Long-term video-EEG in patients with frontal seizures

Abstract

The interictal epileptiform discharge (IED) yield of long-term video-EEG (LTVEEG) monitoring is increased compared to a single out-patient EEG, but was not studied specifically in frontal lobe epilepsy. Since IED recording can influence the length of monitoring when seizures are not recorded during LTVEEG, we aimed to assess the IED yield of LTVEEG recording in patients with frontal seizures. We retrospectively reviewed the medical records of 20 patients with frontal seizures during non-invasive LTVEEG in Tel Aviv Medical Center between 2003 and 2008 and compared them with the results of out-patient EEG. The study group included 11 (55%) men and 9 women aged 15–82 years (mean: 27 years). LTVEEG duration ranged between 4 and 29 days (mean: 14 days). IEDs were detected by each of the tests in eight (40%) patients. We conclude that non-invasive LTVEEG and out-patient EEG have a similar diagnostic yield for IEDs in patients with frontal seizures. Therefore, seizures remain the most relevant clinical outcome of LTVEEG.     

Video-EEG monitoring of paroxysmal events in the elderly

OBJECTIVES: To determine the importance of video-EEG monitoring (VEM) in elderly patients with various paroxysmal events. MATERIAL AND METHODS: We retrospectively identified 16 subjects > or = 60 years old out of 834 (1.9%; 7 females, mean age 67.8 +/- 7.7 years), who were admitted to the Video-EEG Unit between 1997 and 2005 and compared data between those with and without epileptic events. RESULTS: Epilepsy was confirmed in six patients, psychogenic non-epileptic seizures (NES) were diagnosed in seven, one patient had NES and epilepsy whereas the recorded events were non-conclusive in two. NES patients had a higher predisposition to psychiatric disturbances (P<0.02). Following VEM and management alteration, the frequency of monthly events decreased significantly for the cohort as a whole (P<0.001). VEM directly influenced the diagnosis, treatment and outcome of 14 of 16 (88%) patients. CONCLUSION: Video-EEM plays a vital role in the evaluation of paroxysmal events in the elderly, but is vastly underutilized in this population group.     

Hyperorality in epileptic seizures: periictal incomplete Klüver-Bucy syndrome

PURPOSE: To analyze systematically hyperorality associated with epileptic seizures and its relation to the localization of epileptic activity. METHODS: To identify patients with periictal hyperorality, we reviewed video-recordings of 269 patients (aged 6-59 years) who had consecutively undergone presurgical evaluations including ictal video-EEG recordings and high-resolution magnetic resonance imaging (MRI) and had had epilepsy surgery because of intractable frontal (FLE) or temporal lobe epilepsy (TLE). Periictal hyperorality was defined if patients put or unambiguously intended to put nonfood items into their mouths during or after at least one of the reviewed seizures. For the further analysis, we included only patients with periictal hyperorality. We reviewed their medical records and reexamined their ictal video-EEG recordings. RESULTS: We identified eight patients (six women) aged 8-59 years who had hyperorality during or after seizures. Seven patients had TLE, and one patient had frontal lobe epilepsy (FLE). Three of these patients underwent right-sided surgery, whereas five patients had surgery on the left. Three patients exhibited ictal and five showed postictal hyperorality. Interictal EEG suggested bilateral interictal epileptiform discharges (IEDs) in three patients; in two other patients, no IEDs were detected. Ictal EEG suggested bilateral involvement in six cases. Patients with unilateral epileptiform activity had left TLE. CONCLUSIONS: Periictal hyperorality is a rare phenomenon occurring in 3% of the investigated epilepsy population. We suggest that periictal hyperorality is an ictal-postictal mental disturbance, an incomplete Klüver-Bucy syndrome. In most patients, bilateral seizure activity plays an important role in the pathomechanism, but it would appear that left-sided epileptic activity without contralateral involvement also can cause periictal hyperorality.     

Clinical seizure semiology is subtle and identification of seizures by parents is unreliable in infants with tuberous sclerosis complex

Objective

The objectives of this study were to assess the accuracy of parental seizure detection in infants with antenatally diagnosed tuberous sclerosis complex (TSC), and to document the total seizure burden (clinical and subclinical) in those patients who met criteria for prolonged electroencephalography (EEG) recording.

Methods

Consecutive infants at a single institution with antenatally diagnosed TSC who met criteria for prolonged video-EEG (vEEG) were recruited to this study. The vEEG data were reviewed and when a seizure was identified on EEG, the video and audio recording was assessed for evidence of clinical seizure and, if present, whether there was evidence of parent seizure identification.

Results

Nine infants were enrolled, for whom 674 focal seizures were identified in eight of nine patients across 24 prolonged vEEG recordings, with vEEG total duration of 634 h 49 min (average seizure frequency of 1 focal seizure/h). Only 220 of 674 (32.6%) were clinical seizures, 395 of 674 (58.6%) were subclinical seizures, and 59 of 674 seizures could not be classified. Only 63 of 220 clinical seizures (28.6%) were identified by parents, with 157 of 220 (71.4%) not identified. Thirty clusters of epileptic spasms were detected in one patient. At least one clinical epileptic spasm occurred in 2 of 30 clusters (6.7%), 24 of 30 clusters of epileptic spasms (80%) were electrographic only, and classification was uncertain for 4 of 30 clusters (13.3%). No clinical epileptic spasms were detected by parents. Clinical seizure frequency was significantly underestimated by parents for all patients.

Significance

This study demonstrates that in infants with TSC who met criteria for prolonged vEEG, (1) parents significantly under recognize total clinical seizure count, (2) parents fail to identify epileptic spasms, and (3) seizure frequency is high. This highlights that epilepsy treatment decisions should not be based solely on parental clinical seizure identification. Prolonged vEEG monitoring may have an important role in the routine epilepsy care of infants with TSC, as demonstrating undetected high clinical seizure frequency may allow improved epilepsy management decisions.     

Outcome of prolonged video-EEG monitoring at a typical referral epilepsy center

PURPOSE: When seizures do not respond to medications, video-EEG monitoring is the best available diagnostic tool and is the principal activity of epilepsy centers. The purpose of this study was to analyze the eventual disposition of patients who undergo video-EEG monitoring at a typical referral epilepsy center. METHODS: We reviewed the diagnoses and dispositions of all patients (adults and children) who underwent inpatient video-EEG monitoring (> or = 24 h) at our center (University of South Florida-Tampa General Hospital) over a 1-year period (2002). RESULTS: In total, 251 inpatient video-EEG monitoring sessions were performed. Nonepileptic seizures were diagnosed in 75 (30%); 58 (23%) were found to be surgical candidates; seven were implanted with the vagus nerve stimulator. In 47 (19%) patients, seizures were recorded, and the diagnosis of epilepsy was confirmed and clarified (symptomatic/cryptogenic generalized epilepsy, seven; localization-related epilepsy, 35; idiopathic generalized epilepsy, five). CONCLUSIONS: The eventual outcome of video-EEG monitoring is diverse. The largest groups, as expected, are psychogenic nonepileptic seizures (30%), and surgery (23%).     

Importance of access to epilepsy monitoring units during the COVID-19 pandemic: Consensus statement of the International League against epilepsy and the International Federation of Clinical Neurophysiology

Restructuring of healthcare services during the COVID-19 pandemic has led to lockdown of Epilepsy Monitoring Units (EMUs) in many hospitals. The ad-hoc taskforce of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) highlights the detrimental effect of postponing video-EEG monitoring of patients with epilepsy and other paroxysmal events. The taskforce calls for action to continue functioning of Epilepsy Monitoring Units during emergency situations, such as the COVID-19 pandemic. Long-term video-EEG monitoring is an essential diagnostic service. Access to video-EEG monitoring of the patients in the EMUs must be given high priority. Patients should be screened for COVID-19, before admission, according to the local regulations. Local policies for COVID-19 infection control should be adhered to during the video-EEG monitoring. In cases of differential diagnosis where reduction of antiseizure medication is not required, consider home video-EEG monitoring as an alternative in selected patients.     

Focal semiologic and electroencephalographic features in patients with juvenile myoclonic epilepsy

PURPOSE: A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring. METHODS: Twenty-six patients (nine males and 17 females) who had seizures recorded during video-EEG monitoring were included. Age at seizure onset was 0 to 22 years (mean, 12.3 years), and age at monitoring was 12 to 44 years (mean, 26.5 years). In one patient with left parietooccipital epilepsy, primary generalized tonic-clonic seizures developed after resection of the parietal tumor. Two patients had both temporal lobe epilepsy and JME. Videotaped seizures in each patient were analyzed. Interictal and ictal EEG also were analyzed for any focal features. RESULTS: Focal semiologic features were observed in 12 (46%) of 26 patients. Six patients had focal myoclonic seizures, and two had Figure 4 sign: one with version to the left, and another had left version followed by Figure 4 sign, and left arm clonic seizure. Their ictal EEGs were generalized at onset but with a lateralized evolution over the right hemisphere. The patient who had both JME and left parietooccipital epilepsy, right arm clonic seizure, and Figure 4 sign was seen during a generalized EEG seizure. Interictally, one patient had temporal sharp waves, and another had run of spikes in the right frontal region. CONCLUSIONS: Fourteen (54%) of 26 patients with JME exhibited focal semiologic or electroencephalographic features or both. Video-EEG was essential in reaching a correct diagnosis and choosing an appropriate antiepileptic drug regimen.     

The diagnostic value of initial video-EEG monitoring in children--review of 1000 cases

OBJECTIVE: We retrospectively reviewed the clinical utility of initial video-EEG monitoring in a series of 1000 children suspected of epileptic disorders. METHODS: The ages of patients (523 boys and 477 girls) ranged from 1 month to 17 years (median age: 7 years). The mean length of stay was 1.5 days (range: 1-10 days). Outcomes were classified as: 'useful-epileptic' (successful classification of epilepsy), 'useful-nonepileptic' (demonstration of nonepileptic habitual events), 'uneventful' (normal EEG without habitual events captured), and 'inconclusive' (inability to clarify the nature of habitual events with abnormal interictal EEG findings). RESULTS: A total of 315 studies were considered 'useful-epileptic'; 219 'useful-nonepileptic'; 224 'uneventful'; 242 'inconclusive'. Longer monitoring was associated with higher rate of a study classified as 'useful-epileptic' in all age groups (Chi square test: p<0.001). In addition, longer monitoring was associated with lower rate of a study classified as 'inconclusive' in adolescences (p<0.001). Approximately half of the children with successful classification of epilepsy were assigned a specific diagnosis of epilepsy syndrome according to the International League Against Epilepsy (ILAE) classification. We found only 22 children with ictal EEG showing a seizure onset purely originating from a unilateral temporal region. CONCLUSION: Video-EEG monitoring may fail to capture habitual episodes. To maximize the utility of studies in the future, a video-EEG monitoring longer than 3 days should be considered in selected children such as adolescences with habitual events occurring on a less than daily basis. We recognize a reasonable clinical utility of the current ILAE classification in the present study. It may not be common to identify children with pure unilateral temporal lobe epilepsy solely based on video-EEG monitoring.     

“God has sent me to you”: Right temporal epilepsy,left prefrontal psychosis

Religious experiences have long been documented in patients with epilepsy, though their exact underlying neural mechanisms are still unclear. Here, we had the rare opportunity to record a delusional religious conversion in real time in a patient with right temporal lobe epilepsy undergoing continuous video-EEG. In this patient, a messianic revelation experience occurred several hours after a complex partial seizure of temporal origin, compatible with postictal psychosis (PIP). We analyzed the recorded resting-state EEG epochs separately for each of the conventional frequency bands. Topographical analysis of the bandpass filtered EEG epochs revealed increased activity in the low-gamma range (30–40 Hz) during religious conversion compared with activity during the patient's habitual state. The brain generator underlying this activity was localized to the left prefrontal cortex. This suggests that religious conversion in PIP is related to control mechanisms in the prefrontal lobe-related processes rather than medial temporal lobe-related processes.     

Ictal spitting in left temporal lobe epilepsy: report of three cases.

PURPOSE: Ictal spitting is rarely reported in patients with epilepsy. More often it is observed in patients with temporal lobe epilepsy (TLE) and is presumed to be a lateralizing sign to language nondominant hemisphere. We report three patients with left TLE who had ictal spitting registered during prolonged video-EEG monitoring. METHODS: Medical charts of all patients with medically refractory partial epilepsy submitted to prolonged video-EEG monitoring in the Epilepsy Unit at UNIFESP during a 3-year period were reviewed, in search of reports of ictal spitting. The clinical, neurophysiological and neuroimaging data of the identified patients were reviewed. RESULTS: Among 136 patients evaluated with prolonged video-EEG monitoring, three (2.2%) presented spitting automatisms during complex partial seizures. All of them were right-handed, and had clear signs of left hippocampal sclerosis on MRI. In two patients, in all seizures in which ictal spitting was observed, EEG seizure onset was seen in the left temporal lobe. In the third patient, ictal onset with scalp electrodes was observed in the right temporal lobe, but semi-invasive monitoring with foramen ovale electrodes revealed ictal onset in the left temporal lobe, confirming false lateralization in surface records. The three patients became seizure-free following left anterior temporal lobectomy. CONCLUSIONS: Ictal spitting is a rare finding in patients with epilepsy, and may be considered a localizing sign of seizure onset in the temporal lobe. It may be observed in seizures originating from the left temporal lobe, and thus should not be considered a lateralizing sign of nondominant TLE.     

The added value of [18F]-fluoro-D-deoxyglucose positron emission tomography in screening for temporal lobe epilepsy surgery

PURPOSE: [18F]-Fluoro-d-deoxyglucose positron emission tomography (FDG-PET) is an expensive, invasive, and not widely available technique used in the presurgical evaluation of temporal lobe epilepsy. We assessed its added value to the decision-making process in relation to other commonly used tests. METHODS: In a retrospective study of a large series of consecutive patients referred to the national Dutch epilepsy surgery program between 1996 and 2002, the contribution of FDG-PET, magnetic resonance imaging (MRI), and video-electroencephalogram (video-EEG) monitoring findings, alone or in combination, to the decision whether to perform surgery was investigated. The impact of FDG-PET was quantified by comparing documented decisions concerning surgery before and after FDG-PET results. RESULTS: Of 469 included patients, 110 (23%) underwent FDG-PET. In 78 of these patients (71%), FDG-PET findings led clinicians to change the decision they had made based on MRI and video-EEG monitoring findings. In 17% of all referred patients, the decision regarding surgical candidacy was based on FDG-PET findings. FDG-PET was most useful when previous MRI results were normal (p < 0.0001) or did not show unilateral temporal abnormalities (p < 0.0001), or when ictal EEG results were not consistent with MRI findings (p < 0.0001) or videotaped seizure semiology (p = 0.027). The positive and negative predictive values for MRI and video-EEG monitoring, which ranged from 0.48 to 0.67, were improved to 0.62 to 0.86 in combination with FDG-PET. CONCLUSIONS: In patients referred for TLE surgery, FDG-PET findings can form the basis for deciding whether a patient is eligible for surgery, and especially when MRI or video-EEG monitoring are nonlocalizing.     

Focal lesions in the splenium of the corpus callosum in patients with epilepsy

Purpose:   A focal lesion in the splenium of the corpus callosum is a rare finding in patients with epilepsy. Intoxication with antiepileptic drugs, edema after generalized seizures, or a rapid change of antiepileptic drug levels have been proposed as possible mechanisms. The aim of the present study was to analyze the relationship between this lesion and possible etiologic factors.
Patients and methods:   We analyzed the magnetic resonance imaging (MRI) scans of 1,050 patients undergoing prolonged video-EEG (electroencephalography) monitoring and identified 24 patients with a focal lesion in the splenium of the corpus callosum. Twenty-four age- and gender-matched temporal lobe epilepsy patients without such a lesion served as a control group. We evaluated the following parameters for their possible etiologic significance: epilepsy syndrome, seizure types in medical history, seizure frequency during the past year prior to admission for prolonged video-EEG monitoring, localization of interictal spikes and ictal EEG patterns in patients with focal epilepsies as documented during prolonged video-EEG-monitoring, seizure types and seizure frequency during prolonged video-EEG monitoring, past as well as current antiepileptic medication, withdrawal of antiepileptic drugs during monitoring including duration of medication withdrawal, and finally drug levels above the therapeutic range.
Results :  The parameters analyzed showed no significant difference between the group of patients with focal lesions in the splenium of the corpus callosum and the control group.
Conclusion:   We could not identify a single etiologic factor responsible for the lesion in the splenium of the corpus callosum.     

Patients' Experiences of and Satisfaction with Care for Their Epilepsy

Summary: Purpose: To determine condition-specific satisfaction with care, we studied patients'experience of general practitioner (primary physician) and hospital clinic care for their epilepsy and their views about the provision of information concerning the management of their condition. Methods: A postal questionnaire was sent to an unselected, community-based population of patients with epilepsy. In addition to clinical and demographic details and previously validated scales of psychosocial well-being, the instrument contained a series of questions about patients'experiences and views of the care they received for epilepsy from both general practice and the hospital services. Results: Doctors'interpersonal skills were the most influential factors affecting both patient satisfaction overall and the likelihood that doctors might discuss with patients certain clinical and social issues surrounding the management of the patient's condition. A sizable proportion of patients reported that they received insufficient information, about epilepsy, both from hospital doctors and general practitioners. Conclusions: Patients with epilepsy place great importance on having a doctor who is approachable, communicative, and knowledgeable and on receiving adequate information about their condition. Clinicians may need to be made more aware of the importance of accessibility and sensitivity to the nonclinical needs of their patients. Such easily implemented changes in the delivery of care would improve services in the United Kingdom for people with epilepsy.     

Hyperventilation revisited: physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring

PURPOSE: Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring. METHODS: We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures. RESULTS: We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT). CONCLUSIONS: HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.     

Sleep disorders: a sometimes forgotten cause of nonepileptic spells

We present a patient with spells of loss of awareness in which the initial diagnostic consideration was partial epilepsy. The patient underwent video-EEG long-term monitoring which raised suspicion of nonepileptic events, but could not exclude simple partial seizures. A failed therapeutic trial with antiepileptic medication and adverse events prompted reevaluation of the case. Sleep studies, including polysomnography and multiple sleep latency testing (MSLT), confirmed a sleep disorder, i.e., narcolepsy, which responded to specific therapy with resolution of the spells.     

Can an exercise bicycle be safely used in the epilepsy monitoring unit?: An exercise method to provoke epileptic seizures and the related safety issues

Background and purposeLong-term videoelectroencephalogram (video-EEG) monitoring is performed to diagnose an epileptic seizure and to investigate the differential diagnosis of paroxysmal events. To provoke an epileptic seizure, an exercise method is performed in some cases during long-term video-EEG recording in the epilepsy monitoring unit (EMU). The purpose of this study was two-fold: to assess the frequency and severity of adverse events associated with the use of an exercise bicycle and to find a way to safely use it in the EMU.MethodsA retrospective survey was performed on all epileptic seizure videos recorded in the EMU from January 2012 to December 2013. Three hundred and fifty patients were included in this study.ResultsEleven patients experienced an epileptic seizure while riding the exercise bicycle in the EMU. One patient's foot got stuck between the cycling pedal and its strap, and one patient fell off the exercise bicycle during the epileptic seizure. However, there were no serious adverse events over two years.ConclusionEpileptic seizures were not frequent while riding the exercise bicycle, and serious injuries did not occur. But, there is a need to improve the safety in the EMU to control the potentially dangerous factors associated with the use of the exercise bicycle and to continuously monitor the patients with help from the staff.     

Diagnostic usefulness and duration of the inpatient long-term video-EEG monitoring: Findings in patients extensively investigated before the monitoring

Inpatient long-term video-EEG monitoring (LTM) is an important diagnostic tool for patients with seizures and other paroxysmal behavioural events. The main referral categories are diagnosis (epileptic versus non-epileptic disorder), seizure classification and presurgical evaluation. The diagnostic usefulness of the LTM varies considerably (19–75%) depending on how this was defined and on the selection of the patients. The purpose of this study was to assess the diagnostic usefulness and the necessary duration of the LTM for the referral groups, in patients extensively investigated before the monitoring. An LTM was considered diagnostically useful when it provided previously not reported, clinically relevant information on the paroxysmal event. For the presurgical group, reaching a decision concerning surgery was an additional requirement.We reviewed data from 234 consecutive LTM-sessions (221 patients) over a 2-year period. In 44% of the cases the LTM was diagnostically useful. There were no significant differences concerning diagnostic usefulness among the main referral groups: diagnostic (41%), classification (41%) and presurgical (55%). Diagnostic usefulness did not differ among the age groups either. The duration of the successful LTM-sessions was significantly longer in the presurgical group (mean: 3.5 days) than in the diagnostic and classification groups (2.4 and 2.3 days, respectively). We conclude that LTM is a valuable diagnostic tool even in patients extensively investigated before the monitoring, and is equally effective in the referral and age groups. However, patients referred for presurgical evaluation need considerably longer LTM, and this should be taken into account when planning the resources and calculating the costs.     

Botulinum toxin-induced paralysis of frontotemporal muscles improves seizure focus localization.

BACKGROUND: Scalp EEG localization of epileptic foci may be obscured by electromyographic (EMG) artifact produced by ictal contraction of cranial muscles. Injection of botulinum toxin type A (BTX-A) into frontotemporal scalp muscles reduces EMG activity. Initial scalp video-EEG monitoring in three patients suggested partial seizures, but definitive lateralization or localization was precluded by EMG artifact. METHODS: EMG-guided BTX-A injection to bilateral frontotemporal muscles was performed. When artifact persisted, BTX-A administration was selectively repeated. Patients subsequently underwent scalp video-EEG monitoring 1 week later. RESULTS: All patients had reduction of EMG artifact during subsequent scalp video-EEG monitoring. No patient had adverse effects after BTX-A administration. All three patients had localization to either frontal or temporal lobes and definitive lateralization. Two of the three patients were able to proceed to invasive placement of frontotemporal subdural grid electrodes based on the BTX-A scalp video-EEG localization, and the third patient was determined to have a multifocal seizure disorder. CONCLUSIONS: Paralysis of frontotemporal scalp muscle after BTX-A administration reduces EMG artifact and may improve localization and lateralization of a seizure focus, providing a noninvasive technique for advancement toward epilepsy surgery.     

Cough syncope misinterpreted as epileptic seizure

Cough syncopes are rare but may be one of the cause of sudden loss of consciousness. We recorded under video-EEG monitoring a typical syncope triggered by voluntary coughing (video) and Valsava maneuvre in a patient referred for the diagnosis of generalized tonic-clonic seizures. There were no signs of active epilepsy. The attacks were associated with overweight, obstructive sleep apnea and heavy consumption of cigarettes. [Published with video sequences].