Transcranial alternating current stimulation (tACS)—a noninvasive brain stimulation technique that modulates cortical oscillations in the brain—has shown the capacity to enhance working memory (WM) ...abilities in healthy individuals. The efficacy of tACS in the improvement of WM performance in healthy individuals is not yet fully understood.
This meta-analysis aimed to systematically evaluate the efficacy of tACS in the enhancement of WM in healthy individuals and to assess moderators of response to stimulation. We hypothesized that active tACS would significantly enhance WM compared with sham. We further hypothesized that it would do so in a task-dependent manner and that differing stimulation parameters would affect response to tACS.
Ten tACS studies met the inclusion criteria and provided 32 effects in the overall analysis. Random-effect models assessed mean change scores on WM tasks from baseline to poststimulation. The included studies involved varied in stimulation parameters, between-subject and within-subject study designs, and online vs offline tACS.
We observed a significant, heterogeneous, and moderate effect size for active tACS in the enhancement of WM performance over sham (Cohen’s d = 0.5). Cognitive load, task domain, session number, and stimulation region showed a significant relationship between active tACS and enhanced WM behavior over sham.
Our findings indicate that active tACS enhances WM performance in healthy individuals compared with sham. Future randomized controlled trials are needed to further explore key parameters, including personalized stimulation vs standardized electroencephalography frequencies and maintenance of tACS effects, and whether tACS-induced effects translate to populations with WM impairments.
Glioma-related epilepsy (GRE) is a hallmark clinical presentation of gliomas with significant impacts on patient quality of life. The current standard of care for seizure management is comprised of ...anti-seizure medications (ASMs) and surgical resection. Seizures in glioma patients are often drug-resistant and can often recur after surgery despite total tumor resection. Therefore, current research is focused on the pro-epileptic pathological changes occurring in tumor cells and the peritumoral environment. One important contribution to seizures in GRE patients is metabolic reprogramming in tumor and surrounding cells. This is most evident by the significantly heightened seizure rate in patients with isocitrate dehydrogenase mutated (IDH
mut
) tumors compared to patients with IDH wildtype (IDH
wt
) gliomas. To gain further insight into glioma metabolism in epileptogenesis, this review compares the metabolic changes inherent to IDH
mut
vs. IDH
wt
tumors and describes the pro-epileptic effects these changes have on both the tumor cells and the peritumoral environment. Understanding alterations in glioma metabolism can help to uncover novel therapeutic interventions for seizure management in GRE patients.
Electrocorticography (ECoG) data are commonly obtained during drug-resistant epilepsy (DRE) workup, in which subdural grids and stereotaxic depth electrodes are placed on the cortex for weeks at a ...time, with the goal of elucidating seizure origination. ECoG data can also be recorded from neuromodulatory devices, such as responsive neurostimulation (RNS), which involves the placement of electrodes deep in the brain. Of the neuromodulatory devices, RNS is the first to use recorded ECoG data to direct the delivery of electrical stimulation in order to control seizures. In this review, we first introduced the clinical management for epilepsy, and discussed the steps from seizure onset to surgical intervention. We then reviewed studies discussing the emergence and therapeutic mechanism behind RNS, and discussed why RNS may be underperforming despite an improved seizure detection mechanism. We discussed the potential utility of incorporating machine learning techniques to improve seizure detection in RNS, and the necessity to change RNS targets for stimulation, in order to account for the network theory of epilepsy. We concluded by commenting on the current and future status of neuromodulation in managing epilepsy, and the role of predictive algorithms to improve outcomes.
A good response to levodopa is a key factor to indicate device-aided therapies in people with Parkinson's disease (PwPD). The aim of the present study was to analyze the response to levodopa in PwPD ...with motor fluctuations followed for 4 years.
PwPD with motor fluctuations recruited from January 2016 to November 2017 from the COPPADIS cohort and assessed annually (from baseline to 4-year follow-up) during the OFF and ON states were included in this analysis. At each visit, the Unified Parkinson's Disease Rating Scale – part III (UPDRS-III) was applied during the OFF state (without medication during the last 12 h) and during the ON state. General linear model repeated measures were used to test for changes in the mean UPDRS–III–OFF, UPDRS–III–ON, and ΔUPDRS-III (UPDRS–III–OFF – UPDRS–III–ON) between visits. Levodopa equivalent daily dose (LEDD) was included as covariate.
Sixty-three patients (63.94 ± 8.42 years old; 68.3% males) were included. Mean disease duration was 7.81 ± 3.64 years. From baseline to 4-year follow-up visit, a significant increase in both the UPDRS–III–OFF (from 27.98 ± 9.58 to 31.75 ± 12.39; p = 0.003) and the UPDRS–III–ON (from 15.92 ± 7.93 to 18.84 ± 8.17; p = 0.006) was observed despite the significant increase in the LEDD (from 896.35 ± 355.65 to 1085.51 ± 488.29; p = 0.003). However, no significant differences were detected between visits in the ΔUPDRS-III.
In this cohort of PwPD with motor fluctuations, the response to levodopa did not weaken after a 4-year follow-up.
•A good response to levodopa is a key factor to indicate device-aided or on-demand therapies in Parkinson's disease.•Response to levodopa did not weaken after a 4-year follow-up in 63 fluctuators PD patients.•On and off scores worsen at the expense of axial symptoms and in parallel with conservation of the levodopa response.•There were no differences by motor phenotype.
Quality of life (QOL) plays an important role in independent living in Parkinson's disease (PD) patients, being crucial to know what factors impact QoL throughout the course of the disease. Here we ...identified predictors of QoL impairment in PD patients from a Spanish cohort. PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016, to November 2017, were followed up during 2 years. Health-related QoL (HRQoL) and global QoL (GQoL) were assessed with the 39-item Parkinson's disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8), respectively, at baseline (V0) and at 24 months ± 1 month (V2). Clinically significant QoL impairment was defined as presenting an increase (PDQ-39SI) or decrement (EUROHIS-QOL8) at V2 ≥ 10% of the score at baseline (V0). A comparison with a control group was conducted for GQoL. GQoL did not change significantly in PD patients (N = 507; p = 0.686) or in the control group (N = 119; p = 0.192). The mean PDQ-39SI was significantly increased in PD patients (62.7 ± 8.5 years old; 58.8% males; N = 500) by 21.6% (from 16.7 ± 13 to 20.3 ± 16.4; p < 0.0001) at V2. Ninety-three patients (18.6%) presented a clinically significant HRQoL impairment at V2. To be younger (OR = 0.896; 95% CI 0.829-0.968; p = 0.006), to be a female (OR = 4.181; 95% CI 1.422-12.290; p = 0.009), and to have a greater increase in BDI-II (Beck Depression Inventory-II) (OR = 1.139; 95% CI 1.053-1.231; p = 0.001) and NMSS (Non-Motor Symptoms Scale) (OR = 1.052; 95% CI 1.027-1.113; p < 0.0001) total scores from V0 to V2 were associated with clinically significant HRQoL impairment at the 2-year follow-up (Hosmer-Lemeshow test, p = 0.665; R
= 0.655). An increase in ≥5 and ≥10 points of BDI-II and NMSS total score at V2 multiplied the probability of presenting clinically significant HRQoL impairment by 5 (OR = 5.453; 95% CI 1.663-17.876; p = 0.005) and 8 (OR = 8.217; 95% CI, 2.975-22.696; p = 0.002), respectively. In conclusion, age, gender, mood, and non-motor impairment were associated with clinically significant HRQoL impairment after the 2-year follow-up in PD patients.
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