The yield of routine electroencephalography in the detection of incidental nonconvulsive status epilepticus – A prospective study

ObjectiveDiagnosis of NCSE is challenging, because the clinical presentation ranges from minimally altered mental status to coma without tonic–clonic activity. According to the largest retrospective study to date the incidence of NCSE is about 0.2%.MethodsWe prospectively investigated electroencephalography (EEG) recordings of 2514 consecutive patients that were referred to the Electrophysiology Unit of Department of Neurology, Vienna General Hospital between November 2009 and February 2011 (i.e. 16 months).ResultsThe incidence of NCSE in our study population was 0.8%, i.e. the EEG of 19 patients fulfilled the criteria of NCSE. In 53% of these patients the NCSE was not suspected by treating physicians. A severely reduced level of consciousness was found in 78% of patients with a suspected NCSE and in 30% of patients with an unsuspected NCSE, although the results were not statistically significant (p = 0.081). The delay between the admission to the hospital and diagnosis ranged between 0 and 51 days.ConclusionsNCSE was an unsuspected finding in more than half of the patients. Consciousness was severely impaired in only one third of these patients.SignificanceThese results highlight the importance of urgent EEG for the diagnosis of NCSE in patients even without significant impairment of consciousness.     

Use of pregabalin for nonconvulsive seizures and nonconvulsive status epilepticus

PurposeTo determine the efficacy of pregabalin (PGB) in treatment of frequent nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) in critically ill patients.MethodsIn this retrospective study, 21 patients were identified as having received pregabalin for the treatment of NCS as determined by continuous electroencephalographic monitoring. The patients were considered to be responders if their seizures were terminated within 24 h of initiation of PGB without the addition of another antiepileptic agent.ResultsOf the 21 patients who received PGB for treatment of NCS or NCSE, 11 (52%) were responders. PGB was administered via a nasogastric tube or orally and was the 2nd to 4th agent used. The average initial dose and total daily dose of PGB was similar in the responders and non-responders (342 mg vs. 360 mg, respectively). PGB was more effective in aborting NCS (9 patients, 82%) than NCSE (2 patients, 18%). Of the 9 brain tumor patients, PGB resulted in seizure cessation in 67% (6 patients). In contrast, all patients with hypoxic injury (4) did not respond to PGB. The responders were noted to have better clinical outcome (64% vs. 9% discharged home). Most of the patients tolerated the medication without any significant short term adverse effects, except two patients who were noted to have dizziness and sedation.ConclusionsPregabalin may be safe option for add-on treatment for nonconvulsive seizures in critically ill patients when conventional therapy fails.     

Incidence of recurrent seizures following hospital discharge in patients with LPDs (PLEDs) and nonconvulsive seizures recorded on continuous EEG in the critical care setting

PurposeContinuous EEG (cEEG) has helped to identify nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) along with lateralized periodic patterns (LPDs or PLEDs) in ICU patients with much higher frequency than previously appreciated, but understanding their implications may be more complex. The aim of this study was to investigate the incidence of recurrent seizures after hospital discharge and their associated factors in patients with PLEDs and NCS in the critical care setting.MethodsAfter IRB approval, we used our EEG reporting database to find 200 consecutive patients who had PLEDs and/or NCSs on cEEG. Patients with less than 3 months of follow-up were excluded. Remaining patients were divided into three groups: PLEDs + Seizure (NCS/NCSE), PLEDs only, and Seizures (NCS/NCSE) only. Medical records were reviewed to gather demographical and clinical details. Univariate data analysis was done using JMP 9.0 (Marlow, Buckinghamshire, UK).ResultsThere were 51 patients in ‘PLEDs + Seizure’ group, 45 in ‘PLEDs only’ group, and 22 in ‘Seizure only’ group. Ischemic stroke, hemorrhage, and tumors were the top three etiologies. Nearly 47% of our study population had postdischarge seizures during a mean follow-up period of 11.9 (+/− 6) months. We found that 24.4% of patients in the PLEDs only group had seizures after discharge, which increased to 60.7% if they had seizures as well during their ICU stay. Slightly more than 52% of patients had a postdischarge EEG, of which, 59% was in the form of inpatient cEEG during a rehospitalization, accounting for 30.5% of the total study population. It was an indicator of high readmission rates in this population.ConclusionAlmost every other patient with PLEDs and/or NCS on cEEG had seizures after ICU discharge. A quarter of patients on cEEG in the ICU with PLEDs alone had seizures after discharge, and after excluding prior epilepsy, 17% of patients with PLEDs had seizures on follow-up. This was dramatically increased with the recording of PLEDs with NCS, with 60% of patients having seizures after discharge from the ICU and 48% of patients after excluding prior epilepsy. Patients with NCS on cEEG alone had 63% chance of seizure recurrence that dropped to 38% with exclusion of prior epilepsy. Future studies are needed to define the postdischarge outcomes including seizure recurrence in this patient population.This article is part of a Special Issue entitled “Status Epilepticus”.     

Prediction of rhythmic and periodic EEG patterns and seizures on continuous EEG with early epileptiform discharges

BackgroundContinuous EEG (cEEG) is necessary to document nonconvulsive seizures (NCS), nonconvulsive status epilepticus (NCSE), as well as rhythmic and periodic EEG patterns of ‘ictal–interictal uncertainty’ (RPPIIU) including periodic discharges, rhythmic delta activity, and spike-and-wave complexes in neurological intensive care patients. However, cEEG is associated with significant recording and analysis efforts. Therefore, predictors from short-term routine EEG with a reasonably high yield are urgently needed in order to select patients for evaluation with cEEG.ObjectiveThe aim of this study was to assess the prognostic significance of early epileptiform discharges (i.e., within the first 30 min of EEG recording) on the following: (1) incidence of ictal EEG patterns and RPPIIU on subsequent cEEG, (2) occurrence of acute convulsive seizures during the ICU stay, and (3) functional outcome after 6 months of follow-up.MethodsWe conducted a separate analysis of the first 30 min and the remaining segments of prospective cEEG recordings according to the ACNS Standardized Critical Care EEG Terminology as well as NCS criteria and review of clinical data of 32 neurological critical care patients.ResultsIn 17 patients with epileptiform discharges within the first 30 min of EEG (group 1), electrographic seizures were observed in 23.5% (n = 4), rhythmic or periodic EEG patterns of ‘ictal–interictal uncertainty’ in 64.7% (n = 11), and neither electrographic seizures nor RPPIIU in 11.8% (n = 2). In 15 patients with no epileptiform discharges in the first 30 min of EEG (group 2), no electrographic seizures were recorded on subsequent cEEG, RPPIIU were seen in 26.7% (n = 4), and neither electrographic seizures nor RPPIIU in 73.3% (n = 11). The incidence of EEG patterns on cEEG was significantly different between the two groups (p = 0.008). Patients with early epileptiform discharges developed acute seizures more frequently than patients without early epileptiform discharges (p = 0.009). Finally, functional outcome six months after discharge was significantly worse in patients with early epileptiform discharges (p = 0.01).ConclusionsEpileptiform discharges within the first 30 min of EEG recording are predictive for the occurrence of ictal EEG patterns and for RPPIIU on subsequent cEEG, for acute convulsive seizures during the ICU stay, and for a worse functional outcome after 6 months of follow-up.This article is part of a Special Issue entitled Status Epilepticus.     

Salzburg Consensus Criteria for Non-Convulsive Status Epilepticus – approach to clinical application

BackgroundSalzburg Consensus Criteria for diagnosis of Non-Convulsive Status Epilepticus (SCNC) were proposed at the 4th London–Innsbruck Colloquium on status epilepticus in Salzburg (2013).MethodsWe retrospectively analyzed the EEGs of 50 consecutive nonhypoxic patients with diagnoses of nonconvulsive status epilepticus (NCSE) at discharge and 50 consecutive controls with abnormal EEGs in a large university hospital in Austria. We implemented the American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology, 2012 version (ACNS criteria) to increase the test performance of SCNC. In patients without preexisting epileptic encephalopathy, the following criteria were applied: (1) more than 25 epileptiform discharges (ED) per 10-second epoch, i.e., > 2.5/s and (2) patients with EDs ≤ 2.5/s or rhythmic delta/theta activity (RDT) exceeding 0.5/s AND at least one of the additional criteria: (2a) clinical and EEG improvements from antiepileptic drugs (AEDs), (2b) subtle clinical phenomena, or (2c) typical spatiotemporal evolution. In case of fluctuation without evolution or EEG improvement without clinical improvement, “possible NCSE” was diagnosed. For identification of RDT, the following criteria were compared: (test condition A) continuous delta–theta activity without further rules, (B) ACNS criterion for rhythmic delta activity (RDA), and (C) ACNS criteria for RDA and fluctuation.ResultsFalse positive rate in controls dropped from 28% (condition A) to 2% (B) (p = 0.00039) and finally to 0% (C) (p = 0.000042). Application of test condition C in the group with NCSE gives one false negative (2%). Various EEG patterns were found in patients with NCSE: (1) 8.2%, (2a) 2%, (2b) 12.2%, and (2c) 32.7%. Possible NCSE was diagnosed based on fluctuations in 57.1% and EEG improvement without clinical improvement in 14.2%.ConclusionThe modified SCNC with refined definitions including the ACNS terminology leads to clinically relevant and statistically significant reduction of false positive diagnoses of NCSE and to minimal loss in sensitivity.This article is part of a Special Issue entitled “Status Epilepticus”.     

Clinical risk factors for non-convulsive status epilepticus during emergent electroencephalogram

PurposeEmergent electroencephalograms (EmEEG) are performed to exclude non-convulsive status epilepticus (NCSE) but are resource-intensive. Prior studies have identified a seizure or seizures in the acute setting preceding the EmEEG request as a risk factor of NCSE but few other consistent clinical risk factors have been identified. We aimed to identify clinical risk factors for NCSE in EmEEGsMethodsWe conducted a retrospective analysis of consecutive patients who underwent EmEEG to exclude NCSE over a 20-month period. One blinded investigator extracted clinical information from patient case records using a standardized form. Patients were grouped using EmEEG results into those with and without NCSE. We analyzed differences between these two groups.ResultsA total of 2333 EEGs were performed over the study period, 215 (9.3%) were EmEEGs ordered to exclude NCSE. 21 patients (9.8%) of the 215 patients were found to have NCSE. Three independent clinical risk factors for NCSE were identified – seizure(s) in the acute setting, ocular movements (nystagmus and/or gaze deviation) and ongoing CNS infection. The presence of seizure(s) in the acute setting showed the highest adjusted odds ratio (OR = 8.8, 95% CI 2.0–39.4, p = 0.005). In addition, prevalence of NCSE increased as more clinical risk factors were present.ConclusionSeizures in the acute setting, ocular movements and ongoing CNS infection are associated with NCSE. By using these risk factors at the bedside, clinicians can prioritize patients for EmEEG, recognizing that risk of NCSE increases as more clinical risk factors are present.     

Assessment of cerebral blood flow changes in nonconvulsive status epilepticus in comatose patients: A pathophysiological transcranial Doppler study

PurposeWe assessed the accuracy of transcranial Doppler (TCD) in helping to diagnose nonconvulsive status epilepticus (NCSE) in comatose patients admitted to the intensive care unit (ICU) for acute neurological disorders at high risk for NCSE.MethodsA 2-year prospective observational study in 38 consecutive patients requiring continuous electroencephalography (EEG) monitoring and intracranial pressure monitoring with TCD.ResultsOf the 38 patients, 10 (26.3%) had NCSE by continuous EEG monitoring. Bilateral mean and maximal systolic and diastolic TCD velocities were significantly different between patients with and those without NCSE. Areas under the receiver-operating characteristic (ROC) curves of mean and maximal systolic velocities by TCD were 0.82 (95%CI, 0.64–1.00) and 0.79 (95%CI, 0.62–0.95) with cutoffs of 95 cm/s and 105 cm/s, respectively. Areas under the ROC curves of mean and maximal diastolic velocities were 0.76 (95%CI, 0.56–0.95) and 0.78 (95%CI, 0.60–0.96) with cutoffs of 31 cm/s and 40 cm/s, respectively. For none of the velocity parameters did the areas under the ROC curves differ significantly between the left and right sides. The best performance was obtained using mean systolic (SV) and a cutoff of 95 cm/s, which yielded a positive likelihood ratio of 3.8 and a negative likelihood ratio of 0.25.ConclusionOur preliminary results showed a significant association between increased TCD velocities and NCSE in comatose patients. However, the likelihood ratios suggested a limited role for TCD in helping to diagnose seizure activity. Further studies with larger samples of NCSE patients are warranted to determine the exact contribution of TCD for NCSE detection in comatose ICU patients.     

The role of the standard 20 minute EEG recording in the comatose patient

Non-convulsive seizures and non-convulsive status epilepticus (NCSE) are believed common in comatose patients and are suggested to worsen outcome. The purpose of this study was to prospectively evaluate outcome in patients in critical care units in whom NCSE was suspected to determine how often evidence of seizure activity existed based on an isolated standard 20 minute electroencephalogram (EEG) and to determine what clinical factors predicted outcome. We prospectively reviewed EEGs and clinical charts of patients admitted to a critical care unit at a tertiary care center who were suspected to have non-convulsive seizures. Outcomes were correlated with EEG findings, clinical factors, and acute therapies using univariate and multivariate logistic analyses. Of 189 patients, complete information was available in 169. Eighty-one (47.9%) patients died, 67 (39.6%) were discharged home, and 21 (12.4%) were discharged to long-term care. Four patients had electroencephalographic seizures, two of whom had no clinical manifestations (i.e. non-convulsive). On univariate analysis, increased age, an admitting diagnosis of cardiac arrest, a Glasgow Coma Scale (GCS) score ? 8, and burst suppression were correlated significantly with poor outcome. A past history of seizures and unequivocal tonic–clonic convulsions were correlated significantly with a better outcome. On multivariate analysis, increased age, cardiac arrest, and a GCS score ? 8 were associated with increased mortality (p < 0.05). Clinical factors, including age, underlying etiology and GCS score are the most important predicators of outcome in coma. A standard 20 minute EEG did not correlate with a high detection rate of seizure activity. Furthermore, EEG patterns and treatment with anticonvulsant medications did not correlate with outcome.     

Should we treat patients with impaired consciousness and periodic patterns on EEG?

PurposeThe significance of periodic EEG patterns in patients with impaired consciousness is controversial. We aimed to determine if treating these patterns influences clinical outcome.MethodWe studied all patients who had periodic discharges on their EEG recordings from January 2007 to December 2009. Patients with clinical seizures within the preceding 24 h, or with unequivocal electrographical seizure activity were excluded. Logistic regression was performed to analyze for factors associated with (a) mortality (b) functional status (c) resolution of EEG pattern.ResultsOf the 4246 patients who had EEG, 111 (2.6%) had periodic EEG patterns. 64 met inclusion criteria. In adjusted analysis, higher mortality was associated with acute symptomatic etiology (OR 17.74, 95% CI 1.61–196.07, p = 0.019), and presence of clinical seizures (OR 4.73, 95% CI 1.10–20.34, p = 0.037). For each unit decrement of GCS, the odds of inpatient mortality and a poorer functional state on discharge increased by 23% (95% CI 7–37%, p = 0.009) and 33% (95% CI 9–51%, p = 0.011) respectively. Administration of abortive therapy was an independent risk factor for poorer functional status on discharge (adjusted OR 41.39, 95% CI 2.88–594.42, p = 0.006), while patients with history of pre-existing cerebral disease appeared more likely to return to baseline functional status on discharge (unadjusted OR 5.00, 95% CI 1.40–17.86, p = 0.013).ConclusionTreatment of periodic EEG patterns does not independently improve clinical outcome of patients with impaired conscious levels. Occurrence of seizures remote to the time of EEG and lower GCS scores independently predict poor prognoses.     

The value of video-EEG monitoring to diagnose juvenile myoclonic epilepsy

ObjectiveA diagnostic accuracy of conventional electroencephalography (EEG) is approximately 50% at best. We aimed to determine the accuracy of video-EEG monitoring (VEM) for a correct diagnosis and the feasibility of its clinical application. The data from all 55 patients (M:F = 31:24) with juvenile myoclonic epilepsy (JME) who underwent VEM were reviewed according to the clinical history, brain imaging and video-EEG findings.ResultsAge at seizure onset ranged from 10 to 25 (15.5 ± 2.7 years). The age at VEM ranged from 15 to 46 (21.8 ± 5.8 years) and 57% (29/51) showed seizures. Of those, 20 patients (69%) showed myoclonic jerks alone, whereas 3 (10%) showed generalized seizures alone. Both of these conditions were observed in 6 patients (21%). Interictal abnormalities alone without clinical seizures were detected in 16 patients (31%). Atypical semiologies such as asymmetric myoclonus or versive seizures were observed in 18 patients (35%) during video monitoring. Interestingly three patients complained of visual aura on history. The duration of VEM ranged from 1 to 6 days (1.8 ± 1.1). Overall, 88% of patients showed an EEG abnormality with/without seizure, concordant with JME. Among 10 patients with a normal conventional EEG before VEM, 9 showed interictal or ictal EEG abnormalities during approximately 1-day of VEM.ConclusionsVEM for 1 or 2 days is appropriate for making a correct diagnosis of JME, especially in patients having an atypical semiology and a normal result on the conventional EEG.     

Ictal and interictal EEG patterns in patients with nonconvulsive and subtle convulsive status epilepticus

BackgroundElectroencephalography findings in nonconvulsive or subtle convulsive status epilepticus (NCSE and SCSE, respectively) can be heterogenous. We aimed to study the different patterns on EEG in our cohort of patients.ObjectiveOur objective was to study ictal and interictal EEG patterns in patients with NCSE and SCSE.MethodsFrom January 2012 to December 2013, EEGs recorded from patients admitted for altered mental status suspected of having NCSE or SCSE were reviewed retrospectively. Electroencephalography status was defined as having (a) continuous ictal discharges lasting > 5 min or (b) > 2 discrete bursts of ictal discharges, each lasting < 5 min, without returning to previous background rhythm in between these bursts.ResultsAmong 1698 EEGs recorded for at least 30 min from hospitalized patients, 55 (3.23%) satisfied the criteria of EEG SE. The ictal onset was regional in 37 (67.2%) EEGs, multiregional independent in 8 (14.5%), and generalized in 10 (18.4%).The EEG seizure duration was > 5 min in 24 (43.6%) EEGs, between 1 and 5 min in 14 (25.4%), and less than 1 min in 17 (30.8%).Twenty (36.3%) EEGs showed one continuous prolonged seizure episode of > 5-minute duration, 15 (27.2%) had 10 or less discrete episodes, 20 (36.3%) had more than 10 episodes, and 11 (20%) had 2 or more ictal patterns.Thirty (54.5%) EEGs had onset ictal frequency of > 8 Hz whereas the rest had < 8-Hz ictal frequency. In the interictal segment, 29 patients had continuous generalized slow waves, while 12 had intermittent generalized slow waves. Eleven patients had continuous slow waves lateralized to one hemisphere, and these were ipsilateral to the ictal focus in 10 but contralateral in 1. Other interictal waves seen were PLEDS (6), sharp waves (3), suppression (5), and triphasic waves (1).The background alpha rhythm was absent in 36 patients and slow in 14, and normal background alpha was seen in the interictal period in 5 patients.ConclusionThe ictal and interictal EEG patterns in NCSE and SCSE can be varied. Further study to look for etiologic and clinical correlates of each pattern could add to its clinical value.This article is part of a Special Issue entitled “Status Epilepticus”.     

Which EEG patterns in coma are nonconvulsive status epilepticus?

Nonconvulsive status epilepticus (NCSE) is common in patients with coma with a prevalence between 5% and 48%. Patients in deep coma may exhibit epileptiform EEG patterns, such as generalized periodic spikes, and there is an ongoing debate about the relationship of these patterns and NCSE. The purposes of this review are (i) to discuss the various EEG patterns found in coma, its fluctuations, and transitions and (ii) to propose modified criteria for NCSE in coma.Classical coma patterns such as diffuse polymorphic delta activity, spindle coma, alpha/theta coma, low output voltage, or burst suppression do not reflect NCSE. Any ictal patterns with a typical spatiotemporal evolution or epileptiform discharges faster than 2.5 Hz in a comatose patient reflect nonconvulsive seizures or NCSE and should be treated. Generalized periodic diacharges or lateralized periodic discharges (GPDs/LPDs) with a frequency of less than 2.5 Hz or rhythmic discharges (RDs) faster than 0.5 Hz are the borderland of NCSE in coma. In these cases, at least one of the additional criteria is needed to diagnose NCSE (a) subtle clinical ictal phenomena, (b) typical spatiotemporal evolution, or (c) response to antiepileptic drug treatment. There is currently no consensus about how long these patterns must be present to qualify for NCSE, and the distinction from nonconvulsive seizures in patients with critical illness or in comatose patients seems arbitrary.The Salzburg Consensus Criteria for NCSE [1] have been modified according to the Standardized Terminology of the American Clinical Neurophysiology Society [2] and validated in three different cohorts, with a sensitivity of 97.2%, a specificity of 95.9%, and a diagnostic accuracy of 96.3% in patients with clinical signs of NCSE. Their diagnostic utility in different cohorts with patients in deep coma has to be studied in the future.This article is part of a Special Issue entitled “Status Epilepticus”.     

Long-term outcome and prognosis of patients with emergent periodic lateralized epileptiform discharges (ePLEDs)

PurposeEmergent EEG (eEEG) is an EEG performed on a non-elective basis upon request from a clinician for a seemingly emergency indication. Little is known about the long-term prognosis of patients with emergent periodic lateralized epileptiform discharges (ePLEDs).MethodsWe analyzed the EEG and clinical records of patients with ePLEDs from January 2002 to December 2008.ResultsOut of 1948 eEEGs, 79 (4%) patients had ePLEDs. Sixty-three patients had ePLEDs and 16 had eBiPLEDs (emergent bilateral periodic lateralized epileptiform discharges). The etiology of ePLEDs was CNS infection and inflammation (35.4%), stroke (32.9%), and metabolic encephalopathy (11.4%). Of the surviving 52 (65.8%) patients with ePLEDs, 34 (65.4%) had persistent seizures during a mean follow-up of 28 months (range 12–72 months). Seizure as the initial presentation was more commonly seen in children as compared to adults (64% versus 31%, p = 0.005). CNS infection and inflammation were also seen more frequently in the pediatric age group (50% versus 27%, p = 0.04). At follow-up, patients with eBiPLEDs had more seizures than patients with ePLEDs (87.5% versus 61.3%).ConclusionePLEDs is associated with significant morbidity and mortality. However, the etiology of ePLEDs and brain dysfunction will influence the long-term outcome. This information is invaluable for prognostication and underscores the importance of rigorous management of patients with ePLEDs.     

Intravenous lacosamide as treatment option in post-stroke non convulsive status epilepticus in the elderly: A proof-of-concept,observational study

PurposeTo evaluate the efficacy and safety of intravenously administered lacosamide (iv LCM) in post-stroke non convulsive status epilepticus (NCSE) in elderly patients.MethodsWe enrolled 16 patients (7 M/9 F; 77 ± 7 years of age) with NCSE. iv LCM was used in all the patients as initial treatment (i.e. patients were directly started on LCM) at a loading dose of 400 mg over 30 min, followed by a mean maintenance dose of 400 mg per day. iv LCM was considered as effective in patients who experience no NCSE for 24 h following treatment, as evaluated by EEG recording and clinical observation.ResultsLCM was effective in treating NCSE in eight of the sixteen patients in whom epileptic activity disappeared (7/8) or was significantly reduced (1/8) within 45–60 min after administration. None of these patients relapsed in the following 24 h. No adverse events were observed. A partial anterior circulation syndrome (PACS) was present in 10 patients while a total anterior circulation syndrome (TACS) in six.ConclusionsThis pilot study suggests that LCM exhibits safety and efficacy profiles which make it an optimal candidate as a first-choice drug against post-stroke NCSE in elderly patients. A prospective comparative trial is needed to confirm these preliminary data.     

Cortical processing during smartphone text messaging

ObjectiveThe objective of this study was to report the EEG features of text messaging using smartphones.MethodsOne hundred twenty-nine patients were prospectively evaluated during video-EEG monitoring (VEM) over 16 months. A reproducible texting rhythm (TR) present during active text messaging with a smartphone was compared with passive and forced audio telephone use, thumb/finger movements, cognitive testing/calculation, scanning eye movements, and speech/language tasks in patients with and without epilepsy. Statistical significance was set at p < 0.05.ResultsTwenty-seven patients with a TR were identified from a cohort of 129 (93 female, mean age: 36; range: 18–71) unselected VEM patients. Fifty-three out of 129 patients had epileptic seizures (ES), 74/129 had nonepileptic seizures (NES), and 2/129 were dual-diagnosed. A reproducible TR was present in 27/129 (20.9%) specific to text messaging (p < 0.0001) and present in 28% of patients with ES and 16% of patients with NES (p = NS). The TR was absent during independent tasks and audio cellular telephone use (p < 0.0001). Age, gender, epilepsy type, MRI results, and EEG lateralization in patients with focal seizures were unrelated (p = NS).ConclusionsOur results suggest that the TR on scalp EEG represents a novel technology-specific neurophysiological alteration of brain networks. We propose that cortical processing in the contemporary brain is uniquely activated by the use of PEDs.SignificanceThese findings have practical implications that could impact industry and research in nonverbal communication.     

Nonconvulsive status epilepticus in adults: Electroclinical differences between proper and comatose forms

ObjectiveNonconvulsive status epilepticus (NCSE) represents an important percentage of status epilepticus in adults, but detailed studies of both NCSE proper and comatose NCSE are lacking. We retrospectively analyzed a prospectively collected series of 50 adult patients with a diagnosis of NCSE whose electroencephalograms (EEGs) have been interpreted for a period of 10 years by the same investigator.MethodsTwo groups, NCSE proper and comatose NCSE were considered. All clinical, EEGs, neuroimaging data, antiepileptic treatment and outcome were analyzed.ResultsThirty-two patients (64%) had NCSE proper and 18 patients (36%) comatose NCSE. The mean age was 56 years (range 19–89 years). Fourteen (44%) were diagnosed with absence status epilepticus (ASE), one had simple partial status epilepticus (SPSE) and 17 (53%) had complex partial status epilepticus (CPSE). The mean episode duration (33.2 ± 13.9 versus 60.6 ± 34.0), mean number of antiepileptic drugs (AEDs) (1.46 ± 0.5 versus 2.77 ± 1.39) and neuroimaging anomalies (50% versus 16%) was significantly greater in the partial/focal NCSE proper subgroup than in the ASE subgroup. The mean age (56.0 ± 19.9 versus 69.4 ± 12.1), number of elderly individuals (46% versus 77%), mean duration of the episode (49.1 ± 30.4 versus 153.3 ± 142.6), mortality rate (6% versus 61%) and admission at ICU (18% versus 83%) was significantly higher in the comatose NCSE group than in the NCSE proper group (p < .05). Conversely, a previous history of chronic epilepsy was significantly more frequent (62% versus 5.6%) in the NCSE proper group. The mean duration of comatose NCSE was significantly greater in the surviving subgroup (102.5 ± 29.1 versus 233.1 ± 65.3; p < .05).ConclusionsOur study demonstrates that there are sufficient differences regarding age of onset, history of previous epilepsy, episode duration, mortality rate and clinical presentation between NCSE proper and comatose NCSE to recommend adoption in clinical practice. These results should be taken into account when developing future classifications and therapeutic trials on NCSE.SignificanceA distinction between NCSE proper (ambulatory forms of NCSE) and comatose NCSE is useful in the clinical practice and, therefore, it should taken in account in the design of future investigations on this heterogeneous epileptic condition.     

Epidemiology of uncontrolled epilepsy in the Al-Kharga District,New Valley,Egypt

BackgroundDespite advances in treating epilepsy, uncontrolled epilepsy continues to be a major clinical problem. Therefore, this work aimed to study the epidemiology of uncontrolled epilepsy in Al-Kharga District, New Valley.MethodsThis study was carried out in 3 stages via door-to-door screening of the total population (62,583 persons). All suspected cases of epilepsy were subjected to case ascertainment, conventional ElectroEncephaloGraphy (EEG), and the Stanford-Binet Intelligence Scale. Patients who had been receiving suitable anti-epileptic drugs (AEDs) over the previous 6 months and were having active seizures were considered uncontrolled, according to Ohtsuka et al.²³ The patients underwent serum AED level estimation, video EEG monitoring, and brain MRIs. Fifty age- and gender-matched patients with controlled epilepsy were chosen for statistical analysis and compared with true intractable patients.ResultsA total of 437 patients with epilepsy were identified, 30.7% of whom (n = 134/437) were uncontrolled, with a prevalence of 2.1/1000. A total of 52.2% of uncontrolled patients (n = 70/134) were inappropriately treated, while 47.8% (n = 64/134) were compliant with appropriate treatments. Video monitoring EEG of compliant uncontrolled patients demonstrated that 78.1% patients (n = 50/64) had definite epilepsy, while 21.9% (n = 14/64) had psychogenic non-epileptic seizures (PNES). A logistic regression analysis revealed that status epilepticus, focal seizures, and mixed seizure types were risk factors for intractability.     

Automatic seizure detection in long-term scalp EEG using an adaptive thresholding technique: A validation study for clinical routine

ObjectiveIn a previous study we proposed a robust method for automatic seizure detection in scalp EEG recordings. The goal of the current study was to validate an improved algorithm in a much larger group of patients in order to show its general applicability in clinical routine.MethodsFor the detection of seizures we developed an algorithm based on Short Time Fourier Transform, calculating the integrated power in the frequency band 2.5–12 Hz for a multi-channel seizure detection montage referenced against the average of Fz-Cz-Pz. For identification of seizures an adaptive thresholding technique was applied. Complete data sets of each patient were used for analyses for a fixed set of parameters.Results159 patients (117 temporal-lobe epilepsies (TLE), 35 extra-temporal lobe epilepsies (ETLE), 7 other) were included with a total of 25,278 h of EEG data, 794 seizures were analyzed. The sensitivity was 87.3% and number of false detections per hour (FpH) was 0.22/h. The sensitivity for TLE patients was 89.9% and FpH = 0.19/h; for ETLE patients sensitivity was 77.4% and FpH = 0.25/h.ConclusionsThe seizure detection algorithm provided high values for sensitivity and selectivity for unselected large EEG data sets without a priori assumptions of seizure patterns.SignificanceThe algorithm is a valuable tool for fast and effective screening of long-term scalp EEG recordings.     

Seizure frequency in children with epilepsy: Factors influencing accuracy and parental awareness

RationaleThe objective of this study was to ascertain the accuracy of clinical reports to determine the seizure frequency in children diagnosed with epilepsy.MethodsWe reviewed the clinical record of 78 children (January–May of 2006) admitted to the EEG–video monitoring with epilepsy diagnosis. Clinical reports of parents and the files of EEG–video monitoring were reviewed to determine parents’ awareness for seizures.ResultsDuring video–EEG monitoring, 1244 were recorded on 78 children. Seizures were confirmed in 1095 of which 472 were correctly reported (38%) by parents whereas 623 remained under-reported (50%). Parents’ report thus had a sensitivity of 43%, positive predictive value of 76% to identify seizures. Based on the EEG–video monitoring, seizures were reported accurately in 22 (28%) and under-reported in 38 (49%) children. In the under-reported group, none of the seizures were recognized in 10 (13%), only a portion identified in 28 children. The parents’ report describing seizure frequency has limited value for young children (p = 0.01) and children with absence seizures (p = 0.03). However, clinical reports were accurate for the children with developmental delay (p < 0.06) or not being on any anticonvulsant drug (AED) therapy (p = 0.02).ConclusionOur results indicate that a significant number of seizures remain under-reported by parents of children with epilepsy. The current study underscores that the seizure frequency should be interpreted with caution for young children and children with absence seizures. Video–EEG recording has a complimentary role to the clinical observation for the accurate assessment of seizure frequency in children.