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Journal of Wrist Surgery Apr 2023The aim of this study was to compare the rates of recurrence and wound infection in patients with primary dorsal wrist ganglion treated with aspiration (with or...
The aim of this study was to compare the rates of recurrence and wound infection in patients with primary dorsal wrist ganglion treated with aspiration (with or without an injection of an additive), open excision, or arthroscopic resection. This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered on PROSPERO. Systematic electronic searches in PubMed (MEDLINE), EMBASE, Web of Science, and the Cochrane Library of Controlled Trials were performed on May 5, 2020, and June 1, 2021, respectively. All clinical studies written in English determining the recurrence and wound infection rates after treatment of primary dorsal wrist ganglion with aspiration, open excision, or arthroscopic resection in patients over the age of 16 years were eligible for inclusion. Quality assessment was guided by the Cochrane Collaboration's tool for randomized controlled trials (RCTs) and the methodological index for nonrandomized studies (MINORS) tool for observational studies. The literature searches resulted in 1,691 studies. After screening, five RCTs, enrolling 233 patients, and six observational studies, enrolling 316 patients with primary dorsal wrist ganglions were included. Quality assessment of the included RCTs and observational studies determined the existing level of evidence pertaining to primary dorsal wrist ganglion treatment to be low. About 11 studies reported on recurrence rate, which ranged between 7 and 72% for patients initially treated with aspiration (with or without an injection of an additive). In comparison, the recurrence rate for the open excision and arthroscopic resection groups ranged between 6 to 41% and 0 to 16%, respectively. Four studies investigated wound-related complications, for which zero infections were reported, irrespective of treatment. The evidence summarized in this systematic review demonstrates a considerable variability in recurrence rate following aspiration and open or arthroscopic resection of a primary dorsal wrist ganglion. The greatest variability in recurrence was displayed among studies on aspiration. The overall infection rate after treatment of dorsal wrist ganglions seems to be low regardless of the treatment type. However, the divergent results of individual studies highlight a pressing need for prospective controlled trials assessing outcomes following dorsal wrist ganglion treatment. Systematic review on level 1 to 4 clinical therapeutic studies.
PubMed: 36926205
DOI: 10.1055/s-0042-1753542 -
Frontiers in Systems Neuroscience 2022Although neural plasticity is now widely studied, there was a time when the idea of adult plasticity was antithetical to the mainstream. The essential stumbling block...
Although neural plasticity is now widely studied, there was a time when the idea of adult plasticity was antithetical to the mainstream. The essential stumbling block arose from the seminal experiments of Hubel and Wiesel who presented convincing evidence that there existed a critical period for plasticity during development after which the brain lost its ability to change in accordance to shifts in sensory input. Despite the zeitgeist that mature brain is relatively immutable to change, there were a number of examples of adult neural plasticity emerging in the scientific literature. Interestingly, some of the earliest of these studies involved visual plasticity in the adult cat. Even earlier, there were reports of what appeared to be functional reorganization in adult rat somatosensory thalamus after dorsal column lesions, a finding that was confirmed and extended with additional experimentation. To demonstrate that these findings reflected more than a response to central injury, and to gain greater control of the extent of the sensory loss, peripheral nerve injuries were used that eliminated ascending sensory information while leaving central pathways intact. Merzenich, Kaas, and colleagues used peripheral nerve transections to reveal unambiguous reorganization in primate somatosensory cortex. Moreover, these same researchers showed that this plasticity proceeded in no less than two stages, one immediate, and one more protracted. These findings were confirmed and extended to more expansive cortical deprivations, and further extended to the thalamus and brainstem. There then began a series of experiments to reveal the physiological, morphological and neurochemical mechanisms that permitted this plasticity. Ultimately, Mowery and colleagues conducted a series of experiments that carefully tracked the levels of expression of several subunits of glutamate (AMPA and NMDA) and GABA (GABAA and GABAB) receptor complexes in primate somatosensory cortex at several time points after peripheral nerve injury. These receptor subunit mapping experiments revealed that membrane expression levels came to reflect those seen in early phases of critical period development. This suggested that under conditions of prolonged sensory deprivation the adult cells were returning to critical period like plastic states, i.e., developmental recapitulation. Here we outline the heuristics that drive this phenomenon.
PubMed: 36762289
DOI: 10.3389/fnsys.2022.1086680 -
Stem Cell Research & Therapy Apr 2023The first human brain organoid protocol was presented in the beginning of the previous decade, and since then, the field witnessed the development of many new brain...
BACKGROUND
The first human brain organoid protocol was presented in the beginning of the previous decade, and since then, the field witnessed the development of many new brain region-specific models, and subsequent protocol adaptations and modifications. The vast amount of data available on brain organoid technology may be overwhelming for scientists new to the field and consequently decrease its accessibility. Here, we aimed at providing a practical guide for new researchers in the field by systematically reviewing human brain organoid publications.
METHODS
Articles published between 2010 and 2020 were selected and categorised for brain organoid applications. Those describing neurodevelopmental studies or protocols for novel organoid models were further analysed for culture duration of the brain organoids, protocol comparisons of key aspects of organoid generation, and performed functional characterisation assays. We then summarised the approaches taken for different models and analysed the application of small molecules and growth factors used to achieve organoid regionalisation. Finally, we analysed articles for organoid cell type compositions, the reported time points per cell type, and for immunofluorescence markers used to characterise different cell types.
RESULTS
Calcium imaging and patch clamp analysis were the most frequently used neuronal activity assays in brain organoids. Neural activity was shown in all analysed models, yet network activity was age, model, and assay dependent. Induction of dorsal forebrain organoids was primarily achieved through combined (dual) SMAD and Wnt signalling inhibition. Ventral forebrain organoid induction was performed with dual SMAD and Wnt signalling inhibition, together with additional activation of the Shh pathway. Cerebral organoids and dorsal forebrain model presented the most cell types between days 35 and 60. At 84 days, dorsal forebrain organoids contain astrocytes and potentially oligodendrocytes. Immunofluorescence analysis showed cell type-specific application of non-exclusive markers for multiple cell types.
CONCLUSIONS
We provide an easily accessible overview of human brain organoid cultures, which may help those working with brain organoids to define their choice of model, culture time, functional assay, differentiation, and characterisation strategies.
Topics: Humans; Brain; Organoids; Prosencephalon; Induced Pluripotent Stem Cells; Neurons; Cell Differentiation
PubMed: 37061699
DOI: 10.1186/s13287-023-03302-x -
Neural Regeneration Research Nov 2023Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention. Previous clinical and neuroimaging...
Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention. Previous clinical and neuroimaging studies have suggested that the neural mechanisms underlying strabismic amblyopia and anisometropic amblyopia may be different. Therefore, we performed a systematic review of magnetic resonance imaging studies investigating brain alterations in patients with these two subtypes of amblyopia; this study is registered with PROSPERO (registration ID: CRD42022349191). We searched three online databases (PubMed, EMBASE, and Web of Science) from inception to April 1, 2022; 39 studies with 633 patients (324 patients with anisometropic amblyopia and 309 patients with strabismic amblyopia) and 580 healthy controls met the inclusion criteria (e.g., case-control designed, peer-reviewed articles) and were included in this review. These studies highlighted that both strabismic amblyopia and anisometropic amblyopia patients showed reduced activation and distorted topological cortical activated maps in the striate and extrastriate cortices during task-based functional magnetic resonance imaging with spatial-frequency stimulus and retinotopic representations, respectively; these may have arisen from abnormal visual experiences. Compensations for amblyopia that are reflected in enhanced spontaneous brain function have been reported in the early visual cortices in the resting state, as well as reduced functional connectivity in the dorsal pathway and structural connections in the ventral pathway in both anisometropic amblyopia and strabismic amblyopia patients. The shared dysfunction of anisometropic amblyopia and strabismic amblyopia patients, relative to controls, is also characterized by reduced spontaneous brain activity in the oculomotor cortex, mainly involving the frontal and parietal eye fields and the cerebellum; this may underlie the neural mechanisms of fixation instability and anomalous saccades in amblyopia. With regards to specific alterations of the two forms of amblyopia, anisometropic amblyopia patients suffer more microstructural impairments in the precortical pathway than strabismic amblyopia patients, as reflected by diffusion tensor imaging, and more significant dysfunction and structural loss in the ventral pathway. Strabismic amblyopia patients experience more attenuation of activation in the extrastriate cortex than in the striate cortex when compared to anisometropic amblyopia patients. Finally, brain structural magnetic resonance imaging alterations tend to be lateralized in the adult anisometropic amblyopia patients, and the patterns of brain alterations are more limited in amblyopic adults than in children. In conclusion, magnetic resonance imaging studies provide important insights into the brain alterations underlying the pathophysiology of amblyopia and demonstrate common and specific alterations in anisometropic amblyopia and strabismic amblyopia patients; these alterations may improve our understanding of the neural mechanisms underlying amblyopia.
PubMed: 37282452
DOI: 10.4103/1673-5374.371349 -
Developmental Cognitive Neuroscience Dec 2023Resting-state functional connectivity (rsFC) has the potential to shed light on how childhood abuse and neglect relates to negative psychiatric outcomes. However, a... (Review)
Review
Resting-state functional connectivity (rsFC) has the potential to shed light on how childhood abuse and neglect relates to negative psychiatric outcomes. However, a comprehensive review of the impact of childhood maltreatment on the brain's resting state functional organization has not yet been undertaken. We systematically searched rsFC studies in children and youth exposed to maltreatment. Nineteen studies (total n = 3079) met our inclusion criteria. Two consistent findings were observed. Childhood maltreatment was linked to reduced connectivity between the anterior insula and dorsal anterior cingulate cortex, and with widespread heightened amygdala connectivity with key structures in the salience, default mode, and prefrontal regulatory networks. Other brain regions showing altered connectivity included the ventral anterior cingulate cortex, dorsolateral prefrontal cortex, and hippocampus. These patterns of altered functional connectivity associated with maltreatment exposure were independent of symptoms, yet comparable to those seen in individuals with overt clinical disorder. Summative findings indicate that rsFC alterations associated with maltreatment experience are related to poor cognitive and social functioning and are prognostic of future symptoms. In conclusion, maltreatment is associated with altered rsFC in emotional reactivity, regulation, learning, and salience detection brain circuits. This indicates patterns of recalibration of putative mechanisms implicated in maladaptive developmental outcomes.
Topics: Adolescent; Humans; Child; Brain; Amygdala; Brain Mapping; Gyrus Cinguli; Child Abuse; Magnetic Resonance Imaging
PubMed: 37952287
DOI: 10.1016/j.dcn.2023.101322 -
Neuropsychology Review Dec 2023Although attention and early associative learning in preverbal children is predominantly driven by rapid eye-movements in response to moving visual stimuli and... (Meta-Analysis)
Meta-Analysis Review
Although attention and early associative learning in preverbal children is predominantly driven by rapid eye-movements in response to moving visual stimuli and sounds/words (e.g., associating the word "bottle" with the object), the literature examining the role of visual attention and memory in ongoing vocabulary development across childhood is limited. Thus, this systematic review and meta-analysis examined the association between visual memory and vocabulary development, including moderators such as age and task selection, in neurotypical children aged 2-to-12 years, from the brain-based perspective of cognitive neuroscience. Visual memory tasks were classified according to the visual characteristics of the stimuli and the neural networks known to preferentially process such information, including consideration of the distinction between the ventral visual stream (processing more static visuo-perceptual details, such as form or colour) and the more dynamic dorsal visual stream (processing spatial temporal action-driven information). Final classifications included spatio-temporal span tasks, visuo-perceptual or spatial concurrent array tasks, and executive judgment tasks. Visuo-perceptual concurrent array tasks, reliant on ventral stream processing, were moderately associated with vocabulary, while tasks measuring spatio-temporal spans, associated with dorsal stream processing, and executive judgment tasks (central executive), showed only weak correlations with vocabulary. These findings have important implications for health professionals and researchers interested in language, as they advocate for the development of more targeted language learning interventions that include specific and relevant aspects of visual processing and memory, such as ventral stream visuo-perceptual details (i.e., shape or colour).
Topics: Child; Humans; Vocabulary; Memory; Visual Perception; Brain; Language
PubMed: 36136174
DOI: 10.1007/s11065-022-09561-4 -
Qatar Medical Journal 2021The central nervous system is an unusual location of sarcoidosis, which commonly affects the cranial nerves, meninges, hypothalamus, and pituitary gland. Involvement of...
BACKGROUND
The central nervous system is an unusual location of sarcoidosis, which commonly affects the cranial nerves, meninges, hypothalamus, and pituitary gland. Involvement of the pineal region is extremely rare. This systematic review focused on the diagnosis and management of pineal region sarcoidosis, dorsal mesencephalon, and periaqueductal region.
OBJECTIVES
This study aimed to discuss diagnostic modalities and best management tools of the aforementioned pathology.
METHODS
ScienceDirect, PubMed, and Google Scholar databases were searched for English or French articles about sarcoidosis of the pineal region, dorsal mesencephalon, and periaqueductal region. The clinical case of a patient managed at our department that we believe is directly relevant to this review is also presented. Patients' demographics, clinical presentations, presence of hydrocephalus, other sarcoidosis locations in the central nervous system, and medical treatment were collected. Surgical management, surgical approach, and outcomes and complications of each procedure were also obtained. This study was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.
RESULTS
Fifteen cases were examined. The study sample consisted of nine (60%) male and six (40%) female, and the mean age was 32 years. Eight (53%) patients had hydrocephalus, and the predominant clinical presentations were signs of increasing intracranial pressure (headaches, vomiting, and papilledema). Six (40%) patients had diplopia, and convergence-retraction nystagmus was noted in three (20%) patients. Argyll Robertson sign was present in one patient and suspected in another patient (13%). Medical treatment consisted mainly of steroids (93% of cases). Open surgery on the pineal region was performed in five patients, and four of them reported to have serious complications (such as ophthalmoplegia, hemianopsia, hemiparesis, bilateral third cranial nerve paresis, and cerebellar syndrome). Endoscopic management was performed in two patients without complications.
CONCLUSION
To treat hydrocephalus, brain imaging is mandatory in patients with sarcoidosis if intracranial hypertension is suspected. In pineal region sarcoidosis, management of hydrocephalus is the priority, followed by medical treatment of the lesion. Open surgery of any approach presents a high risk of complications; thus, an endoscopic approach is the preferred management, as it treats hydrocephalus and makes biopsy possible with minimal risk.
PubMed: 34466394
DOI: 10.5339/qmj.2021.29 -
Pain and Therapy Jun 2022Systematic literature review. (Review)
Review
STUDY DESIGN
Systematic literature review.
OBJECTIVE
The goal of this systematic review is to assess the clinical safety and potential complications of conventional and pulsed radiofrequency ablations targeting dorsal root entry zone complex (DREZC) components in the treatment of chronic pain.
BACKGROUND
There is a growing popularity for the use of radiofrequency ablation (RFA) techniques targeting DREZC components by pain management physicians for an increasing variety of indications. To date, we lack a systematic review to describe the safety and the type of complications associated with these procedures.
METHODS
This was a systematic literature review. This systematic search was limited to peer-reviewed literature using "radiofrequency ablation" as a search keyword using PubMed's database for manuscripts published between inception and December 2020. Abstracts that involved the application of radiofrequency currents, of any modality, to DREZC components for the treatment of pain were included for full-text review. Search was limited to original data describing clinical outcomes following RFA performed for pain indications only, involving the DREZC components outlined above, in human subjects, and written in English. The primary outcomes were complications associated with conventional RFA and pulsed radiofrequency ablation (PRF). Complications were categorized as type 1 (persistent neurological deficits or other serious adverse events, defined as any event that resulted in permanent of prolonged injury; type 2 (transient neuritis or neurological deficits, or other non-neurological non-minor adverse event); type 3 (minor adverse events (e.g., headache, soreness, bruising, etc.).
RESULTS
Of the 62 selected manuscripts totaling 3157 patients, there were zero serious adverse events or persistent neurological deficits reported. A total of 36 (1.14%) transient neurological deficits, cases of transient neuritis, or non-minor adverse events like uncomplicated pneumothorax were reported. A total of 113 (3.58%) minor adverse events were reported (bruising, transient site soreness, headache).
CONCLUSIONS
This systematic review indicates that the use of RFA lesion of the DREZC for interventional pain management is very safe. There were no serious adverse effects with a sizable sample of randomized controlled trial (RCT), prospective observational, and retrospective studies.
PubMed: 35434768
DOI: 10.1007/s40122-022-00378-w -
Pflugers Archiv : European Journal of... Apr 2022Sensory neurons are responsible for the generation and transmission of nociceptive signals from the periphery to the central nervous system. They encompass a broadly... (Review)
Review
Sensory neurons are responsible for the generation and transmission of nociceptive signals from the periphery to the central nervous system. They encompass a broadly heterogeneous population of highly specialized neurons. The understanding of the molecular choreography of individual subpopulations is essential to understand physiological and pathological pain states. Recently, it became evident that species differences limit transferability of research findings between human and rodents in pain research. Thus, it is necessary to systematically compare and categorize the electrophysiological data gained from human and rodent dorsal root ganglia neurons (DRGs). In this systematic review, we condense the available electrophysiological data defining subidentities in human and rat DRGs. A systematic search on PUBMED yielded 30 studies on rat and 3 studies on human sensory neurons. Defined outcome parameters included current clamp, voltage clamp, cell morphology, pharmacological readouts, and immune reactivity parameters. We compare evidence gathered for outcome markers to define subgroups, offer electrophysiological parameters for the definition of neuronal subtypes, and give a framework for the transferability of electrophysiological findings between species. A semiquantitative analysis revealed that for rat DRGs, there is an overarching consensus between studies that C-fiber linked sensory neurons display a lower action potential threshold, higher input resistance, a larger action potential overshoot, and a longer afterhyperpolarization duration compared to other sensory neurons. They are also more likely to display an infliction point in the falling phase of the action potential. This systematic review points out the need of more electrophysiological studies on human sensory neurons.
Topics: Action Potentials; Animals; Electrophysiological Phenomena; Ganglia, Spinal; Humans; Pain; Rats; Sensory Receptor Cells
PubMed: 35031856
DOI: 10.1007/s00424-021-02656-6 -
Frontiers in Behavioral Neuroscience 2022The midline and intralaminar nuclei of the thalamus form a major part of the "limbic thalamus;" that is, thalamic structures anatomically and functionally linked with...
The midline and intralaminar nuclei of the thalamus form a major part of the "limbic thalamus;" that is, thalamic structures anatomically and functionally linked with the limbic forebrain. The midline nuclei consist of the paraventricular (PV) and paratenial nuclei, dorsally and the rhomboid and nucleus reuniens (RE), ventrally. The rostral intralaminar nuclei (ILt) consist of the central medial (CM), paracentral (PC) and central lateral (CL) nuclei. We presently concentrate on RE, PV, CM and CL nuclei of the thalamus. The nucleus reuniens receives a diverse array of input from limbic-related sites, and predominantly projects to the hippocampus and to "limbic" cortices. The RE participates in various cognitive functions including spatial working memory, executive functions (attention, behavioral flexibility) and affect/fear behavior. The PV receives significant limbic-related afferents, particularly the hypothalamus, and mainly distributes to "affective" structures of the forebrain including the bed nucleus of stria terminalis, nucleus accumbens and the amygdala. Accordingly, PV serves a critical role in "motivated behaviors" such as arousal, feeding/consummatory behavior and drug addiction. The rostral ILt receives both limbic and sensorimotor-related input and distributes widely over limbic and motor regions of the frontal cortex-and throughout the dorsal striatum. The intralaminar thalamus is critical for maintaining consciousness and directly participates in various sensorimotor functions (visuospatial or reaction time tasks) and cognitive tasks involving striatal-cortical interactions. As discussed herein, while each of the midline and intralaminar nuclei are anatomically and functionally distinct, they collectively serve a vital role in several affective, cognitive and executive behaviors - as major components of a brainstem-diencephalic-thalamocortical circuitry.
PubMed: 36082310
DOI: 10.3389/fnbeh.2022.964644