Partial complex seizures in children: an analysis of 69 seizures in 24 patients using EEG FM radiotelemetry and videotape recording

A Review of the New Antiepileptic Drugs for Focal-Onset Seizures in Pediatrics: Role of Extrapolation

Most antiepileptic drugs (AEDs) receive regulatory approval for children years after the drug is available in adults, encouraging off-label use of the drug in children and hindering attempts to obtain quality pediatric data in controlled trials. Extrapolating adult efficacy data to pediatrics can reduce the time between approval in adults and that in children. To extrapolate efficacy from adults to children, several assumptions must be supported, such as (1) a similar disease progression and response to interventions in adults and children, and (2) similar exposure response in adults and children. The Pediatric Epilepsy Academic Consortium for Extrapolation (PEACE) addressed these assumptions in focal-onset seizures (FOS), the most common seizure type in both adults and children. PEACE reviewed the biological and clinical evidence that supported the assumptions that children with FOS have a similar disease progression and response to intervention as adults with FOS. After age 2 years, the pathophysiological underpinnings of FOS and the biological milieu in which seizures are initiated and propagated in children, seizure semiology, electroencephalographic features, etiology and AED response to FOS in children are similar to those in adults with FOS. PEACE concluded that extrapolation of efficacy data in adults to pediatrics in FOS is supported by strong scientific and clinical evidence. However, safety and pharmacokinetic (PK) data cannot be extrapolated from adults to children. Based on extrapolation, eslicarbazepine is now approved for children with FOS, down to age 4 years. Perampanel, lacosamide and brivaracetam are now undergoing PK and safety studies for the purposes of extrapolation down to age 2 or 4 years. When done in conjunction with PK and safety investigations in children, extrapolation of adult data from adults to children can reduce the time delay between approval of effective and safe AEDs in adults and approval in children.

Surgery for childhood epilepsy

Approximately 60% of all patients with epilepsy suffer from focal epilepsy syndromes. In about 15% of these patients, the seizures are not adequately controlled with antiepileptic drugs; such patients are potential candidates for surgical treatment and the major proportion is in the pediatric group (18 years old or less). Epilepsy surgery in children who have been carefully chosen can result in either seizure freedom or a marked (>90%) reduction in seizures in approximately two-thirds of children with intractable seizures. Advances in structural and functional neuroimaging, neurosurgery, and neuroanaesthesia have improved the outcomes of surgery for children with intractable epilepsy. Early surgery improves the quality of life and cognitive and developmental outcome and allows the child to lead a normal life. Surgically remediable epilepsies should be identified early and include temporal lobe epilepsy with hippocampal sclerosis, lesional temporal and extratemporal epilepsy, hemispherical epilepsy, and gelastic epilepsy with hypothalamic hamartoma. These syndromes have both acquired and congenital etiologies and can be treated by resective or disconnective surgery. Palliative procedures are performed in children with diffuse and multifocal epilepsies who are not candidates for resective surgery. The palliative procedures include corpus callosotomy and vagal nerve stimulation while deep brain stimulation in epilepsy is still under evaluation. For children with "surgically remediable epilepsy," surgery should be offered as a procedure of choice rather than as a treatment of last resort.

Prevalence of recurrent symptoms and their association with epilepsy and febrile seizure in school-aged children: a community-based survey in Iceland

We determined the prevalence of common recurrent symptoms in a community-based study of children and investigated whether these symptoms were associated with epilepsy and febrile seizure. A questionnaire was developed and sent to parents of all children attending school in the Reykjavik school district, grades 1-10. The questions assessed personality traits, headache, epilepsy, febrile seizure, and recurrent symptoms. Of the 13,044 questionnaires distributed, 10,578 were returned (81%). We analyzed the subset of 9679 (91%) questionnaires with complete information on relevant factors. The prevalence of epilepsy was 7.7/1000; febrile seizures were reported in 5.1% of children. Prevalence estimates of recurrent symptoms were similar to the published literature. In our cohort, recurrent dizzy spells and recurrent visual disturbances were associated with epilepsy after adjustment for age, migraine and febrile seizure. This association could reflect, only in part, the occurrence of auras in children with epilepsy.

Classification of clinical semiology in epileptic seizures in neonates

The clinical semiology of 61 neonatal seizures with EEG correlates, in 24 babies was analysed. Most seizures (89%) had multiple features during the EEG discharge. The seizures were classified using the prominent clinical feature at onset, and all features seen during the seizure, using an extended classification scheme. Orolingual features occurred most frequently at onset (30%), whereas ocular phenomena occurred most often during the seizure (70%). Orolingual, ocular and autonomic features were seen at onset in 55% of the seizures. Seizure onsets with clonic, tonic and hypomotor features were seen in 20%, 8% and 18% respectively. Clinico-electrical correlations were as follows. The EEG discharge involved both hemispheres in 54% of all seizures, in clonic seizures this was 93%. Focal clonic seizures were associated with EEG seizure onset from the contralateral hemisphere. Majority of the clonic and hypomotor seizures had a left hemisphere ictal EEG onset. Orolingual seizures frequently started from the right hemisphere, whereas ocular and autonomic seizures arose from either hemisphere. There was no significant difference in mortality, morbidity, abnormal neuroimaging and EEG background abnormalities in babies with or without clonic seizures. This study provides insights into neuronal networks that underpin electroclinical seizures, by analysing and classifying the obvious initial clinical features and those during the seizure.

Dissolving oral clonazepam wafers in the acute treatment of prolonged seizures

Klonopin (clonazepam; Genentech Inc, South San Francisco, California) oral wafers are benzodiazepines with anticonvulsive and anxiolytic properties. Our institution has been prescribing clonazepam wafers for acute treatment of prolonged seizures for years. Patients' size determined dosing at 0.25, 0.5, 1, or 2 mg wafers. We proceeded to obtain evidence for efficacy. Hospital Institutional Review Board approval was obtained for anonymous patient survey. All children who had been prescribed clonazepam wafers over a 6-year period at our institution were mailed detailed questionnaires. Three hundred eighty-one questionnaires were mailed with 88 replies but only 56 with meaningful data. Average age was 12.1 years. There were 31 males. Efficacy was defined as stopping seizure within 10 minutes, >50% of the time. Thirty-eight of the 56 (68%) patients met this criterion. From these 38 patients, 19 (50%) had seizures stop within 1 minute. Overall results were comparable to Diastat (rectal diazepam; Valeant Pharmaceuticals International, Aliso Viejo, California). Clonazepam wafers are an effective acute therapy for prolonged seizures.

Surgery for medically intractable temporal lobe epilepsy during early life

PURPOSE

Temporal lobe epilepsy (TLE) in early life is often a catastrophic disorder with pharmacoresistant seizures and secondary neurological deterioration. there is little data available regarding epilepsy surgery performed in infants and young children and no prior study has focused on tle.

METHODS

We analyzed the results of temporal resection for epilepsy as the primary indication in children less than age 5 years who had at least 2 years of follow-up.

RESULTS

20 children (14 males) were identified with a mean age at surgery of 26 months and a mean age at seizure onset of 12 months. Clinical presentation was diverse. Typical psychomotor seizures (n = 4; mean age at surgery 37 months) were followed by prominent motor changes (n = 7; 30 months) and were occasionally isolated (n = 3; 23 months). Epileptic spasms were noted in six patients and were frequently associated with lateralizing features. The interictal EEG was lateralizing in 15 patients and the ictal EEG was lateralizing in 18 patients. Brain MRI provided localizing value in 16 patients, ictal SPECT was concordant in 4/8 cases. Invasive EEG was employed in six cases. At mean follow-up of 5.5 years, 65% of the children were seizure-free and 15% had >90% seizure reduction. Morbidity included infection and hydrocephalus in one case and stroke-related hemiparesis in two cases. Cortical dysplasia was identified in eight children, tumors in eight including two DNET, two ganglioglioma, and four malignant tumors. Hippocampal sclerosis was present in four cases, always as dual pathology.

CONCLUSION

TLE presents in early life with varied and severe manifestations. Excisional procedures in this age group are associated with favorable seizure reduction similar to older children and in adults.

Seizures, syncope, or breath-holding presenting to the pediatric neurologist--when is the etiology a life-threatening arrhythmia?

Using case reports from their own experience and in the literature the authors illustrate the difficulty in distinguishing non-life threatening causes, including epilepsy, from a serious cardiac arrythmia when evaluating children with paroxysmal events. Focusing on long QT syndrome, they suggest an approach for the pediatric neurologist that utilizes the electrocardiogram recorded during the electroencephalogram--direct measurement of the corrected QT interval. This approach requires knowledge of the distribution of the corrected QT interval in long QT syndrome.

The treatment of status epilepticus

Status epilepticus (SE) is a life-threatening emergency that requires prompt treatment, including basic neuroresuscitation principles (the ABCs), antiepileptic drugs to stop the seizure, and identification of etiology. Symptomatic SE is more common in younger children. Treating the precipitating cause may prevent ongoing neurologic injury and facilitates seizure control. A systematic treatment regimen, planned in advance, is needed, including one for refractory status epilepticus (RSE). Here we emphasize definitions, clinical and electroencephalography stages, early treatment, special circumstances that may require immediate seizure control, and treatment of RSE. Because much clinical research in SE has been done in adults, we indicate the patient population studied.

Epilepsy surgery in childhood

Epilepsy surgery in childhood can now be more readily considered as a result of enhanced presurgical investigative techniques and safer neurosurgical practice. As in adults, surgery available may be resective (focal resection or hemispherectomy) or functional. The most common procedures are temporal lobectomy and hemispherectomy, with malformative lesions and developmental tumours the next common pathology. The timing of surgery requires careful consideration, and the definition of drug resistance given specific thought in the young child. Presurgical evaluation should be noninvasive where possible, and should include optimised MRI, including 3D data set and video EEG telemetry to document seizures. Detection of temporal lobe abnormalities in temporal lobe epilepsy with MR may be enhanced using quantitative and semiquantitative techniques. Ictal and interictal SPECT may be useful in providing information about the seizure onset zone, if reviewed in conjunction with MR data and video-EEG. Interictal PET is more likely to demonstrate abnormalities relating to structural defects, but may be particularly useful in infants where incomplete myelination may restrict structural information provided by MRI. Neuropsychology testing plays a major role by the determination of verbal and nonverbal function in older children, and in the determination of cerebral dominance. Functional MRI for determination of language or motor cortex may enhance such evaluation, although it is limited to older unsedated children at present. Although the aims of the presurgical evaluation remain similar to adult practice, the range of children presenting is wide, and the aims and likely outcome of surgery require careful evaluation with the family. This aside, the benefits of seizure elimination or reduction in drug-resistant focal epilepsy prior to adolescence, as well as in certain early catastrophic epilepsies of childhood, remain self apparent.

Five-year follow-up of patients with partial epilepsies in infancy

The aim of this study is to clarify the long-term outcome of patients with partial epilepsies that begin in the first 2 years of age. Thirty-nine infants who experienced partial epilepsies with onset by 2 years of age were followed until they were at least 5 years of age. Seizure and developmental outcome were investigated in relation to the following items: delayed psychomotor development before onset of seizures; interictal electroencephalogram (EEG) abnormalities; abnormal neuroimaging; family history of epilepsy; and history of neonatal seizures. Thirty-three infants achieved freedom from seizures and 27 achieved normal development. Delayed development before the onset and abnormal interictal EEG correlated with both poor seizure and developmental outcome. Abnormal neuroimaging findings correlated with a poor seizure outcome. A history of neonatal seizures and lack of a family history of epilepsy correlated with poor developmental outcome. The combination of the first four factors predicted a normal outcome with a sensitivity of 0.79 and a specificity of 0.87. The seizure and developmental outcomes were better in this study than those in previous studies. The combination of the four factors will be useful for predicting the outcomes in patients with partial epilepsies in infancy.

Epilepsy surgery in children, with special attention to focal cortical resections

Epilepsy surgery is an important alternative for children and adolescents with medically intractable epilepsy. Advances in imaging have allowed the visualization of epileptogenic regions, including cortical dysplasia. The presurgical evaluation will likely become less invasive as imaging technology improves. Long-term development is a critical outcome measure, in addition to seizure control. The long-term prognosis after epilepsy surgery may be related to factors other than seizure control, including the timing of the intervention and the cause of the epilepsy. It may be useful to independently analyze children based on cause, and further studies examining the long-term outcome should become feasible as surgical experience grows.

Symptomatology of epileptic seizures in the first three years of life

PURPOSE

Few data are available concerning symptomatology of epileptic seizures in infants.

METHODS

We reviewed 296 videotaped seizures from 76 patients aged 1-35 months (mean, 15.1 months) who underwent video-EEG monitoring at our institution from 1988 to 1998. Seizure symptomatology was first classified based on observable behavioral and motor manifestations and then correlated with ictal EEG.

RESULTS

Four seizure types accounted for 81% of all seizures seen in this group: epileptic spasms (24%), clonic seizures (20%), tonic seizures (17%), and hypomotor seizures (20%; characterized by arrest or significant decrease of behavioral motor activity with indeterminate level of consciousness). The remaining seizures included small numbers of myoclonic, atonic, and versive seizures. All 12 focal motor seizures and all five versive seizures were associated with focal EEG seizure patterns, seen in the contralateral hemisphere in all but one patient with versive seizures. Generalized motor seizures (clinically generalized at onset) were accompanied either by focal (19 of 51; 37%) or generalized (32 of 51; 63%) EEG seizures. Hypomotor seizures also were associated with focal (14 of 20; 70%) or generalized (six of 20; 30%) EEG seizures. Four patients with generalized epileptic spasms had generalized EEG seizures in the setting of focal epilepsy based on neuroimaging, interictal EEG, and in two cases also on postresection seizure freedom. Seizure types not seen in this age group included auras, seizures with prominent automatisms (except in one case), and classic generalized tonic-clonic seizures.

CONCLUSIONS

The repertoire of seizure manifestation in the first 3 years of life appears to be limited. In infants, focal motor seizures are reliably associated with focal EEG seizures in the contralateral hemisphere, whereas generalized motor and hypomotor clinical seizures may be either focal or generalized on EEG. Epileptic spasms may be seen in focal as well as generalized epilepsies. Video-EEG monitoring and neuroimaging may be critical for clarifying the focal or generalized nature of the epilepsy in infants.

A case of parietal lobe epilepsy with distinctive clinical and neuroradiological features

We present a case of parietal lobe epilepsy, the epileptogenic focus of which was conspicuously demonstrated on magnetoencephalography (MEG). The remarkable fluctuation in the seizure frequency and the presence of atonic seizures were suggestive of atypical partial benign epilepsy of childhood (APBEC). An interictal positron emission tomography (PET) scan performed during the cluster of fits revealed hypermetabolism around the epileptogenic focus, which might be related to the marked tendency of clustering of seizures in this patient.

Temporal lobe epilepsy in infants and children

Temporal lobe epilepsy in adults and adolescents is a fairly homogeneous syndrome, both in terms of seizure semiology and in terms of its pathology, and it has been studied extensively. Temporal lobe epilepsy in infants and young children has begun to receive increasing attention in recent years, and a different clinico-pathological picture has emerged. Clinically, the concept of complex partial seizures, which may be useful in adults, is difficult to apply to infants, since it is often not possible to assess impairment of consciousness in this age group. The main distinctive features of complex partial seizures of temporal lobe origin in infants are (1) a predominance of behavioral arrest with possible impairment of consciousness, (2) no identifiable aura, (3) automatisms that are discrete and mostly orofacial, (4) more prominent convulsive activity, and (5) a longer duration (more than 1 min). In addition, seizures of temporal lobe origin in infants may appear clinically generalized, such as infantile spasms or generalized tonic seizures, or can occasionally represent a benign syndrome. The neuropathological findings of temporal lobe epilepsy in infants differ even more than the clinical seizure semiology. In contrast to adult and adolescent patients, mesial temporal sclerosis is a rare finding in infants, in whom the pathological abnormalities associated with seizures of temporal lobe origin consist mostly of dysplasias, migrational disorders, hamartomas, and low-grade tumors such as gangliogliomas. Mesial temporal sclerosis is seen more often in older children than in infants, and its pathogenesis remains a subject of controversy.

Epileptic drop attacks in partial epilepsy: clinical features, evolution, and prognosis

OBJECTIVES

Sudden falls have been described in patients with partial epilepsy. However, no study has detailed the clinical, EEG, and evolutive features of partial epilepsies with drop attacks.

METHODS

In a consecutive series of 222 patients with partial epilepsy admitted for uncontrolled seizures over a 10 year period, 31 patients presented with epileptic drop attacks during evolution of their illness. Twenty two patients had frontal, five temporal, and four multifocal or undefinable lobe epilepsy; 74% of the cases showed an EEG pattern of secondary bilateral synchrony during evolution. A statistical comparison of some clinical and EEG features between the patients with epileptic drop attacks and patients with partial epilepsy without drop attacks (control group of 191 patients) was carried out.

RESULTS

Seventy four per cent of patients had a poor prognosis and 45% were mentally retarded; 52% of patients with epileptic drop attacks continued to have epileptic falls associated with partial seizures and mental deterioration at the end of the follow up. These characteristics of patients with epileptic drop attacks were significantly different from the control group.

CONCLUSION

Almost all literature reports concur that the physiopathogenetic substrate of epileptic drop attacks is a mechanism of secondary bilateral synchrony. A localised epileptic focus may lead to a process of secondary epileptogenesis involving the whole brain, causing a progressive cerebral disturbance with worsening of the epileptic seizures and higher cerebral functions.

Sensitivity of a seizure activity detection computer in childhood video/electroencephalographic monitoring

PURPOSE

Few data describe the sensitivity of a "Seizure Activity Detection Computer" (SzAC) in childhood video/EEG (VEEG) monitoring, especially for very young children. We examined the accuracy of SzAC in childhood VEEG monitoring in different pediatric age groups.

METHODS

We visually analyzed VEEG monitoring samples for randomly designated subsets of 56 patients with childhood epilepsy, reviewing 335 visually detected electrographic seizures to analyze the sensitivity of SzAC for each age group as well as the electrographic characteristics affecting the sensitivity of automated computer-based seizure detection.

RESULTS

SzAC was positive in 227 of 335 (67.8%) visually identified electrographic seizures in the entire study group. The SzAC sensitivity for infants (age 2 months to 2 years) was 59.7% (43 of 72 seizures); for young children (age 3-10 years), sensitivity 56.5% (91 of 161 seizures). In adolescents (age 11-18 years), SzAC was positive in 93 of 102 (91.2%) seizures--i.e., in a significantly greater number of seizures than in younger age groups. SzAC was significantly less sensitive in detecting electrographic seizures characterized as being of short duration or of low voltage.

CONCLUSIONS

The overall sensitivity of SzAC in detecting childhood electrographic seizures was 67.8%. The sensitivity was significantly less in younger age groups as compared with that in children aged >11 years. Electrographic seizures of relatively short duration or low voltage were often missed by SzAC.

Preoperative clinical, EEG, and imaging findings do not predict seizure outcome following temporal lobectomy in childhood

Although certain clinical, electroencephalographic (EEG), magnetic resonance imaging (MRI), and pathologic findings in adults with intractable temporal lobe epilepsy predict seizure outcome following temporal lobectomy, predictors of seizure outcome have not been studied systematically in pediatric temporal lobectomy series. We retrospectively analyzed preoperative clinical, EEG, and neuroimaging findings with reference to seizure outcome (seizure free or non-seizure free) in 33 children (mean age, 9.3 years) who underwent tailored temporal lobe resections for intractable temporal lobe epilepsy. Trends were apparent with (1) younger age at seizure onset, younger age at surgery, shorter duration of epilepsy, localized unilateral temporal lesions on MRI, and right-sided surgery more frequently associated with a seizure-free outcome, and (2) significant prior history, daily preoperative seizures, generalized motor seizures, mental retardation, and localized unilateral temporal epileptiform EEG activity more frequently associated with a non-seizure-free outcome. However, none of these findings, alone or in combination, correlated with postoperative seizure status at a statistically significant level. Submitting the four variables generally considered to be most predictive of favorable outcome (ie, normal intelligence, unilateral ictal and interictal EEG discharges, and focal temporal MRI lesion) to a multiple-cutoff procedure did not predict seizure freedom. Our data indicate that predictors of outcome of temporal lobectomy in adults may not apply in children, perhaps due to inherent neurobiologic differences in the etiology and expression of temporal lobe epilepsy, and should therefore not be used as sole determinants of surgical candidacy in children.

Intractable epilepsy in children

Although most children with epilepsy have a good prognosis, a small but significant minority have seizures that either do not respond to conventional antiepileptic drugs (AEDs) or have significant adverse reactions to AEDs. Many children may benefit from epilepsy surgery. Surgical treatment of epilepsy is becoming a well-established therapy for infants and young children with severe, medically intractable seizures. As in older children and adults, the presurgical evaluations of possible surgical candidates typically consist of a detailed history, neurologic and neuropsychologic examination, and anatomic and functional neuroimaging. The "gold standard" test, however, is the recording of ictal events by using simultaneous EEG and videomonitoring. Although temporal lobe resection is the most commonly performed surgery in older children and adults, nontemporal lobe resection, corpus callosotomy, and hemispherectomy are commonly performed in younger children. Efficacy of surgery in children compares favorably with results from adult patients. In addition, because the immature brain is more plastic than the mature brain, recovery of function is often greater after surgery in children than in adults. Early surgery in children with intractable epilepsy is recommended.

Proton magnetic resonance spectroscopy in children with temporal lobe epilepsy

We performed proton magnetic resonance spectroscopy of the mesial temporal regions in 20 children with intractable temporal lobe epilepsy and compared results with those from 13 normal subjects. Abnormalities of the ratio of N-acetylaspartate to choline plus creatine (NAA/[Cho+Cr]) were seen in 15 patients (75%). The ratio NAA/(Cho+Cr) was correctly lateralizing in 55% and incorrectly lateralizing in none. Bilateral abnormalities were seen in 45%. Overall there was a unilateral decrease in N-acetylaspartate on the side ipsilateral to the seizure focus (mean 19% decrease vs normals, with 5% decrease on the contralateral side), suggesting neuronal loss or dysfunction. There was also a bilateral increase in creatine and choline (mean 18%), consistent with reactive astrocytosis. We conclude that proton magnetic resonance spectroscopy can contribute to lateralization of the seizure focus, and by detection of bilateral abnormalities, can contribute to the understanding of the underlying pathophysiology in temporal lobe epilepsy.

Children with intractable focal epilepsy: ictal and interictal 99TcM HMPAO single photon emission computed tomography

Fourteen children with intractable complex partial seizures underwent ictal and interictal 99TcM HMPAO single photon emission computed tomography (SPECT) scans. Abnormalities concordant with clinical and/or EEG localisation were present in 13 of 14 ictal and/or interictal scans. Focal hyperperfusion was seen at the seizure focus on ictal scans and focal hypoperfusion was seen on interictal scans. The timing of the injection in relation to the start of the seizure was crucial for reliable localisation. While recognisable patterns of regional cerebral blood flow (rCBF) were seen on either interictal or ictal scans, marked changes in the patterns of rCBF between the ictal study and interictal study provided the most reliable information about seizure localisation. Using both ictal and interictal studies, 99TcM HMPAO SPECT may provide data about both the seizure origin and its relationship to structurally abnormal regions of the brain.

Complex partial status epilepticus in a child

Complex partial status epilepticus (SE) has been reported rarely in children. We describe the clinical case of a 14 year-old girl with complex partial seizures (CPS) since age 10 who developed a complex partial SE probably because she was not adherent to treatment. The neurologic examination and computed tomography scan were normal. During the SE she received diazepam and phenytoin and became free of the seizures after 5 minutes. The ictal EEG showed spikes and slow waves over the right temporal region.

Outpatient video-EEG monitoring in children

Video-EEG monitoring enables correlation of behavioral activity with EEG activity, which is useful in recognition of pseudoepileptic seizures and in investigation of patients for epilepsy surgery. Because most patients are monitored for a prolonged time as in-patients, the cost of the procedure is high. We investigated the value of brief (2-3 h) outpatient video-EEG monitoring in 43 children with frequent seizures, most of whom had symptomatic generalized epilepsy. Indications for monitoring included differentiation of epileptic from nonepileptic behavior, seizure classification, and determination of seizure frequency. Clinical episodes were recorded in 36 of 43 children (83%). A definite diagnosis was established in 9 of the 17 patients investigated to determine the nature of the clinical behavior. Seizures were classified in 15 of the 25 patients investigated to determine seizure type, and classification was different from the original in 9 of the 15 children. A change in epilepsy syndrome classification was made in 9 children. The video-EEG allowed diagnosis in 25 of the 43 children (59.5%). Video-EEG appears to be an effective method for outpatient investigation of children with frequent seizures, particularly those with symptomatic generalized epilepsy.

Diagnosis of childhood seizure disorders

Convulsive epilepsies are generally unmistakable. Absence epilepsies, which are easily recognized by the provocation of an episode during hyperventilation and by the typical features of the EEG, can be overdiagnosed, especially in the child who daydreams in class and has scattered, asymptomatic, epileptogenic EEG changes. As in adults, complex partial seizures in children can be difficult to distinguish from certain behaviors. Several types of benign childhood epilepsies need to be distinguished from the more intractable and lesional childhood epilepsies. Two common examples, benign rolandic epilepsy and benign occipital epilepsy, can be recognized by their unique EEG changes and clinical features. Juvenile myoclonic epilepsy generally does not remit spontaneously but should be recognized because it appears to respond to valproate. Some recurrent nonepileptic events seen in children can be mistaken for seizures, including shuddering attacks, paroxysmal vertigo, breath-holding spells, cardiogenic syncope, night terrors, and movement disorders, such as paroxysmal kinesigenic choreoathetosis.

Recent advances in childhood epilepsy

Recent advances in pediatric epileptology are the consequence of the explosive advance of medical technology in recent years. In this manuscript, some of the major highlights of these technology driven advances will be presented. Recognition of a typical EEG spike pattern leads to the identification of benign focal epilepsy of childhood, an extremely frequent electro-clinical syndrome of excellent prognosis. The development of CT scan and particularly of high resolution MRI, has led to the easy identification of a variety of pathologies which were previously recognized only by pathologists. These include, among others, neuroblast migrational disorders, mesial temporal sclerosis, forme fruste of tuberous sclerosis, and slow growing small temporal neoplasms. PET scanning has also shown to be particularly sensitive in the detection of subtle pathological lesions, which may remain undetected by MRI. This is particularly true in infants in whom the PET scan may uncover an unsuspected focal lesion in patients with hypsarrhythmia, indicating that hypsarrhythmia may be a form of a secondary generalized epilepsy. Advances in surgical techniques have also decreased significantly the risks of callosotomies and hemispherectomies, techniques that are now widely used to improve seizure control in patients with catastrophic seizure disorders. A better understanding of neurotransmitters involved in the generation or inhibition of seizures has led to the development of a variety of new drugs which promise to improve our ability to control seizures conservatively. Finally, advances in molecular biology have also had an impact on epileptology, leading to the discovery of gene abnormalities underlying a number of epileptic syndromes.

Temporal lobe epilepsy in early childhood

To explore the electroclinical features of temporal lobe epilepsy (TLE) in early childhood, we studied results of video-EEG and other tests of 14 children aged 16 months to 12 years selected by seizure-free outcome after temporal lobectomy. Four children had mesiotemporal sclerosis, 1 had cortical dysplasia, and 9 had low-grade temporal neoplasms. The children had complex partial seizures (CPS) with symptomatology similar to that of adults with TLE, including decreased responsiveness and automatisms. Automatisms tended to be simpler in the younger children, typically limited to lip smacking and fumbling hand gestures. Scalp/sphenoidal EEG showed anterior/inferior temporal interictal sharp waves and unilateral temporal seizure onset in the 4 children with mesiotemporal sclerosis and in the child with cortical dysplasia, but EEG findings in 9 children with low-grade temporal tumors were complex, including multifocal interictal sharp waves or poorly localized or falsely lateralized EEG seizure onset. In children without tumors, video-EEG was critical to localization of the epileptogenic zone for resection, but in patients with tumors video-EEG was less localizing and its main value was to confirm that the reported behaviors were epileptic seizures with semiology typical of temporal lobe onset.

Early detection of abnormalities in partial epilepsy using magnetic resonance

The incidence of brain abnormalities determined by magnetic resonance in 30 consecutive children presenting with intractable complex partial seizures is reported. Images were optimised to visualise the hippocampus and cortical grey matter. Abnormalities of the hippocampus or temporal lobe were seen in all 19 children with clinical features of temporal lobe epilepsy and in six of the seven children with clinically unlocalised epilepsy. By contrast, in the four children with a clinical diagnosis of extratemporal epilepsy, no temporal or hippocampal abnormalities were seen. Generalised cortical abnormalities of uncertain significance were found in a total of 14 children from all groups. The identification of focal brain abnormalities using optimised magnetic resonance imaging enables early non-invasive assessment of children with intractable seizure disorders and the identification of patients for whom epilepsy surgery may be appropriate. It may also lead to a better understanding of the structural basis of intractable epilepsy, and thereby contribute to early treatment decisions.

Drop attacks and epileptic syndromes

1. In addition to 4 types of drop attacks previously described by Ikeno et al., we could ascertain the falls of the myoclonic-tonic type in genuine drop attacks. The genuine drop attacks were seen in Lennox-Gastaut syndrome, epilepsy with myoclonic-astatic seizures and other symptomatic generalized epilepsies, and never in partial epilepsies. 2. None of the patients with partial epilepsy revealed genuine drop attacks as defined. Their drop attacks were slower (i.e. the falls were completed in more than 1 sec.). 3. In the 15 patients with Lennox-Gastaut syndrome, the drop attacks disappeared in 8 patients, and decreased in severity and frequency in 3 patients. Namely, the intractability of drop attacks in two-thirds of the children decreased as the patients grew older. This finding must be taken into consideration when patients with drop attacks are considered for surgical treatment of their epilepsy.

Frontal lobe complex partial seizures in children: a form of epilepsy at particular risk of misdiagnosis

The clinical and EEG findings are described of six children considered to have complex partial seizures of frontal lobe origin. The findings correspond generally with those reported for adult patients. Video-recordings of attacks in some cases and ictal cassette EEG recordings provided important diagnostic information. A definite frontal abnormality on neuro-imaging was seen in only one case. The seizures were closely associated with sleep, and anti-epileptic drug treatment was usually of limited value. The considerable diagnostic confusion surrounding seizures of this type, including their misdiagnosis as pseudoseizures or primary sleep disorder, is partly the result of the clinical peculiarities of this type of seizure, but also of clinicians' limited awareness of the condition.

Seizure prognosis and EEG evolution in complex partial seizures of childhood onset

We studied the clinical course and seizure prognosis of 126 children with complex partial seizures regularly followed up for more than 4 years in our clinic. Clinical and EEG features of 63 seizure-free patients were compared with those of 63 patients with persistent seizures. The features contributing to poor prognosis were 1) mental retardation, 2) a history of status epilepticus and 3) abnormal basic rhythm in EEG. CT abnormality, a history of febrile convulsions (FC), the clustering of seizures and association with other types of seizures did not influence prognosis. We divided the patients into four groups according to the evolutionary pattern of seizure discharges: Group A, 55 (43.7%) patients with spike focus always fixed in the same region; Group B, 20 (15.9%) patients with wandering foci; Group C, 10 (7.4%) patients with multifocal spikes; and group D, 41 (32.5%) patients with no focal discharges. There was no difference in seizure prognosis among these four groups, but the patients with a focus in the anterior temporal region in Group A evidenced the worst prognosis.

Electroencephalographic and neuroradiologic evaluation of children with epilepsy

In summary, CT scans are frequently abnormal in children with partial seizures. Although most of the abnormalities will not alter management of the child, in a small but significant percentage an unexpected neoplasm or other treatable lesion will be discovered. In addition, even when the CT scan does not alter therapeutic management, it may offer the clinician valuable information regarding the etiology of the seizures. A normal CT scan also serves to ensure both the physician and the parent that "nothing is being missed." As a guideline, I would recommend that all patients, with the exception of those with absence seizures, benign rolandic epilepsy, febrile seizures, and typical absence seizures have a CT scan with and without contrast enhancement. Even with a normal CT scan, however, the physician should follow the patient closely because a change in neurologic examination or the development of focal slowing on the EEG indicates the necessity for a repeat study.

Sleep, epilepsy, and the EEG in infancy and childhood

Each of the major epileptic syndromes that occur in infants and children demonstrates relationships to sleep and wakefulness that are particular to that syndrome. These relationships include activation or suppression of clinical seizures during certain portions of the sleep-wake cycle, differences in symptomatology of the seizures or in seizure type, alterations in distribution or morphology of epileptiform waveforms, and changes in duration and composition of sleep stages. Knowledge of the interactions between sleep and seizures helps to increase understanding of the physiological mechanisms underlying epilepsy, as well as to improve clinical diagnosis.

Partial seizures in children: clinical features, medical treatment, and surgical considerations

Partial seizures are not uncommon in children. They are classified into two types: simple partial, without impairment of consciousness, and complex partial, with impaired consciousness. For both types, the hallmark is onset of the seizure from a portion of one cerebral hemisphere, as indicated by focal spikes or sharp waves on EEG. The symptoms of simple partial seizures may include focal motor or somatosensory phenomena, special sensory phenomena, autonomic symptoms, or psychic symptoms, and these symptoms may occur alone or they may progress into a complex partial seizure with alteration of consciousness. The complex partial phase may include simply an arrest of ongoing activity with altered awareness and a blank empty stare, or there may also be automatisms, including movements which are gestural, alimentary, mimicking, verbal, or ambulatory. Automatisms are predominantly seen in complex partial seizures arising from temporal areas, but they also may be seen in seizures with extratemporal onset. If the epileptic discharge spreads throughout both cerebral hemispheres, the child will have a secondarily generalized tonic-clonic convulsion. EEG should be performed in any child who is suspected of having partial seizures. If there are focal spikes or sharp waves, then there is strong supportive evidence for a diagnosis of partial seizures in the proper clinical setting. It should be remembered, however, that a normal routine EEG cannot be used to "rule out" a diagnosis of epilepsy in patients who have episodes that sound like simple or complex partial seizures. An underlying etiology may be found in a significant percentage of children with partial seizures. Most of these etiologies are static, and the seizures are the result of a previous cerebral insult, but some patients may have slow-growing gliomas or other mass lesions. MRI or CT is indicated in essentially any child with partial seizures. Medical treatment is based on the idea of using single drugs to maximally tolerated doses, if needed, before beginning with two-drug regimens. If the child continues to have seizures despite aggressive trials of medication, then it is important to consider epilepsy surgery, either temporal lobectomy or other cortical resection. When children are identified as candidates for epilepsy surgery, they should be referred to specialized centers for further testing.(ABSTRACT TRUNCATED AT 400 WORDS)

Temporal lobe syncope: clinical variants

Temporal lobe syncope (TLS) is a term coined by Landolt. Characteristically, the patient has psychomotor and drop attacks, and the interictal electroencephalogram (EEG) shows temporal lobe epileptic abnormalities. TLS is synonymous with type III complex partial seizures (CPSs) in the Delgado Escueta classification. Several variants of TLS can be recognized including atonic akinetic, simple akinetic, atonic, atonic-tonic complex (automatisms), sexual seizures, stress-induced convulsions, and gelastic atonic seizures. TLS must be distinguished from drop attacks of vertebrobasilar insufficiency and associated EEG abnormalities, and from hereditary tachyarrhythmias mimicking stress-induced convulsions. Epileptic falls and drop attacks are discarded by ictal EEG recordings. Recognition of TLS variants is important in the prospective evaluation of the surgical treatment of epilepsy given the past conflicting reports on the differential outcome of surgically treated CPSs. TLS is an attractive clinical term, easy to remember, and with pathophysiologic relevance to the clinician confronting the patient with a history of syncope and whose EEG discloses temporal lobe paroxysmal activity. The detailed ictal electrophysiology of TLS is unknown.

Temporal lobe epilepsy in childhood: reappraisal of etiology and outcome

This article reports the neurologic and psychologic findings, seizure characteristics, family histories, and etiology of clinically and electroencephalographically defined temporal lobe epilepsy in 63 children who were studied retrospectively. Subsequent data were available for 53 patients (84%), 15 of whom had undergone temporal lobectomies; 38 patients had been managed conservatively for at least 2 years. Previous, complicated febrile convulsions were the most common predisposing factor, occurring in 13 patients (21%), while 6 patients had tumors (10%). Of the 10 children whose onset of temporal lobe seizures occurred before 2 years of age, 5 had tumors. The presence of emotional or behavioral problems was related significantly to the presence of borderline or low intelligence, but not to the frequency of seizures. Although there was a tendency for a reduction in seizure frequency over time, only 10% of those managed by medical therapy alone were seizure-free at a mean subsequent examination interval of 6.6 years.

An overview of pediatric seizure disorders and epileptic syndromes

Seizures are common in infants and children and must be differentiated from a wide variety of other neurological and nonneurological disorders which include episodic disturbances of behavior. If the diagnosis is clear, then one must decide if the seizure is an isolated event and unlikely to recur (as are many afebrile generalized convulsive seizures in early childhood), a symptom of underlying cerebral pathology, or part of an epileptic syndrome. The latter may be a potentially lethal neurodegenerative disease or a benign epilepsy with excellent outcome. This review will discuss the various aspects of epilepsy in the pediatric age group, emphasize the benign nature of most seizures in children (including many forms of partial, or focal, seizures), and present an overview of the more serious epileptic syndromes. The myoclonic epilepsies will be used as a model to illustrate the wide scope of epileptic phenomena in infants and children.

Type I/II complex partial seizures: no correlation with surgical outcome

Three complex partial seizure (CPS) types have been described based upon the behaviors seen at the onset of the ictal event. Type I CPSs are preceded by a motionless stare and have been correlated with a temporal focus, whereas Type II CPSs are not preceded by a motionless stare and have been correlated with an extratemporal focus. A third type of CPS, temporal lobe syncope, has been correlated with bilateral mesial temporal foci. We examined the utility of this CPS classification system in predicting surgical outcomes by reviewing our patients who had undergone surgical excision of their epileptogenic foci for the treatment of medically refractory CPSs. Forty-six consecutive patients were evaluated, with the seizure focus ultimately found to be temporal in 41 and frontal in 5. All 5 patients with frontal foci had Type II CPSs; of the 41 patients with temporal foci, 20 had Type I and 21 had the Type II CPSs. Twenty of 26 patients with Type II CPSs and 18 of 20 patients with Type I CPSs had a good or excellent outcome. Although our data suggest that patients with frontal foci have Type II CPSs, the reverse is not true. Furthermore, CPS type is not correlated with the surgical outcome, since there was no significant difference between the CPS type and the category of surgical outcome.