The Electroencephalogram in Attention Deficit-Hyperactivity Disorder: Emphasis on Epileptiform Discharges

This study dealt with the electroencephalograms (EEGs) of 176 children with attention deficit-hyperactivity disorder (ADHD). Of special interest were the patients who had in their EEG some type of spike activity (spike group), in contrast with those without such activity (control group). In the entire group, 27.8% were completely normal and an additional 18.8% had positive spikes as their only finding. Definite noncontroversial, epileptiform activity was seen in 30.1%, mainly focal (usually occipital or temporal), less often generalized, with bilaterally synchronous spike and waves complexes seen in 11 children. Extreme spindles or diffuse slow waves occurred only in the spike group (one exception in each) and slow wave abnormalities (mainly frontal or temporal), nearly always mild in degree, were seen mainly in the spike group. These different findings suggest that ADHD is a condition often with organic changes in the form of EEG abnormality, at times with epileptiform activity that could contribute to a deficit in attention or a plethora of movements.     

Temporal evolution and prognostic significance of postoperative spikes after selective amygdala-hippocampectomy.

The purpose of this study was to quantify the temporal evolution and to determine the prognostic significance of spikes on serial postoperative EEGs after selective amygdala-hippocampectomy. The authors performed postoperative EEGs 4 months, 1 year, and 2 years after surgery in 31 patients with unilateral mesial temporal lobe epilepsy. Spike frequency was determined ipsilateral to the resection (group I, no spikes; group II, 1 to 10 spikes; group III, 11 to 20 spikes; group IV, more than 21 spikes during the 30-minute recording). The temporal evolution of postoperative spike frequency was assessed, and these parameters were correlated with surgical outcome. Twenty-two patients showed spikes on postoperative EEG. Spike frequency decreased over time in 14 patients, while no changes or minimal changes occurred in seven patients, and spike frequency increased in one patient. Nine patients had no spikes. There was no correlation between occurrence, frequency, and temporal evolution of spikes with postoperative seizure control. The authors' results demonstrate a progressive decrease of spike frequency during the postoperative period after selective amygdala-hippocampectomy, although occurrence, frequency, and temporal evolution of postoperative spikes had no implications on surgical outcome.     

Latency to first spike in the EEG of epilepsy patients.

BACKGROUND: Routine EEGs in individuals with epilepsy have interictal spikes in 56% of cases. The availability of prolonged EEG has changed the use of EEG in the assessment of epilepsy. OBJECTIVE: To determine the time to first epileptiform activity on EEG in patients with epilepsy. This data will help optimize the duration of electrographic assessment for interictal activity in epileptic individuals. METHODS: 46 consecutive patients aged 10 years or older with epilepsy were evaluated. Individuals with seizures in the prior 24h or with acute symptomatic seizures were excluded. Continuous EEG (for 1-7 days) was analyzed to find the first definite epileptiform activity and the latency assessed. RESULTS: 37% of the patients had epileptiform activity in the first 20min of the continuous recording (duration of a routine EEG). 89% had epileptiform activity within 24h. The yield drops beyond 24h. 8% of the individuals had no epileptiform activity even after 72h. CONCLUSIONS: The study suggests the need to consider a change in EEG strategy to assess interictal epileptiform activity. The greatest probability of capturing an interictal abnormality within 20min was in individuals with generalized epilepsy. In individuals with suspected epilepsy in whom electrographic interictal spike confirmation is deemed necessary, after a first nonspecific or normal routine EEG, a 24h EEG should be the next step in the electrographic assessment. This study suggests that there may not be much benefit in monitoring for durations longer than 24h, unless capturing a seizure is the intent.     

Epileptiform EEG Discharges in Healthy Children: Prevalence, Emotional and Behavioral Correlates, and Genetic Influences

Summary: Epileptiform discharges in 8 electrode waking EEGs at rest and during hyperventilation in 1,057 healthy children aged 6–12 years from an elementary school were studied: Epileptiform discharges, detected in 53 children (5.0%), consisted of centrotemporal spikes (37 cases), generalized spike ahd slow wave complexes (10 cases), occipital spikes (2 cases), frontal spikes (1 case), and a combination of multiple spike and slow wave complexes and focal spikes (2 cases). The occurrence of a positive past history of febrile convulsions was higher in children with epileptiform discharges (18.9%) than in those without epileptiform discharges (9.4%). Using the Rutter scales for teachers and parents, we compared the emotional and behavioral problems of children with epileptiform EEG discharges with those of children without epileptiform discharges. No statistically significant differences were noted, indicating that the emotional and behavioral problems existing are most probably coincidental and not directly related to the epileptiform discharges. A genetic basis for generalized epileptiform discharges was postulated because the occurrence of generalized discharges in siblings of probands with generalized discharges was higher (4 of 9, 44.4%) than the prevalence in all subjects. However, the occurrence of centrotemporat spikes in the siblings of probands with centrotemporal spikes was not higher (2/38, 5.3%) and an autosomaldominant genetic factor for centrotemporal spikes in waking EEGs of healthy children could not be confirmed.     

Significance of Sharp Waves in Routine EEGs After Epilepsy Surgery

We retrospectively analyzed the presence of sharp waves in 2-h EEGs performed 6 months after epilepsy surgery in 59 patients. To study the significance of the postoperative interictal epileptiform activity in the tissue remaining after resection, we included only patients with a single epileptic focus (as defined preoperatively by prolonged video/EEG recordings and subdural electrode arrays studies) and no progressive structural lesions. Temporal lobectomy was performed in 51 patients (86%); extratemporal resections were performed in the remainder. The epileptogenic focus was completely resected in 26 patients (44%). The immediate postoperative electrocorticograms (EcoG) showed spikes in 13 patients (22%). At 6-month follow-up, 43 patients (73%) were seizure-free or had auras only and 12 patients (20%) had epileptiform activity on EEG. A significant correlation was noted between presence of sharp waves in the 6-month postoperative EEG and recurrence of seizures (Fisher's exact test p = 0.011) and also with the extent of the resection (complete vs. incomplete p = 0.042). We noted no correlation between postoperative epileptiform activity and location of the resection (temporal vs. extratemporal), presence of spikes in immediate postoperative EcoG, or occurrence of auras only at 6-month follow-up.     

The Effect of Vagus Nerve Stimulation on Epileptiform Activity Recorded from Hippocampal Depth Electrodes

PURPOSE: To assess the effect of vagus nerve stimulation (VNS) on interictal epileptiform activity in the human hippocampus. Clinical studies have established the efficacy of vagus nerve stimulation in patients with epilepsy (VNS Study Group, 1995), although the electrophysiologic effects of VNS on the human hippocampus and mesial temporal lobe structures remain unknown. METHODS: We report a case study in which a patient with an implanted VNS underwent intracranial electrode recording before temporal lobectomy for intractable complex partial seizures. Epileptiform spikes and sharp waves were recorded from a depth electrode placed in the patient's left hippocampus. Spike frequencies and sharp-wave frequencies before and during VNS were compared using both a 5- and a 30-Hz stimulus. Different stimulation rates were tested on different days, and all analyses were performed using a Student's t test. RESULTS: We found no significant differences in spike frequency between baseline periods and stimulation at 5 and 30 Hz. In contrast, stimulation at 30 Hz produced a significant decrease in the occurrence of epileptiform sharp waves compared with the baseline, whereas stimulation at 5 Hz was associated with a significant increase in the occurrence of epileptiform sharp waves. CONCLUSIONS: VNS produces a measurable electrophysiologic effect on epileptiform activity in the human hippocampus. Although a clinical response to VNS did not occur in our patient before surgery, 30-Hz VNS suppressed interictal epileptiform sharp waves that were similar in appearance to those seen during the patient's actual seizures. In contrast, 5-Hz stimulation appeared to increase the appearance of interictal sharp waves.     

Video-EEG monitoring in respiratory chain disorders.

Subclinical epileptiform activity in patients with respiratory chain disorders (RCDs) has not been previously investigated by video-EEG monitoring. The purpose of this study was to look for the type and frequency of epileptiform activity during a 24 h-video-EEG recording in RCD patients. Eleven patients with RCD, 7 women and 4 men, aged 24-72 years, underwent a clinical neurologic examination, blood tests, CT/MRI scans of the brain, routine scalp EEG and continuous video-EEG monitoring over 24 consecutive hours. Ten patients had normal 24 h-video-EEG recordings. One of these patients had no CNS involvement; her resting EEGs showed diffuse background slowing. In one patient, automatic spike detection revealed 12 spikes during a 6 hour period. Resting scalp EEG in this patient showed extensive, bilaterally synchronous, pseudoperiodic polyspike-waves. In conclusion, subclinical epileptiform activity could be recorded by 24 h-video-EEG monitoring in only 1 of 11 RCD patients. The single patient with subclinical epileptiform activity presented with intermittent myoclonic jerks.     

Characteristics of dipoles in clustered individual spikes and averaged spikes

The aim of this study is to analyze the characteristics of dipoles in clustered individual spikes and averaged spikes, we compared electroencephalography (EEG) dipole localizations from patients with intractable extratemporal lobe epilepsy (IETLE) and from patients with benign epilepsy with centrotemporal spikes (BECTS).We studied 10 patients; five with IETLE who underwent epilepsy surgery after subdural EEG and five with BECTS. We recorded 19-channel digital scalp EEGs and used clustering analysis for individual spikes to characterize interictal spikes. We selected and averaged one representative spike group at the maximum negative peak electrode. We used a single dipole method with three-shell spherical head model. We compared dipole localizations of both averaged and individual spikes.IETLE data had more identifiable spike clusters and fewer spikes in each cluster than BECTS (P<0.05). Dipole sources with goodness-of-fit >or=95% in averaged spikes were less frequent in IETLE than in BECTS (P<0.05). For IETLE, averaged spikes showed no dipoles (two patients), while individual spikes gave dipole sources reliably in the epileptic region. For BECTS, individual and averaged spike sources were clustered. More than 80% of dipoles in averaged spikes were stable, in close proximity, for prolonged periods in BECTS.More spike groups after clustering and fewer acceptable dipoles from averaged spikes in IETLE reflect variable spike activity over extensive epileptic regions. Fewer spike groups producing more acceptable dipoles in BECTS correlate with stable spike sources within the isolated epileptic central region. Characteristics of clustered interictal spikes need careful examination before the use of dipole analysis of averaged spikes for epilepsy evaluation.     

Left dominance of EEG abnormalities in patients with transient global amnesia

PurposeTransient global amnesia (TGA) is a syndrome of unknown etiology. Electroencephalographic (EEG) abnormalities in TGA have been reported previously. We analyzed the frequency and characteristics of EEG abnormalities in patients with TGA.MethodsWe collected EEGs of patients with a clinical diagnosis of TGA who had visited the emergency room or the outpatient clinic over a period of 8 years and compared clinical and demographic characteristics of the patients with normal EEGs with those with abnormal EEGs.ResultsEEG abnormalities were found in 35 (22.9%) out of 153 patients and epileptiform discharges were seen in 26 (74.3%) out of these 35 patients. Spikes or sharp waves were detected on the left side only (48.6%) or on both sides (25.7%), but none of the patients showed spikes or sharp waves on right side only. In six patients the EEG had normalized within three months of presentation, in ten within six months, and in twelve by one year. The EEG remained abnormal in eleven out of the 23 patients one year after presentation.ConclusionIn this largest consecutive EEG study at one center, the proportion of patients with TGA in whom epileptiform discharges were demonstrated within days of the episode of TGA was significantly higher than in the previous literature. EEG abnormalities such as spikes or sharp waves spontaneously disappeared in almost half of cases over one-year of follow-up. There was a clear left dominance of EEG abnormalities in patients with TGA.     

Transitory effect of spike and spike-and-wave discharges on EEG power in children

Background: Spikes and spike-and-wave discharges on the EEG of children are a strong biomarker of epilepsy. There is increasing evidence that these EEG abnormalities also impair brain function and result in transitory cognitive impairment. Studies in animal models have shown that EEG spikes alters single cell firing and that such impairment in firing may extend beyond the duration of the spike-and-wave discharge. Whether interictal epileptiform discharges have lasting effects on EEG activity in humans is not known. Methods and Results: The EEGs of 60 consecutive children with focal or interictal spike-and-wave discharges were evaluated using power spectral analysis to determine if there were any changes in power spectra from before to after the interictal abnormalities. Neither focal spike-and-wave nor generalized spike-and-wave discharges had any effect on the EEG frequency or spectral power following the discharge. Conclusion: While interictal EEG discharges temporarily alter neural activity during the duration of the spike-and-wave discharge, there is no evidence that alterations of spectral power continue beyond the duration of the interictal discharge. The effects of interictal activity on EEG rhythms therefore appear to be quite transient and confined to the duration of the interictal discharge.     

Epileptogenic effect of hypoxia in the immature rodent brain

The response to cerebral hypoxia/ischemia may be different in the neonate compared to other age groups. An in vivo model was developed in the rat to determine whether there are age-dependent differences in the effects of hypoxia on electroencephalographic (EEG) activity. EEG recordings were obtained from Long Evans hooded rats deprived of oxygen at five ages: postnatal days 5 to 7, 10 to 12, 15 to 17, 25 to 27, and 50 to 60. Oxygen concentration was varied from 0, 2, 3, and 4% between animals. EEGs were recorded in all animals before, during, and at 1 hour after exposure to the hypoxic condition and at 1 to 7 days afterward in a subset of animals. All animals were deprived of oxygen until the onset of apnea and bradycardia to 20 to 40% of baseline heart rate values. Hypoxia resulted in isoelectric EEG significantly more frequently in the animals deprived of oxygen at postnatal days 25 to 27 and 50 to 60 than in the younger age groups. A highly significant effect was that the animals deprived at postnatal days 5 to 17 revealed a high incidence of epileptiform EEG activity during hypoxia. In contrast, the older animals exhibited only rare isolated EEG spikes before reaching an isoelectric EEG. The severity of hypoxia-induced epileptiform EEG changes was highest in the animals subjected to moderately hypoxic conditions (3% and 4% oxygen) at postnatal days 10 to 12. Furthermore, epileptiform changes persisted for hours to days following prolonged episodes of hypoxia in the younger animals. This study demonstrates a unique response of the immature brain to exhibit epileptiform activity during hypoxia.     

Clinical correlations of midline spikes in children

Here we describe the clinical characteristics of children with isolated midline spikes, comparing patients with and without epilepsy, and examining the evolution of midline spikes on repeat EEGs. EEGs and clinical information of 69 patients with isolated midline spikes identified from our EEG database were reviewed. Forty-three patients had a history of seizures. Most patients had complex partial seizures, and had an approximately five times higher chance of having new discharges at other sites on repeat EEGs than the nonepilepsy group (odds ratio = 4.95). Most children without epilepsy had developmental delay, attention deficit hyperactivity disorder, and pervasive developmental disorder. Their repeat EEGs showed disappearance or persistence of the midline discharges, with a two times higher probability of normal repeat EEG (58%) than the epilepsy group (24%) (odds ratio = 2.40). Isolated midline spikes may represent focal epileptiform activity, but are also found in normal children and in children with developmental and behavioral problems.     

Long-Term Prognosis of Patients with Infantile Spasms Following ACTH Therapy

The influence of ACTH on the prognosis of patients with infantile spasms remains controversial. We have examined retrospectively the long-term benefits of initially successful ACTH therapy in patients treated at this institution between 1961 and 1974. Individuals with equivocal or minimal improvement during ACTH therapy were excluded from this study. Eighteen affected infants showed a favorable early response consisting of cessation of seizures for at least 3 weeks during ACTH therapy and concurrent disappearance of the hypsarhythmic EEG pattern. Modal age at last follow-up was 5 years (range, 15 months to 16 years). Infantile spasms recurred in 7 patients (39%), and 8 patients subsequently had other seizure types. All epileptiform (spike) activity disappeared from the EEGs of 8 patients during ACTH therapy, but in 4 of these cases epileptiform activity was present in later tracings. In the remaining 10 patients the hypsarhythmic pattern disappeared in association with ACTH therapy, but the EEG remained epileptiform (often only in sleep). Later EEGs were free of epileptiform activity in 5 of the 10 patients whose tracings contained spike discharges in the early follow-up period. Four patients (22%) were seizure free and without intellectual impairment when last evaluated.     

Real-time detection of epileptiform activity in the EEG: a blinded clinical trial.

The aim of this study was to determine the performance of a PC-based system for real-time detection and topographical mapping of epileptiform activity (EA) in the EEG during routine clinical recordings. The system incorporates a mimetic stage to locate candidate spikes (including sharp-waves) followed by two expert-system-based stages, which utilize spatial and wide-temporal contextual information in deciding whether candidate events are epileptiform or not. The data comprised 521 consecutive routine clinical EEG recordings (173 hours). Performance was evaluated by comparison with three independent electroencephalographers (EEGers-I). A second group of two EEGers (EEGers-II) separately interpreted the spike topographical maps and, for EEGs categorized as containing only questionable EA by the detection system, reviewed 6 sec segments of raw EEG centered on each questionable event. Thirty-eight of the EEGs were considered to contain definite EA by at least two of EEGers-I. The false detection rate of the system was 0.41 per hour. The system was found to have a sensitivity of 76% and a selectivity of 41% for EEGs containing definite EA. However, it only missed detection of EA in 5% of the recordings. EEGers-II agreed with EEGers-I on the distribution (generalized, lateralized, focal, multifocal) of EA in 79% of cases. This is by far the largest clinical evaluation of computerized spike detection reported in the literature and the only one to apply this in routine clinical recordings. The false detection rate is the lowest ever reported, suggesting that this multi-stage rule-based system is a powerful and practical tool in clinical electroencephalography and long-term EEG monitoring.     

Suppression of Interictal Spikes and Seizures by Stimulation of the Vagus Nerve

The effects of electrical stimulation of the vagus nerve, a proposed treatment for patients with intractable epilepsy, on focal interictal spikes produced by penicillin and EEG secondarily generalized seizures induced by pentylenetetrazol were assessed in rats. Interictal spike frequency was reduced by 33% during 20 s of stimulation (p < 0.001) and remained low for ≤3 min. Amplitude of residual spikes was also decreased. Cardiac and respiratory rates were suppressed. Cooling the nerve proximal to the point of stimulation abolished the EEG and respiratory effects. A similar reduction in spike frequency of 39% was obtained by heating the animals' tail (p < 0.01). Vagal stimulation at onset of seizures reduced mean seizure duration from 30.2 ± 15.7 s without stimulation to 5.0 ± 1.8 s (p < 0.01). Only the EEG equivalent of the clonic phase of the seizure was affected. These findings suggest that vagus nerve stimulation can be a potent but nonspecific method to reduce cortical epileptiform activity, probably through an indirect effect mediated by the reticular activating system.     

Change of centrotemporal spikes from onset to remission in self-limited epilepsy with centrotemporal spikes (SLECTS)

ObjectiveTo reveal the changes of centrotemporal spikes that occur during the disease course of self-limited epilepsy with centrotemporal spikes (SLECTS).MethodWe retrospectively reviewed the serial EEGs of 63 patients with SLECTS from initial diagnosis to remission. There were 32 patients who did not undergo treatment and 31 patients who underwent treatment with oxcarbazepine (OXC). The change of occurrence or abundance, voltage, and location of centrotemporal spikes of serial EEGs were analyzed and compared between the two groups. Clinical seizure evidenced and reported was counted. The time gap between seizure remission and EEG remission was measured in the two groups.ResultChanges of occurrence or abundance of the centrotemporal spikes were either abrupt (sudden disappearance of the frequent spikes on following EEG) or gradual (decline in number over 2 or more serial EEGs). Pattern of spike disappearance was not significantly different between the medication naïve group and OXC treated group. The spike voltage or the location of centrotemporal spikes did not change during the disease course in most cases. Delay between seizure remission and EEG normalization was 3.34 ± 1.75 (mean ± standard deviation, range: 0.77–7.97) years in untreated patients and 3.03 ± 1.41 (0.95–6.61) years in OXC-treated group.ConclusionPattern of spike disappearance in SLECTS was either abrupt or gradual. Treatment with OXC had no effect in the disappearance pattern. Precise data regarding the pattern of disappearance and delay between seizure remission and EEG normalization can help to understand the evolution of spike in SLECTS and to predict the timing of normalization of EEG after seizure remission.     

Fast evaluation of interictal spikes in long-term EEG by hyper-clustering

Purpose: The burden of reviewing long‐term scalp electroencephalography (EEG) is not much alleviated by automated spike detection if thousands of events need to be inspected and mentally classified by the reviewer. This study investigated a novel technique of clustering and 24‐h hyper‐clustering on top of automated detection to assess whether fast review of focal interictal spike types was feasible and comparable to the spikes types observed during routine EEG review in epilepsy monitoring. Methods: Spike detection used a transformation of scalp EEG into 29 regional source activities and adaptive thresholds to increase sensitivity. Our rule‐based algorithm estimated 18 parameters around each detected peak and combined multichannel detections into one event. Similarity measures were derived from equivalent location, scalp topography, and source waveform of each event to form clusters over 2‐h epochs using a density‐based algorithm. Similar measures were applied to all 2‐h clusters to form 24‐h hyper‐clusters. Independent raters evaluated electroencephalography data of 50 patients with epilepsy (25 children) using traditional visual spike review and optimized hyper‐cluster inspection. Congruence between visual spike types and epileptiform hyper‐clusters was assessed on a sublobar level using three‐dimensional (3D) peak topographies. Key Findings: Visual rating found 126 different epileptiform spike types (2.5 per patient). Independently, 129 hyper‐clusters were classified as epileptiform and originating in separate sublobar regions (2.6 per patient). Ninety‐one percent of visual spike types matched with hyper‐clusters (temporal lobe spikes 94%, extratemporal 89%). Conversely, 11% of hyper‐clusters rated epileptiform had no corresponding visual spike type. Numbers were comparable in adults and children. On average, 15 hyper‐clusters had to be inspected and rated per patient with an evaluation time of around 5 min. Significance: Hyper‐clustering over 24 h provides an independent tool for rapid daily evaluation of interictal spikes in long‐term video‐EEG monitoring. If used in addition to routine review of 2–5 min EEG per hour, sensitivity and reliability in noninvasive diagnosis of focal epilepsy increases.     

The influence of sulthiame on EEG in children with benign childhood epilepsy with centrotemporal spikes (BECTS)

PURPOSE: To evaluate the effects of sulthiame (Ospolot; STM) monotherapy compared with placebo on the EEG in children with benign childhood epilepsy with centrotemporal spikes (BECTS). METHODS: Sixty-six patients (aged 3-11 years) entered a 6-month double-blind trial and were randomized to either STM (n = 31) or placebo (n = 35). Clinical data and general results have been reported elsewhere (1). One-hundred seventy-nine sleep EEGs were recorded at screening and after 4 weeks, 3 months, and 6 months. EEGs were analyzed by a blind reviewer using a standard protocol for each EEG. This standard protocol collected data on general changes, specific epileptiform, and nonspecific focal and generalized changes. A classification system was defined depending on rating of pathologic EEG changes. Because of the higher number of treatment-failure events (i.e., seizures) in the placebo group, there was an increasing imbalance between the two groups regarding the number of recorded sleep EEGs over time (STM, 104; placebo, 74). A Wilcoxon-Mann-Whitney U test was used to describe differences in the grade of pathology during individual follow-up between the two groups. RESULTS: The sleep-EEG was found to be normalized in 21 patients treated with STM (12/21 transient) and in five patients treated with placebo (4/5 transient). In the STM group, the EEG showed a marked improvement during intraindividual course when comparing the classification of follow-up EEGs at each time point with the screening EEG. Comparable improvements were not observed in the placebo group (exact two-tailed p value at 4 weeks, p < 0.0001; at 3 months, p = 0.0010; and at 6 months, p < 0.0001). CONCLUSIONS: STM had marked effects on the EEG in BECTS, which led to normalization in the majority of the patients. Most of those whose EEGs were not normalized showed improvement in the grade of EEG pathology. Normalization persisted in >50% of patients during the investigation. Spontaneous normalization in the placebo group reflects the wide spectrum of individual courses, which must be considered when analyzing drug effects on EEG in BECTS.     

Electroencephalographic findings in urea-cycle disorders

Eleven electroencephalograms in 4 infants with urea-cycle disorders were reviewed. All infants had one or more abnormal EEGs. The abnormalities consisted mainly of multiareal spikes, spike-waves, or sharp-and-slow-wave activity. In addition, one patient, a term infant, exhibited exaggerated spindle-delta bursts. This infant, and also one other at a similar age, had monorhythmic paroxysmal theta activity. Clinically, all patients had seizures shortly preceding abnormal EEGs. EEG alterations were encountered over a wide range of elevated serum ammonia levels. Normal EEGs occurred in the face of slightly elevated levels. It is concluded that epileptiform EEG alterations may be a characteristic manifestation of urea-cycle disorders.     

EEG and seizures in autistic children and adolescents: further findings with therapeutic implications.

The goal of this study was to investigate the incidence of epilepsy and also the EEG findings among children with autism (A), a devastating disorder, and to compare these data to an EEG control group. EEGs were quantified as to the degree of epileptiform activity and also slow wave abnormalities. Abnormal EEGs were found in 75% of the 59 A children and 82% of their 151 EEGs; 46% had clinical seizures. Nearly all children with seizures had epileptiform activity, but almost 20% of those with spike discharges did not have clinical attacks. Slow wave abnormalities were more frequent and of a greater degree of severity in the A group, compared to controls. One new finding was that a greater variability of EEG abnormalities was found in the A group. Therapeutic implications, based on these latter findings, are discussed.