Outcome of Absence Epilepsy With Onset at 8-11 Years of Age: Watershed Ages When Syndromes Overlap.

Introduction: Absence seizures occur in various epilepsy syndromes, including childhood and juvenile absence epilepsy and juvenile myoclonic epilepsy. When children present with absence seizures at ages when syndromes overlap, initial syndrome designation is not always possible, making early prognostication challenging. For these children, the study objective is to determine clinical and initial electroencephalograph (EEG) findings to predict the development of generalized tonic-clonic seizures, which is a factor that affects outcome. Methods: Children with new-onset absence seizures between 8 and 11 years of age with at least 5 years of follow-up data were studied through the review of medical records and initial EEG tracings. Results: Ninety-eight patients were included in the study. The median age of absence seizure onset was 9 years (interquartile range [IQR] = 8.00, 10.00) and follow-up was 15 years (IQR = 13.00, 18.00). Forty-six percent developed generalized tonic-clonic seizures and 20% developed myoclonic seizures. On multiple regression analysis, a history of myoclonic seizures, anxiety, as well as bifrontal slowing and mild background slowing on initial EEG (P < .05) were associated with generalized tonic-clonic seizures. Although not statistically significant, a shorter duration of shortest EEG burst on baseline EEG was also associated with generalized tonic-clonic seizures. Conclusion: On initial EEG, bifrontal and background slowing and myoclonic seizures and anxiety are associated with developing generalized tonic-clonic seizures, which is of prognostic significance when early syndrome designation is difficult.

School performance in children at the time of new-onset seizures and at long-term follow-up: A retrospective cohort study.

OBJECTIVE: School-performance difficulties (SPD) are common in children with epilepsy. The objectives of this study were to determine if the rate of SPD in children with seizures change from seizure-onset to follow-up and differ from children with psychiatric disorders. METHODS: School-aged children who required an initial electroencephalography (EEG) test in 2016 were reviewed and separated into two groups based on the presence or absence of seizures. Developmental delay and SPD were compared between groups at initial assessment and SPD was assessed after 2-4 years of follow-up. Analysis was also performed on a sub-set of patients with psychiatric disorders. RESULTS: At baseline, the rate of SPD was similar between the seizure (n = 146) and non-seizure (n = 332) groups [26% vs. 27%]. At follow-up, the seizure (n = 119) group had a significantly higher rate of SPD than the non-seizure (n = 215) group (54% vs. 43%). There was no difference in the rate of SPD between the seizure (n = 119) and psychiatric (n = 69) groups at baseline (31% vs. 43%) or follow-up (54% vs. 55%). CONCLUSION: Over time, children with recurrent seizures experience more SPD than children without seizures, but similar SPD to children with psychiatric disorders.

Pediatric Occipital Spikes at a Single Center Over 26 Years and the Significance of Tangential Dipole.

BACKGROUND: Pediatric occipital epileptiform discharges occur in various clinical settings, including self-limited and treatment-resistant epilepsies. The study objective is to determine electro-clinical predictors for prognosis in children with occipital epileptiform discharges. METHODS: 205 patients with occipital epileptiform discharges were classified into seizure groups: self-limited occipital (SLO) (n = 57), including Panayiotopoulos and Gastaut syndrome; non-self-limited occipital (non-SLO) (n = 98), including various seizure etiologies; genetic-generalized (n = 18); febrile (n = 5); and no-seizure (n = 27) groups. Electro-clinical features of the SLO and non-SLO were compared, as this is of most clinical relevance. RESULTS: The median age of seizure onset was 3 years (range: 0-19). Occipital epileptiform discharges with frontal/central positivity were present in both groups, but more common in the SLO than non-SLO groups; 21/57 (36.8%) and 19/98 (19.4%), respectively (P < .022). However, when occipital epileptiform discharges with tangential dipoles (P < .048) were accompanied by abnormal ictal eye movements (P < .037), they were predictive of SLO epilepsy. CONCLUSIONS: In our cohort, occipital epileptiform discharges with tangential dipole detected by visual analysis and abnormal ictal eye movements were predictive of SLO epilepsy.

Infantile Spasms and Trisomy 21: Unfavorable Outcomes with First-line Vigabatrin Therapy.

INTRODUCTION: Among children with infantile spasms (ISs), those with trisomy 21 (T21) and those with normal development at onset and no identifiable etiology (previously referred to as "idiopathic") are expected to have relatively favorable outcomes. The study objective is to determine if differences exist in treatment response, relapse, and subsequent epilepsy between these two groups when vigabatrin is used as first-line treatment. METHODS: In this retrospective study, patients were classified into the following groups and clinical features were compared: T21 (n = 24) and IS with normal development at onset and no identified etiology (n = 40; control group). RESULTS: There was no significant difference in the age of IS onset, sex distribution, or treatment lag between the groups. The T21 compared to the control group required a higher mean number of anti-seizure therapies (3.6 vs. 1.9, p < 0.001), had more relapses [10 (42%) vs. 4 (10%), p < 0.005)], and had higher risk of subsequent epilepsy [11 (46%) vs. 8 (20%), p < 0.003]. Relapses were often delayed in the T21 group, with a mean of 8 months after IS cessation. CONCLUSION: Our results differ from most studies using steroids as first-line treatment where the groups were shown to have similar treatment response and T21 patients had a low risk of relapse and subsequent epilepsy. Therefore, our results suggest that vigabatrin as first-line treatment in T21 with IS may be less favorable than steroids.

Clinical Significance of Incidental Rolandic Spikes in Children With Absence Epilepsy.

PURPOSE: Absence epilepsy and benign epilepsy of childhood with central temporal spikes are common childhood epilepsy syndromes. Although 3-Hz generalized spike-wave discharges are almost always associated with absence seizures, rolandic spikes can be present in individuals without rolandic seizures. The co-occurrence of 3-Hz generalized spike-wave and rolandic spikes is very rare. Our objective was to compare clinical features of patients with absence epilepsy with and without rolandic spikes, to determine if the additional feature of rolandic spikes has any clinical significance. METHODS: Clinical information of 17 children with absence epilepsy and rolandic spikes was compared to an age-matched control group of 90 children with absence epilepsy. RESULTS: Although most patients had excellent seizure control at follow-up, epilepsy comorbidities (cognitive and emotional problems) were observed. Comparing study vs control groups, there was no difference with anxiety (2 [11.8%] vs 8 [9%]), behavioral issues (4 [23.5%] vs 10 [11%]), mood disorders (0 vs 2 [2%]), and attention-deficit hyperactivity disorder (4 [24%] vs 10 [11%]). Significant differences were also observed: more global-developmental (5 [29%] vs 5 [6%], P < .009) and expressive-language (4 [24%] vs 5 [6%], P < .034) delay and more difficulties with school performance (11 [65%] vs 32 [36%], P < .025), especially with language-related tasks (6 [35%] vs 5 [6%], P < .001). CONCLUSION: Our results confirm the presence of additional epilepsy comorbidities in patients with absence epilepsy when rolandic spikes are present. Rolandic spikes in patients with absence epilepsy may be a marker of additional cognitive challenges that physicians should be aware of.

Pattern of Brain Injury Predicts Long-Term Epilepsy Following Neonatal Encephalopathy.

OBJECTIVE: To determine if patterns of hypoxic-ischemic brain injury on magnetic resonance imaging (MRI) in term newborns predict subsequent childhood epilepsy. METHODS: This retrospective cohort study includes term newborns with encephalopathy (n = 181) born between 2004-2012 and admitted to British Columbia Children's Hospital. MRI was performed between 3 and 5 days of age. The predominant patterns of hypoxic-ischemic injury were classified as Normal, Watershed, Basal Nuclei, Total, and Focal-Multifocal. Lesions in hippocampus, motor and occipital cortex were noted. RESULTS: Of 181 newborns, 166 (92%) survived the neonatal period, and 132 (80%) had follow-up with a median duration of 61 months (IQR: 28-95). Twenty-three children (17%) developed epilepsy. A higher proportion with Watershed, Basal Nuclei, or Total patterns developed epilepsy (P < .001). Injury to motor cortex, hippocampus, and occipital lobe (P < .01) were independent risk factors for epilepsy. In the adjusting logistic model, Watershed (odds ratio = 16.0, 95% CI [1.3, 197.2], P = .03) and Basal Nuclei injury (odds ratio = 19.4, 95% CI [1.9, 196.3], P = .01) remained independent risk factors. Therapeutic hypothermia did not alter these associations. Severity of brain injury and recurrent neonatal seizures are other clinical risk factors. SIGNIFICANCE: In term newborns with hypoxic-ischemic encephalopathy, the predominant pattern of Watershed and Basal Nuclei injury are valuable predictors for development of epilepsy in later childhood.

Co-existence of Rolandic and 3 Hz Spike-Wave Discharges on EEG in Children with Epilepsy.

OBJECTIVE: Benign epilepsy of childhood with central temporal spikes (BECTS) and absence epilepsy are common epilepsy syndromes in children with similar age of onset and favorable prognosis. However, the co-existence of the electrocardiogram (EEG) findings of rolandic spike and 3 Hz generalized spike-wave (GSW) discharges is extremely rare, with few cases reported in the literature. Our objective was to characterize the EEG findings of these syndromes in children in our center and review the electro-clinical features. METHODS: All EEGs at BC Children's Hospital are entered in a database, which include EEG findings and clinical data. Patients with both centro-temporal spikes and 3 Hz GSW discharges were identified from the database and clinical data were reviewed. RESULTS: Among the 43,061 patients in the database from 1992 to 2017, 1426 with isolated rolandic discharges and 528 patients with isolated 3 Hz GSW discharges were identified, and 20 (0.05%) patients had both findings: 3/20 had BECTS, and subsequently developed childhood absence epilepsy and 17/20 had no seizures characteristic for BECTS. At follow-up, 17 (85%) were seizure-free, 1 (5%) had rare, and 2 (10%) had frequent seizures. CONCLUSIONS: This is the largest reported group of patients to our knowledge with the co-existence of rolandic and 3 Hz GSW discharges on EEGs in one institution, not drug-induced. As the presence of both findings is extremely rare, distinct pathophysiological mechanisms are likely. The majority had excellent seizure control at follow-up, similar to what would be expected for each type of epilepsy alone.

OBJECTIF: L'épilepsie bénigne de l'enfance à pointes centro-temporales (ou épilepsie rolandique bénigne [ERB]) et l'absence épileptique sont des syndromes épileptiques communs chez des enfants dont le pronostic est favorable et dont l'apparition des premiers symptômes s'est produite à un âge similaire. Cependant, la coexistence, lors d'EEG, de résultats montrant des décharges rolandiques et des décharges à pointes-ondes continues de 3 Hz demeure extrêmement rare, peu de cas ayant été signalés dans la littérature scientifique. Notre objectif a donc consisté à décrire les résultats d'EEG liés à ces syndromes dans le cas d'enfants fréquentant notre établissement et à examiner leurs caractéristiques électro-cliniques. MÉTHODES: En plus de certaines données cliniques, tous les résultats d'EEG réalisés au BC Children's Hospital sont saisis dans une base de données. Tant les jeunes patients donnant à voir des décharges à pointes centro-temporales que ceux atteints de décharges à pointes-ondes continues de 3 Hz ont été identifiés à partir de cette base de données. Leurs données cliniques ont été ensuite passées en revue. RÉSULTATS: Sur un total de 43 061 jeunes patients présents dans la base de données de 1992 à 2017, nous en avons identifié 1426 avec des décharges rolandiques isolées et 528 avec des décharges isolées à pointes-ondes de 3 Hz. À noter que seulement vingt d'entre eux, soit 0,05 %, étaient concernés par ces deux types de décharge. À cet égard, 3 sur 20 étaient atteints d'ERB et ont développé ultérieurement un syndrome d'absence épileptique; chez les 17 autres, aucune convulsion caractéristique de l'ERB n'a été observée. Lors d'un suivi, 17 (85 %) d'entre eux n'avaient plus de crises convulsives tandis que 1 (5 %) avait exceptionnellement des crises et 2 (10 %), des crises fréquentes. CONCLUSIONS: À notre connaissance, il s'agit là du plus vaste groupe déclaré de patients donnant à voir, lors d'EGG menés au sein d'un seul établissement, une coexistence entre des décharges rolandiques et des décharges à pointes-ondes de 3 Hz, et ce, sans qu'elles n'aient été causées par des médicaments. Considérant que la présence de ces deux phénomènes est particulièrement inhabituelle, le rôle de divers mécanismes pathophysiologiques est fort probable. Fait à souligner, la majorité de ces patients ont pu montrer, au moment de leur suivi, une excellente maîtrise de leurs crises convulsives, maîtrise semblable à celle à laquelle on pourrait s'attendre pour chaque type d'épilepsie pris individuellement.

Predictive Value of Midline Spikes on Pediatric EEG for Seizure and Developmental Outcome.

PURPOSE: Midline spikes are epileptiform discharges localized to the midsagittal regions of the brain. Isolated midline spikes are rare, but more common in children. Our objective was to determine whether midline spikes are predictive of seizure characteristics and neurodevelopment. METHODS: EEGs and clinical information of 123 children with isolated midline spikes, and EEG follow-up within 12 to 24 months, were reviewed and compared with controls. RESULTS: Most children with midline spikes had seizures (91%), with an equal predisposition to focal or generalized seizure semiology. There was no difference between the midline spike and control groups in terms of neonatal complications, seizure characteristics (type, frequency, and etiology), and neurologic examination findings. In patients with abnormal neuro-maging, deep gray or white matter abnormalities were more frequent in the midline group (41% vs. 13%, P = 0.02). The midline group had a higher risk of development delay (DD) than controls (43% vs. 29%, odds ratio: 1.8, 95% CI [1.1-3.2], P = 0.03). A higher risk of DD was also noted in the midline group in those aged less than 4 years (52% vs. 26%, odds ratio: 3.1, 95% CI [1.0-9.2], P = 0.04) and in those without seizures (40% vs. 17%, odds ratio: 3.16, 95% CI [1.1-8.8], P = 0.03). CONCLUSIONS: This is the largest reported group of patients with midline spikes. Midline spikes have a strong association with seizures and DD. Our data suggest that midline spikes result from heterogeneous etiologies, are more common in young children, and are not benign.

Reduced Cortical Activity Impairs Development and Plasticity after Neonatal Hypoxia Ischemia.

Survivors of preterm birth are at high risk of pervasive cognitive and learning impairments, suggesting disrupted early brain development. The limits of viability for preterm birth encompass the third trimester of pregnancy, a "precritical period" of activity-dependent development characterized by the onset of spontaneous and evoked patterned electrical activity that drives neuronal maturation and formation of cortical circuits. Reduced background activity on electroencephalogram (EEG) is a sensitive marker of brain injury in human preterm infants that predicts poor neurodevelopmental outcome. We studied a rodent model of very early hypoxic-ischemic brain injury to investigate effects of injury on both general background and specific patterns of cortical activity measured with EEG. EEG background activity is depressed transiently after moderate hypoxia-ischemia with associated loss of spindle bursts. Depressed activity, in turn, is associated with delayed expression of glutamate receptor subunits and transporters. Cortical pyramidal neurons show reduced dendrite development and spine formation. Complementing previous observations in this model of impaired visual cortical plasticity, we find reduced somatosensory whisker barrel plasticity. Finally, EEG recordings from human premature newborns with brain injury demonstrate similar depressed background activity and loss of bursts in the spindle frequency band. Together, these findings suggest that abnormal development after early brain injury may result in part from disruption of specific forms of brain activity necessary for activity-dependent circuit development. SIGNIFICANCE STATEMENT: Preterm birth and term birth asphyxia result in brain injury from inadequate oxygen delivery and constitute a major and growing worldwide health problem. Poor outcomes are noted in a majority of very premature (<25 weeks gestation) newborns, resulting in death or life-long morbidity with motor, sensory, learning, behavioral, and language disabilities that limit academic achievement and well-being. Limited progress has been made to develop therapies that improve neurologic outcomes. The overall objective of this study is to understand the effect of early brain injury on activity-dependent brain development and cortical plasticity to develop new treatments that will optimize repair and recovery after brain injury.

Prognosis of EEG findings in infancy.

OBJECTIVE: To determine how specific early EEG abnormalities correlate with clinical outcome on long-term follow-up for neurological and epilepsy outcomes. Our aim was to revisit how early EEG abnormalities should be weighed for prognosis. METHODS: This is a retrospective study of 358 infants who had EEGs taken between 3 and 12 months of age and subsequent clinical assessment between 4 to 18 years of age. RESULT: Of the 358 infants, 215 had unfavorable neurological outcome (UNO), and 234 had epilepsy on follow-up. Breakdown: 117 had major abnormal EEG background of which 86% had UNO and 75% had epilepsy. One hundred had abnormal sleep potentials of which 89% had UNO and 80% had epilepsy. One hundred seventy-five had interictal epileptiform activity of which 80% had UNO and epilepsy. Sixty had ictal epileptiform activity of which 90% had UNO and 86% had epilepsy. One hundred ninety-two had markedly abnormal overall EEG impression of which 80% had UNO and 79% had epilepsy. CONCLUSIONS: Occurrence of significant EEG abnormalities in the first year was clearly associated with UNO and epilepsy. Current views that certain EEG abnormalities (e.g., interictal spike) may have little prognostic significance would need to be revisited.

Cerebral modulation of circadian sleep-wake rhythms.

The objective of this prospective observational study was to assess the association between dysrhythmia of EEG background (disturbance of cerebral connectivity) and sleep difficulties. Sixty children, aged 4 to 12 years, participated. Hospital records were reviewed, and sleep histories were obtained by interviewing the parents. EEGs of 39 subjects were normal, showed epileptiform activity, and/or mild to moderate background dysrhythmia. Severe unilateral dysrhythmia was noted in 6 and bilaterally in 15 EEGs, with all 15 children having profound neurodevelopmental disabilities and 14 of these 15 having long-standing severe chaotic sleep/wake patterns. Thus, there was a highly significant association between EEG evidence of severe bilateral dysrhythmia and chronic sleep/wake dysregulation. Unilateral dysrhythmia was not associated with sleep difficulties. This study delineates a specific sleep disorder in a group of children with marked neurodevelopmental disabilities and offers insight into how disturbed cerebral connectivity impacts the thalamocortical dynamics relating to neurodevelopmental disabilities, sleep, and melatonin production.

Long-term clinical outcome of neonatal EEG findings.

The aim of the study is to determine how specific EEG findings during neonatal period correlate with clinical outcome on follow-up. This is a retrospective study of 118 term newborns who had EEG in the first month of life and subsequent clinical assessment between 4 and 16 years. Clinical neurologic outcome was classified into "favorable" when patients had no or only mild limitation in assessment, "unfavorable" when patients had moderate to severe abnormalities in assessment, and "epilepsy" when patients had seizures. Of the 118 neonates, 36 (30.5%) had favorable and 82 (69.5%) had unfavorable outcome; 89 (75.4%) had epilepsy and 28 (23.7%) had not. Sixty-seven (57%) had abnormal EEG background of which 56 had both unfavorable outcome and epilepsy; 102 (86%) had sharp transient discharges of which 75 had unfavorable outcome; 20 (17%) had ictal epileptiform discharges of which 18 had unfavorable outcome; 98 (83%) had abnormal overall EEG impression of which 77 had unfavorable outcome and 80 had epilepsy. Abnormal EEG background (particularly suppression) during neonatal period may be predictive of Unfavorable outcome. Overall impression of EEG may be predictive of clinical outcome, even when individual parameters were not predictive. Other findings did not appear to be predictive.

Melatonin has membrane receptor-independent hypnotic action on neurons: an hypothesis.

Melatonin, which is known to have sleep-promoting properties, has no morpho-physiological barriers and readily enters neurons and their subcellular compartments from both the blood and cerebrospinal fluid. It has multiple receptor-dependent and receptor-independent functions. Sleep is a neuronal function, and it can no longer be postulated that one or more anatomical structures fully control sleep. Neurons require sleep for metabolically driven restorative purposes, and as a result, the process of sleep is modulated by peripheral and central mechanisms. This is an important finding because it suggests that melatonin should have intracellular sleep-inducing properties. Based on recent evidence, it is proposed that melatonin induces sleep at the neuronal level independently of its membrane receptors. Thus, the hypnotic action of melatonin and the mechanisms involving the circadian rhythms are separate neurological functions. This is contrary to the presently accepted view.

Effects of d-3-hydroxybutyrate treatment on hypoglycemic coma in rat pups.

d-3-Hydroxybutyrate (3OHB) is an alternative energy substrate for the brain during hypoglycemia, especially in infancy. Knowledge of the capacity and limits of 3OHB to compensate for cerebral glucose depletion during hypoglycemia in developing brain is important for its potential clinical use, but is scarce. We studied the effect of 3OHB treatment during insulin-induced hypoglycemia in 13-day-old rat pups. 3OHB treatment resulted in increased 3OHB plasma levels in hypoglycemic animals (3-4mM vs. 0.5-1mM untreated), and delayed the onset of clinical coma by 70min and of burst-suppression coma by 90min. 3OHB treated animals did not survive after resuscitation with glucose, compared to 80% survival of untreated hypoglycemic pups. Cleaved-caspase-3 immunohistochemistry and double labeling studies demonstrated a 20-fold increase of apoptotic mature oligodendrocytes in white matter of 3OHB treated animals. 3OHB treatment delays the onset of clinical and burst-suppression coma during hypoglycemia, but the prolonged duration of hypoglycemia is associated with increased mortality after resuscitation and cellular white matter injury.

Clinical usefulness of somatosensory evoked potentials for detection of brachial plexopathy secondary to malpositioning in scoliosis surgery.

STUDY DESIGN: A retrospective longitudinal study of 434 consecutive pediatric patients who underwent surgical correction of scoliosis, while being monitored for positional brachial plexopathy. OBJECTIVE: To evaluate the effectiveness of intermittent monitoring of ulnar nerve somatosensory evoked potentials (SSEPs) for detecting brachial plexus injury caused by malpositioning during scoliosis surgery. SUMMARY OF BACKGROUND DATA: Continuous intraoperative SSEP monitoring for spinal cord function has been well reported, and is widely accepted as the standard for spinal deformity correction surgery to detect and avoid neurologic injury. The use of SSEPs for the monitoring of ulnar nerve function intraoperatively as an indicator of brachial plexus function is becoming more accepted as a valid and useful technique to minimize intraoperative neurologic injuries during deformity corrections. METHODS: A review was conducted to assess the effect of ulnar nerve SSEP monitoring, as a measure of brachial plexus function, during anterior, posterior, or combined approach surgeries. The type of scoliosis, type of surgery and positioning, and surgical event at noted amplitude decrease were included in an analysis of variance for repeated measures, and a Student t test was performed for significant differences. RESULTS: A total of 27 patients had ulnar nerve amplitude decreases of > or =30%, resulting in a point prevalence of 6.2% for positional brachial plexopathy during positioning for all scoliosis surgeries. A significant difference was noted between the types of positioning, with prone positioning accounting for a higher rate of brachial plexopathy compared with anterior approach positioning (P < 0.01). No statistical difference exists as to the type of scoliosis present and the incidence of brachial plexopathy (P < 0.01). CONCLUSIONS: Avoidance of neurologic injury to the brachial plexus during scoliosis surgery is possible by early detection with ulnar nerve SSEP monitoring.

Conscious visual abilities in a patient with early bilateral occipital damage.

A 21-year-old male presented with occipital lobes that were extensively damaged by bilateral infarcts present at birth. The absence of the striate cortex was confirmed with anatomic and functional MRI and high-resolution EEG. His cortical visual impairment was severe, but he retained a remarkable ability to see fast-moving stimuli. Horizontal optokinetic nystagmus could be elicited from either eye. Resolution acuity was close to normal providing the patient was allowed to move his head and eyes. The direction of motion in random-dot patterns could be discriminated with perfect accuracy at speeds above 2 deg/s, and the patient reported that he could 'see' the motion at fast but not at slow speeds. This conscious residual vision for motion is known as Riddoch's phenomenon, but it has never been reported in the complete absence of the striate cortex. Functional neuroimaging revealed activation that was outside the motion-responsive regions of the extrastriate cortex. This case demonstrates remarkable plasticity in the human visual system and may have implications for understanding the functional organization of the motion pathways.

Tactile-evoked rolandic discharges: a benign finding?

PURPOSE: This retrospective study was undertaken to determine if patients having tactile-evoked rolandic discharges were a more "benign" patient population than those with spontaneously occurring nontactile rolandic discharges and to determine whether the presence of tactile-evoked rolandic discharges was a marker for the future development of epilepsy, as previously reported. METHODS: During this 8-year study, 304 patients were seen with rolandic discharges. These patients all had tactile stimulation of their hands and/or feet. They formed two groups: patients with spontaneous rolandic discharges that could not be evoked by tactile stimulation (NT) and patients with spontaneous rolandic discharges that could be enhanced with tactile stimulation (TE). Over a 14-month period, every patient had tactile stimulation of both hands and both feet, resulting in a third group of patients having rolandic discharges seen only with tapping (TO). RESULTS: Tactile-enhanced discharges constituted 38.2% of all rolandic discharges. Patients with TE and TO discharges had a higher incidence of normal development and intelligence, normal neurologic examinations, and a lower incidence of seizures and focal or generalized background abnormalities on their EEGs. Only one patient with normal background and no coexisting epileptiform abnormalities had partial motor seizures with corresponding contralateral central discharges. Only two patients who had no seizures at the time of their first EEG subsequently went on to develop seizures. Neither fit the pattern of the seizure disorder described in the literature. CONCLUSIONS: It is hypothesized that tactile-evoked rolandic discharges are a benign, age-related phenomenon, which do not represent a marker for the future development of epilepsy and are not the interictal electrographic correlate to an already existing seizure disorder.

Hyperventilation-induced high-amplitude rhythmic slowing with altered awareness: a video-EEG comparison with absence seizures.

PURPOSE: Hyperventilation-induced high-amplitude rhythmic slowing (HIHARS) in children may be associated with clinical episodes of altered awareness. The presence of automatisms has been proposed as a distinguishing feature that helps to differentiate absence seizures from nonepileptic causes of decreased responsiveness. This retrospective, controlled, video-EEG study compared the clinical characteristics of episodes of HIHARS with loss of awareness with those of absence seizures. METHODS: The database of a tertiary Children's Hospital was searched for patients studied between April 1993 and April 1997 who had at least one episode of HIHARS with loss of awareness. The absence control group was obtained by selecting the next patient, after an HIHARS study subject, who met the following criteria: (a) had at least one absence seizure occurred during hyperventilation in the EEG recording, and (b) had a diagnosis of idiopathic generalized epilepsy. The video-EEG and medical histories of all patients were reviewed and summarized. RESULTS: We reviewed video-EEG recordings of 77 episodes of HIHARS with loss of awareness from 22 children and 107 absence seizures during hyperventilation from 22 children. Eye opening and eyelid flutter were seen more frequently in absence seizures, whereas fidgeting, smiling, and yawning occurred more frequently during HIHARS episodes. Arrest of activity, staring, and oral and manual automatisms were observed in both groups. CONCLUSIONS: Automatisms are common in both HIHARS and absence seizures. Yawning, smiling, and particularly fidgeting occur more commonly and eye opening and eyelid flutter less commonly in HIHARS. However, episodes of HIHARS with loss of awareness clinically mimic absence seizures, and these conditions can be distinguished reliably only by EEG.

Partial status epilepticus in benign childhood epilepsy with centrotemporal spikes: are independent right and left seizures a risk factor?

PURPOSE: To describe an association between continuous simple partial seizures and independent right and left partial seizures in children with benign childhood epilepsy with centrotemporal spikes (BCECTS). METHODS: Three children with BCECTS and episodes of continuous simple partial seizures are described. RESULTS: All three children had a history of typical rolandic seizures occurring on the right and left sides of the body on different occasions. CONCLUSIONS: The occurrence of independent right and left rolandic seizures in children with BCECTS may be a predisposing factor for the development of partial status epilepticus.