A study on epileptic negative myoclonus in atypical benign partial epilepsy of childhood

Objective. To investigate the clinical and neurophysiological characteristics, particularly therapeutic considerations, of epileptic negative myoclonus (ENM) in atypical benign partial epilepsy (ABPE) of childhood. Methods. From 1998 to 2006, 14/242 patients with benign children epilepsy with centrotemporal spikes (BECTS) were diagnosed as having ABPE with ENM. In all 14 patients, we performed video-EEG monitoring along with tests with the patient’s arms outstretched; 6/14 patients were also simultaneously underwent surface electromyogram (EMG). ENM manifestations, electrophysiological features, and responses to antiepileptic drugs were analyzed. Results. In all cases, ENM developed after the onset of epilepsy and during antiepileptic drug therapy, and the appearance of ENM were corresponding to EEG findings of high-amplitude spikes followed by a slow wave in the contralateral motor areas with secondary generalization. This was further confirmed by time-locked silent EMG. During ENM occurrence or recurrence, habitual seizures and interictal discharges were exaggerated. In some patients, the changes in antiepileptic drug regimens in relation to ENM appearance included add-on therapy with carbamazepine, oxcarbazepine, and phenobarbital or withdrawal of valproate. ENM was controlled in most cases by administration of various combinations of valproate, clonazepam, and corticosteroids. Conclusion. The incidence of ENM or ABPE in our center was approximately 5.79%. A combination of video-EEG monitoring with the patient’s arms outstretched and EMG is essential to identify ENM. The aggravation of habitual seizures and interictal discharges indicate ENM. Some antiepileptic drugs, such as carbamazepine, oxcarbazepine, and phenobarbital, may be related to ENM occurrence during spontaneous aggravation of ABPE. Various combinations of valproate, benzodiazepines, and corticosteroids are relatively effective for treating ENM that occurs in ABPE.     

Characterizing magnetoencephalographic spike sources in children with tuberous sclerosis complex

PURPOSE: Tuberous sclerosis complex (TSC) often causes medically intractable seizures. Magnetoencephalography (MEG) localizes epileptiform discharges. To evaluate the use of MEG spike sources (MEGSSs) for localizing epileptic zones in TSC patients, we characterized MEGSSs and correlated them to EEG and magnetic resonance imaging (MRI) results. METHODS: We analyzed data from seven children who underwent prolonged video-EEG, MEG, and MRI. We classified MEGSSs as clusters (six or more spike sources, 1 cm between sources regardless of number of sources). RESULTS: A single, unilateral cluster with additional scatters occurred in two patients; these predominantly lateralized dipoles correlated to prominent tubers on MRI and ictal/interictal EEG zones. Bilateral clusters with scatters existed in two patients; cluster locations partly overlapped multiple prominent tubers. These patients also had bilateral or diffuse interictal discharges, bilateral or generalized seizures, and changing seizure types and EEG findings. Only bilateral scatters occurred in three patients; scatters partly overlapped EEG interictal/ictal-onset regions; one patient had coexisting generalized seizures. In one patient with equally bilateral scatters, scatters overlapped a prominent tuber and interictal/ictal-onset zones in the right frontal region. CONCLUSIONS: MEG contributes to information from EEG and MRI for localizing epileptogenic zones in children with TSC. A single cluster with scatters in a unilateral hemisphere predicts a primary epileptogenic zone or hemisphere; bilateral or multiple clusters indicate bilateral primary or potential epileptogenic zones; and bilateral scatters without clusters may indicate epileptogenic zones that are hidden within extensive areas of scattered MEGSSs.     

Nonconvulsive status epilepticus with continuous diffuse spike-and-wave discharges during sleep in childhood

On three epileptic conditions with common characteristics of almost continuous diffuse spike-and-wave discharges during sleep in EEG, clinical and electroencephalographic studies were undertaken to elucidate their pathophysiologies and interrelationships; namely on five cases of epilepsy with electrical status epilepticus during slow sleep (ESES), seven cases of a peculiar type of nonconvulsive status epilepticus in childhood (PNSE) and three cases of atypical benign partial epilepsy (ABPE). The dominant seizure types were absences and/or GTC in ESES, whereas they were focal motor seizures in PNSE and ABPE with more focalized epileptic discharges on EEGs than those in ESES. All the three conditions showed both features of generalized and partial epilepsies, although the former features were more prominent in ESES and the latter in PNSE and ABPE.     

Atypical "benign" partial epilepsy or pseudo-Lennox syndrome. Part I: symptomatology and long-term prognosis

PURPOSE: Atypical benign partial epilepsy (ABPE) or pseudo-Lennox syndrome (PLS) is characterised by generalised minor seizures and focal sharp slow waves and spikes (SHW) as observed in Rolandic epilepsy (RE), but with exceptional pronounced activation during sleep. The aim of this study was to describe the full spectrum of ABPE in the hitherto largest group of patients. METHODS: We retrospectively analysed the clinical and EEG data of 43 children who fulfilled the following criteria: occurrence of generalised minor seizures as described for ABPE (i.e., atonicastatic seizures, myoclonic seizures, atypical absences) and focal SHW identical to those observed in RE, but with generalisation during sleep. RESULTS: Language development prior to onset of epilepsy was retarded in 26% of patients. In 74%, age at onset of epilepsy ranged from 2 to 6 years. Manifestation occurred earlier in boys than in girls. Generalised minor seizures constituted the predominating seizure type in 67% of patients. Twenty-eight percent of patients suffered from simple partial seizures of the oro-facial region or generalised tonic-clonic seizures originating from the oro-facial region. Additionally, generalised tonic-clonic (44%), unilateral (21%), partial motor (44%), versive (12%), focal atonic (9%), and complex-partial seizures (2%) were observed. A bioelectrical status was recorded in 56% of patients during sleep. No tonic seizures and no fast spike series (bursts of 10-20 Hz rhythms) were observed. At last follow-up, 84% of patients were in clinical remission. All subjects older than age 15 were seizure-free. However, 56% of patients attended a school for mentally handicapped children. CONCLUSIONS: ABPE or PLS broadly overlaps with RE, electrical status epilepticus during sleep, and Landau-Kleffner syndrome. Regarding the epilepsy, the prognosis is excellent, mental deficit, however, seems to be frequent. The differentiation from Lennox-Gastaut syndrome and myoclonic astatic epilepsy is essential. Instead of ABPE, the term pseudo-Lennox syndrome is proposed.     

Epileptic spasms in older pediatric patients: MEG and ictal high-frequency oscillations suggest focal-onset seizures in a subset of epileptic spasms

OBJECTIVES: To elucidate the pathophysiology of intractable epileptic spasms in older children by describing the interictal magnetoencephalography spike sources (MEGSSs), intracranial EEG ictal-onset zones (IOZs) and their ictal high-frequency oscillations (HFOs) and surgical outcomes. METHODS: We studied five patients (4.5-14 years) who underwent surgery following intracranial video-EEG (VEEG) monitoring. We analyzed clinical profiles, MRIs, scalp and intracranial VEEGs, and MEGSSs. We localized ictal HFOs using a sampling rate of 1000 Hz and multiple band frequency analysis (MBFA). RESULTS: Seizure onset ranged from 0.4 to 8 years. Three patients presented with asymmetrical spasms. Interictal scalp VEEG recorded predominantly unilateral epileptiform discharges in four; generalized and multifocal in one. Ictal scalp VEEG showed generalized high-amplitude slow waves with superimposed fast waves in four patients; hemispheric electrodecremental episodes in one. MRI findings were normal in three, hemispheric polymicrogyria and periventricular heterotopia in one each. All patients had unilateral MEGSS clusters. Ictal HFOs, ranging from 150 to 250 Hz, localized over Rolandic and frontal regions in four, with one also having extensive temporo-occipital HFOs. After cortical resection, three patients were seizure free; one had >90% reduction in seizure frequency. One patient experienced residual seizures after resection of the hemispheric ictal HFO region. CONCLUSION: Unilateral clusters of MEGSSs overlapped regional IOZs in older patients with epileptic spasms. High spatio-temporal MBFA before and during spasms revealed the regional ictal HFOs. Seizure-free outcomes following resection of zone with MEGSS clusters and ictal HFOs suggested that a subset of epileptic spasms was focal-onset seizures.     

Epileptic negative myoclonus in a case of atypical benign partial epilepsy of childhood: a detailed video-polygraphic study.

PURPOSE: To describe the clinical and electroencephalographic features of a child diagnosed as having atypical benign partial epilepsy (ABPE) who suffered from frequent lapses of postural tone in the right lower limb that were considered to represent a focal epileptic negative myoclonus (ENM). MATERIAL AND METHODS: Electrophysiological evaluation included four serial waking and two sleep EEGs. Moreover, the investigation included a polygraphic recording with simultaneous video-EEG monitoring performed in rest, during hyperventilation, and while standing up with the aim of capturing patient's typical seizures. RESULTS: During awake the EEG showed frequent bilateral centrotemporal discharges maximal over the left central area. Moreover, we recorded short generalised paroxysms of spike-and-wave discharges accompanied by a clear transient cognitive impairment that were in keeping with absences. We also captured several episodes of sudden and unexpected loss of postural tone in the right lower limb. These focal inhibitory seizures were associated with brief diffuse but asymmetrical paroxysms of irregular spike-and-wave discharges maximal over the left side. EMG flattening of the right quadriceps muscle was time-locked to the midline of the slow-wave component of the diffuse spike-and-wave discharges. CONCLUSIONS: ENM leading to focal lapses of postural tone in lower extremities may be a predominant type of seizures in ABPE. A polygraphic recording with video-EEG monitoring is essential to confirm the diagnosis, and to detect other concomitant seizures, such as atypical absences. In our case, ENM could be more likely due to a transient disruption of cortical function.     

High-frequency oscillations in a spectrum of pediatric epilepsies characterized by sleep-activated spikes in scalp EEG

ObjectiveWe studied ripple-band (80–200 Hz) high-frequency oscillations in scalp electroencephalogram (EEG) in various pediatric epilepsies featuring sleep-activated spikes, such as epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) and investigated their characteristics.MethodsThe subjects were 94 children with epileptic disorders including idiopathic and non-idiopathic CSWS, benign epilepsy with centrotemporal spikes (BECTS), Panayiotopoulos syndrome, other types of focal epilepsies (oFE), and focal spikes without clinical seizures (Latent). We detected ripple oscillations using a semi-automatic detection tool based on localized power increase.ResultsIn the idiopathic CSWS Group, the median ratio of ripples per spike in the initial EEG was 5.73, which was significantly higher than those in the BECTS, Panayiotopoulos syndrome, oFE, and Latent Groups (0.39, 0.02, 0.35, 0, respectively, all with p < 0.01). Ripples were particularly frequent at younger ages.ConclusionsThis paper is the first to confirm a high ratio of ripples per spike in CSWS in the largest number of patients to date.SignificanceThe dense generation of ripples, which occurs through a combination of heavy loading of individual spikes with ripples and large numbers of spikes during sleep, characterizes CSWS and might be closely related to the pathophysiology of this epileptic encephalopathy.     

Rolando-Epilepsie

Rolandic epilepsy (RE) belongs to the most frequent epilepsy syndromes in childhood. Short sensorimotor perioral seizures, frequently occurring during sleep are characteristic. The epilepsy is self-limiting and usually developmental outcome is good. However, in some patients, mostly transient, learning disorders occur. Centrotemporal spikes in the EEG are the neurobiological genetic marker. Atypical benign partial epilepsy of childhood (ABPE) is much rarer than RE. In addition to perioral sensorimotor seizures, atypical absences, astatic seizures, and focal motor seizures are observed. The EEG shows centrotemporal spikes, however, with a much more pronounced sleep activation, sometimes reaching a bioelectrical status epilepticus. Amazingly, genetic factors seem to play an even greater role in ABPE than in RE. Prognosis of the epilepsy is good in ABPE; however, it is guarded concerning developmental outcome. Epilepsy risk for siblings of children with RE is small. However, the EEG trait is present in about 15% of siblings. In siblings of children with ABPE, this rate is elevated to about 40%. Additionally, in a small number of siblings with RE/APRE, sequence variations in KCNQ2, KCNQ3, and ACHRNA7 were detected. A conclusive understanding and extension of these findings will only be possible using new comprehensive molecular genetic tools, e.g., whole exome sequencing.     

Childhood absence epilepsy: Elctroclinical features and diagnostic criteria

Objective: To analyze the electroclinical features of children with childhood absence epilepsy (CAE) and discuss the diagnostic criteria for CAE. Methods: The video-electroencephalogram (VEEG) database in our hospital was searched using “absence seizures” and “3-Hz generalized spike and waves (GSW)” as key-words. Other epileptic syndromes with typical absence seizures were carefully excluded. Children meeting the CAE diagnostic criteria of the International League Against Epilepsy (ILAE) in 1989 were further evaluated with the diagnostic criteria proposed by Panayiotopoulos in 2005. Results: Totally 37 children met the 1989 ILAE criteria of CAE. The onset age of absence seizures ranged from 3 to 11 years. All patients had frequent absence seizures (5-60 times per day). Two patients (5.4%) had generalized tonic-clonic seizures. Hyperventilation induced absences in all patients. VEEG confirmed that 7 patients (18.9%) had only simple absences, 25 patients (67.6%) had only complex absences, and 5 patients (13.5%) had both simple and complex absences. Ictal EEG showed 3 Hz GSW discharges in all patients. The seizure duration ranged from 3 to 40 s. Four patients (10.8%) had two spikes per wave in ictal EEG. GSW fragments were found in 29 patients (78.4%) during sleep. Interictal polyspikes and waves were present in 17 patients (45.9%). Focal discharges predominantly in the anterior regions, were found in 22 patients (56.8%). Only 7 patients (18.9%) met the diagnostic criteria proposed by Panayiotopoulos in 2005. Conclusions: Few patients meeting the 1989 ILAE diagnostic criteria for CAE meet the new diagnostic criteria proposed by Panayiotopoulos in 2005. The new criteria for CAE are too strict to appropriately classify some patients.     

Magnetoencephalography using total intravenous anesthesia in pediatric patients with intractable epilepsy: lesional vs nonlesional epilepsy

Purpose: Magnetoencephalography (MEG) provides source localization of interictal spikes. We use total intravenous anesthesia (TIVA) with propofol to immobilize uncooperative children. We evaluate the effect of TIVA on interictal spikes in children who have intractable epilepsy with or without MRI lesions. Methods: We studied 28 children (3–14 years; mean, 6.6). We intravenously administered propofol (30–60 μg/kg/min) to record MEG with simultaneous EEG. We evaluated MEG spike sources (MEGSSs). We compared spikes on simultaneous EEG under TIVA with those on scalp video-EEG without TIVA. Results: There was a significant decrease in frequent spikes (10 patients, 36%) on simultaneous EEG under TIVA compared to those (22 patients, 79%) on scalp video-EEG without TIVA (P < 0.01). MEGSSs were present in 21 (75%) of 28 patients. Clustered MEGSSs occurred in 15 (83%) of 18 lesional patients but in 3 (30%) of 10 nonlesional patients (P < 0.05). MEGSSs were more frequently absent in nonlesional (6 patients, 60%) than lesional (one patient, 5%) patients (P < 0.01). Thirteen patients with MRI and/or histopathologically confirmed neuronal migration disorder most frequently showed clustered MEGSSs (11 patients, 85%) compared to those of other lesional and nonlesional patients. Conclusion: Propofol-based TIVA reduced interictal spikes on simultaneous EEG. TIVA for MEG still had utility in identifying spike sources in a subset of pediatric patients with intractable epilepsy who were uncooperative and surgical candidates. In lesional patients, MEG under TIVA frequently localized the clustered MEGSSs. Neuronal migration disorders were intrinsically epileptogenic and produced clustered MEGSSs under TIVA. Nonlesional patients often had no MEGSS under TIVA.     

Coexistence of idiopathic rolandic epilepsy and CSWS in two families

PURPOSE: To report two families combining benign childhood epilepsy with centrotemporal spikes (BCECS) and cryptogenic epilepsy with continuous spike-waves during sleep (CSWS) in first-degree relatives. METHODS: Clinical, EEG, and cerebral imaging data are described. RESULTS: FAMILY 1: The proband was 3 years old at epilepsy onset. First seizures were convulsive, with centrotemporal spikes on EEG. At age 5 years, he had complex partial seizures, psychomotor regression, and centrotemporal CSWS. [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) showed left parietal hypermetabolism. After several antiepileptic drug (AED) trials, valproate (VPA) and ethosuximide (ESM) induced seizure remission, CSWS disappearance, and psychomotor improvement. Learning disabilities, however, persisted. Family history was remarkable for BCECS in his father. FAMILY 2: The proband was 2 years old at epilepsy onset. First seizures were convulsive, with centrotemporal CSWS on EEG. Despite several AED trials including corticosteroids, focal negative myoclonia, atypical absences, and psychomotor regression occurred, leading to severe mental retardation. FDG-PET showed bilateral parietal hypermetabolism. Vagus nerve stimulator was implanted. Her family history was remarkable for BCECS in her father and febrile convulsions in infancy in her mother. CONCLUSIONS: These data suggest the existence of a common genetic basis between BCECS and cryptogenic epilepsies with CSWS. The higher expression in patients with CSWS could be related to other genetic or acquired factors. These data suggest that these epileptic syndromes constitute edges of a continuum.     

MEG correlates of epileptic high gamma oscillations in invasive EEG

In patients with pharmacoresistant focal epilepsy, we demonstrate that magnetoencephalography (MEG) detects spike‐locked and spike‐independent epileptic high gamma oscillations (HGOs) using combined MEG and invasive electroencephalography (iEEG) from subdural macroelectrodes. Six patients, who underwent presurgical workup for epilepsy surgery with preoperative simultaneous MEG and subdural iEEG recordings, were investigated. HGOs in iEEG were detected automatically and served as triggers for averaging and localization of simultaneous MEG data. iEEG‐HGOs were detected in all patients and MEG‐HGOs in five patients. HGOs were highly associated with epileptic networks and correctly identified seizure‐onset zones in five (MEG) and six patients (iEEG). Minimum‐norm source analysis of MEG data yielded concordant localizations. Noninvasive analysis of HGOs may allow investigation of epileptic networks independent of spikes and seizures. Determination of sensitivity and specificity, as well as development of MEG‐HGO analysis without the need of iEEG should be addressed in a larger study.     

Encephalopathy related to status epilepticus during slow sleep (ESES) as atypical evolution of Panayiotopoulos syndrome: an EEG and neuropsychological study

Aim: We report two patients with Panayiotopoulos syndrome (PS) who developed encephalopathy related to status epilepticus during slow sleep (ESES) at the peak of their clinical course. Methods: Clinical charts and EEG data were reviewed. Results: The patients exhibited nocturnal autonomic seizures and occipital EEG foci, the latter of which later evolved into multifocal EEG foci with synchronous frontopolar and occipital spikes (Fp‐O EEG foci), and finally into continuous spikes‐waves during sleep (CSWS; spike‐wave index >85% based on whole‐night sleep recording) at eight years and seven years of age, respectively. The occipital spikes always preceded frontopolar spikes by 30～50 mseconds based on the analysis of CSWS. Neuropsychological ability, including IQ, deteriorated during the CSWS period in both patients. The autonomic seizures and focal to bilateral tonic‐clonic seizures were initially resistant to antiepileptic drugs (AEDs), and occurred more than 10 times in both patients. However, the seizures and EEG findings gradually resolved, and AEDs were successfully terminated in both patients. Conclusion: PS can progress to ESES if the clinical course exhibits atypical evolution. The initial autonomic symptom of the seizures and interictal Fp‐O EEG foci should be carefully monitored in patients with CSWS or ESES.     

Early onset and focal spike discharges as indicators of poor prognosis for myoclonic-astatic epilepsy

Background: Myoclonic-astatic epilepsy (MAE) is an epileptic syndrome characterized by unique myoclonus, myoclonic-astatic, or astatic seizures in childhood. MAE prognosis vary from spontaneous remission to intractable seizures with profound mental retardation. Aim: Identifying early risk factors may optimize the treatment of children with MAE. Our hypothesis is early onset age and focal spike discharges on EEG indicate a poor MAE prognosis. Methods: Using the medical records of 9 children with MAE, we analyzed their clinical histories, EEG findings, and seizure symptoms. All patients were given follow-up observations/treatments by our department for at least 2 years after MAE onset. Results: Five of the patients were given favorable prognoses because their seizures disappeared within 2 years of onset; the other 4 received poor prognoses because their seizures continued more than 2 years. MAE onset in patient with refractory seizures was earlier than that in those with a favorable prognosis (7–24 months vs. 23–38 months). All the patients with refractory seizures showed moderate or severe mental retardation. Among the 5 patients with good prognosis, EEGs showed two with focal spike discharges and three with only generalized spike discharges. In contrast, all cases with a poor prognosis had focal spike discharges. Conclusions: MAE onset in patients with refractory seizures occurs earlier than in those with favorable prognosis. Prognosis was excellent when EEG findings show no focal spike discharges. Both early seizure onset and the focal spike discharges associated with MAE are indicators of poor prognosis.     

GRIN2A mutations in epilepsy-aphasia spectrum disorders

Objective

Epilepsy-aphasia spectrum (EAS) are a group of epilepsy syndromes denoting an association between epilepsy, speech disorders and the EEG signature of centrotemporal spikes. Mutations in the GRIN2A gene, encoding the NMDA glutamate receptor α2 subunit were reported in focal epilepsy with speech disorder. We aimed to explore the role of GRIN2A mutations in patients with centrotemporal spikes related epileptic syndromes in a Chinese cohort.

Complementary use of video-electroencephalography and magnetoencephalography in frontal lobe epilepsy

PurposeThe aim of this study was to compare magnetoencephalography (MEG) and video-electroencephalography (VEEG) source localization in frontal lobe epilepsy (FLE) and determine if these methods can be complementary to each other in clinical practice.MethodThirty patients with pharmaco-resistant FLE who underwent epilepsy surgery were retrospectively enrolled. Video EEG was recorded using an IT-med system using 10/20 system. Regional localization of spikes in VEEG was defined as spikes discharged from adjacent electrodes and no further propagation to a large and/or contralateral area. Magnetoencephalography was recorded for the purpose of focus assessment. Magnetoencephalography spikes were detected for dipole localization of the epileptogenic cortex and the epileptogenic area was classified as mono- or multi-focal.ResultsRegional spike discharges were identified in the interictal VEEG of 20 patients and in the ictal VEEG of 17 patients. Thirteen patients had regional spikes in both interictal and ictal VEEG. Mono-focal localization was identified in the MEG of 20 patients. Fourteen of these patients had regional spike discharges in VEEG. In the remaining six patients, sources localization was only identified by MEG and there were no regional spike discharges either interictal or ictal VEEG.ConclusionIn clinical practice, VEEG is the routine procedure in the presurgical evaluation of FLE. However, we found six cases in which VEEG failed to locate the epileptogenic area that was identified by MEG. We therefore propose that combining VEEG and MEG will optimize the noninvasive presurgical evaluation of epileptiform activities in FLE.     

Interictal and ictal magnetoencephalographic study in patients with medial frontal lobe epilepsy

PURPOSE: To determine whether magnetoencephalography (MEG) has any clinical value for the analysis of seizure discharges in patients with medial frontal lobe epilepsy (FLE). METHODS: Four patients were studied with 74-channel MEG. Interictal and ictal electroencephalographic (EEG) and MEG recordings were obtained. The equivalent current dipoles (ECDs) of the MEG spikes were calculated. RESULTS: In two patients with postural seizures, interictal EEG spikes occurred at Cz or Fz. The ECDs of interictal MEG spikes were localized around the supplementary motor area. In the other two patients with focal motor or oculomotor seizures, interictal EEG spikes occurred at Fz or Cz. The ECDs of interictal MEG spikes were localized at the top of the medial frontal region. The ECDs detected at MEG ictal onset were also localized in the same area as those of the interictal discharges. CONCLUSIONS: In medial FLE patients, interictal and ictal MEG indicated consistent ECD localization that corresponded to the semiology of clinical seizures. Our findings demonstrate that MEG is a useful tool for detecting epileptogenic focus.     

伴强直性发作癫痫患儿的临床表现和脑电图特征

目的通过对67例伴强直性发作癫痫患儿的临床表现及视频脑电图(VEEG)特点分析,提高对该发作类型的诊断水平。结果收集河北省儿童医院神经内科67例伴强直性发作的癫痫患儿的病例资料,分析其临床表现和VEEG特征。结果 67例患儿均监测到明确的临床发作,其中清醒期发作19例(28%),睡眠期发作30例(45%),且容易出现在睡眠I期、II期。发作间期脑电图表现:①背景活动正常37例,慢化者15例;②广泛性棘波节律阵发,易出现在非快速眼动期(NREM期);③广泛性及多灶性慢波、棘慢波或多棘慢波阵发;④一侧或双侧前头部棘波、棘慢波或θ活动发放;⑤单侧或双侧Rolandic区棘慢波发放;⑥高度失律。发作期脑电图表现:①局灶起始的棘波节律发放;②广泛性棘波节律发放;③广泛性慢波阵发,其上复合或其后跟随棘波节律;④广泛性4~6Hz棘慢波发放→广泛性棘波节律阵发;⑤广泛性低波幅棘波节律发放→广泛性高波幅棘慢波阵发。以上表现形式有时会组合出现于同一例患者中。发作持续时间与背景活动的关系:发作持续约1~8s者39例(39/67,58.2%),背景活动慢化者4例(4/39,10.3%);发作持续8~15s,甚者更长者(15s)28例(28/67,41.7%),背景活动慢化者11例(11/28,39.3%)。67例患者随访研究1年,最终诊断为:8例(11.9%)诊断为婴儿痉挛征,7例(10.4%)诊断为Lennox-Gastaut综合征(LGS),3例(4.4%)诊断为额叶癫痫,15例(22.3%)诊断为伴有中央颞区棘波的儿童良性癫痫(BECT),34例(50.7%)仅停留在发作类型的诊断层面。结论强直性发作可单独出现,也可出现在多种癫痫综合征中;VEEG可监测患儿发作期临床表现及脑电图异常波形,为临床诊断及鉴别诊断提供理论依据。     

The Long-Term Prognosis of Minor Seizures in Childhood Epilepsy

The long–term clinical and electroence-phalographic follow-up studies were carried out for more than three to 13 years on 72 cases with minor seizures in childhood epilepsy at the Department of Pediatrics of Keio University from January 1963 to January 1973. Minor seizures were classified into typical absences, infantile spasms, Lennox syndrome, myoclonic seizures and atonic seizures. The results of each group were summarized as follows, but atonic seizures were excluded because there were too few cases of this group.

• 1 Some patients with typical absences were not preceded by other epileptic seizures, while some others had generalized tonic-clonic seizures, including febrile convulsions (mixed form by Fukuyama), prior to the onset of typical absences. Typical absences were not transformed into other epileptic seizures excluding generalized tonic-clonic seizures at follow-up. Twenty-one (84%) out of 25 cases with typical absences had ceased having seizures over one year at follow-up. Spontaneous, generalized spike and wave discharges including 3 c/s spike and wave complexes were recorded in about one half of all cases at the final interictal EEG recordings, but focal components were never seen. Mental retardation was very rare.
• 2 The attacks of infantile spasms had a tendency to disappear or be converted to variously other epileptic fits, excluding typical absences, with the development of age. EEG-findings were transformed into focal or Muse paroxysmal discharges and basic dysrhythmia from hyp-sarhythmia after many years, but classical 3 c/s spike and wave discharges were never seen. Moderately or severely mental retardation was found in most of these patients.
• 3 It was characteristic of Lennox syndrome that the improvements or successions of tonic seizures and atypical absences were repeated and diffuse slow spike and wave discharges were sustained in most of children during the periods of follow-up. Mental retardation was found in half of all cases.
• 4 Myoclonic seizures had ceased in most of children without transformations to other epileptic fits at follow-up, but some tendency toward relative dirsculty in control of clinical seizures was noted. Two thirds of these patients were of normal intelligence, while one third had retarded intelligence at follow-up.

Based on the above–mentioned results, the literatures concerning prognosis of various types of minor seizures in childhood epilepsy were studied.     

Is sleep-related consolidation impaired in focal idiopathic epilepsies of childhood? A pilot study

We investigated sleep-related declarative memory consolidation in four children with focal idiopathic epilepsy. In a population of healthy control children, recall of learned pairs of words was increased after a night of sleep, but not after a daytime wakefulness period. In children with epilepsy (1 case of benign epilepsy with centro-temporal spikes, 1 case of benign childhood epilepsy with occipital paroxysms, and 2 cases of epileptic encephalopathy (EE) with continuous spike and waves during slow-wave sleep, CSWS), recall performance significantly decreased overnight, suggesting impairment in sleep-related declarative memory consolidation. Hydrocortisone treatment in one patient with EE with CSWS resulted in normalization of the sleep EEG together with normalization of overnight memory performance, which was not the case in the other EE/CSWS patient whose sleep EEG was only partially improved. These preliminary results suggest that interictal epileptiform discharges in idiopathic focal epilepsies may disrupt the brain processes underlying sleep-related memory consolidation.