Unpleasant thoughts and anxiety induced by electrical cortical stimulation.

Emotional processing has been attracting increased attention. We herein present three patients with intractable epilepsy in whom emotional responses were elicited by electrical cortical stimulation. Negative feelings were produced in all patients; however, the content of each differed.

An anatomo-functional study of the interactivity between the paracentral lobule and the primary motor cortex.

Objective: The purpose of this study was to understand the anatomical and functional connections between the paracentral lobule (PCL) and the primary motor cortex (M1) of the human brain.

Methods: This retrospective study included 16 patients who underwent resection of lesions located near M1. Nine patients had lesions in the dominant hemisphere.

Intraoperative nerve stimulation during vagal nerve stimulator placement.

Background: Vagal nerve stimulation (VNS) is a palliative treatment for refractory epilepsy and intraoperative nerve stimulation is applied to the vagal and other nerves to prevent electrode misplacement. We evaluated these thresholds to establish intraoperative monitoring procedures for VNS surgery.

Methods: Forty-six patients who underwent intraoperative nerve stimulation during VNS placement were enrolled.

Visual networks: Electric brain stimulation and diffusion tensor imaging.

Objective: The present study investigated the networks of visual functional areas using electric brain stimulation (EBS) and diffusion tensor imaging (DTI).

Methods: Thirteen patients with intractable focal epilepsy in which visual functional areas were identified by EBS were enrolled. An electric stimulation at 50Hz was applied to electrodes during several tasks.

Computational Fluid Dynamics Analysis Features in Aneurysm Development in Rats.

The investigation of how to control the development and growth of cerebral aneurysms is important for the prevention of subarachnoid hemorrhage. Although there have been several types of research studies on computational fluid dynamics (CFD) analysis of brain aneurysm development and growth, there has been no unified interpretation of the CFD analysis results. The purpose of this study is to clarify the characteristics of CFD analysis results related to the development of cerebral aneurysms using an animal model.

Transcranial electrical stimulation technique for induction of unilateral motor evoked potentials.

Objective: Transcranial electrical stimulation motor evoked potentials (TES-MEP) are widely used to monitor motor function; however, broad current spread and induced body movement are limitations of this technique. We herein report a localized stimulation technique for TES-MEP that induces unilateral MEP responses.

Methods: The stimulation of C1(+)-C4(-) or C2(+)-C3(-) was performed to induce right- or left-sided muscle contraction, respectively, in 70 patients.

Microbleeds Due to Reperfusion Enhance Early Seizures after Carotid Ligation in a Rat Ischemic Model.

Impaired reperfusion in ischemic brain disease is a condition that we are increasingly confronted with owing to recent advances in reperfusion therapy. In the present study, rat models of reperfusion were investigated to determine the causes of acute seizures using magnetic resonance imaging (MRI) and histopathological specimens. Rat models of bilateral common carotid artery ligation followed by reperfusion and complete occlusion were created.

Deep learning for the diagnosis of mesial temporal lobe epilepsy.

Objective: This study aimed to enable the automatic detection of the hippocampus and diagnose mesial temporal lobe epilepsy (MTLE) with the hippocampus as the epileptogenic area using artificial intelligence (AI). We compared the diagnostic accuracies of AI and neurosurgical physicians for MTLE with the hippocampus as the epileptogenic area.

Method: In this study, we used an AI program to diagnose MTLE.

Usefulness of Intraoperative Electrocorticography for the Localization of Epileptogenic Zones.

Intraoperative electrocorticography (iECoG) is widely performed to identify irritative zones in the cortex during brain surgery; however, several limitations (e.g., short recording times and the effects of general anesthesia) reduce its effectiveness.

Comparison of Thresholds between Bipolar and Monopolar Electrical Cortical Stimulation.

Electrical cortical stimulation is widely performed and is the gold standard for functional mapping in intractable epilepsy patients; however, a standard protocol has not yet been established. With respect to stimulation methods, two techniques can be applied: monopolar and bipolar stimulation. We compared the threshold to induce clinical symptoms between these two stimulation techniques.

Effect of Early Surgical Intervention for Brain Tumors Associated with Epilepsy on the Improvement in Memory Performance.

We evaluated the effect of early surgical intervention on the change in memory performance of patients with low-grade brain tumors associated with epilepsy. Twenty-three adult patients with low-grade brain tumors and epilepsy who underwent surgery at our institution between 2010 and 2019 were included. The Wechsler Memory Scale-Revised (WMS-R) was used to assess cognitive memory performance.

Motor Mapping with Functional Magnetic Resonance Imaging: Comparison with Electrical Cortical Stimulation.

The aim of the present study was to evaluate motor area mapping using functional magnetic resonance imaging (fMRI) compared with electrical cortical stimulation (ECS). Motor mapping with fMRI and ECS were retrospectively compared in seven patients with refractory epilepsy in which the primary motor (M1) areas were identified by fMRI and ECS mapping between 2012 and 2019. A right finger tapping task was used for fMRI motor mapping.

Cortical regions and networks of hyperkinetic seizures: Electrocorticography and diffusion tensor imaging study.

Objective: The present study investigated the cortical areas and networks responsible for hyperkinetic seizures by analyzing invasive recordings and diffusion tensor imaging (DTI) tractography.

Methods: Seven patients with intractable focal epilepsy in whom hyperkinetic seizures were recorded during an invasive evaluation at Sapporo Medical University between January 2012 and March 2020 were enrolled in the present study. Intracranial recordings were analyzed to localize seizure-onset zones (SOZs) and symptomatogenic zones (spread areas at clinical onset).

Effects of polarity of bipolar sensorimotor direct cortical stimulation on intraoperative motor evoked potentials.

Objective: The present study investigated the effects of the stimulus polarity and location of motor evoked potential (MEP) to establish a stimulation protocol.

Methods: Nineteen patients who intraoperatively underwent MEP in bipolar direct cortical stimulation were enrolled in the present study. Somatosensory evoked potentials (SEP) of the contralateral median nerve stimulation were recorded to determine stimulation sites.

Steady-State Cortico-Cortical Evoked Potential.

Purpose: The present study evaluated the utility of the steady-state responses of cortico-cortical evoked potentials (SSCCEPs) and compared them with the responses of conventional CCEPs.

Methods: Eleven patients with medically intractable focal epilepsy who underwent the implantation of subdural electrodes or stereoelectroencephalography were enrolled. Conventional CCEPs were obtained by averaging responses to alternating 1-Hz electrical stimuli, and 5-Hz stimuli were delivered for recording SSCCEPs.

A case of paroxysmal kinesigenic dyskinesia suspected to be reflex epilepsy.

An 11-year-old male patient developed weakness or right arm elevation after sudden movement at the age of eight. Reflex epilepsy was initially suspected; however, magnetic resonance imaging and electroencephalography (EEG) revealed no abnormality. Video-EEG monitoring was performed, but no change was noted during attacks of weakness.

Pitfalls of Commonly Used Ischemic and Dementia Models Due to Early Seizure by Carotid Ligation.

While the bilateral common carotid artery (CCA) ligation model is widely used in cerebrovascular disease and dementia studies, it can frequently cause seizures. We examined the validity of seizure as an experimental model of ischemia. Eight-week-old male Wistar and Sprague-Dawley (SD) rats were implanted with electrocorticography (ECoG) electrodes and bilateral CCA ligation was performed and compared to the sham groups.

Eye Movement Network Originating from Frontal Eye Field: Electric Cortical Stimulation and Diffusion Tensor Imaging.

This study investigated the networks originating from frontal eye fields (FEFs) using electric cortical stimulation and diffusion tensor imaging (DTI). Seven patients with intractable focal epilepsy, in which FEFs were identified by electrical cortical stimulation, were enrolled in this study. Electric stimulation at 50 Hz was applied to the electrodes for functional mapping.

Preoperative Prediction of Communication Difficulties during Awake Craniotomy in Glioma Patients: A Retrospective Evaluation of 136 Cases at a Single Institution.

Awake craniotomy has been widely performed in patients with glioma in eloquent areas to minimize postoperative brain dysfunction. However, neurological examination in awake craniotomy is sometimes problematic due to communication difficulties during the intraoperative awake period. We evaluated preoperative predictors of these difficulties in awake craniotomy for patients with glioma.

Preoperatively estimated graft flow rate contributes to the improvement of hemodynamics in revascularization for Moyamoya disease.

Objectives: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass operation is an effective treatment for patients with Moyamoya disease, and the hemodynamic parameters are reported to be improved after operation. However, there is no report concerning hemodynamic changes from the viewpoint of the preoperative anatomical structure of grafts. In this study, we evaluated the correlation between the preoperatively estimated blood flow of the graft obtained through image-based computational fluid dynamics (CFD) analysis and the hemodynamic changes in the acute phase after revascularization.

Target Selection of Directional Lead in Patients with Parkinson's Disease.

Several structures including subthalamic nucleus (STN), the caudal zona incerta (cZI), the prelemniscal radiation (Raprl), and the thalamic ventral intermediate nucleus (Vim) have been reported to be useful for improving symptoms of Parkinson's disease (PD). However, the effect of each target is still unclear. Therefore, we investigated each structure's effects and adverse effects using a directional lead implanted in the posterior STN adjacent to the cZI and Raprl in two patients with tremor-dominant PD.

Forgetting to take antiseizure medications is associated with focal to bilateral tonic-clonic seizures, as revealed by a cross-sectional study.

Objectives: To evaluate the effects of nonadherence to antiseizure medications (ASMs) and clinical characteristics on seizure control, we employed a prospective cohort cross-sectional study using self-reports and medical records of patients with epilepsy (PWEs).

Methods: Eight hundred and fifty-five PWEs taking ASMs were enrolled from fourteen collaborative outpatient clinics from January 2018 to March 2019. Questions from the Morisky Medication Adherence Scale were used as adherence self-reports.

Effect of Cycling Thalamosubthalamic Stimulation on Tremor Habituation and Rebound in Parkinson Disease.

Background: Deep brain stimulation is an effective treatment for severe tremor in essential tremor and Parkinson disease (PD). However, progressive loss of the beneficial effects of deep brain stimulation may occur due to several factors.

Case Description: We assessed the effects of different temporal patterns of cycling stimulation in the posterior subthalamic area, subthalamic nucleus, and the ventral intermediate nucleus of the thalamus in 3 PD patients with early decline of tremor suppression associated with severe tremor rebound.