Publications by authors named "Hagai Bergman"

Schizophrenia, a complex neuropsychiatric disorder, manifests severe impairments in social cognition, notably in Theory of Mind (ToM), empathy, and emotion recognition, which significantly influence social competence and overall functioning. These aspects are crucial for prognosis in individuals diagnosed with schizophrenia (SZ). This study validates a comics strip paradigm for ToM and empathy assessment, the Montreal Affective Voices (MAV) for measuring emotion recognition, and a Go-NoGo task for inhibition control estimation in individuals diagnosed with SZ, comparing their performance with healthy controls.

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The subthalamic nucleus (STN) is pivotal in basal ganglia function in health and disease. Micro-electrode recordings of >25,000 recording sites from 146 Parkinson's patients undergoing deep brain stimulation (DBS) allowed differentiation between subthalamic input, represented by local field potential (LFP), and output, reflected in spike discharge rate (SPK). As with many natural systems, STN neuronal activity exhibits power-law dynamics characterized by the exponent α.

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Article Synopsis
  • Extracellular recordings from the external globus pallidus (GPe) in monkeys help link neuronal activity to behavior.
  • The procedure includes stereotaxic surgery for chamber implantation, post-operative MRI for GPe localization, and data collection methods.
  • The outlined protocol allows researchers to study the electrophysiological characteristics of GPe neurons while the monkeys engage in specific behavioral tasks.
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The Deep Brain Stimulation (DBS) Think Tank XI was held on August 9-11, 2023 in Gainesville, Florida with the theme of "Pushing the Forefront of Neuromodulation". The keynote speaker was Dr. Nico Dosenbach from Washington University in St.

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Article Synopsis
  • The study explores a new anesthesia method using ketamine-induced conscious sedation during deep brain stimulation (DBS) surgery for Parkinson's patients, aiming to improve patient experience while maintaining safety and surgical effectiveness.
  • Patients were randomly assigned to receive either ketamine or saline during the physiological testing phase, with both groups receiving moderate sedation before and after.
  • Results showed that ketamine provided similar quality of microelectrode recordings and lead localization compared to the traditional awake method, while significantly enhancing patient satisfaction without negative impacts on health or cognitive function.
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Frontal circuits play a critical role in motor, cognitive and affective processing, and their dysfunction may result in a variety of brain disorders. However, exactly which frontal domains mediate which (dys)functions remains largely elusive. We studied 534 deep brain stimulation electrodes implanted to treat four different brain disorders.

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Background: Deep brain stimulation (DBS) is an invasive treatment option for patients with Parkinson's disease. Recently, adaptive DBS (aDBS) systems have been developed, which adjust stimulation timing and amplitude in real-time. However, it is unknown how changes in parameters, movement states and the controllability of subthalamic beta activity affect aDBS performance.

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Subthalamic nucleus deep brain stimulation is commonly indicated for symptomatic relief of idiopathic Parkinson's disease. Despite the known improvement in motor scores, affective, cognitive, voice and speech functions might deteriorate following this procedure. Recent studies have correlated motor outcomes with intraoperative microelectrode recordings.

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Genetic subtyping of patients with Parkinson's disease (PD) may assist in predicting the cognitive and motor outcomes of subthalamic deep brain stimulation (STN-DBS). Practical questions were recently raised with the emergence of new data regarding suboptimal cognitive outcomes after STN-DBS in individuals with PD associated with pathogenic variants in glucocerebrosidase gene (GBA1-PD). However, a variety of gaps and controversies remain.

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Rest tremor is one of the most prominent clinical features of Parkinson's disease (PD). Here, we hypothesized that cortico-basal ganglia neurons tend to fire in a pattern that matches PD tremor frequency, suggesting a resonance phenomenon. We recorded spiking activity in the primary motor cortex (M1) and globus pallidus external segment of 2 female nonhuman primates, before and after parkinsonian state induction with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

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Essential tremor (ET) is a common disease in the elderly population. Severe, medication-refractory ET may require surgical intervention via ablation or deep brain stimulation (DBS). Thalamic Vim (Ventral intermediate nucleus), targeted indirectly using atlas-based coordinates, is the classical target in these procedures.

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Parkinson's disease (PD) is associated with excessive beta activity in the basal ganglia. Brain sensing implants aim to leverage this biomarker for demand-dependent adaptive stimulation. Sleep disturbance is among the most common non-motor symptoms in PD, but its relationship with beta activity is unknown.

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Background: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an effective and evidence-based treatment for idiopathic Parkinson's disease (iPD). A minority of patients does not sufficiently benefit from STN-DBS.

Objective: The predictive validity of the levodopa challenge for individual patients is analyzed.

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Frontal circuits play a critical role in motor, cognitive, and affective processing - and their dysfunction may result in a variety of brain disorders. However, exactly which frontal domains mediate which (dys)function remains largely elusive. Here, we study 534 deep brain stimulation electrodes implanted to treat four different brain disorders.

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Alzheimer's disease is one of the most common neurodegenerative conditions, which are ascribed to extracellular accumulation of β-amyloid peptides into plaques. This phenomenon seems to typify other related neurodegenerative diseases. The present study uses classical molecular-dynamics simulations to decipher the aggregation-disintegration behavior of β-amyloid peptide plaques in the presence of static and oscillating oriented external electric fields (OEEFs).

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Background: It is unknown whether Parkinson's disease (PD) genetic heterogeneity, leading to phenotypic and pathological variability, is also associated with variability in the unique PD electrophysiological signature. Such variability might have practical implications for adaptive deep brain stimulation (DBS).

Objective: The aim of our work was to study the electrophysiological activity in the subthalamic nucleus (STN) of patients with PD with pathogenic variants in different disease-causing genes.

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Article Synopsis
  • The study investigates two types of neurons in the non-human primate external globus pallidus: low-frequency discharge (LFD) and high-frequency discharge (HFD) neurons, highlighting a gap in previous research that often overlooked LFD neurons.
  • It found that LFD neurons showed burst activity, were linked to the importance of behavioral cues, and had correlated spiking activity, while HFD neurons were more likely to pause and focused on cue value with uncorrelated spiking.
  • These results suggest a complex organization in the external globus pallidus that plays a crucial role in the normal functioning of the basal ganglia.
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Sleep spindles are crucial for learning in the cortex and basal ganglia (BG) because they facilitate the reactivation of previously active neuronal ensembles. Studying field potentials (FPs) and spiking in the cortex and BG during sleep in non-human primates following pre-sleep learning, we show that FP sleep spindles are widespread in the BG and are similar to cortical spindles in morphology, spectral content, and response to the pre-sleep task. Further, BG spindles are concordant with electroencephalogram (EEG) spindles and associated with increased cortico-BG correlation.

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Objective: It has been argued that the incidence of multiple step saccades (MSS) in voluntary saccades could serve as a complementary biomarker for diagnosing Parkinson's disease (PD). However, voluntary saccadic tasks are usually difficult for elderly subjects to complete. Therefore, task difficulties restrict the application of MSS measurements for the diagnosis of PD.

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The tonic activity of striatal cholinergic interneurons (CINs) is modified differentially by their afferent inputs. Although their unitary synaptic currents are identical, in most CINs cortical inputs onto distal dendrites only weakly entrain them, whereas proximal thalamic inputs trigger abrupt pauses in discharge in response to salient external stimuli. To test whether the dendritic expression of the active conductances that drive autonomous discharge contribute to the CINs' capacity to dissociate cortical from thalamic inputs, we used an optogenetics-based method to quantify dendritic excitability in mouse CINs.

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Spontaneous pauses in firing are the hallmark of external pallidum (GPe) neurons. However, the role of GPe pauses in the basal ganglia network remains unknown. Pupil size and saccadic eye movements have been linked to attention and exploration.

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Article Synopsis
  • - The study explores the use of low-dose ketamine for conscious sedation during deep brain stimulation (DBS) surgeries in Parkinson's disease patients, aiming to improve patient comfort while maintaining effective intra-operative monitoring.
  • - Three anesthesia methods were compared in a total of 38 operations, including combinations of propofol and ketamine, and results showed that all methods accurately identified critical brain areas.
  • - Findings indicate that low-dose ketamine is an effective and safe option for sedation during DBS, yielding results comparable to those achieved with traditional awake anesthesia approaches.
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Article Synopsis
  • DBS Think Tank IX took place from August 25-27, 2021, in Orlando, FL, featuring both in-person U.S. attendees and international participants joining via video conferencing.
  • Founded in 2012, the Think Tank serves as a collaborative space for clinicians, engineers, and researchers to discuss advancements in deep brain stimulation (DBS) technologies and address related logistical and ethical challenges.
  • This year's meeting highlighted the growing application of DBS across various brain disorders, estimating over 230,000 devices implanted globally, with special focus areas including neuromodulation strategies, innovative technologies, neuroethics, and specific applications for pain, epilepsy, and traumatic brain injuries.
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