Norwegian population-based study of effectiveness of vagus nerve stimulation in patients with developmental and epileptic encephalopathies.

Objective: Evaluate the long-term efficacy of vagus nerve stimulation (VNS) in patients with developmental and epileptic encephalopathies (DEE) compared with epilepsy patients without intellectual disability (ID).

Methods: Long-term outcomes from a Norwegian VNS quality registry are reported in 105 patients with DEEs (Lennox-Gastaut syndrome [LGS] n = 62; Dravet n = 16; Rett n = 9; other syndromes n = 18) were compared with 212 epilepsy patients without ID, with median follow-up of 88 and 72 months, respectively. Total seizure reduction was evaluated at 6, 12, 24, 36, and 60 months.

Ramping dynamics and theta oscillations reflect dissociable signatures during rule-guided human behavior.

Contextual cues and prior evidence guide human goal-directed behavior. The neurophysiological mechanisms that implement contextual priors to guide subsequent actions in the human brain remain unclear. Using intracranial electroencephalography (iEEG), we demonstrate that increasing uncertainty introduces a shift from a purely oscillatory to a mixed processing regime with an additional ramping component.

Anatomical registration of intracranial electrodes. Robust model-based localization and deformable smooth brain-shift compensation methods.

Background: Intracranial electrodes are typically localized from post-implantation CT artifacts. Automatic algorithms localizing low signal-to-noise ratio artifacts and high-density electrode arrays are missing. Additionally, implantation of grids/strips introduces brain deformations, resulting in registration errors when fusing post-implantation CT and pre-implantation MR images.

Anatomical registration of intracranial electrodes. Robust model-based localization and deformable smooth brain-shift compensation methods.

Precise electrode localization is important for maximizing the utility of intracranial EEG data. Electrodes are typically localized from post-implantation CT artifacts, but algorithms can fail due to low signal-to-noise ratio, unrelated artifacts, or high-density electrode arrays. Minimizing these errors usually requires time-consuming visual localization and can still result in inaccurate localizations.

Modeling intracranial electrodes. A simulation platform for the evaluation of localization algorithms.

Introduction: Intracranial electrodes are implanted in patients with drug-resistant epilepsy as part of their pre-surgical evaluation. This allows the investigation of normal and pathological brain functions with excellent spatial and temporal resolution. The spatial resolution relies on methods that precisely localize the implanted electrodes in the cerebral cortex, which is critical for drawing valid inferences about the anatomical localization of brain function.

Monitoring the Awake and Anesthetized Unconscious States Using Bispectral Index and Electroencephalographic Connectivity Measures.

Our objective was to compare three electroencephalography (EEG)-based methods with anesthesiologist clinical judgment of the awake and anesthetized unconscious states. EEG recorded from 25 channels and from four channel bilateral Bispectral index (BIS) electrodes were collected from 20 patients undergoing surgery with general anesthesia. To measure connectivity we applied Directed Transfer Function (DTF) in eight channels of the EEG, and extracted data from BIS over the same time segments.

Episodic Memory Dysfunction and Effective Connectivity in Adult Patients With Newly Diagnosed Nonlesional Temporal Lobe Epilepsy.

Objective: Epilepsy is associated with both changes in brain connectivity and memory function, usually studied in the chronic patients. The aim of this study was to explore the presence of connectivity alterations measured by EEG in the parietofrontal network in patients with temporal lobe epilepsy (TLE), and to examine episodic memory, at the time point of diagnosis.

Methods: The parietofrontal network of newly diagnosed patients with TLE ( = 21) was assessed through electroencephalography (EEG) effective connectivity and compared with that of matched controls ( = 21).

Norwegian population-based study of long-term effects, safety, and predictors of response of vagus nerve stimulation treatment in drug-resistant epilepsy: The NORPulse study.

Objective: This study was undertaken to evaluate the efficacy of vagus nerve stimulation (VNS) over time, and to determine which patient groups derive the most benefit.

Methods: Long-term outcomes are reported in 436 epilepsy patients from a VNS quality registry (52.8% adults, 47.

Cognition in adult patients with newly diagnosed non-lesional temporal lobe epilepsy.

Objective: To evaluate whether cognitive performance is affected in newly diagnosed temporal lobe epilepsy (TLE) and to determine the most vulnerable cognitive domains.

Methods: In this baseline longitudinal study, differences in memory and non-memory cognitive functions were assessed using comprehensive neuropsychological test batteries in 21 adult patients with newly diagnosed non-lesional TLE and individually matched controls. In addition, the analyses included ratings of self-perceived emotional status.

Utilisation and polypharmacy aspects of antiepileptic drugs in elderly versus younger patients with epilepsy: A pharmacoepidemiological study of CNS-active drugs in Norway, 2004-2015.

Background And Purpose: Many patients with epilepsy use antiepileptic drugs (AEDs) in combination. The elderly is a vulnerable group regarding polypharmacy. The purpose of this study was to investigate changes in utilisation of AEDs, and the extent of polypharmacy with other CNS-active drugs in elderly versus younger patients in Norway.

Ictal EEG source imaging in presurgical evaluation: High agreement between analysis methods.

Purpose: To determine the agreement between five different methods of ictal EEG source imaging, and to assess their accuracy in presurgical evaluation of patients with focal epilepsy. It was hypothesized that high agreement between methods was associated with higher localization-accuracy.

Methods: EEGs were recorded with a 64-electrode array.

Seizure outcomes in relation to the extent of resection of the perifocal fluorodeoxyglucose and flumazenil PET abnormalities in anteromedial temporal lobectomy.

Background: The area of predominant perifocal [(18)F]fluorodeoxyglucose ((18)F-FDG) hypometabolism and reduced [(11)C]flumazenil ((11)C-FMZ) -binding on PET scans is currently considered to contain the epileptogenic zone and corresponds anatomically to the area localizing epileptogenicity in patients with temporal lobe epilepsy (TLE). The question is whether the volume of the perifocal pre-operative PET abnormalities, the extent of their resection, and the volume of the non-resected abnormalities affects the post-operative seizure outcome.

Methods: The sample group consisted of 32 patients with mesial temporal sclerosis who underwent anteromedial temporal lobe resection for refractory TLE.

Subclinical epileptiform activity in children with electrical status epilepticus during sleep: effects on cognition and behavior before and after treatment with levetiracetam.

We performed a double-blind placebo-controlled crossover study of the effects of spike activity during sleep and when awake on learning, long-term memory, vigilance and behavior before and after treatment with levetiracetam in children with electrical status epilepticus during sleep. At baseline, verbal learning declined with increasing spike activity, but there were no relations between spike activity and memory, vigilance or behavior. Levetiracetam was effective in reducing sleep-related spike activity, but on a group level, this had no clear effects on behavior, vigilance or learning and memory.

The effect of levetiracetam on focal nocturnal epileptiform activity during sleep--a placebo-controlled double-blind cross-over study.

Electric Status Epilepticus during Sleep (ESES) occurs in children with and without epilepsy. It may be related to disturbances as autism spectrum disorder, attention-deficit hyperactivity disorder and acquired aphasia (Landau-Kleffner syndrome). Antiepileptic drug (AED) treatment has been reported in small studies without placebo control.

Attention-deficit hyperactivity disorder and nocturnal epileptiform activity in children with epilepsy admitted to a national epilepsy center.

The aim of this study was to determine if there exists a relationship between attention-deficit hyperactivity disorder (ADHD) and the quantity of focal nocturnal epileptiform activity on the EEG (FNEA) measured as the percentage of epileptiform activity during non-REM sleep (spike index). This was accomplished with a prospective study of children aged 6-14 years consecutively admitted to our center. Of 362 patients, 44 (12.