Automatic Analysis of EEGs Using Big Data and Hybrid Deep Learning Architectures

Periodic lateralized epileptiform discharges with transitional rhythmic discharges: association with seizures

La Crosse virus encephalitis is the most common mosquito-borne virus in children in the United States. La Crosse virus encephalitis has emerged as a significant health concern due to its potential for acute morbidity, including seizures, alterations in mental status, and, in rare cases, death, as well as the potential for chronic morbidity, including, epilepsy and cognitive and behavioral disorders. The aim of this study is to provide a clinical description of the largest series of children reported with periodic lateralizing epileptiform discharges (PLEDS) associated with La Cross virus encephalitis with reference to their clinical course, seizure type, electroencephalogram (EEG) patterns, and 2- and 10-year long-term neurologic outcome. In addition, to evaluate whether this subset of children may indeed have more severe disease than children with La Crosse virus encephalitis without PLEDS, comparisons are made between the 2 groups on specific variables. All patients presented with fever and disorientation; 6 of the 9 (66%) presented with seizures. PLEDS localized to the temporal lobe in 7 patients (77%). The children with PLEDS had longer intensive care unit stays (6.5 +/- 2.4 vs 3.2 +/- 1.9; P < .0001), a higher rate of intubation (88% vs 20%; P < .001), and a higher rate of cerebral herniation (1%; P < .05) than children with La Crosse virus encephalitis without PLEDS. Follow-up data on the subset with PLEDS also suggest a relatively high rate of epilepsy and behavioral difficulties with hyperactivity symptoms, memory deficits, and school difficulties. The implications for recognition, management, and follow-up of this worrisome subset of patients with La Crosse virus encephalitis are discussed.

Periodic lateralized epileptiform discharges of pediatric patients in Taiwan

The periodicity of lateralized epileptiform discharges

Background. Periodic lateralized epileptiform discharges (PLEDs) are a rare phenomenon in electroencephalography, occurring in acute structural brain lesions. In general, PLEDs appear transiently in acute lesions, but a few reports have described persistent PLEDs in chronic lesions. Case report. An 86-year-old female was admitted, in 1999, with a left MCA stroke associated with right hand focal motor seizures. The first EEG in February of 2002 showed PLEDs over the left hemisphere associated with rhythmic discharges (PLEDs-plus). The patient was admitted on a second occasion in 2003 because of three sequential seizures and the EEG showed a similar pattern. Finally in 2006, the patient was admitted again because of sequential complex partial seizures and an EEG showed the same PLEDS-plus pattern as the EEGs of 2002 and 2003. Discussion. We report an unusual case of chronic PLEDs associated with rhythmic discharges in a patient with recurrent seizures and remote stroke.

We report a patient who presented with adversive seizures associated with periodic lateralised epileptiform discharges (PLEDs), a month after head trauma. The PLEDs predominantly involving the left frontal contacts became more frequent at the onset of adversive seizures during EEG. Brain MRI demonstrated a contusion scar in the left orbital cortex with reduced diffusion, not only around this orbital lesion but also in the ipsilateral anteromedial thalamus. Single photon emission computed tomography revealed focal cerebral hyperperfusion in the left medial orbitofrontal region, basal ganglia, and thalamus. The abnormal metabolism involving the thalamus and striatum could be associated with the ipsilateral orbital contusion and might have been caused by cortical-subcortical, trans-synaptic hyperactivity. Further studies are warranted to determine the role of subcortical structures in the generation of PLEDs and adversive seizures. [Published with video sequences].

Periodic lateralized epileptiform discharges (PLEDs) are typically associated with encephalitis, cerebral abscess, cerebral infarct, and status epilepticus. There is considerable debate as to whether this pattern is ictal or interictal when seen in association with status epilepticus. We present a patient with complex partial status epilepticus who developed PLEDs and remained comatose despite optimal drug therapy. Technetium 99m single-photon emission computed tomography (SPECT) showed hyperperfusion that resolved with further aggressive antiepileptic drug therapy, indicating that this pattern may indeed be ictal. Further studies are needed to define the significance of PLEDs in patients with status epilepticus. The role of SPECT in differentiating PLEDs as an interictal or ictal pattern also requires further study.

خلفية البحث: الأشخاص الذين يعانون من اضطراب طيف التوحد لديهم معدل انتشار مرتفع للنوبات الصرعية مقارنة بالأشخاص العامة وفقا لمجموعة كبيرة من الابحاث أيضا تم العثور على مرضى طيف التوحد الذين لا يعانون من نوبات صرعية لديهم معدلات عالية من موجات صرعية. ومع ذلك، لا يزال من غير المعروف كيف ترتبط هذه الموجات الصرعية بين أعراض التوحد. الأهداف: استخدمت هذه الدراسة تخطيط كهربية الدماغ للتحقيق في العلاقة بين موجات الصرع البيني وشدة التوحد عند الأطفال. المواد وطرق العمل: أجريت دراسة مقطعية على 30 طفلا مصابا بالتوحد، (23) ذكورا، و (7) إناث. تراوحت أعمار الأطفال بين (2 سنة و12 سنة). استوفى أطفال التوحد معاييرالدليل التشخيصي والإحصائي للاضطرابات العقلية، الإصدار الخامس وتم استخدام مقياس تصنيف التوحد في مرحلة الطفولة لتحديد شدة التوحد. النتائج: اكتشفنا أن 33.4٪ من الأطفال المصابين بالتوحد لديهم نتائج تخطيط كهربية الدماغ غير طبيعية. كانت شدة التوحد وتشوهات تخطيط كهربية الدماغ مرتبطة احصائيا بشكل كبير. الإستنتاجات: وفقا للنتائج هناك علاقة بين تشوهات مخطط كهربية الدماغ ودرجة شدة التوحد. وفقا للننتائج هناك علاقة بين تشوهات مخطط كهربية الدماغ ودرجة التوحد.

A 50-year-old woman with systemic lupus erythematosus was admitted in an obtunded state. An EEG recorded while she was unconscious demonstrated one episode of rhythmic sharp wave activity in the left occipital area that lasted for 5 minutes and was followed later in the same recording by an episode of high amplitude sharp wave discharges in the right posterior temporal and occipital areas. When the patient regained consciousness, she had an Anton's syndrome of cortical blindness with denial. When she recovered light perception only, the EEG demonstrated synchronous and independent right and left occipital-posterior temporal periodic lateralized epileptiform discharges (PLEDs). Cortical blindness (Anton's syndrome) associated with abnormal electrical activity in the occipital areas has only rarely been reported. Our case is significant for the following reasons: 1) PLEDs maximal right and left occipital areas associated with bilateral visual loss has not previously been observed; 2) abnormal electrical activity in the occipital lobes may be a reversible cause of Anton's syndrome.

Electroencephalographic Cerebral Dysrhythmic Abnormalities in the Trinity of Nonepileptic General Population, Neuropsychiatric, and Neurobehavioral Disorders

Pyridoxine-dependent epilepsy (PDE) is a rare disease, of which the EEG manifestations are only partially characterised. We report our observations of EEG recordings in four patients with PDE. EEG tracings from four patients fulfilling the clinical criteria for PDE were reviewed. Relative to the time of treatment with pyridoxine, EEG recordings were available before treatment in two patients (at ages four and 10 months), immediately after treatment in two patients and during long-term follow-up with treatment in all four patients. Pre-pyridoxine interictal EEG findings included: diffuse slowing, bilateral independent multifocal epileptiform discharges, generalized bursts of polyspike slow waves and focal or generalized sharp waves. In addition, the EEG was often asymmetrical and included: generalized semi-rhythmic sharp and slow waves, a burst suppression pattern and continuous generalized spike and slow waves. In one patient, who was followed subsequently, a decrease in multifocal spikes and sharp waves and permanent cessation of clinical seizures, within 10 minutes of concurrent reduction of spikes in the pre-existing generalized spike slow wave pattern, was observed immediately after pyridoxine treatment. However, despite the clinical response in this patient we observed persistent generalized burst suppression for four days, and fluctuation of the EEG with diffuse slowing on day four and transient exacerbation of discharges with continuous spike slow waves on day 22. This was followed by intermittent sharp waves at eight and 20 months, mild slowing at 31 months and normal EEG at 43 months. Long-term EEG findings in the other three patients receiving pyridoxine ranged between normal and intermittent multifocal sharp waves. Our data confirm previous observations and provide the following new findings: (1) the presence of burst suppression pattern after cessation of seizures can occur for up to five days after initiation of pyridoxine and should not exclude the diagnosis of PDE, (2) possible fluctuation and even transient worsening of electrographic discharges were observed for up to three weeks after initiation of pyridoxine and (3) the abnormal EEG can persist for up to 43 months before normalizing (range 1-43 months) and in other cases in which it continues to be abnormal it may still improve after increasing the dose of pyridoxine.

The availability of video electroencephalography monitoring (VEEGM) in neurological intensive care units has allowed the recognition and treatment of nonconvulsive status epilepticus (NCSE). However, little is known about characteristics, management, and outcomes in patients with NCSE in developing countries. We retrospectively reviewed the video-EEG reports of 120 patients who were monitored from November 2009 to March 2013. Indications for video-EEG were mostly unexplained alterations of consciousness or witnessed convulsive seizures. We identified the clinical characteristics, treatment regimes, and outcomes of patients with NCSE and tried to determine which parameters were associated with prognosis. NCSE was detected in 12/120 (10%) patients (3 females, 9 males; age 24-86 years). Admission diagnoses were: stroke (3), epilepsy (3), autoimmune limbic encephalitis (3), herpes encephalitis (1), presumed encephalitis-cardiac arrest (1), and malignancy (1). Eight patients had witnessed convulsive seizures before video-EEG. Interictal periodic epileptiform discharges were detected in 9 patients. In one-third of patients, ≥2 EEG recordings were required to capture seizures. In addition to anticonvulsants, 3 patients received immunosuppressive therapy, while intravenous anesthetics were given to 7 patients. Four patients (33.3%; 1 female, 3 males; age 51-67 years; etiology: stroke, autoimmune encephalitis, encephalitis-cardiac arrest, and malignancy; Glasgow coma scale (GCS) score <8 in 3 patients; all had periodic discharges; intravenous anesthetics were used) died in the intensive care unit. NCSE is not an infrequent finding in neurological intensive care units, thus necessitating prolonged video-EEG monitoring in patients at risk. Witnessed convulsions may indicate the presence of nonconvulsive seizures in patients with altered consciousness. Repeated recordings may increase the detection of ictal events. Periodic epileptiform discharges are commonly observed and may predict poor prognosis. Mortality seems to be influenced mostly by the underlying etiology.

INTRODUCTION: Seizures are well-recognized complications of ischemic strokes (IS). The risk of subsequent development of epilepsy has been shown to be 2-4% in acute IS and much higher in remote IS. However, the risk of epilepsy in IS who have nonconvulsive seizures on cEEG is not well characterized. We present here a five-year retrospective study of IS patients who have nonconvulsive seizures on cEEG identifying risk factors for the development of epilepsy. METHODS: We retrospectively reviewed prospectively collected cEEG and clinical data on consecutive patients monitored from January 1, 2007, to December 31, 2011. We identified those patients with cEEG seizures that were secondary to either acute (&lt;30 days) or remote (&gt;30 days) ischemic stroke (IS; n=109) and then included in this study only those patients with follow-up encounters. Statistical analyses were performed with JMP 9.0. RESULTS: Sixty-five (41.5% acute IS, 58.5% remote IS) patients met inclusion criteria for this study. All patients were discharged on at least one antiepileptic. Nineteen (29.2%) patients were found to have seizure recurrence (i.e., epilepsy) with 84.2% being remote IS (p=0.0116). Periodic lateralized epileptiform discharges (PLEDs) were seen on cEEG in 21.5% (22.2% acute IS, 21.1% remote IS). 15.8% with PLEDs on initial cEEG developed epilepsy (p=0.74). 33.3% of patients classified as stupor/coma at the time of nonconvulsive seizures were found to have seizure recurrence compared to 24.1% of patients classified as awake/lethargy (p=0.5841). On follow up EEG (mean (SEM) 384.4 (59.1) days), the finding of sharp wave/spike (12.1%) significantly correlated with seizure recurrence (p=0.0175). DISCUSSION: This retrospective study found that patients with remote IS are at a higher risk of developing epilepsy when nonconvulsive seizures are recorded on cEEG in the hospital. Additionally, the finding of sharp waves on follow-up routine EEG further identifies those at risk for recurrence. This study highlights the usefulness of cEEG in patients in patients with acute or remote strokes and provides guidance on utility of follow-up EEG.

Of 1,114 EEG recordings obtained for 592 neonates, focal periodic discharges were noted on 57 (5%) of recordings for 34 neonates (26 preterm and eight term). Periodic lateralized epileptiform discharges (PLEDs) were noted on four of these recordings. Sixteen patients (47%) with focal periodic discharges also had electrographic seizures on the same or a subsequent record. Stroke was the most common brain lesion (53%) in this neonatal population. Preterm neonates had discharges that were less than 60 seconds in duration and located in the parasagittal regions, while discharges in term neonates were longer in duration and were located in the temporal regions. Of the 34 neonates, 15 (44%) died, and 58% (11/19) of the survivors were abnormal with respect to neurological development. Focal periodic discharges in neonates, including PLEDs, have the same clinical significance as PLEDs recorded on EEGs in older children and adults.

A review of clinical data from 18 pediatric patients with periodic lateralized epileptiform discharges and bilateral independent periodic lateralized epileptiform discharges (PLEDs and BIPLEDs) showed 2 with chronic neurologic illness, 6 with a history of prior seizures, 14 with depressed sensorium at the time of EEG, 5 deaths, and 8 of 13 survivors with neurologic deficits. These findings are similar to the combined data from reports involving adult patients only. Separating pediatric patients with PLEDs from those with BIPLEDs shows some influence from patients with BIPLEDs. Overall, our data do not suggest significant clinical differences for PLEDs between children and adults.