Zhiyi Sha

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Approximately 30-50% of patients with brain tumors present with seizures as the initial symptom. Seizures play a very important role in the quality of life, particularly in patients with slow-growing primary brain tumors. Tumor-related seizures are often refractory to antiepileptic treatment. Despite the importance of this subject to the fields of(More)
RATIONALE Seizures are among the most common clinical presentations of posterior reversible encephalopathy syndrome (PRES). This syndrome has rarely been reported to cause chronic epilepsy or persistent cortical dysfunction. The prognostic value of EEG findings during PRES is unknown. We retrospectively evaluated EEG characteristics in patients with PRES in(More)
PURPOSE To determine if ultrahigh-field-strength magnetic resonance (MR) imaging can be used to detect subregional hippocampal alterations. MATERIALS AND METHODS Subjects provided written consent to participate in this prospective institutional review board-approved HIPAA-compliant study. T1- and T2-weighted 7-T brain MR images were acquired in 11 healthy(More)
PURPOSE In this study, we investigate the modification to cortical oscillations of patients with Parkinson disease (PD) by subthalamic deep brain stimulation (STN-DBS). METHODS Spontaneous cortical oscillations of patients with PD were recorded with magnetoencephalography during on and off subthalamic nucleus deep brain stimulation states. Several(More)
During awake brain surgeries, electrocorticogram (ECoG) was recorded using a high density electrode grid from the motor cortex of two subjects while they were asked to execute spontaneous hand extension and flexion. Firstly, we characterized the spatio-spectral patterns of high-density ECoG during the hand movements. In both subjects, we observed event(More)
OBJECTIVE High frequency oscillations (HFOs) in intracranial electroencephalography (iEEG) recordings are considered as promising clinical biomarkers of epileptogenic regions in the brain. The aim of this study is to improve and automatize the detection of HFOs by exploring the time-frequency content of iEEG and to investigate the seizure onset zone (SOZ)(More)
High frequency oscillations (HFOs) have been considered as reliable biomarkers for seizure onset zone (SOZ) that may potentially benefit the presurgical evaluation in epilepsy surgery. By applying an automatic technique, we explored the spatial characteristics of ripples (80-250 Hz), fast ripples (250-500 Hz) and spikes using human iEEG data recorded in 5(More)
Unlike focal or partial epilepsy, which has a confined range of influence, idiopathic generalized epilepsy (IGE) often affects the whole or a larger portion of the brain without obvious, known cause. It is important to understand the underlying network which generates epileptic activity and through which epileptic activity propagates. The aim of the present(More)
High frequency oscillations (HFOs) during inter-ictal state have been considered as a potential biomarker of epileptogenic regions in brain. The purpose of the current study is to improve and automatize the detection of HFOs basing on HFO distinguishing features followed by unsupervised clustering method, and to predict seizure onset zone (SOZ) using the(More)
BACKGROUND Patients afflicted with low-grade glioma (LGG) frequently suffer from seizures. The mechanisms of seizure initiation in these patients remain poorly understood. Tumor location has been correlated with seizure initiation. However, these correlative studies relied on dichotomized data analysis based on arbitrary lobe assignments. As a result, the(More)