Epileptic seizures difficult to differentiate from alternating hemiplegia in infants: a case report

A child with epileptic seizures had a clinical course similar to that of alternating hemiplegia of infancy (AHI). Tonic hemiplegia began at 2 months of age, and atonic alternating hemiplegia and tetraplegic attacks began at 2 years of age. Clinical findings were paroxysmal ocular movement abnormalities, choreoathetotic involuntary movements, and severe developmental retardation. An interictal EEG at 6 years of age showed multiple independent spike discharges. An ictal EEG showed diffuse irregular spike-wave and slow wave bursts following focal spikes. The present case suggests that a long-term extensive follow-up is necessary to differentiate epileptic seizures from AHI.     

伴中央-中颞棘波的儿童良性癫癎与弥漫性棘慢波综合及失神发作的关系

目的 探讨弥漫性棘慢波综合(GSWD)及失神发作(AS)在儿童良性癫痫伴中央，中颞棘波发放(BECCT)患者中的发生情况，分析BECCT与AS间的可能的相互联系。方法 回顾性分析5年来诊断为BECCT的524例患者的临床及录像脑电图(VEEG)资料。我们对GSWD的入选标准为：在正常背景活动中，突然发生和中止、频率2.5～3．5Hz、双侧对称或大致对称的棘慢波综合(棘波数≤2)。结果在524例BECCT患者中，GSWD及AS的发生率分别为5．3％和2．0％。绝大多数合并有AS的BECCT患者对单药治疗效果较好。结论 BECCT和AS可发生在同一例患者中，提示这两种常见的癫痫综合征之间可能存在某些类似的发病机制。     

Rasmussen syndrome: absence seizures may be induced by oxcarbazepine

A female patient with electroclinical and neuroradiological features compatible with Rasmussen syndrome developed a particular clinical and EEG pattern. As the seizures were refractory to valproate at 750 mg/kg/day, oxcarbazepine (OXC) at 30 mg/kg/day was added. Seizures became more frequent and on neurological examination, no hemiparesis was detected. The interictal EEG showed focal spikes and diffuse paroxysms in the right fronto‐temporal regions. Brain MRI revealed right hemiatrophy, mainly at the Sylvian fissure. After initiating OXC daily, brief absence seizures, lasting less than 20 seconds and associated with bilateral and synchronous 2.5‐3‐Hz spike‐and‐waves compatible with typical absences, were observed. OXC was discontinued and the typical absences disappeared. Treatment with intravenous gammaglobulin was started. At the last control visit, at nine years of age, no absence seizures were observed either by the parents or on the EEG recording. Our patient who met the diagnostic criteria for Rasmussen syndrome presented with absence seizures that may have been induced by OXC. The absence seizures disappeared after OXC was discontinued.     

Treatment with flunitrazepam of continuous spikes and waves during slow wave sleep (CSWS) in children.

We describe our treatment of two boys with continuous spikes and waves during slow wave sleep (CSWS). One of the boys was suffering from non-convulsive status epilepticus and the other from conscious disturbance with automatism. Their ictal EEG readings showed continuous diffuse spike and wave complexes, which were considered to show electrical status. The boys were diagnosed as having CSWS, and were later diagnosed with Landau-Kleffner syndrome (LKS). EEG readings returned to normal on intravenous injection of flunitazepam (FZP) at a dose of 0.02 mg/kg, suggesting that FZP is an effective treatment for CSWS.     

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。     

Nocturnal complex partial seizures precipitated by REM sleep. A case report

A 16-year-old patient presenting with complex partial seizures occurring in the transition from a REM period to wakefulness is described. His baseline EEG showed generalized and symmetrical slow spike and wave complexes, on a normal background activity, activated by NREM sleep. Polygraphic and videotape recordings, carried out for several nights, showed that after nearly each REM period, he would wake up briefly, presenting eye blinking followed by a burst of generalized hypersynchronous theta to start his seizures. These were characterized by moaning and autoaggressive behaviour, the ictal EEG showing generalized slow spike and wave complexes in the midst of several movement artifacts. At the end of each fit he fell back to REM sleep. Carbamazepine treatment completely resolved his symptoms, with full normalization of EEG activity.     

Longitudinal study of epileptiform EEG patterns in normal children

EEG were recorded in 3,726 children, from 6 to 13 years of age who were neurologically normal and had no history of epileptic seizures. The records were taken during wakefulness, at rest, and during hyperventilation. In 131 cases (3.54%) epileptiform patterns were found. They consisted of 3 count/sec spike and slow waves discharges (4 cases), multiple spike and slow wave complexes (37 cases), midtemporal spikes (50 cases), rolandic or parietal spikes (27 cases), occipital spikes (2 cases), and multifocal spikes (11 cases). Half of the subjects with EEG abnormalities had behavior problems and/or slight psychomotor ability disturbances. Follow-up studies over an 8 to 9 year period were performed. These demonstrated the spontaneous disappearance of the EEG abnormalities, usually within school age or, at the latest, during adolesence. Only seven individuals developed epileptic seizures of the primary generalized type which responded well to anticonvulsant drug treatment. From this study we can deduce that the epileptiform EEG patterns that often are found in children during school age have no clinical relationship to epilepsy in the great majority of cases. The relationship with epilepsy exists probably on a genetic level for the generalized discharges. The spike foci are non-epileptic in nature in all probability, especially if they emerge from a fairly normal background activity and their duration is very similar to that of the constituents of the background activity, as found in the majority of these subjects. On the contrary, it is probable that these alterations express difficulties in affective or motor adaptation during childhood.     

Prolonged Psychic Epileptic Seizures: A Study of the Absence Status

Long-lived epileptic seizures associated with spike-and-wave complexes are presently considered to be the absence status, i.e., the generalized nonconvulsive status. EEG radiotelemetry allowed us to record three prolonged seizures of 3 epileptic patients. Clinical manifestations included selective rather than global impairment of higher cortical functions. Clinical impairment appeared only when patients were in a state of activity and if those altered functions were used. EEG abnormalities were diffuse, but among them spike-and-wave complexes were never diffuse. It was impossible to establish close electroclinical correlation. However, the clinical and electrical evolution was roughly isomorphic, i.e., cyclic. Major clinical manifestations were associated with spikes rather than with slow waves. Lastly, patients showed common ictal psychopathological symptoms. The problem of classifying such seizures in either the generalized or partial status is discussed. The role of selective impairment of mental functions in psychopathological symptoms is also dealth with.     

Electroencephalographic evidence for a dose-related biphasic effect of morphine on bicuculline-induced seizures in the rat

The effects of systemic pretreatment with morphine sulfate (MS) on electroencephalographic (EEG) manifestations of seizures due to bicuculline (BIC) were studied in freely moving rats. Electrodes were placed on frontal and occipital cortices, into the hippocampus and into a region of the prepiriform cortex, area tempestas (AT). BIC (0.1-0.25 mg/kg i.v.) elicited dose-dependent changes in electrocortical activity, consisting of 3 stages: stage 1, slight increase in periods of desynchronization; stage 2, trains of 4-6 Hz spike-and-wave complexes and of 2-4 Hz slow waves; stage 3, 'grand mal' seizures. Isolated spikes and hypersynchronous high voltage spikes occurred in the hippocampus during stage 2 and stage 3, respectively. In the AT, EEG abnormalities were observed during stage 3 only. During the recovery period, cortical synchronization occurred associated with the presence of occasional synchronous spikes in both deep areas. After pretreatment with MS (2, 12, and 25 mg/kg), stage 3 EEG seizures occurred with doses of BIC (0.12 or 0.18 mg/kg i.v.) that in the absence of MS produced only stage 1 or 2. In contrast, after pretreatment with a low dose of MS(0.5 mg/kg) the seizures induced by a maximally effective dose of BIC (0.25 mg/kg) were markedly attenuated. Thus, the effect of MS on BIC-induced seizure activity appears to be biphasic, potentiating seizures at doses at or above 2 mg/kg and inhibiting seizures at lower doses.     

Lennox-Gastaut syndrome (childhood epileptic encephalopathy).

Lennox-Gastaut syndrome (LGS) is a childhood epileptic encephalopathy characterized by an electroclinical triad of generalized slow spike wave (SSW) activity in the EEG, multiple types of epileptic seizures, and slow mental development. It is usually subdivided into symptomatic and cryptogenic types, the latter accounting for at least one fourth of all patients. Symptomatic cases are due to diverse cerebral conditions, which are usually bilateral, diffuse, or multifocal, involving cerebral gray matter. Twenty percent of all patients with LGS have prior infantile spasms with hypsarrythmia. The characteristic interictal EEG pattern of LGS is 1.5 to 2.5 Hz SSW activity, which is bilaterally synchronous, dominant over the frontocentral regions, and usually symmetric. There are varying degrees of slowing of the background. Sleep discloses paroxysms of generalized fast (10 to 25 Hz) rhythmic activity.     

Chronological change of EEG findings in a case of pyridoxine dependency seizures

A patient of pyridoxine dependent seizures was reported. He was born at 34 weeks' gestation and weighted 2,760 g. Apgar scores were 6 and 9 at 1 and 5 minutes, respectively. He showed the first seizure 2 hours after his birth. Phenobarbital, phenytoin, sodium valproate, diazepam and clonazepam were not effective. Pyridoxal phosphate (50 mg) was given intravenously, resulting in suppression of convulsions. However, muscle tonus was severely depressed. In EEG, a discontinuous pattern was found in quiet and indeterminate sleep on the 2nd day of life. At 5th week multifocal spikes were found, and the discontinuous pattern persisted. Ictal discharges at 13th week showed generalized, continuous, irregular and high voltage slow waves with multifocal spikes. At 27th week of life, high voltage slow waves disappeared and multifocal spike discharges decreased. At 2 years and 10 months of age, the patient was suffering from athetotic cerebral palsy and severe mental retardation. Pyridoxal phosphate at the doses of 35-40 mg/kg/day had been administered. Irritability sometimes occurred and additional 50 mg of pyridoxal phosphate controlled this irritability effectively.     

Epileptiform EEG Activity of the Centromedian Thalamic Nuclei in Children with Intractable Generalized Seizures of the Lennox-Gastaut Syndrome

Centromedian thalamic nuclei (CM) epileptiform EEG activities were recorded in children with intractable generalized seizures of Lennox-Gastaut syndrome (LGS) through implanted recording-stimulating electrodes used for seizure control. Ictal CM epileptiform activities were consistently correlated to widespread surface cortical EEG activities and symptoms in all patients and all types of generalized seizures; i.e., fast spike discharges at CM correlated at onset of tonic and tonic-clonic generalized seizures; slow (1-2 Hz) spike-wave complex discharges at CM correlated for atypical absence seizures; slow polyspike-wave complex discharges correlated for myoclonic seizures; and spike bursts and suppression patterns correlated for combined tonic-atonic-myoclonic seizures. Ictal EEG activities occurred simultaneously at right and left CM and surface at onset of all seizure types, with the exception of myoclonic seizures where CM complete discharges and individual spike-wave complexes significantly lead those of the surface. Brief tonic-atonic spasms clinically undistinguishable from "real" epileptic seizures showed no EEG counterparts at CM and surface. Interictal CM spike-wave complete discharges and individual spike-wave complexes showed variable amplitude-temporal patterns. Amplitude emphasis on CM and frontopolar regions was observed in most of complete discharges, however, and phase shifts between CM and frontopolar regions were observed in individual spike-wave complexes.     

EEG abnormalities in nonepileptic patients

A total of 202 nonepileptic patients (120 males and 82 females) who exhibited spike abnormalities at least twice in their EEG examinations were studied. The incidence of spike abnormalities among nonepileptic patients was 8.1% (847/10,473). The majority (90%) were under age 19. Headache, dizziness and vomiting, and abdominal pain were more frequently observed compared with controls. Mild paroxysmal EEG abnormalities such as diffuse irregular slow wave bursts with spike (27%), positive spikes (25%) or small spike (8.4%) were commonly detected. In three patients who developed epileptic seizures during the follow-up period, more specific EEG abnormalities were often exhibited. Other factors like the age at onset before 9, characteristic clinical symptoms or a positive family history of seizures were confirmed to be necessary for the manifestation of clinical seizures.     

EEG Abnormalities in Nonepileptic Patients

Abstract: A total of 202 nonepileptic patients (120 males and 82 females) who exhibited spike abnormalities at least twice in their EEG examinations were studied. The incidence of spike abnormalities among nonepileptic patients was 8.1% (847/10,473). The majority (90%) were under age 19. Headache, dizziness and vomiting, and abdominal pain were more frequently observed compared with controls. Mild paroxysmal EEG abnormalities such as diffuse irregular slow wave bursts with spike (27%), positive spikes (25%) or small spike (8.4%) were commonly detected.
In three patients who developed epileptic seizures during the follow-up period, more specific EEG abnormalities were often exhibited. Other factors like the age at onset before 9, characteristic clinical symptoms or a positive family history of seizures were confirmed to be necessary for the manifestation of clinical seizures.     

A case of Panayiotopoulos syndrome showing an atypical course

We describe herein a patient with Panayiotopoulos syndrome (PS) showing an atypical course. The patient initially had seizures typical of this syndrome from 3 to 5 years of age. EEG showed right occipital high-amplitude sharp and slow-wave complexes followed by brief generalized discharges of slow waves. Sequential EEGs obtained from 5 to 11 years of age showed both multifocal discharges and generalized spike and wave complexes. With these changes in EEG findings, the patient experienced various types of seizures. The seizures were frequent and showed oculocephalic deviation followed by absence, atonic seizures, generalized tonic clonic convulsions and clonic seizures of the eyelids, which were observed between 7 and 10 years of age. Antiepileptic drugs were only partially effective for these seizures. Ictal EEG recorded at 8 years of age revealed high-voltage slow waves from the bilateral frontal and occipital regions prior to diffuse high-amplitude spike-wave bursts. At 9 years of age, magnetoencephalography (MEG) revealed the calculated dipoles of the preceding bifrontal spike-wave discharges to be in the frontal areas, while those of the following generalized spike-wave bursts were in the bilateral mid-temporal areas. In PS, reportedly, dipoles of multifocal epileptic discharges are usually located in the occipital and Rolandic areas. The unique clinical evolution in our case may be associated with the unusual frontal localization of dipoles detected by MEG.     

Development of Epileptic Activity in Embryos and Newly Hatched Chicks of the Fayoumi Mutant Chicken

Summary: The homozygous Fayoumi strain of epileptic chickens (Fepi) is affected by generalized convulsions consistently induced by intermittent light stimulation (ILS) and by intense sound. Although interictal EEG recordings show continuous spikes and spike and wave activity, desynchronization and flattening (DF) of the EEG are observed during seizures. We have studied development of the epileptic phenotype in embryonic (E) and posthatching (P) Fepi. As compared with those of chicken embryos of a normal strain, no differences were observed in the EEG before embryonic day (E) 16. Clearly differentiated spikes and spike and waves appeared at E17 in Fepi. Metrazol-induced EEG seizures were observed at E16 in normal embryos and at E17 in Fepi. The Fepi showed some characteristics: Spontaneous EEG seizure-like discharges also appeared at E17 but decreased to-ward hatching; visual or acoustic hyperexcitability developed at E20 together with evoked responses in normal chickens; desynchronization of the EEG, typical of the epileptic seizure of the adult, could be induced by ILS at E20, but ILS- or sound-induced generalized motor seizures appeared at P1, a few hours after hatching. Results show that Fepi phenotype reaches full expression at P1, but the electric paroxysms are expressed earlier, paralleling synaptic maturation.     

Reflex petit mal absence?

The importance of tactile somatosensory stimuli as a triggering mechanism in provoking epileptic seizures is widely acknowledged. These seizures are mostly partial ones with secondary generalization, but may also be, rarely, primary generalized seizures. Up to now, no case of petit mal absence, triggered by somatosensory stimuli, has been described. The subject of this report is a 15-month-old girl, who for a period of 3 months presented absence induced by finger tapping on her forehead or in the parietal region; the duration of the attacks ranged from 6 to 12 seconds. The EEG showed a characteristic pattern of diffuse discharges of 3 Hz/sec spike and wave complexes. During this critical period, the child was well, except for the seizures. Possible mechanisms for triggering this type of seizure are discussed.     

Evolution of seizures and electroencephalographical findings in 23 cases of deletion type Angelman syndrome

Angelman syndrome (AS) is a genetic disorder with characteristic clinical and EEG findings. We report here the results of long-term follow-up studies on the epileptic seizures and EEG findings of 23 cases of deletion type AS confirmed by FISH analysis, including seven cases previously reported by Matsumoto et al. in 1992. The age at last follow-up in 23 patients was from 1 to 37 years of age (average: 18.0 years), with 10 patients (43.5%) in their 20s, and five over 30. Epileptic seizures were seen in all patients, and the age at seizure onset ranged from 3 to 50 months (average: 21.7 months). Status epilepticus was seen in 11 patients (47.8%). The percentages of cases seizure-free for more than 3 years were 25% (4/16) at 10 years of age, 70% (7/10) at 20, and 80% (4/5) at 30. The EEG findings were classified into six patterns according to the previous report: N (no spike, including focal slow waves), HVS (diffuse high-voltage slow bursts with or without spikes), F (focal spikes or multifocal spikes), S (diffuse spike and waves), C (continuous diffuse spike and waves), Hy (hypsarrythmia or hypsarrhythmia like waves). Hy was noted at ages 0-2 years in two cases. C was observed from the ages 2 to 15 years, being most frequently noted at 3-6 years of age, and it was never seen after 16 years of age. S was observed from ages 1 to 21 years. F was seen from 2 to 21 years of age, and most frequently during the ages of 2-7 years. HVS was seen from 0 years, and still remained after the age of 20. After 22 years of age, all patients showed N pattern including focal slow waves. One of the two patients who had bilateral frontal dominant delta slow waves in their 30s, had a recent seizure. Even if the spikes disappear with age, when bi-frontal focal slow waves remain, seizures may occur even in patients over 30.     

Generalized absence seizures with 10-15 Hz fast discharges.

OBJECTIVE: To report clinical and EEG features in 5 adults with unusual, fast rhythmic discharges accompanying absence seizures. DESIGN AND METHODS: The 5 patients presented with uncontrolled seizures. All had EEG-video monitoring with recorded seizures. Video seizures were reviewed and ictal as well as interictal epileptiform activity was analyzed. The patients were followed up after appropriate therapy for a minimum of 6 months. RESULTS: There were 3 women and two men, with a mean age of 37 years (range: 23-59). Two patients had onset of absence seizures in childhood, one in adolescence and two after age 20. All patients also had generalized tonic-clonic seizures. Ictal EEG recordings showed generalized spike and wave (SW) discharges of variable dominant frequencies (2.5-6 Hz) and intermingled 10-15 Hz generalized rhythmic discharges which also occurred in isolation or as the dominant activity. Interictal recordings showed similar but shorter 2.5-6 Hz generalized SW discharges. The background activity was normal in 3 patients and mildly slow in two who had very frequent absence seizures during the recording period. Four patients became seizure free and one had 75% improvement on appropriate antiabsence therapy. CONCLUSIONS: The fast 10-15 Hz rhythmic discharges that we report appear to occur mostly in adult patients with absence, as well as, generalized tonic-clonic seizures. They can occur in isolation or be embedded in more typical SW discharges accompanying typical absence seizures. Their presence does not imply a poor prognosis for seizure control.     

EEG findings in a case of acute necrotizing encephalopathy of childhood associated with influenza A virus infection

We reported here a case of symptomatic partial epilepsy following acute necrotizing encephalopathy of childhood associated with influenza A virus infection. This 2-year-old boy underwent repeated EEG recordings, which at the acute stage was dominated by diffuse 1-2 Hz slow waves. The background activity was 5 Hz theta waves on the 49th day. Paroxysmal activities appeared after the 89th day of illness. On the 231st day, EEG showed spike-and-waves on the left and right frontal areas. Interestingly, paroxysmal activities preceded the onset of epileptic seizures by 7 months, and spike-and-waves by 2 months. After 10 months, he had generalized seizures with fever, and partial seizures on awakening without fever. Interictal EEG showed spike-and-waves on the bilateral frontal areas, and diffuse polyspikes and slow waves were occasionally seen. Though the background activity improved, his consciousness level did not recover probably because the thalamus, basal ganglia, brainstem were damaged more severely than the cerebral cortex.