Background
Transcranial direct current stimulation (tDCS) is a safe non‐invasive brain stimulation (NIBS) procedure which helps to stimulate a particular region of interest by modulating the neuronal ...firing rate, thereby modulating the cognitive functioning. The tDCS intervention is known to show improvement on memory recall and recognition in patients with mild cognitive impairment (MCI) and mild Alzheimer’s Disease (mild AD)
Method
We investigated the effect of anodal stimulation at the left dorsolateral prefrontal cortex (DLPFC) and cathodal stimulation at the right supra‐orbital area in patients with MCI (n = 18) and mild AD (n = 20) (Refer Table 1), after due approval from Institute Ethics Committee NIMHANS. Both baseline and post‐intervention assessments for a single patient were administered by the different assessors allocated randomly using NIMHANS neuropsychological battery for elderly (NNB‐E). Two resting state functional magnetic resonance imaging (rsfMRI) acquisitions, before and after the ten sessions of tDCS, each session lasting 20 minutes. A spherical mask of 5 mm diameter was chosen a priori on the left middle frontal gyrus (LMFG) as a seed for performing seed based functional connectivity (sbFC) analysis using default preprocessing pipeline and pre‐post analysis setup in CONN 18b toolbox.
Result
The combined sample of patients with MCI and mild AD showed significant improvement in word list learning trial 3 (pre tDCS 5.85 (1.59); post tDCS 6.63 (1.67); Z = 3.586, p<0.0001) and delayed recall (pre tDCS 1.50 (1.88); post tDCS 2.45 (2.33); Z = 3.656, p<0.0001) scores using NNB‐E. The sbFC analysis showed significantly reduced functional connectivity between left MFG (the region of anodal stimulation) and posterior cingulate cortex (PCC) as well as precuneus cortex (cluster‐level extent threshold p‐FDR <0.05) after tDCS. Post‐hoc tests showed that these reductions after tDCS intervention were also found to be significantly associated with attention and auditory verbal learning memory scores (Refer Figure 1 and Table 2).
Conclusion
The tDCS intervention helped reducing the functional connectivity at rest, which was responsible for compensatory neuronal processes found in early AD. These findings unravel the therapeutic role of tDCS by enhancing auditory verbal memory performance and altering the functional connectivity at PCC and precuneus cortex in earlier stages of AD.
In the last few decades, it has been largely perceived that the factors affecting the immune system and its varying pathways lead to the pathological progression of inflammation and inflammatory ...conditions. Chronic inflammation also contributes to common diseases, such as diabetes mellitus, ischemic heart disease, cancer, chronic renal inflammatory disease, non-alcoholic fatty hepat-ic disease, autoimmune diseases and neurodegenerative diseases.
Interestingly, plant sources and secondary metabolites from plants have been increasingly employed in managing acute and chronic inflammatory diseases for centuries. Boswellic acids are pentacyclic triterpenoidal moieties obtained from the oleo gum resin of different
species.
Detailed data was collected revealing the anti-inflammatory potential of Boswellic acids through various databases.
These are pharmacologically active agents that possess promising anti-inflammatory, anti-arthritic, antirheumatic, anti-diarrheal, anti-hyperlipidemic, anti-asthmatic, anti-cancer, and anti-microbial effects.
Boswellic acids have been in use since ancient times primarily to treat acute and chronic inflammatory diseases. This review discusses the various mechanisms underlying the inflammatory process and the necessity of such natural products as a medication to treat inflammatory diseases. In addition, a discussion has also been extended to understand the primary targets involved in inflammation. The review further explores the therapeutic potential of boswellic acids in.
The pathophysiology of the memory impairment following Herpes Simplex virus encephalitis is not yet established and understood. This study attempts to elucidate the role of white matter injury and ...its impact on neuropsychological outcome in patients with history of Herpes Simplex virus encephalitis. This is a single-institution prospective study assessing 9 patients and 15 matched controls utilizing a combination of MRI with diffusion tensor imaging and neuropsychological testing. Tract-based spatial statistics analysis was performed and correlated with neuropsychological outcomes. Significantly decreased fractional anisotropy (FA) values were noted in corpus callosum, corona radiata, left posterior thalamic radiation, cingulum, superior longitudinal fasciculus, fornix, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and uncinated fasciculus. Impaired facial recognition significantly correlated with reduction in FA of right uncinate fasciculus, right inferior longitudinal fasciculus, and splenium genu of corpus callosum. FA value of left cingulum significantly correlated with logical memory, auditory verbal learning. FA value of fornix correlated with visual recognition; FA value of left uncinate fasciculus with auditory verbal learning and delayed recall. In conclusion, this study demonstrates microstructural abnormalities involving several white matter tracts corresponding to neuropsychological deficits.
Alzheimer disease (AD) is a neurodegenerative disorder characterized by progressive disconnection of various brain networks leading to neuropsychological impairment. Pathology in the visual ...association areas has been documented in presymptomatic AD and therefore we aimed at examining the relationship between brain connectivity and visuospatial (VS) cognitive deficits in early AD.
Tests for VS working memory, episodic memory and construction were used to classify patients with AD (n = 48) as having severe VS deficits (n = 12, female = 4) or mild deficits (n = 11, female = 4). Resting-state functional magnetic resonance imaging and structural images were acquired as per the standard protocols. Between-group differences in resting-state functional connectivity (rsFC) were examined by dual regression analysis correcting for age, gender, and total brain volume.
Patients with AD having severe VS deficits exhibited significantly reduced rsFC in bilateral lingual gyri of the visual network compared to patients with mild VS deficits.
Reduced rsFC in the visual network in patients with more severe VS deficits may be a functional neuroimaging biomarker reflecting hypoconnectivity of the brain with progressive VS deficits during early AD.
Amnestic Mild Cognitive Impairment (aMCI) represents the transition between healthy aging and Alzheimer’s dementia (AD) wherein gradual impairment of cognitive abilities, especially memory sets in. ...Impairment in episodic memory, especially delayed recall, is a hallmark of AD and therefore, patients with aMCI with more severe impairment in episodic memory are considered to be at greater risk of imminent conversion to AD. Brain structural and functional abnormalities were examined by comparing gray matter volumes, white matter micro-structural integrity and resting state functional connectivity (rsFC), between patients with aMCI (
n
= 46) having lower vs. higher episodic memory delayed recall (EM-DR) performance scores, correcting the influences of age, sex, number of years of formal education and total brain volumes using voxel-based morphometry, whole-brain tract based spatial statistics and dual regression analysis respectively. ‘Low’ performers (
n
= 27) when compared to ‘high’ performers (
n
= 19) showed significantly increased rsFC in the dorsal attention network (DAN) and central executive network (CEN) in the absence of demonstrable gray matter volumetric or white matter micro-structural integrity differences at family-wise error (FWE) corrected (
p < 0.05
) significance threshold. Follow-up data available for 38 (low performers = 22; high performers = 16) of the above 46 subjects (82.60% follow-up rate) over a median follow-up period of 24.5 months revealed that 7 subjects (18.42%) had converted to dementia. These converted subjects included 5 of the 22 low performers (22.72%) and 2 of the 16 high performers (12.5%) within the follow-up sample (
n
= 38). The results of the study indicate that imminent conversion of aMCI to dementia is higher in low performers in comparison to high performers, which may be characterized by increased rsFC in task positive networks, viz., DAN and CEN, as opposed to gray or white matter structural changes. This finding, therefore, might be considered as a prognostic indicator of progression from aMCI to dementia.
Background
Working memory and executive function deficits are the characteristic features of Mild Cognitive Impairment and mild Alzheimer’s Disease (mild AD). Studies exploring the alterations in ...working memory and executive functions show disrupted functional connectivity in Dorsolateral Pre Frontal Cortices (DLPFC) and Angular Gyrus (AG). Transcranial direct current stimulation (tDCS), by stimulating these brain regions, can alter resting‐state functional connectivity (rs‐FC) and has emerged as a safe and non‐invasive technique that has the potential to enhance neuroplasticity and cognitive improvement.
Method
We investigated the effect of anodal stimulation at the left DLPFC and cathode placed at the right supra‐orbital area to observe the rsFC changes in patients with MCI and mild AD (n=12; Age=67.58 ± 8.59 years, Gender ratio 1:1, formal years of education= 14.58±3.55 years, Hindi mental Status examination=26.91±3.1), who attended the outpatient services of Geriatric Clinic and Services, after due approval from institute ethics committee NIMHANS. The resting‐state functional magnetic resonance imaging (rsfMRI) acquisitions were performed before and after the ten sessions of tDCS, each session lasting 20 minutes. Investigations were performed on subregions of DLPFC (left Superior Frontal Gyrus (LSFG), Right SFG, left Middle Frontal Gyrus (LMFG) and Right MFG) and Angular Gyrus (Right Angular Gyrus (RAG) and Left AG), chosen a priori as seeds for the seed based FC (sbFC) analysis after correcting for the influences of age and gender using CONN 18b toolbox. Spherical masks of size 5 mm diameter were also created for the above‐mentioned seeds.
Result
The pre‐post tDCS comparisons of sbFC showed significant (FDR; p<0.05) reduction of rsFC in patients with MCI and mild AD at right supramarginal gyrus, right angular gyrus, right frontal pole (for Seed‐RAG, Voxel‐ whole brain), supramarginal gyrus (for Seed‐RAG, Voxel‐ RAG), and Middle Temporal gyrus, left Temporo‐Occipital part (for Seed‐ RSFG, Voxel‐ whole brain) as shown in Figure 1 a, b, and c respectively (Refer Table 1).
Conclusion
The results support that anodal stimulation using tDCS at left DLPFC may lead to the reduction of aberrantly increased functional connectivity between brain regions involved in working memory and executive functions in MCI and mild AD.
Abstract Background Mesial temporal sclerosis (MTS) is the most common cause of drug resistant epilepsy amenable for surgical treatment and seizure control. Methods This study analyzed the outcome of ...patients with MTS following anterior temporal lobectomy and amygdalohippocampectomy (ATL-AH) over 10 years and correlated the electrophysiological and radiological factors with the post operative seizure outcome. Results Eighty seven patients were included in the study. Sixty seven (77.2%) patients had an Engel Class 1 outcome, 9 (11.4%) had Class 2 outcome. Engel's class 1 outcome was achieved in 89.9% at 1 year, while it reduced slightly to 81.9% at 2 years and 76.2% at 5 year follow up. Seventy seven (88.5%) patients had evidence of hippocampal sclerosis on histopathology. Dual pathology was observed in 19 of 77 specimens with hippocampal sclerosis, but did not influence the outcome. Factors associated with an unfavorable outcome included male gender ( p = 0.04), and a higher frequency of pre-operative seizures ( p = 0.005), whereas the presence of febrile seizures ( p = 0.048) and loss of hippocampal neurons in CA4 region on histopathology ( p = 0.040) were associated with favorable outcome. The effect of CA4 loss on outcome is probably influenced by neuronal loss in other subfields as well since isolated CA4 loss was rare. Abnormal post operative EEG at the end of 1 week was found to be a significant factor predicting unfavorable outcome ( p = 0.005). On multivariate analysis, the pre-operative seizure frequency was the only significant factor affecting outcome. Conclusions The present study observed excellent seizure free outcome in a carefully selected cohort of patients with MTS with refractory epilepsy. The presence of dual pathology did not influence the outcome.
Brain resting-state functional connectivity (rsFC), white matter (WM) integrity, and cortical morphometry, as well as neuropsychological performance, have seldom been studied together to ...differentiate Alzheimer's disease (AD), mild cognitive impairment (MCI), and elderly cognitively healthy comparison (eCHC) samples in the context of the same study. We examined brain rsFC in samples of patients with mild AD (
= 50) and MCI (
= 49) in comparison with eCHC samples (
= 48) and then explored whether rsFC abnormalities can be linked to underlying gray matter (GM) volumetric and/or WM microstructural abnormalities. The mild AD sample showed significantly increased rsFC in the executive control network (ECN) and dorsal attention network (DAN) compared with the eCHC sample, and increased rsFC in ECN compared with MCI. Brain regions corresponding to both these resting-state networks (RSNs) showed significant reduction in fractional anisotropy in mild AD in comparison with eCHC. Significant GM volumetric reductions were observed in brain regions corresponding to both RSNs in the mild AD sample compared with MCI as well as eCHC samples. The association of default mode network-DAN anticorrelation with cognitive performances differentiated mild AD and MCI from eCHC sample. These findings highlight the association between brain structural and functional abnormalities as well as cognitive impairment that enables differentiation between early AD, MCI, and eCHC samples.
OBJECTIVESThis study aimed to localise the eloquent cortex and measure evoked field (EF) parameters using magnetoencephalography in patients with epilepsy and tumours near the eloquent cortex. ...METHODSA total of 41 patients (26 with drug-refractory epilepsy and 15 with tumours), with a mean age of 33 years, were recruited. Visual evoked field (VEF), auditory evoked field (AEF), sensory evoked field (SSEF), and motor-evoked field (MEF) latencies, amplitudes, and localisation were compared with those of a control population. Subgroup analyses were performed based on lobar involvement. Evoked Field parameters on the affected side were compared with those on the opposite side. The effect of distance from the lesion on nearby and distant evoked fields was evaluated. RESULTSAEF and VEF amplitudes and latencies were reduced bilaterally (p < 0.05). Amplitude in the ipsilateral SSEF was reduced by 29.27% and 2.16% in the AEF group compared to the contralateral side (p = 0.02). In patients with temporal lobe lesions, the SSEF amplitude was reduced bilaterally (p < 0.02), and latency was prolonged compared with controls. The MEF amplitude was reduced and latency was prolonged in patients with frontal lobe lesions (p = 0.01). EF displacement was 32%, 57%, 21%, and 16% for AEF, MEF, VEF, and SSEF respectively. Patients in the epilepsy group had distant EF abnormalities. CONCLUSIONSEF amplitude was reduced and latency was prolonged in the involved hemisphere. Distant EF amplitudes were more affected than latencies in epilepsy. Amplitude and distance from the lesion had negative correlation for all EF. EF changes indicated eloquent cortical displacement which may not be apparent on MRI.
•MSI showed clusters in 74.5% of children with DRE.•MSI/MEG showed concordance with MRI lesion in 61% of children with DRE.•Concordance with the presumed epileptogenic zone was 81% in non-lesional ...DRE.•Good surgical outcome is seen with Clusterectomy and regular orientation of dipoles.•MEG scatters in children with FCD were associated with poor surgical outcome.
This study aims to evaluate the utility of magnetoencephalography in presurgical planning and in predicting post-surgical seizure outcome.
This study included a cohort of 231 children (1–18 years) with focal drug-resistant epilepsy who underwent MEG as a part of their presurgical workup. Characteristics of MEG observations were described in all children. The concordance and agreement of Magnetic Source Imaging (MSI) of interictal discharges (IED) was estimated with either of the 3 subgroups - MRI lesion; presumed epileptogenic zone (EZ); or resection cavity. In operated children group, MEG dipole characteristics between good and poor outcome groups were assessed.
A total of 153 cases (66.2%) showed frequent IEDs (60 spikes/60 min). Of the 173 cases where MSI showed clusters (74.9%), 151 had lesions and 22 were non-lesional. amongst patients with lesional epilepsy and MEG clusters, class I concordance (MEG localization either completely included or overlapped at least 60% with the MRI lesion) was seen in 60.92% with a Cohen's kappa of 0.608. In non-lesional epilepsy, class I concordance of MEG with presumed EZ was found in (81.81%) with an agreement of 0.317. Fifty-three children underwent surgery of whom 39 (73.58%) showed a good outcome (Engel I). In operated children, concordance between MEG focus and resection cavity was observed in 23 (58.97%) with good outcome and in 12 (86.72%) with poor outcome with no significant difference (p>0.05). However, MEG cluster regular organization and clusterectomy are associated with good seizure outcome postoperatively (p< 0.05). Presence of scatters were associated with poor outcome (p<0.05) in children with focal cortical dysplasia.
MEG provides useful information that can serve as a biomarker for prognosticating the surgical outcome in paediatric epilepsy. Cluster removal and regular cluster organization shows predictive power in post-surgical prognostication in children and the presence of scatters predicts poor outcome in children with focal cortical dysplasia.
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