Non-dominant Hemisphere Research Articles

The role of cognitive load on interlimb differences in motor coordination in older adults.

While the dominant hand has been shown to have performance advantages over the nondominant hand, these interlimb differences have found to be dependent on task and biomechanical demands. The dynamic dominance hypothesis suggests that the left hemisphere is specialized for the control of intersegmental dynamics while the nondominant right hemisphere is specialized for postural control, in right-handers. In a real-world scenario, however, cognitive challenges might be expected to modulate these specialized behaviors. Therefore, we hypothesized that with increased cognitive load, lateralized motor control processes would become even more asymmetrical. We recruited 16 right-handed older adults (11 females, 5 males; 65.88 years ± 1.99 SEM) to perform 170 trials of a unilateral reaching task with each of their hands on the Kinereach system. In each trial, participants rapidly committed to memory a set of pictorial instructions before identifying and reaching for the correct object on a screen. The complexity of the task increased over the course of the experiment. Our results demonstrated higher reaction times in the right compared to left hand (p = 0.0004). Movements became increasingly curved and erroneous with cognitive load, but interlimb differences in movement quality were absent. We found higher joint cocontraction in the right compared to left arm (p < 0.05), but these differences were unaffected by cognitive load. Hence, with the addition of a cognitive load, we observed asymmetries in reaction time but not in joint coordination or movement quality. This highlights the role of cognitive load in modulating limb/hemisphere specializations for control processes.

CTNI-69. A FIRST-IN-HUMAN FEASIBILITY STUDY TO EVALUATE THE SAFETY OF SELECTIVE YTTRIUM-90 ENDOVASCULAR RADIOTHERAPY IN PATIENTS WITH RECURRENT GBM: INTERIM RESULTS FROM THE FRONTIER TRIAL

Abstract BACKGROUND Yttrium-90 (Y90) microsphere treatment is an FDA-approved endovascular radiotherapy for Hepatocellular Carcinoma; however, extra-hepatic experience is limited. The FRONTIER trial (NCT05303467) is a first-in-human study conducted under an IDE from the FDA evaluating the safety and feasibility of intra-arterial Y90 endovascular radiotherapy in patients with recurrent glioblastoma (rGBM). METHODS The primary endpoint is the incidence of treatment-related limiting toxicities through 30 days, in 12 patients with rGBM. Eight subjects (50% male) with non-dominant hemisphere rGBM have been enrolled to date, with 6 patients reported herein. The treatment region, encompassing the recurrent lesion, excluding eloquent regions, and defined using cerebral angiography-MRI fusion, was selectively targeted with 40±4Gy. Immediate post-treatment imaging included MRI to evaluate acute treatment-related effects and Y90-PET to evaluate the absorbed dose distribution. Neurological assessments were performed pre- and post-treatment. Analysis of post-contrast T1w enhancing tissue volume (T1wvol) inside and outside the treated region was performed longitudinally. RESULTS All patients tolerated the procedure well and were discharged the following day. No decrease in neurological function and no limiting toxicities were reported through 30 days. Post-treatment MRI revealed no device-related acute ischemia or hemorrhage. Mean absorbed dose to the treatment region was 42.1±2.4Gy, within 3% of the targeted value, suggesting technical feasibility. Mean tumor absorbed dose within the treatment region was 65.1±22.6Gy most likely due to increased tumor perfusion in the treatment region. A reduction in T1wvol at 2m was observed in 4/6 patients, with the remaining 2 patients showing increased T1wvol. Disease progression by T1wvol occurred more rapidly outside the treatment region than within. All patients received subsequent therapy, with 2 patients receiving surgery 82 and 120 days post Y90 treatment. CONCLUSION Interim results in this first-in-human feasibility study demonstrated technical feasibility and no limiting toxicities through 30 days. Enrollment is ongoing. These data warrant additional investigation.

Brainwave Patterns and Metabolic Adaptations in Rowers Crossing the Atlantic: A Case Series Pilot Study.

This pilot study was designed to test the hypothesis that quantitative electroencephalographic (qEEG) measurements reflect physiological adaptations for brain energy reallocation. The study focused on a team of three well-matched male rowers participating in a 30-day, 2,650-mile continuous transatlantic rowing competition, examining the effects of extreme, prolonged stress on brain function and metabolic adaptations. Measurements at the start and finish lines included body weight, height, waist circumference, body fat, and a panel of hormones and biochemical markers. Post-race qEEG parameters were recorded under eyes-open (EO) and eyes-closed (EC) conditions. qEEG data were compared to a reference population (ages 6-90 years) and to an age-matched 27-year-old male medical student serving as a control subject. qEEG analysis evaluated voltage amplitudes, wave distribution patterns, theta-to-beta ratios (TBR), and coherence levels. Hormonal changes and oxidative stress markers were also assessed before and after race. Two rowers exhibited post-race dominance of high-frequency beta activity, while one displayed co-dominance of delta and beta waves. Compared to the control subject (TBR = 1.25), the rowers' low TBRs (< 0.2) indicated high vigilance and low relaxation during EC conditions. Cortisol levels increased in all rowers and were associated with beta coherence >1 SD above the reference mean. Testosterone decreased in two rowers but increased in one; the smallest cortisol increase corresponded with the largest testosterone decrement. Decreases in oxidative stress markers correlated with a shift from right- to left-sided alpha asymmetry, consistent with redistribution of alpha wave energy to the nondominant hemisphere. This pattern was also observed in the control subject. Increased testosterone in one rower was linked to a decrease in the percentage of sites exhibiting normal theta frequencies, indicating a potential role for testosterone in brain energy reallocation. The findings suggest that qEEG measurements reflect physiological adaptations in response to extreme stress, supporting the hypothesis that metabolic energy is reallocated to optimize vigilance and performance. The observed correlations between hormonal changes, oxidative stress markers, and qEEG parameters provide preliminary evidence of mechanisms for brain energy reallocation. These insights highlight the potential for qEEG to identify biomarkers of stress adaptation and lay the groundwork for larger studies to further elucidate these mechanisms.

The association between serum S100β levels and prognosis in acute stroke patients after intravenous thrombolysis: a multicenter prospective cohort study

BackgroundS100β is a biomarker of astroglial damage, the level of which is significantly increased following brain injury. However, the characteristics of S100β and its association with prognosis in patients with acute ischemic stroke following intravenous thrombolysis (IVT) remain unclear.MethodsPatients in this multicenter prospective cohort study were prospectively and consecutively recruited from 16 centers. Serum S100β levels were measured 24 h after IVT. National Institutes of Health Stroke Scale (NIHSS) and hemorrhagic transformation (HT) were measured simultaneously. NIHSS at 7 days after stroke, final infarct volume, and modified Rankin Scale (mRS) scores at 90 days were also collected. An mRS score ≥ 2 at 90 days was defined as an unfavorable outcome.ResultsA total of 1072 patients were included in the analysis. The highest S100β levels (> 0.20 ng/mL) correlated independently with HT and higher NIHSS at 24 h, higher NIHSS at 7 days, larger final infarct volume, and unfavorable outcome at 3 months. The patients were divided into two groups based on dominant and non-dominant stroke hemispheres. The highest S100β level was similarly associated with the infarct volume in patients with stroke in either hemisphere (dominant: β 36.853, 95% confidence interval (CI) 22.659–51.048, P < 0.001; non-dominant: β 23.645, 95% CI 10.774–36.516, P = 0.007). However, serum S100β levels at 24 h were more strongly associated with NIHSS scores at 24 h and 3-month unfavorable outcome in patients with dominant hemisphere stroke (NIHSS: β 3.470, 95% CI 2.392–4.548, P < 0.001; 3-month outcome: odds ratio (OR) 5.436, 95% CI 2.936–10.064, P < 0.001) than in those with non-dominant hemisphere stroke (NIHSS: β 0.326, 95% CI − 0.735–1.387, P = 0.547; 3-month outcome: OR 0.882, 95% CI 0.538–1.445, P = 0.619). The association of S100β levels and HT was not significant in either stroke lateralization group.ConclusionsSerum S100β levels 24 h after IVT were independently associated with HT, infarct volume, and prognosis in patients with IVT, which suggests the application value of serum S100β in judging the degree of disease and predicting prognosis.

INVOLVEMENT OF THE LOCATION OF INTRAPARENCHYMAL EDEMA AFTER A CEREBROVASCULAR EVENT IN THE APPROACH OF A DECOMPRESSIVE CRANIECTOMY

Introduction: Decompressive craniectomy, introduced by Kocher in 1901, reduces intracranial pressure by removing part of the skull. It is used in severe neurological conditions such as brain injury and stroke, allowing the swollen brain to expand, thereby reducing mortality and improving function. Objective: To evaluate the effect of the location of intraparenchymal edema on the efficacy of decompressive craniectomy and postoperative clinical outcomes. Methods: A systematic search was performed in PubMed, Cochrane Library and Scopus. This search was focused on studies related to intracranial hypertension and its neurosurgical approach. Results: In this study, the following risk factors for mortality after decompressive craniotomy were identified: male sex, age over 50 years and late surgery. Operating between 12-24 hours improves results, especially in the non-dominant hemisphere. Correct surgical technique minimizes complications and improves the healing process of patients. Discussions: This study demonstrates that the location of intra-abdominal edema affects the results of craniectomy, with better results in the non-dominant hemisphere. A better understanding of brain anatomy and individualization of surgical techniques are essential to reduce complications and improve surgical outcomes after stroke. Conclusions: In conclusion, patient survival and functionality can be improved as seen from a modified Rankin scale by precise knowledge of the location of intraparenchymal edema and an approach with reduced damage to collateral structures.

White Matter Magnetic Resonance Diffusion Measures in Multiple Sclerosis with Overactive Bladder.

Lower urinary tract (LUT) symptoms are reported in more than 80% of patients with multiple sclerosis (MS), most commonly an overactive bladder (OAB). The relationship between brain white matter (WM) changes in MS and OAB symptoms is poorly understood. We aim to evaluate (i) microstructural WM differences across MS patients (pwMS) with OAB symptoms, patients without LUT symptoms, and healthy subjects using diffusion tensor imaging (DTI), and (ii) associations between clinical OAB symptom scores and DTI indices. Twenty-nine female pwMS [mean age (SD) 43.3 years (9.4)], including seventeen with OAB [mean age (SD) 46.1 years (8.6)] and nine without LUT symptoms [mean age (SD) 37.5 years (8.9)], and fourteen healthy controls (HCs) [mean age (SD) 48.5 years (20)] were scanned in a 3T MRI with a DTI protocol. Additionally, clinical scans were performed for WM lesion segmentation. Group differences in fractional anisotropy (FA) were evaluated using tract-based spatial statistics. The Urinary Symptom Profile questionnaire assessed OAB severity. A statistically significant reduction in FA (p = 0.004) was identified in microstructural WM in pwMS, compared with HCs. An inverse correlation was found between FA in frontal and parietal WM lobes and OAB scores (p = 0.021) in pwMS. Areas of lower FA, although this did not reach statistical significance, were found in both frontal lobes and the rest of the non-dominant hemisphere in pwMS with OAB compared with pwMS without LUT symptoms (p = 0.072). This study identified that lesions affecting different WM tracts in MS can result in OAB symptoms and demonstrated the role of the WM in the neural control of LUT functions. By using DTI, the association between OAB symptom severity and WM changes were identified, adding knowledge to the current LUT working model. As MS is predominantly a WM disease, these findings suggest that regional WM involvement, including of the anterior corona radiata, anterior thalamic radiation, superior longitudinal fasciculus, and superior frontal-occipital fasciculus and a non-dominant prevalence in WM, can result in OAB symptoms. OAB symptoms in MS correlate with anisotropy changes in different white matter tracts as demonstrated by DTI. Structural impairment in WM tracts plays an important role in LUT symptoms in MS.

Hebbian plasticity induced by temporally coincident BCI enhances post-stroke motor recovery

Functional electrical stimulation (FES) can support functional restoration of a paretic limb post-stroke. Hebbian plasticity depends on temporally coinciding pre- and post-synaptic activity. A tight temporal relationship between motor cortical (MC) activity associated with attempted movement and FES-generated visuo-proprioceptive feedback is hypothesized to enhance motor recovery. Using a brain–computer interface (BCI) to classify MC spectral power in electroencephalographic (EEG) signals to trigger FES-delivery with detection of movement attempts improved motor outcomes in chronic stroke patients. We hypothesized that heightened neural plasticity earlier post-stroke would further enhance corticomuscular functional connectivity and motor recovery. We compared subcortical non-dominant hemisphere stroke patients in BCI-FES and Random-FES (FES temporally independent of MC movement attempt detection) groups. The primary outcome measure was the Fugl-Meyer Assessment, Upper Extremity (FMA-UE). We recorded high-density EEG and transcranial magnetic stimulation-induced motor evoked potentials before and after treatment. The BCI group showed greater: FMA-UE improvement; motor evoked potential amplitude; beta oscillatory power and long-range temporal correlation reduction over contralateral MC; and corticomuscular coherence with contralateral MC. These changes are consistent with enhanced post-stroke motor improvement when movement is synchronized with MC activity reflecting attempted movement.

Microsurgery of Cerebral Arteriovenous Malformations in a Resource-Limited Setting: The First Case-Series from Iraq

Cerebral arteriovenous malformations (AVMs) can lead to significant morbidity and are particularly challenging to manage in resource-limited settings where endovascular treatment modalities are unaffordable for most patients. To describe the first case series of AVM from Iraq with an analysis of the related clinicoradiologic characteristics, operative features, and outcomes. A single-center database from October 2018 to December 2022 was reviewed to analyze the characteristics of cerebral AVMs who underwent surgical treatment in Baghdad, Iraq. We collected patient demographics, clinical, radiologic, operative, and the follow-up combined outcome results (modified Rankin Scale score and the presence of AVM remnants). Of the 54 AVM patients treated with microsurgery, the majority of lesions have Spetzler-Martin grade of 3 (31.5%), followed by grade 1 (29.6%). The parietal lobe was the most common location of AVM in 25.9% of the cases, and the temporal location had better outcomes. The mean duration of surgery was 8.5 hours, ranging from 3 to 14 hours, with 20.3% of cases having undergone preoperative stereotactic radiosurgery, and just one patient received preoperative embolization. Good combined outcome (modified Rankin Scale 0-2 and no AVM remnant) was associated with lower SM grades (P=0.003); location in the nondominant hemisphere (P=0.036), and noneloquent regions (P=0.006); absence of deep venous drainage (P=0.042) and no intraoperative brain swelling (P=0.004). The mortality rate in our series was 5.5%. Good clinicoradiologic outcomes can be achieved through microsurgery in a setting where endovascular treatment is inaccessible to patients due to limited resources.

Distribution of control during bimanual movement and stabilization

In two-handed actions like baseball batting, the brain can allocate the control to each arm in an infinite number of ways. According to hemispheric specialization theory, the dominant hemisphere is adept at ballistic control, while the non-dominant hemisphere is specialized at postural stabilization, so the brain should divide the control between the arms according to their respective specialization. Here, we tested this prediction by examining how the brain shares the control between the dominant and non-dominant arms during bimanual reaching and postural stabilization. Participants reached with both hands, which were tied together by a stiff virtual spring, to a target surrounded by an unstable repulsive force field. If the brain exploits each hemisphere’s specialization, then the dominant arm should be responsible for acceleration early in the movement, and the non-dominant arm will be the prime actor at the end when holding steady against the force field. The power grasp force, which signifies the postural stability of each arm, peaked at movement termination but was equally large in both arms. Furthermore, the brain predominantly used the arm that could use the stronger flexor muscles to mainly accelerate the movement. These results point to the brain flexibly allocating the control to each arm according to the task goal without adhering to a strict specialization scheme.

Non-Dominant Hemisphere Excitability Is Unaffected during and after Transcranial Direct Current Stimulation of the Dominant Hemisphere.

Transcranial direct current stimulation (tDCS) increases primary motor cortex (M1) excitability and improves motor performance when applied unilaterally to the dominant hemisphere. However, the influence of tDCS on contralateral M1 excitability both during and after application has not been quantified. The purpose was to determine the influence of tDCS applied to the dominant M1 on the excitability of the contralateral non-dominant M1. This study employed a double-blind, randomized, SHAM-controlled, within-subject crossover experimental design. Eighteen young adults performed two experimental sessions (tDCS, SHAM) in counterbalanced order separated by a one-week washout. Transcranial magnetic stimulation (TMS) was used to quantify the excitability of the contralateral M1 to which anodal tDCS was applied for 20 min with a current strength of 1 mA. Motor evoked potential (MEP) amplitudes were assessed in 5 TMS test blocks (Pre, D5, D10, D15, and Post). The Pre and Post TMS test blocks were performed immediately before and after tDCS application, whereas the TMS test blocks performed during tDCS were completed at the 5, 10, and 15 min stimulation timepoints. MEPs were analyzed with a 2 condition (tDCS, SHAM) × 5 test (Pre, D5, D10, D15, Post) within-subject ANOVA. The main effect for condition (p = 0.213), the main effect for test (p = 0.502), and the condition × test interaction (p = 0.860) were all not statistically significant. These results indicate that tDCS does not modulate contralateral M1 excitability during or immediately after application, at least under the current set of common tDCS parameters of stimulation.

Effectiveness of Detailed Information on Subconscious Motor Sequence Learning in Acute Stroke

Introduction: Stroke is defined as a rapidly developing clinical sign of focal disturbance of central function of presumed vascular origin &amp; of more than 24-hours duration1. Clinically a variety of deficits are possible including changes in the level of consciousness &amp; impairment of sensory, motor, cognitive , perceptual &amp; language functions2. Although it is unequivocal that the extremities contra lateral to the unilateral cerebral lesion are more affected than the ipsilesional extremities, there is now a large body of research that suggests that the ipsilesional extremities are not normal often clinically assumed as “the non affected side” ,particular to the upper extremity there is increasing evidence of sensory-motor control deficits on the ipsilesional side3. These ipsilesional deficits may reflect motor control deficits that are masked on the contralateral side by hemiplegia and hemisensory loss3. The non-dominant hemisphere plays a primary role in the function of complex visuo-spatial accuracy, whereas the dominant hemisphere is mainly involved in the motor control of bilateral upper limbs as well as the performance of complex tasks. Although the cause of ipsilesional movement abnormalties have not been elucidated accurately, several possible mechanisms have been suggested i.e. the injury of the uncrossed corticospinal system, inhibitory transcallosal influence on the unaffected hemisphere, the different roles of side-to-side hemispheric function depending on the specific properties of the task &amp; bilateral hemispheric processing for high cognitive activity4. In persons with stroke, deficits in targeted movements, compared with comparison groups, have been identified in the ipsilateral extremities, even when clinical measures of the upper extremities reveal little or no deficit5 Objective: To study effectiveness of detailed information on subconscious motor sequence learning in acute stroke Research Design: Observational design Methodology: A total of 22 subjects with anterior circulation stroke (diagnosed by neurologist) were included in the study. In the group A (No-Explicit Information group) 13 subjects were recruited (total 15 subjects were recruited, but 2 patients left in between). In the group B (Explicit Information Group) 9 subjects were recruited. Result: Descriptive statistics is used to analyze subject characteristics. 22 subjects recruited for the study were randomly assigned to each group, group A (Non EI) with 9 males and 4 females with mean age of 59.94 years and mean score on MMSE, &amp; COVS, were 27.92 and 6.00. Group B (EI) with 8 males and 1 female with mean age of 58.22 years and mean score on MMSE, &amp; COVS were 29.00 and 6.56.On comparing the Age (p=0.75), MMSE score (p=0.09), and COVS score (p=0.08) between the two groups, the results were not significant (at p&lt;0.05). Thus both the groups are comparable. Conclusion: Our findings suggest that explicit information when given prior to physical practice improved implicit motor sequence learning in subjects with acute stroke; however subjects were not able to express it explicitly. Keywords: non-dominant hemisphere, Stroke, disability, uncrossed corticospinal, explicit and implicit learning

Long-term seizure outcome after epilepsy surgery of neuroglial tumors

PurposeNeuroglial tumors are frequently associated with pharmacorefractory epilepsies. However, comprehensive knowledge about long-term outcomes after epilepsy surgery and the main prognostic factors for outcome is still limited. We sought to evaluate long-term outcomes and potential influencing factors in a large cohort of patients who underwent surgery for neuroglial tumors in a single-center setting.MethodsThe study analyzed the outcomes of 107 patients who underwent epilepsy surgery for neuroglial tumors between 2001 and 2020 at the Department of Epileptology, University Hospital Bonn, in Germany. The outcomes were evaluated using Engel classification. Differences in outcome related to potential prognostic factors were examined using the Chi2-test, Fisher’s exact test and sign test. Additionally, stepwise logistic regression analysis was employed to identify independent prognostic factors.ResultsComplete seizure freedom (Engel Class IA) was achieved in 75% of the operated patients at 12 months, and 56% at the last follow-up visit (70.4 ± 6.2 months, median: 40 months). Completeness of resection was a crucial factor for both 12-month follow-up outcomes and the longest available outcomes, whereas lobar tumor localization, histology (ganglioglioma vs. dysembryoplastic neuroepithelial tumor), history of bilateral tonic–clonic seizures prior to surgery, invasive diagnostics, side of surgery (dominant vs. non-dominant hemisphere), age at epilepsy onset, age at surgery, and epilepsy duration did not consistently impact postsurgical outcomes. Among temporal lobe surgeries, patients who underwent lesionectomy and lesionectomy, including hippocampal resection, demonstrated similar outcomes.ConclusionNeuroglial tumors present as excellent surgical substrates in treating structural epilepsy. To achieve an optimal postsurgical outcome, a complete lesion resection should be pursued whenever possible.

The complementary dominance hypothesis: a model for remediating the 'good' hand in stroke survivors.

The complementary dominance hypothesis is a novel model of motor lateralization substantiated by decades of research examining interlimb differences in the control of upper extremity movements in neurotypical adults and hemisphere-specific motor deficits in stroke survivors. In contrast to earlier ideas that attribute handedness to the specialization of one hemisphere, our model proposes complementary motor control specializations in each hemisphere. The dominant hemisphere mediates optimal control of limb dynamics as required for smooth and efficient movements, whereas the non-dominant hemisphere mediates impedance control, important for countering unexpected mechanical conditions and achieving steady-state limb positions. Importantly, this model proposes that each hemisphere contributes its specialization to both arms (though with greater influence from either arm's contralateral hemisphere) and thus predicts that lesions to one hemisphere should produce hemisphere-specific motor deficits in not only the contralesional arm, but also the ipsilesional arm of stroke survivors - a powerful prediction now supported by a growing body of evidence. Such ipsilesional arm motor deficits vary with contralesional arm impairment, and thus individuals with little to no functional use of the contralesional arm experience both the greatest impairments in the ipsilesional arm, as well as the greatest reliance on it to serve as the main or sole manipulator for activities of daily living. Accordingly, we have proposed and tested a novel intervention that reduces hemisphere-specific ipsilesional arm deficits and thereby improves functional independence in stroke survivors with severe contralesional impairment.

Ictal Coprolalia: Three Cases with Nondominat Frontal Lobe Involvement and Review of the Literature.

Objective: Coprolalia is defined as the involuntary use of obscene, socially unacceptable, and derogatory words. Ictal coprolalia is a rare presentation of epilepsy. This study aimed to determine the localizing and lateralizing value and frequency of ictal coprolalia in epilepsy patients. Methods: Medical files, discharge summaries, and electroencephalography (EEG) reports of 2238 patients were reviewed retrospectively. We identified patients who suffered from ictal coprolalia. Electroencephalography reports, neuroimaging [brain magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computerized tomography (SPECT)] records, F-18 FDG fused on MRI images, and ictal SPECT fused on MRI images were evaluated. Also, original and review articles were identified through a systematic search of Pubmed, Scopus, and Clarivate Analytics. Results: Ictal coprolalia was detected in 3 male (0.15%) patients. In all patients, ictal semiology was extratemporal-frontal type, and potential/proven epileptic focus was non-dominant hemisphere frontal lobe. Topectomy was done in one of the patients, including the suspected dysplastic area plus the area where the electroencephalographic ictal and interictal changes occur, on the left frontal lobe, and the patient had an Engel's classification class IIA. The data depending on the published cases showed that ictal coprolalia was dominant in the male gender and the responsible epileptic area tended to be located in the non-dominant hemisphere frontotemporal region. Conclusion: The rate of ictal coprolalia in the Turkish population is lower compared to other series. Our results are consistent with previous studies in which reported that male preponderance for ictal coprolalia and involvement of non-dominant frontal lobe.

Functional and oncological outcomes after right hemisphere glioma resection in awake versus asleep patients: a systematic review and meta-analysis.

The right hemisphere has been underestimated by being considered as the non-dominant hemisphere. However, it is involved in many functions, including movement, language, cognition, and emotion. Therefore, because lesions on this side are usually not resected under awake mapping, there is a risk of unfavorable neurological outcomes. The goal of this study is to compare the functional and oncological outcomes of awake surgery (AwS) versus surgery under general anesthesia (GA) in supratentorial right-sided gliomas. A systematic review of the literature according to PRISMA guidelines was performed up to March 2023. Four databases were screened. Primary outcome to assess was return to work (RTW). Secondary outcomes included the rate of postoperative neurological deficit, postoperative Karnofsky Performance Status (KPS) score and the extent of resection (EOR). A total of 32 articles were included with 543 patients who underwent right hemisphere tumor resection under awake surgery and 294 under general anesthesia. There were no significant differences between groups regarding age, gender, handedness, perioperative KPS, tumor location or preoperative seizures. Preoperative and long-term postoperative neurological deficits were statistically lower after AwS (p = 0.03 and p < 0.01, respectively), even though no difference was found regarding early postoperative course (p = 0.32). A subsequent analysis regarding type of postoperative impairment was performed. Severe postoperative language deficits were not different (p = 0.74), but there were fewer long-term mild motor and high-order cognitive deficits (p < 0.05) in AwS group. A higher rate of RTW (p < 0.05) was documented after AwS. The EOR was similar in both groups. Glioma resection of the right hemisphere under awake mapping is a safer procedure with a better preservation of high-order cognitive functions and a higher rate of RTW than resection under general anesthesia, despite similar EOR.

Near-Infrared Spectroscopy Regional Oxygen Saturation Based Cerebrovascular Reactivity Assessments in Chronic Traumatic Neural Injury versus in Health: A Prospective Cohort Study.

Near-infrared spectroscopy (NIRS) regional cerebral oxygen saturation (rSO2)-based cerebrovascular reactivity (CVR) monitoring has enabled entirely non-invasive, continuous monitoring during both acute and long-term phases of care. To date, long-term post-injury CVR has not been properly characterized after acute traumatic neural injury, also known as traumatic brain injury (TBI). This study aims to compare CVR in those recovering from moderate-to-severe TBI with a healthy control group. A total of 101 heathy subjects were recruited for this study, along with 29 TBI patients. In the healthy cohort, the arterial blood pressure variant of the cerebral oxygen index (COx_a) was not statistically different between males and females or in the dominant and non-dominant hemispheres. In the TBI cohort, COx_a was not statistically different between the first and last available follow-up or by the side of cranial surgery. Surprisingly, CVR, as measured by COx_a, was statistically better in those recovering from TBI than those in the healthy cohort. In this prospective cohort study, CVR, as measured by NIRS-based methods, was found to be more active in those recovering from TBI than in the healthy cohort. This study may indicate that in individuals that survive TBI, CVR may be enhanced as a neuroprotective measure.

Comparison of consistency in acute stroke: Automated ASPECT score software tools and manual consensus scores

PurposeThe Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a standardized semi-quantitative scoring system. It is widely used to assess the extent of acute ischemic stroke (AIS). We evaluated the consistency of three automatic software packages with the overall and region-specific manual ASPECTS scores of AIS patients. MethodsRetrospectively, we gathered patients who presented with stroke symptoms between February 2019 and June 2022, and 174 cases were eventually included in the trial. Two radiologists reviewed the NCCT images independently; After four weeks, the same two radiologists began randomly reviewing the DWI images, discussed different scores and give consistent results as ground truth. ResultsMedian ASPECTS of the expert consensus reading was 7 (5–9). Good to excellent correlation of ASPECTS total scores among the three software tools (0.70, 0.74 and 0.83). Correlation among ground truth and Rapid-ASPECTS, RealNow-ASPECTS, ShuKun-ASPECTS (ICC = 0.51, Cronbach's α = 0.53), (ICC = 0.60, Cronbach's α = 0.70) and (ICC = 0.52, Cronbach's α = 0.64) respectively. The AUCs for Rapid, RealNow and ShuKun were 0.61, 0.67, and 0.62 respectively. The region-specific results showed a poor to good correlation. The correlations between the non-dominant and dominant cerebral hemispheres and the ground truth were statistically different (P < 0.05). ConclusionsOverall, the scoring consistency between the three automated scoring software and the ground truth is comparable, with RealNow-ASPECTS being no less consistent and effective than Rapid-ASPECTS and ShuKun-ASPECTS, and even better than both. But the consistency grade that still is developable.

Awake Craniotomy for Gliomas in the Non-Dominant Right Hemisphere: A Comprehensive Review.

Awake surgery has become a standard practice for managing diffuse low-grade gliomas (LGGs), particularly in eloquent brain areas, and is established as a gold standard technique for left-dominant-hemisphere tumors. However, the intraoperative monitoring of functions in the right non-dominant hemisphere (RndH) is often neglected, highlighting the need for a better understanding of neurocognitive testing for complex functions in the right hemisphere. This article aims to comprehensively review the current literature on the benefits of awake craniotomy in gliomas of the non-dominant right hemisphere. A systematic review was conducted using the PubMed and ScienceDirect databases with keywords such as "right hemisphere", "awake surgery", "direct electrical brain stimulation and mapping", and "glioma". The search focused on anatomical and surgical aspects, including indications, tools, and techniques of awake surgery in right cerebral hemisphere gliomas. The literature search identified 74 sources, including original articles, books, monographs, and review articles. Two papers reported large series of language assessment cases in 246 patients undergoing awake surgery with detailed neurological semiology and mapping techniques, while the remaining studies were predominantly neuroradiological and neuroimaging in nature. Awake craniotomy for non-dominant-hemisphere gliomas is an essential tool. The term "non-dominant" should be revised, as this hemisphere contributes significantly to essential cognitive functions in the human brain.

Volumetric analysis of hippocampal subregions and subfields in left and right semantic dementia.

Two variants of semantic dementia are recognized based on the laterality of temporal lobe involvement: a left-predominant variant associated with verbal knowledge impairment and a right-predominant variant associated with behavioural changes and non-verbal knowledge loss. This cross-sectional clinicoradiologic study aimed to assess whole hippocampal, subregion, and/or subfield volume loss in semantic dementia versus controls and across its variants. Thirty-five semantic dementia participants and 15 controls from the Neurodegenerative Research Group at Mayo Clinic who had completed 3.0-T volumetric magnetic resonance imaging and 18F-fluorodeoxyglucose-positron emission tomography were included. Classification as left-predominant (n = 25) or right-predominant (n = 10) variant was based on temporal lobe hypometabolism. Volumes of hippocampal subregions (head, body, and tail) and subfields (parasubiculum, presubiculum, subiculum, cornu ammonis 1, cornu ammonis 3, cornu ammonis 4, dentate gyrus, molecular layer, hippocampal-amygdaloid transition area, and fimbria) were obtained using FreeSurfer 7. Subfield volumes were measured separately from head and body subregions. We fit linear mixed-effects models using log-transformed whole hippocampal/subregion/subfield volumes as dependent variables; age, sex, total intracranial volume, hemisphere and a group-by-hemisphere interaction as fixed effects; and subregion/subfield nested within hemisphere as a random effect. Significant results (P < 0.05) are hereby reported. At the whole hippocampal level, the dominant (predominantly involved) hemisphere of both variants showed 23-27% smaller volumes than controls. The non-dominant (less involved) hemisphere of the right-predominant variant also showed volume loss versus controls and the left-predominant variant. At the subregional level, both variants showed 17-28% smaller dominant hemisphere head, body, and tail than controls, with the right-predominant variant also showing 8-12% smaller non-dominant hemisphere head than controls and left-predominant variant. At the subfield level, the left-predominant variant showed 12-36% smaller volumes across all dominant hemisphere subfields and 14-15% smaller non-dominant hemisphere parasubiculum, presubiculum (head and body), subiculum (head) and hippocampal-amygdaloid transition area than controls. The right-predominant variant showed 16-49% smaller volumes across all dominant hemisphere subfields and 14-22% smaller parasubiculum, presubiculum, subiculum, cornu ammonis 3, hippocampal-amygdaloid transition area (all from the head) and fimbria of non-dominant hemisphere versus controls. Comparison of dominant hemispheres showed 16-29% smaller volumes of the parasubiculum, presubiculum (head) and fimbria in the right-predominant than left-predominant variant; comparison of non-dominant hemispheres showed 12-15% smaller cornu ammonis 3, cornu ammonis 4, dentate gyrus, hippocampal-amygdaloid transition area (all from the head) and cornu ammonis 1, cornu ammonis 3 and cornu ammonis 4 (all from the body) in the right-predominant variant. All hippocampal subregion/subfield volumes are affected in semantic dementia, although some are more affected in both dominant and non-dominant hemispheres of the right-predominant than the left-predominant variant by the time of presentation. Involvement of hippocampal structures is apparently more subregion dependent than subfield dependent, indicating possible superiority of subregion volumes as disease biomarkers.

Computational strategy for aphasia support

Aphasia, a language disorder resulting from brain lesions, impacts communication abilities, and is commonly diagnosed through formal tests assessing speech fluency, comprehension, naming, and repetition abilities. These tests aid in devising treatment plans and evaluating recovery potential. Technological advances have enabled the development of devices and techniques for recording brain activity. Despite their potential, the high cost, device robustness, and complexity often limit their application in rehabilitation centers outside hospitals. In this study, we propose a computational strategy that uses electroencephalography devices to support aphasia rehabilitation therapies. The research was conducted with aphasic participants undergoing rehabilitation at the Center for Prevention and Rehabilitation of People with Disabilities within the Unified Health System in Bahia-Brazil. Preliminary results obtained from the silent word generation task, as outlined in the adult language paradigm by the American Society for Functional Neuroradiology, suggest that increased electrical activation in the right hemisphere may indicate language migration to the non-dominant hemisphere, potentially leading to improved recovery.