Graph neural networks in EEG spike detection.

Objective: This study develops new machine learning architectures that are more adept at detecting interictal epileptiform discharges (IEDs) in scalp EEG. A comparison of results using the average precision (AP) metric is made with the proposed models on two datasets obtained from Baptist Hospital of Miami and Temple University Hospital.

Methods: Applying graph neural networks (GNNs) on functional connectivity (FC) maps of different frequency sub-bands to yield a novel architecture we call FC-GNN.

Rapid Passive Gamma Mapping as an Adjunct to Electrical Stimulation Mapping for Functional Localization in Resection of Primary Brain Neoplasms.

Objective: We examined the utility of passive high gamma mapping (HGM) as an adjunct to conventional awake brain mapping during glioma resection. We compared functional and survival outcomes before and after implementing intraoperative HGM.

Methods: This was a retrospective cohort study of 75 patients who underwent a first-time, awake craniotomy for glioma resection.

Dynamics and Distant Effects of Frontal/Temporal Epileptogenic Focus Using Functional Connectivity Maps.

Objective: Connectivity patterns of interictal epileptiform discharges are all subtle indicators of where the three-dimensional (3D) source of a seizure could be located. These specific patterns are explored in the recorded electroencephalogram (EEG) signals of 20 individuals diagnosed with focal epilepsy to assess how their functional brain maps could be affected by the 3D onset of a seizure.

Methods: Functional connectivity maps, estimated by phase synchrony among EEG electrodes, were obtained by applying a data-driven recurrence-based method.

Intraoperative Neurophysiologic Monitoring for Adult Patients Undergoing Posterior Spinal Fusion.

Background: Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) are frequently used to monitor neurologic function during spinal deformity surgery. The sensitivity and specificity of intraoperative neurophysiologic monitoring (IONM) in patients undergoing posterior spinal fusion (PSF) is debatable.

Methods: A retrospective review of all patients undergoing PSF with IONM from October 2008 to December 2012 was performed.

Intraoperative neurophysiological monitoring in anterior lumbar interbody fusion surgery.

Purpose: Somatosensory evoked potential (SSEP) and motor evoked potentials (MEP) are frequently fused to monitor neurological function during spinal deformity surgery. However, there are few studies regarding the utilization of intraoperative neuromonitoring during anterior lumbar interbody fusion (ALIF). This study presents the authors' experience with intraoperative neuromonitoring in ALIF.

Quasi-stationarity of EEG for intraoperative monitoring during spinal surgeries.

We present a study and application of quasi-stationarity of electroencephalogram for intraoperative neurophysiological monitoring (IONM) and an application of Chebyshev time windowing for preconditioning SSEP trials to retain the morphological characteristics of somatosensory evoked potentials (SSEP). This preconditioning was followed by the application of a principal component analysis (PCA)-based algorithm utilizing quasi-stationarity of EEG on 12 preconditioned trials. This method is shown empirically to be more clinically viable than present day approaches.

Intraoperative neurophysiological monitoring of somatosensory evoked potentials during hip arthroscopy surgery.

Arthroscopic hip surgery is used to treat many of the causes of hip pain, hip instability, and hip disorders. Hip pain and instability are often caused by injuries to the acetabular labrum. Repairing labral tears, suturing, and debridement involve stabilizing the hip and placing the operative side leg in traction (Phillipon 2006, Phillipon and Schenker 2006) to allow for instrument clearance and to avoid iatrogenic injury to the chondral surfaces.

Peak detection of somatosensory evoked potentials using an integrated principal component analysis-walsh method.

Clinical application of somatosensory evoked potentials (SSEP) in intraoperative neurophysiological monitoring still requires anywhere between 200 to 500 trials, which is excessive and introduces a delay during surgery. In this study, the analysis was performed on the data recorded in 20 patients undergoing surgery during which the posterior tibial nerve was stimulated and SSEP response was recorded from scalp. The first 10 trials were analyzed using an eigen decomposition technique, and a signal extraction algorithm eliminated the common components of the signals not contributing to the SSEP.

An effective intra-operative neurophysiological monitoring scheme for aneurysm clipping and spinal fusion surgeries.

Somatosensory-evoked potentials (SSEPs) have been widely used for intra-operative neurophysiological monitoring (IONM). Currently at least 200-300 trials are required to generate a readable SSEP signal. This study introduces a novel approach that yields accurate detection results of the SSEP signal yet with a significantly reduced number of trials, resulting in an effectual monitoring process.

Diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury.

Background: Detailed evaluation of a brachial plexus birth injury is important for treatment planning.

Objective: To determine the diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury.

Materials And Methods: Included in the study were 31 children with perinatal brachial plexus injury who underwent surgical intervention.

Near infrared spectroscopy in the management of status epilepticus in a young infant.

We report the medication management of electroencephalographic status epilepticus with subtle clinical manifestations in a young infant while simultaneously recording electroencephalographic activity and cerebral regional oxygen saturation (rSO(2)) index using near infrared spectroscopy (NIRS). We found that antiepileptic drugs equally influence the frequency of rSO(2) index fluctuations and electroencephalographic seizures. The purpose of this report is to illustrate the use of NIRS in the medication management of an infant with status epilepticus and subtle or no clinical manifestations; and to suggest that if future studies confirm our finding, NIRS may be reliably used to gauge the effects of antiepileptic medications in similar patients.

Near-infrared spectroscopy to define cognitive frontal lobe functions.

Near-infrared spectroscopy (NIRS) monitors changes in the regional cerebral oxygenation (rSO) and has been used to study cerebral physiologic functions in normal states and during epileptic seizures. Yet, the limitations and pitfalls of the technique are not fully understood. The authors evaluated NIRS changes over the frontal lobes during language tasks known to be associated with the integrity of the dominant frontal lobe in 17 normal adults (handedness: 14 right, 3 left).

An interactive interface for seizure focus localization using SPECT image analysis.

Accurate epileptic focus localization using single photon emission computed tomography (SPECT) images has proven to be a challenging endeavor. First, commonly used radiopharmaceuticals such as hexamethylpropylene amine oxime (HMPAO) quantitatively underestimate large blood flows, leading to subtracted SPECT images that do not reflect the true cerebral physiological conditions, and often display non-distinct epileptic foci. The proposed relative change subtraction method of SPECT image analysis helps alleviate this quantitative burden.

Detection of interictal spikes and artifactual data through orthogonal transformations.

This study introduces an integrated algorithm based on the Walsh transform to detect interictal spikes and artifactual data in epileptic patients using recorded EEG data. The algorithm proposes a unique mathematical use of Walsh-transformed EEG signals to identify those criteria that best define the morphologic characteristics of interictal spikes. EEG recordings were accomplished using the 10-20 system interfaced with the Electrical Source Imaging System with 256 channels (ESI-256) for enhanced preprocessing and on-line monitoring and visualization.

Cerebral regional oxygen fluctuations and decline during clinically silent focal electroencephalographic seizures in a neonate.

We describe a neonate with tuberous sclerosis complex and right frontal cortical dysplasia who underwent simultaneous near-infrared spectroscopy and electroencephalography (EEG) during repetitive clinically silent right frontal EEG seizures. The seizures produced a progressive decline in regional oxygen saturation index and wider regional oxygen saturation index fluctuations in the right hemisphere than in the left hemisphere. We conclude that recurrent clinically silent focal EEG seizures in this neonate were associated with lateralizing near-infrared spectroscopy changes suggestive of relative cerebral hypoxia.

Intrauterine shoulder weakness and obstetric brachial plexus palsy.

Obstetrical brachial plexus injury occurs when the forces preventing the stretch of the brachial plexus are overcome by the forces stretching it. This report describes an 8-day-old male delivered by uncomplicated cesarean section with right obstetrical brachial plexus palsy and congenital arm atrophy. The patient had a history of decreased right arm movement detected by fetal ultrasound at 18 to 20 weeks of gestation.

Shoulder function following late neurolysis and bypass grafting for upper brachial plexus birth injuries.

Eleven children ranging in age from 9 to 21 months underwent late nerve reconstruction for persistent shoulder paralysis following an upper brachial plexus birth injury. Only neurolysis was performed in three patients. Neurolysis and nerve grafting bypassing the neuroma with proximal and distal end-to-side repairs was performed in the other eight.

Bilateral decreased oxygenation during focal status epilepticus in a neonate with hemimegalencephaly.

Early surgical removal of a dysplastic hemisphere appears to be beneficial for neonates with hemimegalencephaly and medically resistant seizures. We analyzed the changes in the cerebral regional oxygen saturation index in a neonate with tuberous sclerosis and right hemimegalencephaly (1) during seven episodes of right hemisphere electroencephalographic status epilepticus with and without clinical manifestations and (2) after right hemispherectomy. The cerebral regional oxygen saturation index demonstrated marked fluctuations and progressive decline in both hemispheres during the episodes and normal values in the remaining hemisphere after surgery.

An integrated auditory-comprehension process augmented through topographical maps and a new eigensystem study.

The algorithm developed in this study integrates a frequency analysis of key frequency bands (Alpha, Beta, Delta, and Theta) with the principal component analysis (PCA) in order to validate brain functional mappings associated with the characterization effects of an Auditory/Comprehension task. This study provides added insight to earlier findings involving the Wernicke and Broca's brain areas in relation to language comprehension. A thorough examination of the electroencephalograph (EEG) recordings through the PCA reveals that eigenvectors associated with the largest eigenvalues produce an interesting activity pattern directly attributable to those characteristic behaviors found in the Alpha, Beta, Delta, and Theta frequency bands.

An optimization approach to recognition of epileptogenic data using neural networks with simplified input layers.

This study introduces a simplified approach for the implementation of artificial neural networks (ANN) for the recognition of epileptic data in electroencephalograph (EEG) recordings. The training set construction is based on a trend-adaptive polygon which simplifies the search process as it reduces the size of the training set. This data reduction, at a sampling rate of 200 Hz, yielded a reduction ratio of 34% as a minimum to an 81% in the best case scenario.

A new mathematical approach based on orthogonal operators for the detection of interictal spikes in epileptogenic data.

This study focuses on the design of orthogonal operators based on unique Electroencephalograph (EEG) signal decompositions in order to detect interictal spikes that characterize epileptic seizures in EEG data. The merits of the algorithm are: (a) in elaborating a unique analysis scheme that scrutinizes EEG data through orthogonal operators designed to extract features that best characterize spikes in epileptogenic EEG data; and (b) in establishing mathematical derivations that provide quantitative measures through the designed operators, and characterize and locate the event of an interictal spike. The uniqueness of this algorithm is in its good performance and simplicity of implementation.

Interictal spike detection using the Walsh transform.

The objective of this study was to evaluate the feasibility of using the Walsh transformation to detect interictal spikes in electroencephalogram (EEG) data. Walsh operators were designed to formulate characteristics drawn from experimental observation, as provided by medical experts. The merits of the algorithm are: 1) in decorrelating the data to form an orthogonal basis and 2) simplicity of implementation.

3-d source localization of epileptic foci integrating EEG and MRI data.

This study evaluates the utility of 3-D localization of interictal spike activity on the electroencephalographs (EEG) superimposed on magnetic resonance imagery (MRI) in a pediatric population with extra-temporal lesional epileptic foci. 3-D software programming based on the CURRY platform (a multimodal neuro-imaging software) was adapted for analyzing scalp EEG data and reconstructing superimposed images in 10 children who underwent extensive pre-surgical evaluation for intractable partial seizures. The results of 3-D spike source localization were assessed in relationship to focal lesions evident on the patient's MRI scans.