Midline Regions Research Articles

This Month in Anesthesiology

This Month in Anesthesiology

The Stressed Brain: Neural Underpinnings of Social Stress Processing in Humans.

As humans, we face a variety of social stressors on a regular basis. Given the established role of social stress in influencing physical and psychological functioning, researchers have focused immense efforts on understanding the psychological and physiological changes induced by exposure to acute social stressors. With the advancement of functional magnetic resonance imaging (fMRI), more recent work has sought to identify the neural correlates of processing acute social stress. In this review, we provide an overview of research on the neural underpinnings of social stress processing to date. Specifically, we summarize research that has examined the neural underpinnings of three types of social stressors commonly studied in the literature: social rejection, social evaluation, and racism-related stress. Within our discussion of each type of social stressor, we describe the methods used to induce stress, the brain regions commonly activated among studies investigating that type of stress, and recommendations for future work. This review of the current literature identifies activity in midline regions in both prefrontal and parietal cortices, as well as lateral prefrontal regions, as being associated with processing social rejection. Activity in the insula, thalamus, and inferior frontal gyrus is often found in studies using social evaluation tasks. Finally, racism-related stress is associated with activity in the ventrolateral prefrontal cortex and rostral anterior cingulate cortex. We conclude by taking a "30,000-foot view" of this area of research to provide suggestions for the future of research on the neuroscience of social stress.

A hospital based cross sectional study of midline cutaneous lesions in neonates and its association with spinal dysraphism detected using ultrasound

Background:Spinal dysraphism occurs due to incomplete fusion of the midline mesenchymal, bony, or neural elements of the spine. The defects in the spinal cord can be associated with skin lesion since both have same embryonic origin.Aims and Objectives:This study was conducted to determine the association of midline and paramedian cutaneous lesions with spinal dysraphism by using spinal ultrasonography.Materials and Methods:Two thousand apparently healthy neonates were screened in the postnatal ward of a tertiary care center in South India. Those neonates with cutaneous lesions in the midline and paramedian region were screened for evidence of spinal dysraphism by using spinal ultrasonography.Results:Among 2000 neonates, 120 (6%) had at least one cutaneous lesion, of which 114 (5.7%) were in the midline and 6 (0.3%) were on the paramedian region of dorsal and ventral aspect of the body. Among these neonates, two cases had more than one skin lesions. The most common cutaneous lesion observed was typical dimple (82, 68%) followed by hypertrichosis (12, 10%). Ultrasonography revealed spinal anomaly in six (5%) of them. The cutaneous lesions associated with spinal dysraphism were obvious midline swelling, dermal sinus, and multiple skin lesions.Conclusion:Congenital midline and paramedian skin lesions may be the marker of spinal dysraphism. In the presence of such cutaneous lesions, only 5% of them had associated spinal anomaly in our study.

A Case of Three Impacted Supernumerary Teeth in the Mid-line Region of the Maxilla

A Case of Three Impacted Supernumerary Teeth in the Mid-line Region of the Maxilla

A Rare Compound Odontoma in Mandibular Midline Region: Case Report and Literature Review

Background: Odontomas are the most common odontogenic tumors of the oral cavity. Although compound odontomas are common in the pediatric population, they are rare in the mandibular midline region during the primary dentition stage. Case Description: This article provides a rare case-report and literature review of a compound odontoma in the mandibular midline region during the primary dentition stage. A routine occlusal radiograph in an asymptomatic six-year-old patient demonstrated mixed, radiolucent-radiodense lesion apical to #N-#P (mandibular primary incisors) with intact lamina dura. Minor expansion and thinning of labial and lingual cortices were noted on cone beam computed tomographic (CBCT) images. This report discusses surgical management, histopathologic diagnosis, and 36-month clinical-radiographic follow-up of our case. Practical Implications: Compound odontomas are highly rare during the primary dentition stage in the mandibular midline (0.3%). Routine radiographs are vital for a timely diagnosis and treatment of these pathologies to prevent future orthodontic complications.

Altered brain responses to specific negative emotions in schizophrenia

Deficits in emotion processing are a core feature of schizophrenia, but their neurobiological bases are poorly understood. Previous research, mainly focused on emotional face processing and emotion recognition deficits, has shown controverted results. Furthermore, the use of faces has been questioned for not entailing an appropriate stimulus to study emotional processing. This highlights the importance of investigating emotional processing abnormalities using evocative stimuli. For the first time, we have studied the brain responses to scenic stimuli in patients with schizophrenia. We selected scenes from the IAPS that elicit fear, disgust, happiness, and sadness. Twenty-six patients with schizophrenia and thirty age-, sex- and premorbid IQ-matched healthy controls were included. Behavioral task results show that patients tended to misclassify disgust and sadness as fear. Brain responses in patients were different from controls in images eliciting disgust and fear. In response to disgust images, patients hyperactivated the right temporal cortex, which was not activated by the controls. With fear images, hyperactivation was observed in brain regions involved in fear processing, including midline regions from the medial frontal cortex to the anterior cingulate cortex, the superior frontal gyrus, inferior and superior temporal cortex, and visual areas. These results suggest that schizophrenia is characterized by hyper-responsivity to stimuli evoking high-arousal, negative emotions, and a bias towards fear in emotion recognition.

LOCALIZED PECTUS EXCAVATUM TREATED WITH BRACE AND EXERCISE: LONG TERM RESULTS OF A BRAZILIAN TECHNIQUE.

ABSTRACTObjective:Pectus excavatum is a deformity that affects aesthetics and causes emotional disorders. Surgical correction is well established, but conservative treatment is less common. We investigated the long-term results of using a brace and performing specific physical exercises to treat localized pectus excavatum, a type of deformity in which the depressed area is restricted to the midline region along the nipple line. Methods:We selected 115 patients (mean age 12.8 years), with a minimum follow-up of 36 months, who were evaluated more than one year after the end of treatment and skeletal maturity. Results were correlated with deformity flexibility, severity, regular use of the device, and performance of specific exercises. The chi-square (χ2) and the Cochran-Mantel-Haenszel tests were used for statistical analysis. Results:Treatment was successful in 58% of patients, however, when exercises were performed and the brace was used regularly by patients with flexible deformities, the rate increased to 83% (p = 0.005). Severity and adherence to treatment greatly impacted successful treatment (p = 0.009 and < 0.001, respectively). Conclusion:The proposed treatment method was effective for correction or partial correction of the deformity in motivated patients followed up until skeletal maturity, especially when started early in milder and more flexible deformities. Level of Evidence V, Expert opinion.

Altered gamma band noise power in schizophrenia and bipolar patients during a cognitive task

Background and Objectives“Noise power” (NP) is a measure that allows the assessment of the fast-firing synchronization of neural oscillations. We aimed to replicate higher gamma NP values in frontal and midline regions in patients with schizophrenia and re-evaluate its specificity to this disorder. We also aimed to assess the relationship of higher gamma NP values with drug treatment, chronicity, cognition and symptoms. MethodsGamma NP values were obtained from electroencephalograms recorded during an oddball paradigm from 29 patients with schizophrenia, 27 with bipolar disorder and 36 healthy controls. We compared these values between the groups to evaluate the specificity to diagnosis. Altered gamma NP values were compared between the patients who had and had not received different treatments to assess the relationship with drug treatment. We also analyse the correlation between gamma NP values and chronicity, symptoms, and cognition. ResultsCompared to controls, patients with schizophrenia presented increased gamma NP values in frontal and parietal midline regions, while bipolar patients showed increased gamma NP in the left frontal region. There was no significant relationship between drug treatment or chronicity with altered values. Increased gamma NP correlated with higher negative symptom scores in the schizophrenia group, but not with cognitive impairment in any of the groups of patients. ConclusionsWe replicated an increase in gamma NP in patients with schizophrenia and found that this alteration was also present in a milder form in bipolar patients. These alterations seem to be independent of pharmacological treatment and illness duration.

DIPG-41. DISSECTING THE MECHANISTIC BASIS FOR ACVR1 AND PIK3CA MUTATION CO-OCCURRENCE IN DIFFUSE MIDLINE GLIOMAS USING GENETICALLY ENGINEERED MOUSE MODELS

Diffuse midline gliomas (DMGs) are aggressive childhood brain tumors with a dismal prognosis. Most of these tumors carry K27M mutations in histone H3-encoding genes, particularly H3F3A and HIST1H3B. In addition, activating mutations in ACVR1 and PIK3CA co-occur in a subset of DMGs. To understand how these lesions drive the development of DMGs, we generated genetically engineered mouse models in which Acvr1G328V, Hist1h3bK27M, and Pik3caH1047R are targeted to the OLIG2-expressing cell lineage. Animals carrying Acvr1G328V and Pik3caH1047R, with (“AHPO”) or without (“APO”) Hist1h3bK27M, developed high-grade diffuse gliomas involving midline and forebrain regions. Neither Acvr1G328V nor Pik3caH1047R drove tumorigenesis by themselves, but Acvr1G328V was sufficient to cause oligodendroglial differentiation arrest, pointing to a role in the earliest stages of gliomas formation. Transcriptomic analyses of AHPO and APO tumors indicated a predominantly proneural and oligodendrocyte precursor-like gene expression signature, consistent with the corresponding human pathology. Genes encoding transcription factors (TFs) with dual roles in controlling glial and neuronal differentiation were upregulated in tumors. Some of these genes were mildly induced by Acvr1G328V alone. Functional experiments using CRISPR/Cas9-mediated gene editing in patient-derived cell lines confirmed a role for some of these TFs in controlling DMG cell fitness. Overall, our results suggest that Pik3caH1047R consolidates Acvr1G328V-induced glial differentiation arrest to drive DMG development and progression.

A rater agreement study on measurements in cross-sectional CBCT images exploring the association between alveolar bone morphology and craniofacial height

ObjectivesTo investigate rater agreement regarding measurements of height and width of the maxilla and mandible using cross-sectional images from CBCT examinations. Furthermore, to explore the association between vertical craniofacial height and alveolar bone morphology.MethodsPre-treatment CBCT scans from 450 patients referred for treatment to a private clinic for orthodontics and oral surgery in Scandinavia were available and of these, 180 were selected. Lateral head images were generated from the CBCT volumes to categorise subjects into three groups based on their craniofacial height. Cross-sectional images of the maxillary and mandibular bodies at three locations in the maxilla and mandible, respectively, were obtained and measured at one height and two width recordings by five raters. One-way analysis of variance with a Tukey post hoc test was performed. A significance level of 5% was used.ResultsRater agreement was mostly excellent or good when measuring height and width of the maxilla and mandible in cross-sectional CBCT images. For height (of the alveolar bone/bodies), there were statistically significant differences between the low- and the high-angle groups for all the observers when measuring in the premolar and midline regions, both in the maxilla and in the mandible.ConclusionThe high agreement found ensures a reliable measurement technique and confirms the relation between craniofacial height and alveolar bone height and width.

The Paramedian Supracerebellar Approach: A Less Disruptive and More Flexible Operative Corridor to the Pineal and Posterior Upper Brainstem Regions

The paramedian supracerebellar craniotomy is an underrecognized route to the midline and paramedian regions of the upper posterior brainstem. As compared with its midline supracerebellar counterpart, this less disruptive approach preserves the majority of the midline bridging veins, requires less cerebellar retraction, and is significantly more efficient. In this offering, I will emphasize the realities of this flexible route and its remarkable advantages in reaching deep-seated lesions.

Cortical midline structures associated with rumination in women with PTSD

Elevated rumination, characterized by repetitive, negative self-focused cognition, is common in posttraumatic stress disorder (PTSD) and has been shown to predict the onset and maintenance of the disorder. Neuroimaging research has implicated cortical midline brain structures, including the rostral anterior cingulate cortex (rACC), posterior cingulate cortex (PCC), and isthmus cingulate (IsthCing), in rumination in healthy and depressed populations. While past research has revealed dysfunction in cortical midline regions in PTSD, no studies have yet investigated the structural and functional neural mechanisms underlying rumination in women with PTSD. In the current study, we used structural MRI and resting-state fMRI to examine relationships between rumination and brain volume, as well as resting-state functional connectivity (rsFC) of cortical midline structures in women with PTSD due to interpersonal trauma (N = 71). We performed multiple linear regression analyses to relate brain volume in rACC, PCC, and IsthCing regions to self-reported rumination, after controlling for age and total intracranial volume. We also conducted standard seed-based voxelwise rsFC analyses for significant regions identified in the structural analysis. We found a significant relationship between greater rumination and volume in the left IsthCing (p = .025). Results from the rsFC analyses revealed a significant relationship between greater rumination and diminished rsFC between the left IsthCing and left precuneus (pFWE < .05). These findings provide novel support for alterations in the neural substrates of ruminative thought in women with PTSD. More broadly, we discuss clinical implications for targeted interventions to reduce rumination through psychotherapy or non-invasive brain stimulation.

PARTIAL MANDIBULAR RESECTION AS TREATMENT OF AN AGGRESSIVE CENTRAL GIANT CELL LESION: A CASE REPORT

A 13-year-old female patient presented with a history of symptomatic volume increase in the mandible with approximately 3 years’ of evolution. Physical examination revealed a significant volume increase, painful and hardened to palpation, affecting the entire mandibular contour with bulging in the buccal and lingual region causing dysphagia and dysphonia. The imaging exams revealed a multiloculated intraosseous lesion in the mandible that extended posteriorly to the mandible region bilaterally, presenting bone expansion without cortical rupture. An incisional biopsy of the lesion was performed, which was diagnosed as central giant cell lesion. Due to the extension of the lesion, surgical treatment was performed for partial resection of the mandible with installation of a reconstruction plate through extended submandibular surgical approaches joined in the midline region. The patient has been in postoperative follow-up for 2 years without complaints and with preservation of mandibular functions, awaiting surgery for reconstruction with microvascularized fibular graft.

Direct brain recordings identify hippocampal and cortical networks that distinguish successful versus failed episodic memory retrieval

Human data collected using noninvasive imaging techniques have established the importance of parietal regions towards episodic memory retrieval, including the angular gyrus and posterior cingulate cortex. Such regions comprise part of a putative core episodic retrieval network. In free recall, comparisons between contextually appropriate and inappropriate recall events (i.e. prior list intrusions) provide the opportunity to study memory retrieval networks supporting veridical recall, and existing findings predict that differences in electrical activity in these brain regions should be identified according to the accuracy of recall. However, prior iEEG studies, utilizing principally subdural grid electrodes, have not fully characterized brain activity in parietal regions during memory retrieval and have not examined connectivity between core recollection areas and the hippocampus or prefrontal cortex. Here, we employed a data set obtained from 100 human patients implanted with stereo EEG electrodes for seizure mapping purposes as they performed a free recall task. This data set allowed us to separately analyze activity in midline versus lateral parietal brain regions, and in anterior versus posterior hippocampus, to identify areas in which retrieval-related activity predicted the recollection of a correct versus an incorrect memory. With the wide coverage afforded by the stereo EEG approach, we were also able to examine interregional connectivity. Our key findings were that differences in gamma band activity in the angular gyrus, precuneus, posterior temporal cortex, and posterior (more than anterior) hippocampus discriminated accurate versus inaccurate recall as well as active retrieval versus memory search. The left angular gyrus exhibited a significant power decrease preceding list intrusions as well as unique phase–amplitude coupling properties, whereas the prefrontal cortex was unique in exhibiting a power increase during list intrusions. Analysis of connectivity revealed significant hemispheric asymmetry, with relatively sparse left-sided functional connections compared to the right hemisphere. One exception to this finding was elevated connectivity between the prefrontal cortex and left angular gyrus. This finding is interpreted as evidence for the engagement of prefrontal cortex in memory monitoring and mnemonic decision-making.

ROS Regulate Caspase-Dependent Cell Delamination without Apoptosis in the Drosophila Pupal Notum.

SummaryThorax fusion occurs in the midline of the Drosophila pupal notum and involves epithelial cell delamination requiring apoptotic signaling. By genetic screening, we found that NADPH oxidases (Nox and Duox) associated with superoxide anion (O˙-2) are responsible for caspase-3 activation and delamination. We observed that Nox is upregulated in cells that undergo delamination and that delamination depends on caspase activation. However, the cell morphology and the almost complete lack of propidium iodide incorporation suggested little membrane disruption and signified apoptotic modulation. These results demonstrate that most delaminating cells undergo caspase activation, but this activation is not sufficient for apoptosis. We showed that the expression of Catalase, encoding an H2O2 scavenger in the cytosol, increases delamination and induces apoptotic nuclear fragmentation in caspase-3-activated cells. These findings suggest that the roles of O˙-2 and intracellular H2O2 for delamination differs before and after caspase-3 activation, which involves live cell delamination.

Changes in the neural correlates of self-blame following mindfulness-based cognitive therapy in remitted depressed participants

Mindfulness-Based-Cognitive-Therapy (MBCT) reduces vulnerability for relapse into depression by helping individuals to counter tendencies to engage in maladaptive repetitive patterns of thinking and respond more compassionately to negative self-judgment. However, little is known about the neural correlates underlying these effects. To elucidate these correlates, we investigated fMRI brain activation during a task eliciting feelings of blaming oneself or others. Sixteen participants in remission from major depressive disorder (MDD) completed fMRI assessments before and after MBCT, alongside self-reported levels of self-compassion, mindfulness, and depression symptoms. Analyses of self-blame versus other-blame contrasts showed a reduction in activation in the bilateral dorsal anterior cingulate/medial superior frontal gyrus after MBCT compared to baseline. Further, exploratory analyses showed that increases in self-kindness after MBCT correlated with reduced activation in the posterior cingulate cortex (PCC)/precuneus in self-blame versus rest contrasts. These findings suggest that MBCT is associated with a reduction in activations in cortical midline regions to self-blame which may be mediated by increasing self-kindness. However, this is a small, uncontrolled study with 16 participants and therefore our results will need confirmation in a controlled study.

Projections from the lowest thoracic and upper lumbar segments to the cerebellar cortex in the rat: An anterograde tracing study

The projections from the lowest thoracic and upper lumbar (T13 to L3) segments to the cerebellar cortex were examined by anterograde tracing with biotinylated dextran amine in the rat. Unilateral injections resulted in bilateral labeling of mossy fiber terminals in lobules Ib to VI, VIII, IX and copula pyramidis. The majority (64 % of the total 30,526 labeled terminals) were present ipsilaterally in lobules II (8.5 %), III (20 %), IV (11 %), V (12 %), VIII (4.1 %), and copula pyramidis (6.8 %). The projection field in the anterior lobe was composed of five longitudinal areas: area 1 in the midline region, areas 2 and 3 in the middle and lateral parts of the vermis, and areas 4 and 5 in the medial part of the intermediate region of the hemisphere. The projection areas are characteristically localized in the apical to the middle part of the lobule. In the posterior lobe, the longitudinal areas were present in the midline region, the middle and lateral parts of lobules VIIIa and VIIIb, and the medial and middle parts of copula pyramidis. The present study reveals the whole areas and the pattern of projections from the segments containing the cells of origin of the dorsal and ventral spinocerebellar tracts.

Two sequential surgeries in infant with multiple floor of the mouth dermoid cysts: A case report

Multiple intraoral dermoid cysts of large magnitude generally appear in the second or third decade of life. They are rare in infants and are usually solitary. In this case, a large mass was identified in utero during prenatal exams. We introduce a rare case on multiple dermoid cysts in the floor of the mouth of an infant who underwent two surgeries for this. Preoperative magnetic resonance imaging confirmed a large well-circumscribed cystic lesion that originated at the former midline region in the floor of the mouth in which a suspicious lesion of minute size was likely compressed by the bulkier mass and overlooked. Therefore, the infant underwent two surgeries by an intraoral approach within 9 mo. At 5 mo after the second operation, a routine follow-up ultrasound showed evidence of an additional cyst. No further surgery was planned because the tumor had no immediate effect. This report demonstrates the importance of carefully analyzing preoperative imaging to avoid multiple operations for a seemingly isolated oral cyst.

Inferior temporal tau is associated with accelerated prospective cortical thinning in clinically normal older adults

Neurofibrillary tau tangles are a hallmark pathology of Alzheimer's disease (AD) and are more closely associated with AD-related cortical atrophy and symptom severity than amyloid-beta (Aβ). However, studies regarding the effect of tau on longitudinal cortical thinning, particularly in healthy aging and preclinical AD, have been limited in number due to the relatively recent introduction of in vivo PET tracers for imaging tau pathology. Here, we investigate [18F]-flortaucipir (FTP, a marker of paired helical filament tau) PET as a predictor of atrophy in healthy aging and preclinical AD. We examine longitudinal structural MRI brain imaging data, retrospectively and prospectively relative to FTP imaging, using piecewise linear mixed-effect models with time centered at each participant's FTP-PET session. Participants include 111 individuals from the Harvard Aging Brain Study who underwent at least three MRI sessions over an average of 4.46 years and one FTP-PET at the approximate midpoint of the observation period. Our primary analyses focus on inferior temporal (IT) FTP standardized uptake value ratios and longitudinal FreeSurfer defined cortical regions of interest. Relationships were also explored using other regional FTP measures (entorhinal, composite, and local), within high and low Pittsburgh compound-B (PiB) PET groups, and with longitudinal subcortical volume. Strong associations between IT FTP and cortical thinning were found, most notably in temporal, midline, and prefrontal regions, with stronger effects generally observed in the prospective as compared to retrospective time frame. Significant differences between prospective and retrospective rates of thinning were found in the inferior and middle temporal gyri, cingulate areas, as well as pars orbitalis such that higher IT FTP was associated with greater prospective rates of thinning. Within the high PiB group, significant differences between prospective and retrospective rates of thinning were similarly observed. However, no consistent pattern of tau-related change in cortical thickness within the low PiB group was discerned. These results provide support for the hypothesis that tau pathology is a driver of future atrophy as well as provide additional evidence for tau-PET as an effective AD biomarker for interventional clinical trials.

Predictors of chronicity in alcohol use disorder: an evoked response potential study

Introduction Evoked response potentials (ERP) can reliably map key neurocognitive processes which are putatively responsible for chronic alcohol use disorder (AUD). Aim of the present study was to study P300 auditory odd ball and N400 visual semantic incongruity paradigm mapping executive functions rubric as a potential biomarker predicting chronicity in AUDs. Methodology: 60 right handed 18 to 54 years age subjects were divided into chronic “CAD” and non chronic alcohol dependence “NAD” in addition to healthy control “HC” (N = 30). Subjects were assessed by Addiction Severity Index (ASI), P300 auditory odd ball paradigm in midline region and visual N400 semantic incongruity task in centro-parietal region in a cross sectional design. Results: All the three groups differed significantly for P300 and N400 amplitude in all the leads with maximum attenuation seen in CAD. On discriminant function analysis (DFA), P300 Pz and N 400 C2 amplitude values could accurately classified 78.3% subjects. Composite sensitivity and specificity of the two predictor variables differentiating CAD subjects from NAD were 79.31 and 77.41%. receiver operating characteristic curve generated an area under the curve of .758 and .847 i.e., “fair to good” ability to predict CAD from NAD. Conclusion: We conclude that specific ERP paradigm can be used as a state marker to map the cognitive deficits and as a biomarker to detect chronic AUDs.