Robert P. Turner

Standardized database development for EEG epileptiform transient detection: EEGnet scoring system and machine learning analysis

The routine scalp electroencephalogram (rsEEG) is the most common clinical neurophysiology procedure. The most important role of rsEEG is to detect evidence of epilepsy, in the form of epileptiform transients (ETs), also known as spike or sharp wave discharges. Due to the wide variety of morphologies of ETs and their similarity to artifacts and waves that are part of the normal background activity, the task of ET detection is difficult and mistakes are frequently made. The development of reliable computerized detection of ETs in the EEG could assist physicians in interpreting rsEEGs. We report progress in developing a standardized database for testing and training ET detection algorithms. We describe a new version of our EEGnet software system for collecting expert opinion on EEG datasets, a completely web-browser based system. We report results of EEG scoring from a group of 11 board-certified academic clinical neurophysiologists who annotated 30-s excepts from rsEEG recordings from 100 different patients. The scorers had moderate inter-scorer reliability and low to moderate intra-scorer reliability. In order to measure the optimal size of this standardized rsEEG database, we used machine learning models to classify paroxysmal EEG activity in our database into ET and non-ET classes. Based on our results, it appears that our database will need to be larger than its current size. Also, our non-parametric classifier, an artificial neural network, performed better than our parametric Bayesian classifier. Of our feature sets, the wavelet feature set proved most useful for classification.

Reduction of seizure occurrence from exposure to auditory stimulation in individuals with neurological handicaps: a randomized controlled trial.

Background The purpose of this work was to determine in a clinical trial the efficacy of reducing or preventing seizures in patients with neurological handicaps through sustained cortical activation evoked by passive exposure to a specific auditory stimulus (particular music). The specific type of stimulation had been determined in previous studies to evoke anti-epileptiform/anti-seizure brain activity. Methods The study was conducted at the Thad E. Saleeby Center in Harstville, South Carolina, which is a permanent residence for individuals with heterogeneous neurological impairments, many with epilepsy. We investigated the ability to reduce or prevent seizures in subjects through cortical stimulation from sustained passive nightly exposure to a specific auditory stimulus (music) in a three-year randomized controlled study. In year 1, baseline seizure rates were established. In year 2, subjects were randomly assigned to treatment and control groups. Treatment group subjects were exposed during sleeping hours to specific music at regular intervals. Control subjects received no music exposure and were maintained on regular anti-seizure medication. In year 3, music treatment was terminated and seizure rates followed. We found a significant treatment effect (p = 0.024) during the treatment phase persisting through the follow-up phase (p = 0.002). Subjects exposed to treatment exhibited a significant 24% decrease in seizures during the treatment phase, and a 33% decrease persisting through the follow-up phase. Twenty-four percent of treatment subjects exhibited a complete absence of seizures during treatment. Conclusion/Significance Exposure to specific auditory stimuli (i.e. music) can significantly reduce seizures in subjects with a range of epilepsy and seizure types, in some cases achieving a complete cessation of seizures. These results are consistent with previous work showing reductions in epileptiform activity from particular music exposure and offers potential for achieving a non-invasive, non-pharmacologic treatment of epilepsy. Trial Registration Clinicaltrials.gov NCT01459692

Web-based collection of expert opinion on routine scalp EEG: software development and interrater reliability.

Computerized detection of epileptiform transients (ETs), characterized by interictal spikes and sharp waves in the EEG, has been a research goal for the last 40 years. A reliable method for detecting ETs would assist physicians in interpretation and improve efficiency in reviewing long-term EEG recordings. Computer algorithms developed thus far for detecting ETs are not as reliable as human experts, primarily due to the large number of false-positive detections. Comparing the performance of different algorithms is difficult because each study uses individual EEG test datasets. In this article, we present EEGnet, a distributed web-based platform for the acquisition and analysis of large-scale training datasets for comparison of different EEG ET detection algorithms. This software allows EEG scorers to log in through the web, mark EEG segments of interest, and categorize segments of interest using a conventional clinical EEG user interface. This software platform was used by seven board-certified academic epileptologists to score 40 short 30-second EEG segments from 40 patients, half containing ETs and half containing artifacts and normal variants. The software performance was adequate. Interrater reliability for marking the location of paroxysmal activity was low. Interrater reliability of marking artifacts and ETs was high and moderate, respectively.

Sudden Appearance of New Upper Extremity Motor Function While Performing Neurophysiologic Intraoperative Monitoring During Tethered Cord Release: A Case Report

&NA; Tethered cord syndrome occurs when the distal spinal cord or filum adheres to adjacent structures resulting in progressive sensorimotor deficits in the lower extremities, fecal and/or urinary incontinence, and musculoskeletal deformities. Tethering of the distal cord may be idiopathic, may be associated with an intraspinal abnormality such as a lipoma, but most commonly the distal spinal cord remnant is adherent to the area of the original dysraphism repair in patients with myelodysplasia. Surgery to untether the cord is indicated in patients with worsening pain symptoms, progressive limb deformity or spasticity, or before any acute correction of an associated spinal deformity. Neurophysiologic intraoperative monitoring is used to minimize the risk of inadvertent nerve root or spinal cord injury during the untethering procedure and to assess any changes in cord function at the time of an associated spinal deformity correction. We present a patient with a lumbar level myelodysplasia, Chiari II malformation, severe scoliosis, and tethered cord that underwent concurrent scoliosis correction and tethered cord syndrome surgery, who demonstrated immediate intraoperative improvement in neurophysiologic responses in a previously flaccid upper extremity after untethering. These monitoring changes correlated with clinical improvements noted by physicians and family postoperatively. Level of Evidence Level IV.

Acute Disseminated Encephalomyelitis Following Infectious Mononucleosis

Two months following an Epstein-Barr virus infection, a 17-year-old white female presented with seizures, intermittent visual changes, and altered mental status. Magnetic resonance imaging showed white matter changes of acute disseminated encephalomyelitis with a predilection for posterior cerebral artery distributions but without radiological evidence of arteritis. Epstein-Barr virus titers and polymerase chain reaction analysis results for the virus were consistent with postinfectious acute disseminated encephalomyelitis. The symptoms and signs improved following treatment with high-dose corticosteroids and intravenous immunoglobulin. Although Epstein-Barr virus can cause acute viral encephalomyelitis, the authors report a case of acute disseminated encephalomyelitis months after acute Epstein-Barr virus infection.

Childhood paroxysmal kinesigenic dyskinesia: Report of seven cases with onset at an early age

We report on seven children who developed abnormal involuntary movements as early as 1.5 years after unremarkable term births. The paroxysmal episodes of abnormal movements were typically precipitated by sudden, voluntary movements, or a startle. The clinical features in each case were consistent with the diagnosis of paroxysmal kinesigenic dyskinesia (PKD). The episodes of abnormal movements are described. EEG was obtained in all cases, and video/electroencephalography (VEEG) monitoring was performed to exclude the possibility of epilepsy in six patients. VEEG studies revealed multiple events consistent with PKD; no ictal epileptiform discharges were recorded. The apparent benign nature of the disorder, as well as treatment options with antiepileptic drugs, was discussed with the parents, and most chose no pharmacologic treatment. We discuss clinical characteristics of PKD, treatment with anticonvulsant therapy, and recent insights into its possible pathophysiology.

Neurophysiologic intraoperative monitoring during selective dorsal rhizotomy.

Selective dorsal rootlet rhizotomy (SDR) is a neurosurgical procedure designed to reduce spasticity in the legs, although preserving motor and sensory function, of appropriately selected children with spastic quadraparesis. This is accomplished by neurophysiologicially guided (e.g., selective) severing of specific dorsal rootlets in the cauda equina. This decreases facilitatory input to spinal anterior motor neurons, thereby reducing spasticity in the legs. This first portion of this article discusses the neurophysiologic intraoperative monitoring techniques during SDR, with the understanding that there are no universally agreed upon protocols nor standards of care. The second portion of the article reviews supporting data for the utility of SDR and long-term outcomes. With major benefits attributed to the selective nature of the procedure, SDR was increasingly used in the 1980-1990s after its introduction by Fasano et al. (Neurochirurgie. 1976;22:23-34; Acta Neurochir. 1977;suppl 24:53-57; Childs Brain. 1978;4:289-305) and revision by Peacock and colleagues (S Afr Med J. 1981;60:849-850;S Afr Med J. 1982;62:119-124). More extensive SDR discussions of its history, theoretical and physiological bases, patient selection criteria, neurosurgical techniques, and postoperative and long-term management, may be found elsewhere.

Integration of EEG into Psychiatric Practice: A Step Toward Precision Medicine for Autism Spectrum Disorder.

Introduction: Data from an EEG is not commonly used by psychiatrists to plan treatment and medication. However, EEG abnormalities such as isolated epileptiform discharges are found to be more prevalent in psychiatric patients, particularly those diagnosed with autism spectrum disorder (ASD). Most medications prescribed for ASD lower seizure threshold and increase side effects. Therefore, it may be prudent to order an EEG for ASD cases, especially those categorized as refractory. Methods: The data set was obtained from a multidisciplinary practice that treats a wide variety of neuroatypical children and adolescent refractory patients. This study investigated 140 nonepileptic subjects diagnosed with ASD, aged 4 to 25 years. Visual inspection of the EEG was performed to search for paroxysmal, focal, or lateralizing patterns. Results: Of the 140 subjects, the EEG data identified 36% with isolated epileptiform discharges. The &khgr;2 analysis found no significant difference between genders among the three age groups. Findings indicated a high prevalence of isolated epileptiform discharges among individuals with ASD. Conclusions: Our results find that compared with the healthy population, a large number of patients with ASD have isolated epileptiform discharges despite never having a seizure. Our findings support the use of EEG in children, adolescents, and young adults with ASD, regardless of gender or age. This is particularly true for those who exhibit aggressive behaviors or those who have failed previous medication attempts with stimulants, antidepressants, and/or antipsychotics.