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Frontiers in Pain Research (Lausanne,... 2022Chronic neuropathic pain refractory to medical management can be debilitating and can seriously affect one's quality of life. The interest of ablative surgery for the... (Review)
Review
Chronic neuropathic pain refractory to medical management can be debilitating and can seriously affect one's quality of life. The interest of ablative surgery for the treatment or palliation of chronic neuropathic pain, cancer-related or chemotherapy-induced, has grown. Numerous regions along the nociceptive pathways have been prominent targets including the various nuclei of the thalamus. Traditional targets include the medial pulvinar, central median, and posterior complex thalamic nuclei. However, there has been little research regarding the role of the central lateral nucleus. In this paper, we aim to summarize the anatomy, pathophysiology, and patient experiences of the central lateral thalamotomy.
PubMed: 36176711
DOI: 10.3389/fpain.2022.999891 -
Psychiatry Research Sep 2023Identifying objective biological subtypes that predict long-term functional outcomes is crucial for understanding neurobiological mechanisms and identifying potential...
Identifying objective biological subtypes that predict long-term functional outcomes is crucial for understanding neurobiological mechanisms and identifying potential targets. Using resting-state functional magnetic resonance imaging data from 178 patients and 70 controls, we explored social function patterns using latent profile analysis. Long-term outcomes were compared among the biological subtypes using K-means clustering. Partial least squares regression (PLSR) was used to identify gene expression profiles associated with alterations in activity by leveraging transcriptional data from the Allen Human Brain Atlas. In patients with more functional impairment, left medial pulvinar (PM) exhibited significantly lower regional homogeneity of brain activity (ReHo, [95% CI (0.06-0.27), P = 0.002), a finding validated in the independent cohort. Functional connectivity between PM and secondary visual cortex displayed a suggestive decrease. Patients belonging to "higher pulvinar ReHo - better information processing" demonstrated better long-term outcomes and acute treatment response [95% CI (11.2-34.4), P < 0.001]. The PLSR component of imaging-transcriptomic associations partly explained the ReHo differences among patients with varying levels of functional impairment. It revealed enrichment of genes in the synaptic signaling pathway. Pathological changes in the pulvinar may affect social functioning. Higher pulvinar ReHo and better information processing, two objective biomarkers, have a predictive value for better long-term functional outcomes.
Topics: Humans; Schizophrenia; Pulvinar; Brain; Cluster Analysis; Cognition
PubMed: 37598626
DOI: 10.1016/j.psychres.2023.115419 -
Sleep Medicine Sep 2023Brain iron status is fundamental in RLS pathogenesis. The aim of this study was to determine the clinical efficacy and brain iron concentration improvement in RLS... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Brain iron status is fundamental in RLS pathogenesis. The aim of this study was to determine the clinical efficacy and brain iron concentration improvement in RLS patients with IDA, using 1500 mg FCM.
METHODS
This is a randomized, double-blinded, placebo-controlled study. RLS patients with IDA were grouped into either 1500 mg FCM or placebo. The primary outcomes were the change from baseline on the International Restless Legs Syndrome Study Group scale (IRLS) and brain iron measured by QSM and R2∗.
RESULTS
A total of 18 RLS patients with IDA were enrolled, 10 in the FCM group and 8 in the placebo. At the week 6 endpoint, the FCM group showed significant improvement in both IRLS (-13.60 ± 9.47 vs. -3.63 ± 5.40, p = 0.011) and VAS (-40.50 ± 28.81 vs. -0.63 ± 28.28, p = 0.004) from baseline. Change from baseline with R2∗ techniques showed a treatment effect for the thalamus and QSM technique for both the substantia nigra and pulvinar. A correlation was proved between the IRLS difference and the difference of QSM in thalamus (p = 0.028).
CONCLUSION
This study demonstrates that 1500 mg FCM effectively treats RLS symptoms in IDA patients over six weeks, with MRI measurements of improved brain iron content serving as a potential biomarker for RLS patients.
Topics: Humans; Iron; Anemia, Iron-Deficiency; Restless Legs Syndrome; Ferric Compounds; Brain; Treatment Outcome
PubMed: 37437492
DOI: 10.1016/j.sleep.2023.06.023 -
NeuroImage Nov 2022The thalamus is a central integration structure in the brain, receiving and distributing information among the cerebral cortex, subcortical structures, and the...
The thalamus is a central integration structure in the brain, receiving and distributing information among the cerebral cortex, subcortical structures, and the peripheral nervous system. Prior studies clearly show that the thalamus atrophies in cognitively unimpaired aging. However, the thalamus is comprised of multiple nuclei involved in a wide range of functions, and the age-related atrophy of individual thalamic nuclei remains unknown. Using a recently developed automated method of identifying thalamic nuclei (3T or 7T MRI with white-matter-nulled MPRAGE contrast and THOMAS segmentation) and a cross-sectional design, we evaluated the age-related atrophy rate for 10 thalamic nuclei (AV, CM, VA, VLA, VLP, VPL, pulvinar, LGN, MGN, MD) and an epithalamic nucleus (habenula). We also used T1-weighted images with the FreeSurfer SAMSEG segmentation method to identify and measure age-related atrophy for 11 extra-thalamic structures (cerebral cortex, cerebral white matter, cerebellar cortex, cerebellar white matter, amygdala, hippocampus, caudate, putamen, nucleus accumbens, pallidum, and lateral ventricle). In 198 cognitively unimpaired participants with ages spanning 20-88 years, we found that the whole thalamus atrophied at a rate of 0.45% per year, and that thalamic nuclei had widely varying age-related atrophy rates, ranging from 0.06% to 1.18% per year. A functional grouping analysis revealed that the thalamic nuclei involved in cognitive (AV, MD; 0.53% atrophy per year), visual (LGN, pulvinar; 0.62% atrophy per year), and auditory/vestibular (MGN; 0.64% atrophy per year) functions atrophied at significantly higher rates than those involved in motor (VA, VLA, VLP, and CM; 0.37% atrophy per year) and somatosensory (VPL; 0.32% atrophy per year) functions. A proximity-to-CSF analysis showed that the group of thalamic nuclei situated immediately adjacent to CSF atrophied at a significantly greater atrophy rate (0.59% atrophy per year) than that of the group of nuclei located farther from CSF (0.36% atrophy per year), supporting a growing hypothesis that CSF-mediated factors contribute to neurodegeneration. We did not find any significant hemispheric differences in these rates of change for thalamic nuclei. Only the CM thalamic nucleus showed a sex-specific difference in atrophy rates, atrophying at a greater rate in male versus female participants. Roughly half of the thalamic nuclei showed greater atrophy than all extra-thalamic structures examined (0% to 0.54% per year). These results show the value of white-matter-nulled MPRAGE imaging and THOMAS segmentation for measuring distinct thalamic nuclei and for characterizing the high and heterogeneous atrophy rates of the thalamus and its nuclei across the adult lifespan. Collectively, these methods and results advance our understanding of the role of thalamic substructures in neurocognitive and disease-related changes that occur with aging.
Topics: Adult; Aged; Aged, 80 and over; Aging; Atrophy; Cross-Sectional Studies; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Thalamic Nuclei; Thalamus; Young Adult
PubMed: 36007822
DOI: 10.1016/j.neuroimage.2022.119584 -
Journal of Cognitive Neuroscience May 2021How do humans learn from raw sensory experience? Throughout life, but most obviously in infancy, we learn without explicit instruction. We propose a detailed biological...
How do humans learn from raw sensory experience? Throughout life, but most obviously in infancy, we learn without explicit instruction. We propose a detailed biological mechanism for the widely embraced idea that learning is driven by the differences between predictions and actual outcomes (i.e., predictive error-driven learning). Specifically, numerous weak projections into the pulvinar nucleus of the thalamus generate top-down predictions, and sparse driver inputs from lower areas supply the actual outcome, originating in Layer 5 intrinsic bursting neurons. Thus, the outcome representation is only briefly activated, roughly every 100 msec (i.e., 10 Hz, alpha), resulting in a temporal difference error signal, which drives local synaptic changes throughout the neocortex. This results in a biologically plausible form of error backpropagation learning. We implemented these mechanisms in a large-scale model of the visual system and found that the simulated inferotemporal pathway learns to systematically categorize 3-D objects according to invariant shape properties, based solely on predictive learning from raw visual inputs. These categories match human judgments on the same stimuli and are consistent with neural representations in inferotemporal cortex in primates.
Topics: Animals; Neocortex; Neurons; Pulvinar; Visual Cortex
PubMed: 34428793
DOI: 10.1162/jocn_a_01708 -
Journal of Neurosurgery Dec 2023Anatomical taxonomy is a practical tool to successfully guide clinical decision-making for patients with brain arteriovenous malformations and brainstem cavernous...
OBJECTIVE
Anatomical taxonomy is a practical tool to successfully guide clinical decision-making for patients with brain arteriovenous malformations and brainstem cavernous malformations (CMs). Deep cerebral CMs are complex, difficult to access, and highly variable in size, shape, and position. The authors propose a novel taxonomic system for deep CMs in the thalamus based on clinical presentation (syndromes) and anatomical location (identified on MRI).
METHODS
The taxonomic system was developed and applied to an extensive 2-surgeon experience from 2001 through 2019. Deep CMs involving the thalamus were identified. These CMs were subtyped on the basis of the predominant surface presentation identified on preoperative MRI. Six subtypes among 75 thalamic CMs were defined: anterior (7/75, 9%), medial (22/75, 29%), lateral (10/75, 13%), choroidal (9/75, 12%), pulvinar (19/75, 25%), and geniculate (8/75, 11%). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome and > 2 as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes.
RESULTS
Seventy-five patients underwent resection of thalamic CMs and had clinical and radiological data available. Their mean age was 40.9 (SD 15.2) years. Each thalamic CM subtype was associated with a recognizable constellation of neurological symptoms. The common symptoms were severe or worsening headaches (30/75, 40%), hemiparesis (27/75, 36%), hemianesthesia (21/75, 28%), blurred vision (14/75, 19%), and hydrocephalus (9/75, 12%). The thalamic CM subtype determined the selection of surgical approach. A single approach was associated with each subtype for most patients. The main exception to this paradigm was that in the surgeons' early experience, pulvinar CMs were resected through a superior parietal lobule-transatrial approach (4/19, 21%), which later evolved to the paramedian supracerebellar-infratentorial approach (12/19, 63%). Relative outcomes implied by mRS scores were unchanged or improved in most patients (61/66, 92%) postoperatively.
CONCLUSIONS
This study confirms the authors' hypothesis that this taxonomy for thalamic CMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the clarity of clinical communications and publications, and improve patient outcomes.
Topics: Humans; Adult; Hemangioma, Cavernous, Central Nervous System; Treatment Outcome; Brain; Neurosurgical Procedures; Brain Neoplasms; Retrospective Studies
PubMed: 37209072
DOI: 10.3171/2023.3.JNS23234 -
Journal of Neurosurgery Nov 2022Stereoelectroencephalography (sEEG) is a well-established surgical method for defining the epileptogenic network. Traditionally reserved for identifying discrete... (Review)
Review
OBJECTIVE
Stereoelectroencephalography (sEEG) is a well-established surgical method for defining the epileptogenic network. Traditionally reserved for identifying discrete cortical regions for resection or ablation, sEEG in current practice is also used for identifying more broadly involved subcortical epileptic network components, driven by the availability of brain-based neuromodulation strategies. In particular, sEEG investigations including thalamic nuclei are becoming more frequent in parallel with the increase in therapeutic strategies involving thalamic targets such as deep brain stimulation (DBS) and responsive neurostimulation (RNS). The objective to this study was to evaluate existing evidence and trends regarding the purpose, techniques, and relevant electrographic findings of thalamic sEEG.
METHODS
MEDLINE and Embase databases were systematically queried for eligible peer-reviewed studies involving sEEG electrode implantation into thalamic nuclei of patients with epilepsy. Available data were abstracted concerning preoperative workup and purpose for implanting the thalamus, thalamic targets and trajectories, and electrophysiological methodology and findings.
RESULTS
sEEG investigations have included thalamic targets for both basic and clinical research purposes. Medial pulvinar, dorsomedial, anterior, and centromedian nuclei have been the most frequently studied. Few studies have reported any complications with thalamic sEEG implantation, and no studies have reported long-term complications. Various methods have been utilized to characterize thalamic activity in epileptic disorders including evoked potentials, power spectrograms, synchronization indices, and the epileptogenicity index. Thalamic intracranial recordings are beginning to be used to guide neuromodulation strategies including RNS and DBS, as well as to understand complex, network-dependent seizure disorders.
CONCLUSIONS
Inclusion of thalamic coverage during sEEG evaluation in drug-resistant epilepsy is a growing practice and is amenable to various methods of electrographic data analysis. Further study is required to establish well-defined criteria for thalamic implantation during invasive investigations as well as safety and ethical considerations.
PubMed: 35276641
DOI: 10.3171/2022.1.JNS212613 -
International Journal of Molecular... Feb 2021Post-traumatic stress disorder (PTSD) has a high lifetime prevalence and is one of the more serious challenges in mental health care. Fear-conditioned learning involving... (Review)
Review
Post-traumatic stress disorder (PTSD) has a high lifetime prevalence and is one of the more serious challenges in mental health care. Fear-conditioned learning involving the amygdala has been thought to be one of the main causative factors; however, recent studies have reported abnormalities in the thalamus of PTSD patients, which may explain the mechanism of interventions such as eye movement desensitization and reprocessing (EMDR). Therefore, I conducted a miniature literature review on the potential contribution of the thalamus to the pathogenesis of PTSD and the validation of therapeutic approaches. As a result, we noticed the importance of the retinotectal pathway (superior colliculus-pulvinar-amygdala connection) and discussed therapeutic indicators.
Topics: Amygdala; Animals; Conditioning, Psychological; Connectome; Diffusion Tensor Imaging; Disease Models, Animal; Eye Movement Desensitization Reprocessing; Fear; Humans; Hyperbaric Oxygenation; Oxytocin; Pulvinar; Retina; Stress Disorders, Post-Traumatic; Superior Colliculi; Treatment Outcome; Visual Pathways
PubMed: 33572198
DOI: 10.3390/ijms22041730 -
Medicina (Kaunas, Lithuania) Jun 2021In adults, developmental dysplasia of the hip (DDH) represents a spectrum of disorders. It is commonly found in women in routine orthopedic practice. Hip dysplasia is a... (Review)
Review
In adults, developmental dysplasia of the hip (DDH) represents a spectrum of disorders. It is commonly found in women in routine orthopedic practice. Hip dysplasia is a leading precursor of joint laxity; when untreated, it can contribute to chronic modifications, such as thickening of the pulvinar and ligamentum teres (which can also elongate), hypertrophy of the transverse acetabular ligament, and osteoarthritis. DDH is presumed to be associated with alterations in pelvic morphology that may affect vaginal birth by the reduction in the transverse diameter of the pelvic inlet or outlet. Here, we provide an overview of the current knowledge of pregnancy-associated DDH. We primarily focused on how a surgical DDH treatment might influence the pelvic shape and size and the effects on the mechanism of birth. We presented the female pelvis from the standpoint of bone and ligament morphology relative to a pelvic osteotomy. Then, we described whether the pregnancy was impacted by previous surgical DDH treatments, performed from infancy to adulthood. In conclusion, hip dysplasia is not associated with high-risk complications during pregnancy or with increased difficulty in vaginal delivery.
Topics: Adult; Developmental Dysplasia of the Hip; Female; Hip Dislocation; Hip Dislocation, Congenital; Hip Joint; Humans; Pregnancy; Retrospective Studies
PubMed: 34206824
DOI: 10.3390/medicina57070655 -
The Journal of Comparative Neurology Jan 2021The extrageniculate visual pathway, which carries visual information from the retina through the superficial layers of the superior colliculus and the pulvinar, is...
The extrageniculate visual pathway, which carries visual information from the retina through the superficial layers of the superior colliculus and the pulvinar, is poorly understood. The pulvinar is thought to modulate information flow between cortical areas, and has been implicated in cognitive tasks like directing visually guided actions. In order to better understand the underlying circuitry, we performed retrograde injections of modified rabies virus in the visual cortex and pulvinar of the Long-Evans rat. We found a relatively small population of cells projecting to primary visual cortex (V1), compared to a much larger population projecting to higher visual cortex. Reciprocal corticothalamic projections showed a similar result, implying that pulvinar does not play as big a role in directly modulating rodent V1 activity as previously thought.
Topics: Animals; Female; Primary Visual Cortex; Pulvinar; Rats; Rats, Long-Evans; Visual Cortex; Visual Pathways
PubMed: 32361987
DOI: 10.1002/cne.24937