Status epilepticus in Indian children in a tertiary care center
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《美国医学杂志》
Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
Abstract
OBJECTIVE: To study the clinical profile, immediate outcome and possible risk factors of SE in pediatric age group admitted to pediatric intensive care unit (PICU) in a tertiary care center. METHODS: A retrospective study of case records of 451 neuroemergency patients admitted in PICU in a tertiary care center between January 1993 to April 2000, out of which 30 patients had status epilepticus. They were evaluated for their clinical presentation, laboratory parameters, treatment profile and immediate outcome. RESULTS: The age group varied from 1 to 120 months with mean of 56.6± 46.5 months. Seventeen patients were less than 60 months. Sixteen patients (53.3%) presented with SE as first presentation without prior history of seizure activity. Nine patients died (30%) during hospital course. Seizure duration >45 minutes (p-0.001) and presence of septic shock (p-0.001) were associated with significantly more mortality. CONCLUSION: There is a need to abort seizure activity at the earliest and this improves immediate outcome.
Keywords: Status epilepticus; Clinical profile; Immediate outcome; Risk factors
Status epilepticus (SE) is a major medical and neurological emergency. Despite advances in treatment, it is still associated with significant morbidity and mortality.[1] Conventional definition of status epilepticus is 'Continuous seizure activity lasting for 30 minutes or longer [2], or intermittent seizure activity lasting for more than 30 minutes from which patient does not regain consciousness'.[3] Lately it is becoming increasingly recognized that seizure duration of more than 10 minutes can lead to brain damage and duration of seizure activity in definition of status epilepticus is being decreased.[3] The longer the SE is present, more difficult is the control and more is the risk of permanent neurological damage. Immediate intervention is important whenever the patient has SE. It is important to consider SE whenever a seizure activity or a series of seizure activity persist for more than 10minutes or even for 5 minutes and to consider therapy.[4],[5] Several studies have provided information concerning some of the important clinical features of this condition and developed insights in to the prediction of indicators of out come.[6] However there is not much published data either population based or hospital-based studies from the Indian subcontinent.
The objectives of the study were to determine the clinical profile, immediate outcome and possible risk factors of SE in pediatric age group admitted to pediatric intensive care unit (PICU) in a tertiary care center.
Materials and methods
We studied retrospectively case records of 451 neuroemergency patients admitted to PICU between January 1993 to April 2000, whose files could be retrieved. Out of these, 30 patients had status epilepticus. These patients were evaluated for their clinical presentation, laboratory parameters, treatment profile and immediate outcome.
Inclusion criteria included patients aged >1 month fulfilling the definition of SE as per International Classification of Epileptic Seizure as 'Continuous seizure activity lasting for 30 minutes or longer, or intermittent seizure activity lasting for more than 30 minutes from which patient does not regain consciousness'.[7],[8],[9],[10]
Exclusion criteria included patients with seizure activity lasting for less than 30 minutes, patients aged less than 1 month and more than 120 months and those patients where the duration of seizure activity could not be documented with or without regaining consciousness or patients whose case records had no time specification.
Definitions
Seizures were classified as per International League Against Epilepsy Group Definitions.[7],[8],[9],[10] History of epilepsy is defined as two or more unprovoked seizures in the past whether on treatment or not. Initial seizure control was based on seizure control by drugs at the time of first contact with the emergency services. Good response was defined as seizure activity controlled with antiepileptic drugs (AED) within 60 minutes of contact with hospital and initiation of therapy. SE was defined as refractory, if the duration for control of seizure activity was more than one hour. Mortality was defined as death occurring in PICU during the course of treatment of SE irrespective of whether it was controlled or not.
Patient Data
It was carefully obtained by reviewing the case records. The details were based on information provided by parents, time of onset of seizures, their presentation to emergency department, documentation by the casualty medical officer (CMO) on duty and the doctor on duty in PICU, so as to be very clear about the duration of seizure, as this was the most important criteria for definition. These patients' records were systematically studied for their clinical profile, investigations, their immediate outcome and possible risk factors for mortality.
Statistical Analysis of risk factors for immediate mortality was analyzed using Chi-Square (Fisher-Exact) test.
Results
There were 30 pediatric patients with SE who were admitted in PICU from Jan 1993 to April 2000. This was out of 451 neuroemergency case records, which could be retrieved. Salient clinical features, seizure pattern and causes are tabulated in table1. Most common seizure type was generalized tonic clonic seizure (GTCS) in 19 patients. Eight patients had history of developmental delay among which 3 had cerebral palsy; one had Sturge- Weber syndrome More Details More Details and another intractable epilepsy.
Fourteen patients with SE had previous history of epilepsy. In remaining 16, 1 was idiopathic, 3 had febrile status epilepticus and 12 had acute symptomatic (intra cranial bleeding 1, superior sagittal sinus thrombosis 1, tubercular meningitis 1, viral encephalitis 1, pyogenic meningitis 1, septic shock 2, chronic renal failure 2, aspiration pneumonia 2, Steven Johnson syndrome 1) . Thus sixteen (53.3%) presented with SE as first presentation without prior history of seizure activity. Among these 16, 11 (68.7%) were less than 60 months ages. Five died in this group.
Predisposing factors for SE revealed fever in 16,upper respiratory tract infection in 7, gastroenteritis, hypoxia and uremia in 2 each and premature withdrawal of drug in 1. Fourteen had past history of seizures, out of which 4 had poorly controlled seizures. Among these four, 2 patients also had past history of status epilepticus. Eighteen patients had received some treatment before coming to emergency services, 6 had received injection diazepam and 4 midazolam details of remaining patient's were not known. Among 12 patients who had not received treatment 5 died later. Most commonly used drugs for initial seizure control was a combination of diazepam and phenytoin in 28 patients. More than 3 drugs were required to control SE in 10. In 18 (56.7%) seizures were controlled within one hour and 12 had refractory status epilepticus. Most common side effects were sedation in 27, followed by respiratory depression requiring ventilatory support in 19.
Lumbar puncture was done during the hospital stay in 24 patients and cerebrospinal fluid (CSF) was normal in 17. Computed tomography (CT) of cranium was done in 20 patients and was abnormal in 14 (68.4%). The most common CT abnormality was cerebral edema in 7, followed by inflammatory granuloma in 5, atrophy in 1 and superior sagittal sinus thrombosis in 1. Cerebral edema was associated with intracranial bleed in one and infarction in another. CT was done in 6 who had died. Abnormalities included a single calcified inflammatory granuloma, superior sagittal sinus thrombosis, evidence of Sturge Weber syndrome, infarction with cerebral edema and intraparenchymal bleed on NCCT in one each. EEG was done in 14, of whom 13 were abnormal, all had generalized cerebral dysfunction.
Over all immediate outcome revealed 9 deaths (30%) during hospital course. Among those who died risk factors were analyzed and are detailed in table2. Seizure duration >45 minutes (p-0.001) and presence of septic shock (p-0.001) were associated significantly with more mortality. Patients of septic shock (4 in those with past history of seizure and 2 in no seizure group) were diagnosed at admission and patients were very sick and their sickness could have predisposed to seizure. Children under 36 month's age had greater mortality (44.4% versus 23.8%; p-0.487). Six patients (6/16) with lag time for treatment, more than equal to 1 hour died in comparison to 3 with lag time for treatment less than 1 hour (p-0.196). Six with response to treatment more than equal to 1 hour died in comparison to 3 who responded in less than 1 hour (p-0.068)
Discussion
The incidence of SE in Indian subcontinent is not known. Our study revealed 30/451(6.6%) patients had SE. The incidence of SE varies from 3.7%-9.1% as per western literature and our results are corroborative to the reports.[11],[12] Younger age group is most commonly affected. 56% of patients were less than 5 years in our study. Predominant involvement of younger age group as been reported previously.[1],[13],[14] The reason for this predominance of SE in younger children is not known. Probably, mechanisms for control of seizure activity are fragile in younger children and may get disrupted with minimal abnormalities in neurofunction.
Sixteen patients (53.3%) presented as SE without prior history of seizures. This is more than reported earlier by Shinnar et al 12%.[15] Herdorffer et al reported when SE was associated with epilepsy it tended to be the first unprovoked seizure in 30% or it tended to be the seizure leading to diagnosis of epilepsy in 35%.[13] They also reported 18% of unprovoked SE occurred in people with established epilepsy.[13]
Intravenous diazepam and phenytoin were common antiepileptic drugs used for control of initial seizure activity. The most important adverse effect of combination therapy was sedation in 90% and respiratory depression requiring ventilation 63.3%. Because of this life threatening adverse reaction of drugs used in control of SE it is always recommended to manage these patients in PICU setting. An immediate investigation of these patients while they are not adequately managed for seizure activity control is not recommended as it could be life threatening. Investigations need to be done only after initial stabilization of patient's hemodynamic status. The primary aim is to control and abort SE as the duration of seizure activity is directly proportional to immediate mortality and later morbidity.
Immediate mortality in this study was 30%, this includes the mortality that occurred during seizure activity and hospital course. Significant association was seen in-patients having seizure activity lasting for more than 45 minutes and with septic shock. The other risk factors for immediate mortality were age less than 36 months, lag time in the treatment of more than equal to 1 hour and patients responding after 1 hour of treatment. Mortality in SE varies from 11%-53%.[16],[17],[5] Most of these patients were acute symptomatic and this was not purely a pediatric study. The risk for death increased with age, and was lower in women. Seizure type and duration of SE did not affect the risk of dying within 30 days.[17] Whereas in our study more males died (6/9) and more deaths (4/9) occurred in less than 3 years age group.
Logroscino et al reported 1% mortality (2/37) in age group 1-19 years. They studied risk factors as a whole but did not analyse risk factors in pediatric age group as it was mainly adult based study.[17] Delorenzo et al using SE lasting <1 hour as the reference category, found longer duration to be associated with higher 30-day mortality 30% vs. 2.7% and drug dose required for control of seizures was a risk factor for mortality in a univariate analysis.[5] This was similar to our study in which patients who experienced >45 minutes of seizure activity had more mortality (p-0.001), all patients (n-7) who had >45 minutes seizure activity died. Other risk factors that have been reported include drug overdose, decrease in antiepileptic drugs, hemorrhage in CNS, infections, cerebrovascular accidents tumors etc.[5]
Conclusion
We conclude that there is a need to abort seizure activity at the earliest and this improves immediate outcome.
References
1. DeLorenzo RJ, Hauser WA, Towne AR et al. A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia. Neurology 1996; 46: 1029-1035.
2. Walker MC. The epidemiology and management of status epilepticus. Curr Opin Neurol 1998; 11: 149-154.
3. Khurana DS. Treatment of status epilepticus. Ind J Pediatr 2000; 67; 1: S80-S87.
4. Phillips SA, Shanahan RJ. Etiology and mortality of status epilepticus in children a recent update. Arch Neurol 1989; 46(1): 74-76.
5. Lorenzo RJ, Towne AR, Pellock JM and Ko D. Status epilepticus in children, adults and the elderly. Epilepsia 1992; 33: S15-S25.
6. Towne AR, Pellock J M, Ko D, Delorenzo RJ. Determinants of mortality in status epilepticus. Epilepsia 1994; 35 (1): 27-34.
7. Commission on Classification and Terminology of the International League Against Epilepsy, Proposal for revised clinical and electrographic classification of epileptic seizures. Epilepsia 1981; 22: 489-501.
8. Commission on Classification and Terminology of the International League Against Epilepsy, Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30:389-399.
9. Commission on Epidemiology and prognosis, International League Against Epilepsy, Guidelines for epidemiologic studies on epilepsy. Epilepsia 1993; 34: 592-596
10. Epilepsy foundation of America's Working Group on Status Epilepticus: treatment of convulsive status epilepticus. JAMA 1993; 270: 854-859.
11. Maytal J, Shinnar S. Febrile status epilepticus. Pediatrics 1990; 86: 611-616.
12. Berg AT, Shinnar S, Levy SR, Testa FM. Status epilepticus in children with newly diagnosed epilepsy. Ann Neurol 1999;45: 618-623.
13. Hesdorffer DC, Logroscino G, Cascino G, Annegers JF, Hauser WA. Incidence of status epilepticus in Rochester, Minnesota. 1965-1984. Neurology 1998; 50: 735-741.
14. Hauser WA. Status epilepticus: epidemiologic considerations. Neurology 1990; 40: S9-S13.
15. Shinnar S, Berg AT, Moshe SL. The risk of seizure recurrence after a first unprovoked afebrile seizure in childhood: an extended followup. Pediatrics 1996; 98: 216-225.
16. Knowng KL, Lee SL, Yung A. Status epilepticus in 37 Chinese children: etiology of outcome. J Ped Child Health 1995; 31(5): 395-398.
17. Longroscino G, Hesdorffer DC, Cascino G, Annegers JF, Hauser WA. Short term mortality after a first episode of status epilepticus. Epilepsia 1997; 38: 1344-1349.(Gulati Sheffali, Kalra Ve)
Abstract
OBJECTIVE: To study the clinical profile, immediate outcome and possible risk factors of SE in pediatric age group admitted to pediatric intensive care unit (PICU) in a tertiary care center. METHODS: A retrospective study of case records of 451 neuroemergency patients admitted in PICU in a tertiary care center between January 1993 to April 2000, out of which 30 patients had status epilepticus. They were evaluated for their clinical presentation, laboratory parameters, treatment profile and immediate outcome. RESULTS: The age group varied from 1 to 120 months with mean of 56.6± 46.5 months. Seventeen patients were less than 60 months. Sixteen patients (53.3%) presented with SE as first presentation without prior history of seizure activity. Nine patients died (30%) during hospital course. Seizure duration >45 minutes (p-0.001) and presence of septic shock (p-0.001) were associated with significantly more mortality. CONCLUSION: There is a need to abort seizure activity at the earliest and this improves immediate outcome.
Keywords: Status epilepticus; Clinical profile; Immediate outcome; Risk factors
Status epilepticus (SE) is a major medical and neurological emergency. Despite advances in treatment, it is still associated with significant morbidity and mortality.[1] Conventional definition of status epilepticus is 'Continuous seizure activity lasting for 30 minutes or longer [2], or intermittent seizure activity lasting for more than 30 minutes from which patient does not regain consciousness'.[3] Lately it is becoming increasingly recognized that seizure duration of more than 10 minutes can lead to brain damage and duration of seizure activity in definition of status epilepticus is being decreased.[3] The longer the SE is present, more difficult is the control and more is the risk of permanent neurological damage. Immediate intervention is important whenever the patient has SE. It is important to consider SE whenever a seizure activity or a series of seizure activity persist for more than 10minutes or even for 5 minutes and to consider therapy.[4],[5] Several studies have provided information concerning some of the important clinical features of this condition and developed insights in to the prediction of indicators of out come.[6] However there is not much published data either population based or hospital-based studies from the Indian subcontinent.
The objectives of the study were to determine the clinical profile, immediate outcome and possible risk factors of SE in pediatric age group admitted to pediatric intensive care unit (PICU) in a tertiary care center.
Materials and methods
We studied retrospectively case records of 451 neuroemergency patients admitted to PICU between January 1993 to April 2000, whose files could be retrieved. Out of these, 30 patients had status epilepticus. These patients were evaluated for their clinical presentation, laboratory parameters, treatment profile and immediate outcome.
Inclusion criteria included patients aged >1 month fulfilling the definition of SE as per International Classification of Epileptic Seizure as 'Continuous seizure activity lasting for 30 minutes or longer, or intermittent seizure activity lasting for more than 30 minutes from which patient does not regain consciousness'.[7],[8],[9],[10]
Exclusion criteria included patients with seizure activity lasting for less than 30 minutes, patients aged less than 1 month and more than 120 months and those patients where the duration of seizure activity could not be documented with or without regaining consciousness or patients whose case records had no time specification.
Definitions
Seizures were classified as per International League Against Epilepsy Group Definitions.[7],[8],[9],[10] History of epilepsy is defined as two or more unprovoked seizures in the past whether on treatment or not. Initial seizure control was based on seizure control by drugs at the time of first contact with the emergency services. Good response was defined as seizure activity controlled with antiepileptic drugs (AED) within 60 minutes of contact with hospital and initiation of therapy. SE was defined as refractory, if the duration for control of seizure activity was more than one hour. Mortality was defined as death occurring in PICU during the course of treatment of SE irrespective of whether it was controlled or not.
Patient Data
It was carefully obtained by reviewing the case records. The details were based on information provided by parents, time of onset of seizures, their presentation to emergency department, documentation by the casualty medical officer (CMO) on duty and the doctor on duty in PICU, so as to be very clear about the duration of seizure, as this was the most important criteria for definition. These patients' records were systematically studied for their clinical profile, investigations, their immediate outcome and possible risk factors for mortality.
Statistical Analysis of risk factors for immediate mortality was analyzed using Chi-Square (Fisher-Exact) test.
Results
There were 30 pediatric patients with SE who were admitted in PICU from Jan 1993 to April 2000. This was out of 451 neuroemergency case records, which could be retrieved. Salient clinical features, seizure pattern and causes are tabulated in table1. Most common seizure type was generalized tonic clonic seizure (GTCS) in 19 patients. Eight patients had history of developmental delay among which 3 had cerebral palsy; one had Sturge- Weber syndrome More Details More Details and another intractable epilepsy.
Fourteen patients with SE had previous history of epilepsy. In remaining 16, 1 was idiopathic, 3 had febrile status epilepticus and 12 had acute symptomatic (intra cranial bleeding 1, superior sagittal sinus thrombosis 1, tubercular meningitis 1, viral encephalitis 1, pyogenic meningitis 1, septic shock 2, chronic renal failure 2, aspiration pneumonia 2, Steven Johnson syndrome 1) . Thus sixteen (53.3%) presented with SE as first presentation without prior history of seizure activity. Among these 16, 11 (68.7%) were less than 60 months ages. Five died in this group.
Predisposing factors for SE revealed fever in 16,upper respiratory tract infection in 7, gastroenteritis, hypoxia and uremia in 2 each and premature withdrawal of drug in 1. Fourteen had past history of seizures, out of which 4 had poorly controlled seizures. Among these four, 2 patients also had past history of status epilepticus. Eighteen patients had received some treatment before coming to emergency services, 6 had received injection diazepam and 4 midazolam details of remaining patient's were not known. Among 12 patients who had not received treatment 5 died later. Most commonly used drugs for initial seizure control was a combination of diazepam and phenytoin in 28 patients. More than 3 drugs were required to control SE in 10. In 18 (56.7%) seizures were controlled within one hour and 12 had refractory status epilepticus. Most common side effects were sedation in 27, followed by respiratory depression requiring ventilatory support in 19.
Lumbar puncture was done during the hospital stay in 24 patients and cerebrospinal fluid (CSF) was normal in 17. Computed tomography (CT) of cranium was done in 20 patients and was abnormal in 14 (68.4%). The most common CT abnormality was cerebral edema in 7, followed by inflammatory granuloma in 5, atrophy in 1 and superior sagittal sinus thrombosis in 1. Cerebral edema was associated with intracranial bleed in one and infarction in another. CT was done in 6 who had died. Abnormalities included a single calcified inflammatory granuloma, superior sagittal sinus thrombosis, evidence of Sturge Weber syndrome, infarction with cerebral edema and intraparenchymal bleed on NCCT in one each. EEG was done in 14, of whom 13 were abnormal, all had generalized cerebral dysfunction.
Over all immediate outcome revealed 9 deaths (30%) during hospital course. Among those who died risk factors were analyzed and are detailed in table2. Seizure duration >45 minutes (p-0.001) and presence of septic shock (p-0.001) were associated significantly with more mortality. Patients of septic shock (4 in those with past history of seizure and 2 in no seizure group) were diagnosed at admission and patients were very sick and their sickness could have predisposed to seizure. Children under 36 month's age had greater mortality (44.4% versus 23.8%; p-0.487). Six patients (6/16) with lag time for treatment, more than equal to 1 hour died in comparison to 3 with lag time for treatment less than 1 hour (p-0.196). Six with response to treatment more than equal to 1 hour died in comparison to 3 who responded in less than 1 hour (p-0.068)
Discussion
The incidence of SE in Indian subcontinent is not known. Our study revealed 30/451(6.6%) patients had SE. The incidence of SE varies from 3.7%-9.1% as per western literature and our results are corroborative to the reports.[11],[12] Younger age group is most commonly affected. 56% of patients were less than 5 years in our study. Predominant involvement of younger age group as been reported previously.[1],[13],[14] The reason for this predominance of SE in younger children is not known. Probably, mechanisms for control of seizure activity are fragile in younger children and may get disrupted with minimal abnormalities in neurofunction.
Sixteen patients (53.3%) presented as SE without prior history of seizures. This is more than reported earlier by Shinnar et al 12%.[15] Herdorffer et al reported when SE was associated with epilepsy it tended to be the first unprovoked seizure in 30% or it tended to be the seizure leading to diagnosis of epilepsy in 35%.[13] They also reported 18% of unprovoked SE occurred in people with established epilepsy.[13]
Intravenous diazepam and phenytoin were common antiepileptic drugs used for control of initial seizure activity. The most important adverse effect of combination therapy was sedation in 90% and respiratory depression requiring ventilation 63.3%. Because of this life threatening adverse reaction of drugs used in control of SE it is always recommended to manage these patients in PICU setting. An immediate investigation of these patients while they are not adequately managed for seizure activity control is not recommended as it could be life threatening. Investigations need to be done only after initial stabilization of patient's hemodynamic status. The primary aim is to control and abort SE as the duration of seizure activity is directly proportional to immediate mortality and later morbidity.
Immediate mortality in this study was 30%, this includes the mortality that occurred during seizure activity and hospital course. Significant association was seen in-patients having seizure activity lasting for more than 45 minutes and with septic shock. The other risk factors for immediate mortality were age less than 36 months, lag time in the treatment of more than equal to 1 hour and patients responding after 1 hour of treatment. Mortality in SE varies from 11%-53%.[16],[17],[5] Most of these patients were acute symptomatic and this was not purely a pediatric study. The risk for death increased with age, and was lower in women. Seizure type and duration of SE did not affect the risk of dying within 30 days.[17] Whereas in our study more males died (6/9) and more deaths (4/9) occurred in less than 3 years age group.
Logroscino et al reported 1% mortality (2/37) in age group 1-19 years. They studied risk factors as a whole but did not analyse risk factors in pediatric age group as it was mainly adult based study.[17] Delorenzo et al using SE lasting <1 hour as the reference category, found longer duration to be associated with higher 30-day mortality 30% vs. 2.7% and drug dose required for control of seizures was a risk factor for mortality in a univariate analysis.[5] This was similar to our study in which patients who experienced >45 minutes of seizure activity had more mortality (p-0.001), all patients (n-7) who had >45 minutes seizure activity died. Other risk factors that have been reported include drug overdose, decrease in antiepileptic drugs, hemorrhage in CNS, infections, cerebrovascular accidents tumors etc.[5]
Conclusion
We conclude that there is a need to abort seizure activity at the earliest and this improves immediate outcome.
References
1. DeLorenzo RJ, Hauser WA, Towne AR et al. A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia. Neurology 1996; 46: 1029-1035.
2. Walker MC. The epidemiology and management of status epilepticus. Curr Opin Neurol 1998; 11: 149-154.
3. Khurana DS. Treatment of status epilepticus. Ind J Pediatr 2000; 67; 1: S80-S87.
4. Phillips SA, Shanahan RJ. Etiology and mortality of status epilepticus in children a recent update. Arch Neurol 1989; 46(1): 74-76.
5. Lorenzo RJ, Towne AR, Pellock JM and Ko D. Status epilepticus in children, adults and the elderly. Epilepsia 1992; 33: S15-S25.
6. Towne AR, Pellock J M, Ko D, Delorenzo RJ. Determinants of mortality in status epilepticus. Epilepsia 1994; 35 (1): 27-34.
7. Commission on Classification and Terminology of the International League Against Epilepsy, Proposal for revised clinical and electrographic classification of epileptic seizures. Epilepsia 1981; 22: 489-501.
8. Commission on Classification and Terminology of the International League Against Epilepsy, Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30:389-399.
9. Commission on Epidemiology and prognosis, International League Against Epilepsy, Guidelines for epidemiologic studies on epilepsy. Epilepsia 1993; 34: 592-596
10. Epilepsy foundation of America's Working Group on Status Epilepticus: treatment of convulsive status epilepticus. JAMA 1993; 270: 854-859.
11. Maytal J, Shinnar S. Febrile status epilepticus. Pediatrics 1990; 86: 611-616.
12. Berg AT, Shinnar S, Levy SR, Testa FM. Status epilepticus in children with newly diagnosed epilepsy. Ann Neurol 1999;45: 618-623.
13. Hesdorffer DC, Logroscino G, Cascino G, Annegers JF, Hauser WA. Incidence of status epilepticus in Rochester, Minnesota. 1965-1984. Neurology 1998; 50: 735-741.
14. Hauser WA. Status epilepticus: epidemiologic considerations. Neurology 1990; 40: S9-S13.
15. Shinnar S, Berg AT, Moshe SL. The risk of seizure recurrence after a first unprovoked afebrile seizure in childhood: an extended followup. Pediatrics 1996; 98: 216-225.
16. Knowng KL, Lee SL, Yung A. Status epilepticus in 37 Chinese children: etiology of outcome. J Ped Child Health 1995; 31(5): 395-398.
17. Longroscino G, Hesdorffer DC, Cascino G, Annegers JF, Hauser WA. Short term mortality after a first episode of status epilepticus. Epilepsia 1997; 38: 1344-1349.(Gulati Sheffali, Kalra Ve)