefits as well as unique challenges.
Topics: Child; Humans; Deep Brain Stimulation; Epilepsy; Seizures; Cerebral Cortex; Thalamus
PubMed: 36762660
DOI: 10.1097/WCO.0000000000001138 -
Neurobiology of Disease Feb 2020Sleep and circadian rhythms are among the most powerful but least understood contributors to cognitive performance and brain health. Here we capitalize on the circadian... (Randomized Controlled Trial)
Randomized Controlled Trial
A randomized, double-blind, placebo-controlled trial of blue wavelength light exposure on sleep and recovery of brain structure, function, and cognition following mild traumatic brain injury.
Sleep and circadian rhythms are among the most powerful but least understood contributors to cognitive performance and brain health. Here we capitalize on the circadian resetting effect of blue-wavelength light to phase shift the sleep patterns of adult patients (aged 18-48 years) recovering from mild traumatic brain injury (mTBI), with the aim of facilitating recovery of brain structure, connectivity, and cognitive performance. During a randomized, double-blind, placebo-controlled trial of 32 adults with a recent mTBI, we compared 6-weeks of daily 30-min pulses of blue light (peak λ = 469 nm) each morning versus amber placebo light (peak λ = 578 nm) on neurocognitive and neuroimaging outcomes, including gray matter volume (GMV), resting-state functional connectivity, directed connectivity using Granger causality, and white matter integrity using diffusion tensor imaging (DTI). Relative to placebo, morning blue light led to phase-advanced sleep timing, reduced daytime sleepiness, and improved executive functioning, and was associated with increased volume of the posterior thalamus (i.e., pulvinar), greater thalamo-cortical functional connectivity, and increased axonal integrity of these pathways. These findings provide insight into the contributions of the circadian and sleep systems in brain repair and lay the groundwork for interventions targeting the retinohypothalamic system to facilitate injury recovery.
Topics: Actigraphy; Adolescent; Adult; Brain; Brain Concussion; Brain Mapping; Cognition; Double-Blind Method; Female; Humans; Light; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Phototherapy; Sleep; Treatment Outcome; Young Adult
PubMed: 31751607
DOI: 10.1016/j.nbd.2019.104679 -
Annual Review of Psychology Jan 2020Spatial attention is comprised of neural mechanisms that boost sensory processing at a behaviorally relevant location while filtering out competing information. The... (Review)
Review
Spatial attention is comprised of neural mechanisms that boost sensory processing at a behaviorally relevant location while filtering out competing information. The present review examines functional specialization in the network of brain regions that directs such preferential processing. This attention network includes both cortical (e.g., frontal and parietal cortices) and subcortical (e.g., the superior colliculus and the pulvinar nucleus of the thalamus) structures. Here, we piece together existing evidence that these various nodes of the attention network have dissociable functional roles by synthesizing results from electrophysiology and neuroimaging studies. We describe functional specialization across several dimensions (e.g., at different processing stages and within different behavioral contexts), while focusing on spatial attention as a dynamic process that unfolds over time. Functional contributions from each node of the attention network can change on a moment-to-moment timescale, providing the necessary cognitive flexibility for sampling from highly dynamic environments.
Topics: Attention; Cerebral Cortex; Humans; Nerve Net; Pulvinar; Space Perception; Superior Colliculi
PubMed: 31514578
DOI: 10.1146/annurev-psych-010418-103429 -
Neuropsychopharmacologia Hungarica : a... Mar 2013The pulvinar is the largest nucleus of the thalamus. Its lateral and inferior areas have rich connections with the visual- and dorsolateral parietal cortices. Several... (Review)
Review
The pulvinar is the largest nucleus of the thalamus. Its lateral and inferior areas have rich connections with the visual- and dorsolateral parietal cortices. Several cells in the medial and upper area connect the anterior cingulum and the premotor and prefrontal association areas. This neuronal network was considered to organize the saccades and visual attention. Other cells in the medial nucleus have axonal connections with paralimbic-, insular and higher order association-cortices. The medial structure integrates complex sensory information with limbic reactivity settings, transmitting these to the temporal and parieto-occipital centres. The pulvinar is supplied by the posterior chorioideal artery. Visual salience is considered to be an important function of the pulvinar. Visual selection enables subjects to choose the actually adequate behavioral act. To serve the visual salience the pulvinar may also inhibit inappropriate eye movements. The pulvinar appears to be a key structure of the EEG's alpha rhythm generator, acting together with the parietooccipital and temporal cortices. Dynamic fluctuation of BOLD signals on fMRI correlates well with the change of alpha power even in resting state. We presume that the pulvinar is part of a closed cortico-subcortical circuit, analogous with the striatum, but the output of the pulvinar initiates complex behavioral reactions, including perception, selective attention and emotions. Damage of the pulvinar may elicit contralateral visual neglect, because of the dissociation of the neuronal network integrated by the superior temporal area. Increased activity of the pulvinar was found during abrupt reaction to fearful visual signals; and also in the etiopathology of endogenous depressions through the alteration of serotonin transporters. Increased bilateral signal intensity of the pulvinar on MRI was detected in cases of the new variants of Creutzfeldt-Jakob- and Fabry diseases.
Topics: Alpha Rhythm; Attention; Cerebral Cortex; Humans; Intention; Neural Pathways; Perceptual Disorders; Pulvinar; Space Perception; Thalamus; Vision, Ocular
PubMed: 23542756
DOI: No ID Found -
The Journal of Physiology Jan 2023The thalamus and cortex are interconnected both functionally and anatomically and share a common developmental trajectory. Interactions between the mediodorsal thalamus... (Review)
Review
The thalamus and cortex are interconnected both functionally and anatomically and share a common developmental trajectory. Interactions between the mediodorsal thalamus (MD) and different parts of the prefrontal cortex are essential in cognitive processes, such as learning and adaptive decision-making. Cortico-thalamocortical interactions involving other dorsal thalamic nuclei, including the anterior thalamus and pulvinar, also influence these cognitive processes. Our work, and that of others, indicates a crucial influence of these interdependent cortico-thalamocortical neural networks that contributes actively to the processing of information within the cortex. Each of these thalamic nuclei also receives potent subcortical inputs that are likely to provide additional influences on their regulation of cortical activity. Here, we highlight our current neuroscientific research aimed at establishing when cortico-MD thalamocortical neural network communication is vital within the context of a rapid learning and memory discrimination task. We are collecting evidence of MD-prefrontal cortex neural network communication in awake, behaving male rhesus macaques. Given the prevailing evidence, further studies are needed to identify both broad and specific mechanisms that govern how the MD, anterior thalamus and pulvinar cortico-thalamocortical interactions support learning, memory and decision-making. Current evidence shows that the MD (and the anterior thalamus) are crucial for frontotemporal communication, and the pulvinar is crucial for frontoparietal communication. Such work is crucial to advance our understanding of the neuroanatomical and physiological bases of these brain functions in humans. In turn, this might offer avenues to develop effective treatment strategies to improve the cognitive deficits often observed in many debilitating neurological disorders and diseases and in neurodegeneration.
Topics: Animals; Male; Humans; Macaca mulatta; Learning; Thalamus; Prefrontal Cortex; Neural Pathways
PubMed: 35851953
DOI: 10.1113/JP282626 -
Entropy (Basel, Switzerland) May 2019Contemporary neurodynamical frameworks, such as coordination dynamics and winnerless competition, posit that the brain approximates symbolic computation by transitioning... (Review)
Review
Contemporary neurodynamical frameworks, such as coordination dynamics and winnerless competition, posit that the brain approximates symbolic computation by transitioning between metastable attractive states. This article integrates these accounts with electrophysiological data suggesting that coherent, nested oscillations facilitate information representation and transmission in thalamocortical networks. We review the relationship between criticality, metastability, and representational capacity, outline existing methods for detecting metastable oscillatory patterns in neural time series data, and evaluate plausible spatiotemporal coding schemes based on phase alignment. We then survey the circuitry and the mechanisms underlying the generation of coordinated alpha and gamma rhythms in the primate visual system, with particular emphasis on the pulvinar and its role in biasing visual attention and awareness. To conclude the review, we begin to integrate this perspective with longstanding theories of consciousness and cognition.
PubMed: 33267214
DOI: 10.3390/e21050500 -
Annals of Clinical and Translational... Jul 2023Deep brain stimulation (DBS) is a promising treatment for drug-refractory epilepsies (DRE) when targeting the anterior nuclei of thalamus (ANT). However, targeting other...
Deep brain stimulation (DBS) is a promising treatment for drug-refractory epilepsies (DRE) when targeting the anterior nuclei of thalamus (ANT). However, targeting other thalamic nuclei, such as the pulvinar, shows therapeutic promise. Our pioneering case study presents the application of ambulatory seizure monitoring using spectral fingerprinting (12.15-17.15 Hz) recorded through Medtronic Percept DBS implanted bilaterally in the medial pulvinar thalami. This technology offers unprecedented opportunities for real-time monitoring of seizure burden and thalamocortical network modulation for effective seizure reduction in patients with bilateral mesial temporal and temporal plus epilepsies that are not suitable for resection.
Topics: Humans; Pulvinar; Deep Brain Stimulation; Electrodes, Implanted; Epilepsy; Seizures
PubMed: 37231611
DOI: 10.1002/acn3.51815 -
Neurology International Jun 2022Background: Fabry disease (FD) is the second most common lysosomal storage disorder. This disorder affects multiple systems that include the cardiac, renal, and nervous... (Review)
Review
Background: Fabry disease (FD) is the second most common lysosomal storage disorder. This disorder affects multiple systems that include the cardiac, renal, and nervous system. The pulvinar sign (PS) is a relatively common sign seen in patients with FD. The PS is a bilateral, symmetrical pulvinar high signal relative to the signal intensity seen on unenhanced T1-weighted brain MR imaging. Methods: We conducted a systematic review with metanalysis to analyze the pool prevalence of the disorder. We used the Moose Guidelines and PRISMA Protocol for this systematic review and Robins 1 to access the BIAS of the study. To analyze the pool prevalence, we used “Open Meta-Analysis” software for analyzing the study. We used “Review Manager 5.4” to analyze the odds ratio between patients with and without the PS and patients with and without stroke among patients with FD. Results: We gather 12 studies from 2003 to 2021 for the analysis of this study. The pool prevalence of the study was 0.146 (0.076−0.217) (62/385 cases) with a 95% CI (0.0945−0.415) (p < 0.01). The prevalence was much higher in men (59 cases) than in women (3 cases). There was no relationship between the pulvinar sign and patients with stroke among patients with Fabry disease. Odds ratio 1.97 95% CI (0.35−11.21), p = 0.44; Tau2 = 0.77. There seems to be a correlation with renal failure (RF), but there were very few studies to conduct a metanalysis with RF. Conclusions: The prevalence of the PS among all studies was 23.9%; the prevalence of this sign is higher among males. We found that FD patients who had strokes did not have higher odds of presenting with the Pulvinar Sign than the FD patients who did not suffer a stroke. Patients with renal failure and FD seem to have a higher tendency to have the PS, but there were not enough studies to analyze that theory. Overall, we think the pulvinar sign has a poor prognostic value in patients with Fabry’s disease.
PubMed: 35736622
DOI: 10.3390/neurolint14020041