Dynamic functional connectivity is related to cognitive performance of prodromal Lewy body dementia

15 Jul

Multifocal Noninvasive Deep Brain Stimulation to Enhance Cognition in Mild Cognitive Impairment: A Crossover Trial

Importance: Impairment of working memory (WM), which relies on distributed cortical and subcortical structures, including cerebello-striatal pathways, is a core contributor to functional decline in patients with mild cognitive impairment (MCI) and dementia. Because the striatum is affected early in dementia, whereas the cerebellum remains relatively preserved, the cerebellum may offer support for maintaining striatal function in neurodegenerative diseases.

Objective: To evaluate whether sequential cerebellar transcranial magnetic stimulation (TMS) and striatal transcranial temporal interference stimulation (tTIS) enhances WM in patients with MCI, especially those with early striatal degeneration, like MCI with Lewy bodies (MCI-LB).

Design, setting, and participants: This randomized, quadruple-blind, placebo-controlled, crossover trial was conducted from August 2023 to October 2024 at 1 site in Switzerland and 1 in Czech Republic. Participants included individuals with MCI-LB or amnestic MCI (aMCI) and age-matched healthy controls (HCs).

15 Jul

Relative entropy as a biomarker for vagus nerve stimulation response in epilepsy: Insights from intracerebral electroencephalography

Objective: This study aims to analyze differences in pre-implantation invasive electroencephalographic (IEEG) data between vagus nerve stimulation (VNS) responders (>50% seizure reduction) and VNS nonresponders (<50% seizure reduction).

Methods: We retrospectively identified 19 patients with drug-resistant focal epilepsy who underwent IEEG followed by VNS implantation instead of resective brain surgery. Resting-state IEEG recordings (30 min) were selected for all patients. Three biomarkers were analyzed in the IEEG data: (1) the number of interictal epileptiform discharges (IEDs), (2) the number of high-frequency oscillations (HFOs; ripples: 80-250 Hz, fast ripples: 250-600 Hz), and (3) relative entropy (all frequency bands, 80-250 Hz, and 250-600 Hz). Analyses were performed in three regions of interest: (1) the all contact zones (ACZ), (2) the seizure-onset zones (SOZ), and (3) the non-seizure onset zones (NON SOZ). Differences between VNS responders and nonresponders were then evaluated. Finally, a statistical classifier was constructed to predict VNS efficacy based on all three biomarkers in the ACZ, SOZ, and non-SOZ.