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Cureus Jul 2021Locked-in syndrome (LIS) is a neurological disorder in which there is damage to the ventral pons and caudal midbrain. An ischemic cause, such as basilar artery... (Review)
Review
Locked-in syndrome (LIS) is a neurological disorder in which there is damage to the ventral pons and caudal midbrain. An ischemic cause, such as basilar artery occlusion, can often lead to LIS. LIS has three subtypes: classical, partial, and total. There is loss of motion in the four extremities in classical LIS, loss of horizontal gaze, and aphasia. In partial LIS, the patient still has some motor function. Complete LIS has the worst outcome because patients cannot blink or have vertical gaze, thus rendering them incapable of communicating. Most cases of LIS occur due to ischemic infarcts. These patients require a great deal of physical rehabilitation to regain partial motor ability and a means to communicate. While the clinical features and pathophysiology are known, the prognosis and long-term treatment remain unknown. We conducted a systematic review using the Meta-Analysis Of Observational Studies in Epidemiology (MOOSE) protocol. We use an advanced PubMed strategy using the inclusion criteria of observational studies or clinical trials conducted in the last 20 years, written in English, and conducted on humans. We excluded systematic reviews, literature reviews, metanalysis, and studies that did not meet the outcomes of our objectives. The prognosis of LIS is not good, and most patients remain locked in, with poor quality of life, especially motor functions. Respiratory failure and depression are big comorbidities. In the acute setting, patients benefit from rapid intervention. The subacute treatment needs to manage aggressively to improve functional scores best. The long-term treatment focus is on the quality of life and managing comorbidities.
PubMed: 34471579
DOI: 10.7759/cureus.16727 -
PloS One 2021While multiple studies have examined the brain functional correlates of reward, meta-analyses have either focused on studies using the monetary incentive delay (MID)... (Meta-Analysis)
Meta-Analysis
BACKGROUND
While multiple studies have examined the brain functional correlates of reward, meta-analyses have either focused on studies using the monetary incentive delay (MID) task, or have adopted a broad strategy, combining data from studies using both monetary and non-monetary reward, as probed using a wide range of tasks.
OBJECTIVE
To meta-analyze fMRI studies that used monetary reward and in which there was a definable cue-reward contingency. Studies were limited to those using monetary reward in order to avoid potential heterogeneity from use of other rewards, especially social rewards. Studies using gambling or delay discounting tasks were excluded on the grounds that reward anticipation is not easily quantifiable.
STUDY ELIGIBILITY
English-language fMRI studies (i) that reported fMRI findings on healthy adults; (ii) that used monetary reward; and (iii) in which a cue that was predictive of reward was compared to a no win (or lesser win) condition. Only voxel-based studies were included; those where brain coverage was incomplete were excluded.
DATA SOURCES
Ovid, Medline and PsycInfo, from 2000 to 2020, plus checking of review articles and meta-analyses.
DATA SYNTHESIS
Data were pooled using Seed-based d Mapping with Permutation of Subject Images (SDM-PSI). Heterogeneity among studies was examined using the I2 statistic. Publication bias was examined using funnel plots and statistical examination of asymmetries. Moderator variables including whether the task was pre-learnt, sex distribution, amount of money won and width of smoothing kernel were examined.
RESULTS
Pooled data from 45 studies of reward anticipation revealed activations in the ventral striatum, the middle cingulate cortex/supplementary motor area and the insula. Pooled data from 28 studies of reward delivery again revealed ventral striatal activation, plus cortical activations in the anterior and posterior cingulate cortex. There was relatively little evidence of publication bias. Among moderating variables, only whether the task was pre-learnt exerted an influence.
CONCLUSIONS
According to this meta-analysis monetary reward anticipation and delivery both activate the ventral but not the dorsal striatum, and are associated with different patterns of cortical activation.
Topics: Magnetic Resonance Imaging; Motivation; Reward
PubMed: 34351957
DOI: 10.1371/journal.pone.0255292 -
Brain and Behavior Aug 2021Many researchers took advantage of the well-established rubber hand illusion (RHI) paradigm to explore the link between the sense of body ownership and the different... (Review)
Review
INTRODUCTION
Many researchers took advantage of the well-established rubber hand illusion (RHI) paradigm to explore the link between the sense of body ownership and the different brain structures and networks. Here, we aimed to review the studies that have investigated this phenomenon by means of neurophysiological techniques.
METHODS
The MEDLINE, accessed by Pubmed and EMBASE electronic databases, was searched using the medical subject headings: "Rubber hand illusion" AND "Transcranial magnetic stimulation (TMS)" OR "Evoked potentials (EP)" OR "Event related potentials (ERP)" OR "Electroencephalography (EEG)".
RESULTS
Transcranial magnetic stimulation studies revealed a significant excitability drop in primary motor cortex hand circuits accompanying the disembodiment of the real hand during the RHI experience and that the perceived ownership over the rubber hand is associated with normal parietal-motor communication. Moreover, TMS provided causal evidence that the extrastriate body area is involved in the RHI and subsequently in body representation, while neuromodulation of ventral premotor area and the inferior parietal lobe did not result in an enhancement of embodiment. EP and ERP studies suggest that pre-existing body representations may affect larger stages of tactile processing and support predictive coding models of the functional architecture of multisensory integration in bodily perceptual experience. High-frequency oscillations on EEG play a role in the integrative processing of stimuli across modalities, and EEG activity in γ band activity in the parietal area reflects the visuotactile integration process. EEG studies also revealed that RHI is associated with the neural circuits underlying motor control and that premotor areas play a crucial role in mediating illusory body ownership.
CONCLUSION
Neurophysiological studies shed new light on our understanding of the different aspects that contribute to the formation of a coherent self-awareness in humans.
Topics: Body Image; Hand; Humans; Illusions; Parietal Lobe; Proprioception; Touch Perception; Visual Perception
PubMed: 34288558
DOI: 10.1002/brb3.2124 -
Frontiers in Psychiatry 2021Deep brain stimulation (DBS) was proposed in 1999 to treat refractory obsessive-compulsive disorder (OCD). Despite the accumulated experience over more than two...
Deep brain stimulation (DBS) was proposed in 1999 to treat refractory obsessive-compulsive disorder (OCD). Despite the accumulated experience over more than two decades, 30-40% of patients fail to respond to this procedure. One potential reason to explain why some patients do not improve in the postoperative period is that DBS might not have engaged structural therapeutic networks that are crucial to a favorable outcome in non-responders. This article reviews magnetic resonance imaging diffusion studies (DTI-MRI), analyzing neural networks likely modulated by DBS in OCD patients and their corresponding clinical outcome. We used a systematic review process to search for studies published from 2005 to 2020 in six electronic databases. Search terms included obsessive-compulsive disorder, deep brain stimulation, diffusion-weighted imaging, diffusion tensor imaging, diffusion tractography, tractography, connectome, diffusion analyses, and white matter. No restriction was made concerning the surgical target, DTI-MRI technique and the method of data processing. Eight studies published in the last 15 years were fully assessed. Most of them used 3 Tesla DTI-MRI, and different methods of data acquisition and processing. There was no consensus on potential structures and networks underlying DBS effects. Most studies stimulated the ventral anterior limb of the internal capsule (ALIC)/nucleus accumbens. However, the contribution of different white matter pathways that run through the ALIC for the effects of DBS remains elusive. Moreover, the improvement of cognitive and affective symptoms in OCD patients probably relies on electric modulation of distinct networks. Though, tractography is a valuable tool to understand neural circuits, the effects of modulating different fiber tracts in OCD are still unclear. Future advances on image acquisition and data processing and a larger number of studies are still required for the understanding of the role of tractography-based targeting and to clarify the importance of different tracts for the mechanisms of DBS.
PubMed: 34276448
DOI: 10.3389/fpsyt.2021.680484 -
Neuropsychopharmacology : Official... Oct 2021Loneliness is associated with increased morbidity and mortality. Deeper understanding of neurobiological mechanisms underlying loneliness is needed to identify potential...
Loneliness is associated with increased morbidity and mortality. Deeper understanding of neurobiological mechanisms underlying loneliness is needed to identify potential intervention targets. We did not find any systematic review of neurobiology of loneliness. Using MEDLINE and PsycINFO online databases, we conducted a search for peer-reviewed publications examining loneliness and neurobiology. We identified 41 studies (n = 16,771 participants) that had employed various methods including computer tomography (CT), structural magnetic resonance imaging (MRI), functional MRI (fMRI), electroencephalography (EEG), diffusion tensor imaging (DTI), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and post-mortem brain tissue RNA analysis or pathological analysis. Our synthesis of the published findings shows abnormal structure (gray matter volume or white matter integrity) and/or activity (response to pleasant versus stressful images in social versus nonsocial contexts) in the prefrontal cortex (especially medial and dorsolateral), insula (particularly anterior), amygdala, hippocampus, and posterior superior temporal cortex. The findings related to ventral striatum and cerebellum were mixed. fMRI studies reported links between loneliness and differential activation of attentional networks, visual networks, and default mode network. Loneliness was also related to biological markers associated with Alzheimer's disease (e.g., amyloid and tau burden). Although the published investigations have limitations, this review suggests relationships of loneliness with altered structure and function in specific brain regions and networks. We found a notable overlap in the regions involved in loneliness and compassion, the two personality traits that are inversely correlated in previous studies. We have offered recommendations for future research studies of neurobiology of loneliness.
Topics: Alzheimer Disease; Brain; Diffusion Tensor Imaging; Humans; Loneliness; Magnetic Resonance Imaging
PubMed: 34230607
DOI: 10.1038/s41386-021-01058-7 -
BJS Open May 2021
PubMed: 34131707
DOI: 10.1093/bjsopen/zrab047 -
Brain and Cognition Aug 2021Affective prosody, or the changes in rate, rhythm, pitch, and loudness that convey emotion, has long been implicated as a function of the right hemisphere (RH), yet...
Affective prosody, or the changes in rate, rhythm, pitch, and loudness that convey emotion, has long been implicated as a function of the right hemisphere (RH), yet there is a dearth of literature identifying the specific neural regions associated with its processing. The current systematic review aimed to evaluate the evidence on affective prosody localization in the RH. One hundred and ninety articles from 1970 to February 2020 investigating affective prosody comprehension and production in patients with focal brain damage were identified via database searches. Eleven articles met inclusion criteria, passed quality reviews, and were analyzed for affective prosody localization. Acute, subacute, and chronic lesions demonstrated similar profile characteristics. Localized right antero-superior (i.e., dorsal stream) regions contributed to affective prosody production impairments, whereas damage to more postero-lateral (i.e., ventral stream) regions resulted in affective prosody comprehension deficits. This review provides support that distinct RH regions are vital for affective prosody comprehension and production, aligning with literature reporting RH activation for affective prosody processing in healthy adults as well. The impact of study design on resulting interpretations is discussed.
Topics: Adult; Comprehension; Emotions; Humans; Speech Perception; Stroke
PubMed: 34118500
DOI: 10.1016/j.bandc.2021.105759 -
The Cochrane Database of Systematic... May 2021The use of a mesh in primary ventral or incisional hernia repair lowers the recurrence rate and is the accepted standard of care for larger defects. In... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The use of a mesh in primary ventral or incisional hernia repair lowers the recurrence rate and is the accepted standard of care for larger defects. In laparoscopic primary ventral or incisional hernia repair the insertion of a mesh is indispensable. Different mesh fixation techniques have been used and refined over the years. The type of fixation technique is claimed to have a major impact on recurrence rates, chronic pain, health-related quality of life (HRQOL) and complication rates.
OBJECTIVES
To determine the impact of different mesh fixation techniques for primary and incisional ventral hernia repair on hernia recurrence, chronic pain, HRQOL and complications.
SEARCH METHODS
On 2 October 2020 we searched CENTRAL, MEDLINE (Ovid MEDLINE(R)) Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R)), Ovid Embase, and two trials registries. We also performed handsearches, and contacted experts from the European Hernia Society (EHS).
SELECTION CRITERIA
We included randomised controlled trials (RCTs) including adults with primary ventral or incisional hernia that compared different types of mesh fixation techniques (absorbable/nonabsorbable sutures, absorbable/nonabsorbable tacks, fibrin glue, and combinations of these techniques).
DATA COLLECTION AND ANALYSIS
We extracted data in standardised piloted tables, or if necessary, directly into Review Manager 5. We assessed risks of bias with the Cochrane 'Risk of bias' tool. Two review authors independently selected the publications, and extracted data on results. We calculated risk ratios (RRs) for binary outcomes and mean differences (MDs) for continuous outcomes. For pooling we used an inverse-variance random-effects meta-analysis or the Peto method in the case of rare events. We prepared GRADE 'Summary of findings' tables. For laparoscopic repair we considered absorbable tacks compared to nonabsorbable tacks, and nonabsorbable tacks compared to nonabsorbable sutures as key comparisons.
MAIN RESULTS
We included 10 trials with a total of 787 participants. The number of randomised participants ranged from 40 to 199 per comparison. Eight studies included participants with both primary and incisional ventral hernia. One study included only participants with umbilical hernia, and another only participants with incisional hernia. Hernia size varied between studies. We judged the risk of bias as moderate to high. Absorbable tacks compared to nonabsorbable tacks Recurrence rates in the groups were similar (RR 0.74, 95% confidence interval (CI) 0.17 to 3.22; 2 studies, 101 participants). It is uncertain whether there is a difference between absorbable tacks and nonabsorbable tacks in recurrence because the certainty of evidence was very low. Evidence suggests that the difference between groups in early postoperative, late follow-up, chronic pain and HRQOL is negligible. Nonabsorbable tacks compared to nonabsorbable sutures At six months there was one recurrence in each group (RR 1.00, 95% CI 0.07 to 14.79; 1 study, 36 participants). It is uncertain whether there is a difference between nonabsorbable tacks and nonabsorbable sutures in recurrence because the certainty of evidence was very low. Evidence suggests that the difference between groups in early postoperative, late follow-up and chronic pain is negligible. We found no study that assessed HRQOL. Absorbable tacks compared to absorbable sutures No recurrence was observed at one year (very low certainty of evidence). Early postoperative pain was higher in the tacks group (VAS 0 - 10: MD -2.70, 95% CI -6.67 to 1.27; 1 study, 48 participants). It is uncertain whether there is a difference between absorbable tacks compared to absorbable sutures in early postoperative pain because the certainty of evidence was very low. The MD for late follow-up pain was -0.30 (95% CI -0.74 to 0.14; 1 study, 48 participants). We found no study that assessed HRQOL. Combination of different fixation types (tacks and sutures) or materials (absorbable and nonabsorbable) There were mostly negligible or only small differences between combinations (e.g. tacks plus sutures) compared to a single technique (e.g. sutures only), as well as combinations compared to other combinations (e.g. absorbable sutures combined with nonabsorbable sutures compared to absorbable tacks combined with nonabsorbable tacks) in all outcomes. It is uncertain whether there is an advantage for combining different fixation types or materials for recurrence, chronic pain, HRQOL and complications, because the evidence certainty was very low or low, or we found no study on important outcomes. Nonabsorbable tacks compared to fibrin sealant The two studies showed different directions of effects: one showed higher rates for nonabsorbable tacks, and the other showed higher rates for fibrin sealant. Low-certainty evidence suggests that the difference between groups in early postoperative, late follow-up, chronic pain and HRQOL is negligible. Absorbable tacks compared to fibrin sealant One recurrence in the tacks group and none in the fibrin sealant group were noted after one year (low certainty of evidence). Early postoperative pain might be slightly lower using tacks (VAS 0 - 100; MD -12.40, 95% CI -27.60 to, 2.80;1 study, 50 participants; low-certainty evidence). The pattern of pain and HRQOL course over time (up to 1 year) was similar in the groups (low certainty of evidence).
AUTHORS' CONCLUSIONS
Currently none of the techniques can be considered superior to any other, because the certainty of evidence was low or very low for all outcomes.
Topics: Adult; Fibrin Tissue Adhesive; Hernia, Umbilical; Hernia, Ventral; Herniorrhaphy; Humans; Incisional Hernia; Middle Aged; Pain, Postoperative; Recurrence; Secondary Prevention; Surgical Mesh; Sutures; Tissue Adhesives
PubMed: 34046884
DOI: 10.1002/14651858.CD011563.pub2 -
Frontiers in Neurology 2021Magnetic resonance guided focused ultrasound (MRgFUS) is a relatively novel technique to treat essential tremor (ET). The objective of this review was to analyze the...
Magnetic resonance guided focused ultrasound (MRgFUS) is a relatively novel technique to treat essential tremor (ET). The objective of this review was to analyze the efficacy and the safety profile of MRgFUS for ET. A systematic literature review was done. The post procedure changes in the Clinical Rating Scale for Tremor (CRST) score, hand score, disability and quality of life scores were analyzed. We found 29 studies evaluating 617 patients. DTI based targeting was utilized in six cohorts. A significant difference was observed in the pooled standard mean difference between the pre and postoperative total CRST score (-value < 0.001 and 0.0002), hand score (-value 0.03 and 0.02); and the disability at 12 months (-value 0.01). Head pain and dizziness were the most in procedure complications. The immediate pooled proportion of ataxia was 50%, while it was 20% for sensory complications, which, respectively, declined to 31 and 13% on long term follow up. A significant reduction ( = 0.03) in immediate ataxia related complications was seen with DTI targeting. MRgFUS for ET seems to be an effective procedure for relieving unilateral tremor. Use of DTI based targeting revealed a significant reduction in post procedure ataxia related complications as compared to traditional targeting techniques. Analysis of other complications further revealed a decreasing trend on follow up.
PubMed: 34025558
DOI: 10.3389/fneur.2021.654711 -
The Journal of Surgical Research Oct 2021As the population ages, the incidence of ventral hernias in older adults is increasing. Ventral hernia repairs (VHR) should not be considered low risk operations,...
BACKGROUND
As the population ages, the incidence of ventral hernias in older adults is increasing. Ventral hernia repairs (VHR) should not be considered low risk operations, particularly in older adults who are disproportionately affected by multiple age-related factors that can complicate surgery and adversely affect outcomes. Although age-related risk factors have been well established in other surgical fields, there is currently little data describing their impact on VHR.
METHODS
We performed a systematic review of the literature to identify studies that examine the effects of age-related risk factors on VHR outcomes. This was conducted using Cochrane Library, Embase, PubMed (Medline), and Google Scholar databases, all updated through June 2020. We selected relevant studies using the keywords, multimorbidity, comorbidities, polypharmacy, functional dependence, functional status, frailty, cognitive impairment, dementia, sarcopenia, and malnutrition. Primary outcomes include mortality and overall complications following VHR.
RESULTS
We summarize the evidence basis for the significance of age-related risk factors in elective surgery and discuss how these factors increase the risk of adverse outcomes following VHR. In particular, we explore the impact of the following risk factors: multimorbidity, polypharmacy, functional dependence, frailty, cognitive impairment, sarcopenia, and malnutrition. As opposed to chronological age itself, age-related risk factors are more clinically relevant in determining VHR outcomes.
CONCLUSIONS
Given the increasing complexity of VHR, addressing age-related risk factors pre-operatively has the potential to improve surgical outcomes in older adults. Preoperative risk assessment and individualized prehabilitation programs aimed at improving patient-centered outcomes may be particularly useful in this population.
Topics: Age Factors; Hernia, Ventral; Herniorrhaphy; Humans; Postoperative Complications; Risk Factors; Treatment Outcome
PubMed: 34015515
DOI: 10.1016/j.jss.2021.04.004