Delineation of cryptogenic Lennox-Gastaut syndrome and myoclonic astatic epilepsy using multiple correspondence analysis.

PURPOSE: To distinguish various types of childhood severe cryptogenic/idiopathic generalised epilepsy on the basis of reproducible diagnostic criteria, using multiple correspondence analysis (MCA). METHODS: We applied MCA to a series of 72 children with no evidence of brain damage, starting epilepsy between 1 and 10 years, with two or more types of generalised seizures. We excluded patients with infantile spasms or typical absences. MCA was performed on all clinical and EEG parameters, first throughout follow-up, then restricted to the first year of the disease. RESULTS: When including all follow-up variables, there were three groups: (1) Thirty-seven children with male predominance, familial history of epilepsy, simple febrile convulsions, massive myoclonus, tonic-clonic fits. Outcome was favourable, with no seizures and mildly affected cognitive functions. Interictal EEG showed short sequences of irregular 3-Hz spike-waves. (2) In 18 children, clinical characteristics were similar to those of the first group at the early stage, but 95% exhibited myoclonic status and vibratory tonic seizures, with persisting seizures on follow-up. EEG showed long sequences of generalised irregular spike and slow waves. Those two groups meet the characteristics of childhood onset myoclonic-astatic epilepsy (MAE) with respectively, favourable and unfavourable outcome. (3) Eleven children had later onset, atypical absences, tonic and partial seizures, and no myoclonus, or vibratory tonic seizures. All had mental retardation and persisting seizures. EEG showed long sequences of slow spike-wave activity and half the patients had spike and slow wave foci. These patients met the major characteristics of Lennox-Gastaut syndrome. Initial parameters failed to distinguish the first two groups, but Lennox-Gastaut syndrome (the third group) was distinct from both groups of myoclonic astatic epilepsy from the onset. Within MAE groups combined, clinical and EEG risk factors for mental retardation could be identified. CONCLUSION: It is possible to validate statistically the distinction between discrete epileptic syndromes. Myoclonic astatic epilepsy is therefore distinct from Lennox-Gastaut syndrome, and the distinction appears from the first year of the disorder.     

Distribution of Epilepsy Syndromes in a Cohort of Children Prospectively Monitored from the Time of Their First Unprovoked Seizure

PURPOSE: To assess the distribution of epilepsy syndromes and their stability in children. METHODS: A cohort of 407 children with a first unprovoked seizure was prospectively recruited and followed up for a mean of 9.4 years. Etiology and epilepsy syndromes were classified by using the International League Against Epilepsy (ILAE) guidelines in the 182 children with two or more seizures. Classification was done both at time of second seizure and at last follow-up. Two-year terminal remission also was analyzed by etiology and epilepsy syndrome. RESULTS: Etiology of epilepsy syndromes was idiopathic in 45 (25%), cryptogenic in 89 (49%), and remote symptomatic in 48 (26%). In the initial classification, 114 (63%) children had a localization-based epilepsy syndrome including idiopathic in 26, cryptogenic in 34, and symptomatic based on localization or etiology in 54. Twenty-one (12%) children had a generalized epilepsy syndrome, including 19 with primary generalized epilepsy. Forty-seven (26%) cases were in the category of undetermined if focal or generalized. At last follow-up, there was a change in either etiology (n = 16) or the final epilepsy syndrome classification (n = 33) or both (n = 15) in 34 (19%) cases. At time of last follow-up, 144 (79%) of the children with epilepsy were in 2-year terminal remission, and 108 (59%) were in 2-year terminal remission without medications. Factors associated with a favorable prognosis included an idiopathic or cryptogenic etiology and having a localization-based idiopathic epilepsy syndrome. CONCLUSIONS: After two seizures, childhood-onset epilepsy can be classified by etiology and epilepsy syndrome. Prognosis is favorable in the majority of cases. However, the apparent syndrome may change with longer follow-up. The ability to classify these cases early in the clinical course is important if they are to be used for prognostic purposes.     

Long-Term Prognosis of Convulsive Disorders in the First Year of Life: Mental and Physical Development and Seizure Persistence

Summary: A follow-up study was made on 304 children (164 boys, 140 girls) with convulsive disorders, excluding occasional convulsions, in the first year of life. All patients except 45 who died were followed until 6 years of age or older. At the final follow-up, the subjects were divided into six groups according to the degree of mental and physical development (groups I-VI). Seizures were regarded as absent if the patient had been seizure free for more than 3 years. At the final follow-up, seizures had ceased in 57.7%, and 43.4% had normal mental and physical development (group I). As to the initial diagnosis, the percentage of group I at the final follow-up was 81.8% with febrile convulsions and 37.6% with epilepsy. In patients without seizures it was 69.7% with febrile convulsions and 55.8% with epilepsy. Some 80.6% of patients with unclassified generalized motor seizures, 11.5% of those with infantile spasms, 2.9% of those with secondary generalized epilepsy other than infantile spasms, 46.4% of those with partial seizures, and 25.0% of those with hemiconvulsive seizures were finally placed in group I. The percentage of patients without seizures was 81.4, 33.0, 34.4, 57.7, and 100%, respectively. As has been suggested, among the first-year epilepsies, a subgroup with a more favorable prognosis may exist. Further studies regarding the etiology, ictal EEGs, and effectiveness of treatment and long-term prognosis of these cryptogenic benign infantile convulsions are needed to provide a firm basis for understanding convulsive disorders in the first year of life.     

热性惊厥持续状态复发的危险因素分析

目的探讨儿童热性惊厥持续状态(FSE)复发的危险因素。方法收集138例FSE患儿的临床资料,并于出院后进行2个月至8.3年的随访。根据随访结果,将患儿分为热性惊厥复发组、癫痫进展组及无惊厥复发组,分析FSE复发的相关因素。结果根据随访结果,热性惊厥复发30例(21.7%)(热性惊厥复发组),8例(5.8%)进展为癫痫(癫痫进展组),100例(72.5%)无复发(无惊厥复发组)。与无惊厥复发组比较,热性惊厥复发组低热时出现惊厥、既往有热性惊厥病史、阳性惊厥家族史及异常EEG的比率显著升高(P<0.05~0.01)。多因素Logistic回归分析显示,低热时出现惊厥、既往有热性惊厥病史及阳性惊厥家族史为FSE热性惊厥复发的独立危险因素(P<0.05~0.01)。FSE进展为癫痫的危险因素为低热时出现惊厥、既往有热性惊厥病史、异常EEG及异常头颅MRI(P<0.05~0.01)。结论低热时出现惊厥、既往有热性惊厥病史及阳性惊厥家族史为FSE热性惊厥复发的独立危险因素。低热时出现惊厥、既往有热性惊厥病史、异常EEG及异常头颅MRI为FSE进展为癫痫的危险因素。对于有危险因素的FSE患儿,应早期合理选择预防用药,改善预后。     

Somatosensory evoked spikes and epileptic seizures: a study of 385 cases.

We examined 385 children whose EEG showed high voltage potentials evoked by taps applied to one or both feet or hands (SES). The relationship between characteristics of SES and the occurrence of epileptic seizures and the characterization of epileptic syndromes were studied. Ninety-one children (23.6%) had epilepsy, 42 (10.9%) had only febrile convulsions and 252 children had other complaints. Epilepsy occurred in a higher proportion of cases when: SES by foot tapping were multiphasic, with high amplitude or SES were obtained by hand stimulation and there was spontaneous epileptiform activity in the EEG. The following epileptic syndromes were diagnosed: benign childhood epilepsy with centrotemporal spikes in 21 cases, benign epilepsy of childhood with occipital paroxysms in 2, benign psychomotor epilepsy in 1, "partial idiopathic others" in 43, generalized idiopathic in 8, symptomatic epilepsies in 13 and undetermined in 3 cases. In most cases SES were observed in children without evidence of cerebral organic lesion, suggesting the existence of an age-related, functional mechanism. Some characteristics of SES and the occurrence of spontaneous epileptiform activity showed a positive association with epileptic seizures. SES occurred in different types of partial and generalized epilepsies of childhood but in nearly 50% of the cases with epilepsy, there was a benign condition involving mainly the parietal lobe with versive, unilateral and sleep-generalized seizures.     

Unprovoked seizures after complex febrile convulsions

Children with complex febrile convulsions bear a higher risk of developing epilepsy than children with simple febrile convulsions. Complex febrile convulsions are defined by the presence of prolonged seizures, partial seizures and multiple seizures occurring during the same day. The aim of this study is to delineate the relative significance of each of the three criteria defining complex febrile convulsions. Fifty-seven out of 477 children (12%) admitted for febrile convulsions had complex febrile convulsions and normal neurological examination. Follow-up was available for 48 (84%) of them. Thirteen of these 48 (27%) had epilepsy at follow-up. The mean age of seizure onset among the patients with subsequent afebrile seizures was significantly lower than the rest (10.8 months versus 16.8 months). The patients with partial febrile convulsions showed a trend toward a higher risk (45%) of developing epilepsy than the patients with multiple febrile convulsions (21%).     

Early development of intractable epilepsy in children: a prospective study

BACKGROUND: Little is known about early prediction of intractable epilepsy (IE) in children. Such information could help guide the early use of new therapies in selected patients. METHODS: Children with newly diagnosed epilepsy (n = 613) were prospectively identified from child neurology practices in Connecticut (1993--1997) and followed-up for the occurrence of IE (failure of > or = 2 drugs, > or = 1 seizure/month, over 18 months) [corrected]. Etiology and epilepsy syndromes were classified per International League Against Epilepsy guidelines. RESULTS: The median follow-up is 4.8 years, and 599 (97.7%) have been followed for more than 18 months. Sixty children (10.0%) have met the criteria for IE, including 34.6% with cryptogenic/symptomatic generalized, 2.7% with idiopathic, 10.7% with other localization-related, and 8.2% with unclassified epilepsy (p < 0.0001). After multivariable adjustment for epilepsy syndrome, initial seizure frequency (p < 0.0001), focal EEG slowing (p = 0.02), and acute symptomatic or neonatal status epilepticus (p = 0.001) were associated with an increased risk of IE, and age at onset between 5 and 9 years was associated with a lowered risk (p = 0.03). The absolute number of seizures and unprovoked or febrile status epilepticus were not associated substantially with IE. CONCLUSIONS: Approximately 10% of children meet criteria for IE early in the course of their epilepsy. Cryptogenic/symptomatic generalized syndromes carry the highest risk and idiopathic syndromes the lowest. Half of IE occurs in children with nonidiopathic localization-related syndromes. Initial seizure frequency is highly predictive of IE. By contrast, absolute number of seizures and unprovoked or febrile status epilepticus are not.     

Idiopathic West Syndrome followed by childhood absence epilepsy

West Syndrome (WS) is a severe epileptic encephalopathy occurring in the first year of life. According the ILAE classification of epileptic seizures and epilepsy the etiology could be symptomatic or cryptogenic. Some authors identified a small group of patients (5%) with a particular good outcome, a complete recovery from seizures and a normal cognitive development within the cryptogenic group that they suggested to be idiopathic. Between 1996 and 2007, at the Neurology Division of the Bambino Gesù Children's Hospital in Rome, we collected 241 patients with WS. Sixteen (6.6%) were considered with idiopathic aetiology. All clinical notes of these patients were reviewed in order to evaluate the prevalence of other epileptic syndrome after WS. Two of them had at the age of 8 and 3 months idiopathic WS, and at the age of 6 and 4 years respectively, they presented with childhood absence epilepsy (CAE) successfully treated with valproate.The favorable evolution of the WS and the later occurrence of an idiopathic form of epilepsy, such as CAE, confirm the possibility of an idiopathic aetiology for WS that, although rare, can represent one of the etiologies of otherwise severe syndrome. Even if a common physiophatogenetic role, probably related to a genetic predisposition, could be hypothesized and appears to be intriguing, no data are available and more studies are needed to confirm this hypothesis.     

Predicting Favorable Outcome in Idiopathic West Syndrome

Summary: Among 45 patients with cryptogenic West Syndrome (WS) we report 30 with a favorable outcome consisting of normal psychomotor development and cessation of epilepsy with at least 2 years follow-up (mean 4 years 7 months). These favorable patients could be recognized from onset by (a) absence of significant mental regression with a preserved visual function; (b) absence of focal interictal EEG abnormalities after intravenous diazepam; and (c) reappearance of hypsarrhythmia between consecutive spasms of a cluster. The latter criterion requires EEG recording of a series of spasms. The favorable outcome in these patients suggests that they had no cortical brain lesions. This new type of idiopathic epilepsy referred to as idiopathic West syndrome has important prognostic, therapeutic, and etiologic implications.     

Clinical evaluation of the patients with epilepsy following febrile convulsions

We studied clinical, EEG and developmental features of 46 epileptic children following febrile convulsions. Incidence of developing epilepsy was 9.9 percent. Eleven patients (group G) out of 46 had generalized epileptic seizures, and 34 patients (group P) had partial seizures. Febrile convulsions of early onset, partial seizures and postictal neurological symptoms were more striking in group P (p less than 0.05), whereas febrile convulsions of late onset and prolonged seizures were slightly dominant in group G. And EEG abnormalities were more frequent in group P (p less than 0.05). Group P patients had significant number of risk factors (complex features of febrile convulsions) than group G patients (p less than 0.01). The interval between the last febrile convulsion and subsequent epileptic seizures was shorter in group G (p less than 0.01). Although subsequent epileptic seizures were well controlled in the both groups (91% in group G and 82% in group P), intractable seizures were recognized in 9% of group P patients. The patients who had risk factors of prolonged seizures, postictal neurological symptoms and early onset manifested poor controlled epileptic seizures (p less than 0.01). Motor or mental deficits were more frequently associated with group P: in some patients they had been observed before the onset of febrile convulsions. These results suggest that pathogenesis of epilepsy following febrile convulsions may be different among various seizure types of subsequent epilepsy. And the risk factors during febrile convulsions may be related to the prognosis of subsequent epileptic seizures as well as the incidence of developing epilepsy.