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39. Apley J, Naish N. Recurrent abdominal pains: a field study of 1,000 school children. Arch Dis Child 1958;33:165–70. 40. Feldman W, Rosser W, McGrath P. Recurrent abdominal pain in children. Can Fam Physician 1988;34:629–30. 41. Rosenberg AJ. Constipation and encopresis. In: Wyllie R, Hyams JS, editors. Pediatric gastrointestinal disease: pathophysiology, diagnosis, management. Philadelphia: W.B. Saunders Com- pany; 1993. p. 198–208. 42. Loening-Baucke V. Constipation in early childhood: patient characteristics, treatment and long- term follow-up. Gut 1993;34:1400–4. 43. Abrahamian FP, Lloyd-Still JD. Chronic constipation in childhood: a longitudinal study of 186 patients. J Pediatr Gastroenterol Nutr 1984;3(3):460–7. 44. Israel EJ. Inflammatory bowel disease. In: Dershewitz RA, editor. Ambulatory pediatric care, Vol 1, 2nd ed. Philadelphia: J.B. Lippincott Company; 1993. p. 415–8. 45. Winesett M. Inflammatory bowel disease in children and adolescents. Pediatr Ann 1997;26(4):227–34. 46. Shanon A, Martin DJ, Feldman W. Ultrasonographic studies in the management of recurrent abdominal pain. Pediatrics 1990;86(1):35–8. 47. Wewer V, Strandberg C, Paerregaard A, Krasilnikoff PA. Abdominal ultrasonography in the diagnostic work-up in children with recurrent abdominal pain. Eur J Pediatr 1997;156:787–8. 48. Hotopf M, Carr S, Mayou R, et al. Why do children have chronic abdominal pain, and what hap- pens to them when they grow up? Population based cohort study. Br Med J 1998;316:1196–200. 49. Sanders MR, Shepherd RW, Cleghorn G, Woodford H. The treatment of recurrent abdominal pain in children: a controlled comparison of cognitive-behavioral family intervention and standard pediatric care. J Consulting Clin Psychol 1994;62(2):306–14. 50. Feldman W, McGrath P, Hodgson C, et al. The use of dietary fiber in the management of simple, childhood, idiopathic, recurrent, abdominal pain. Am J Dis Childhood 1985;139:1216–8. 51. Anderson DM. Dorland’s illustrated medical dictionary. 28th ed. Philadelphia: W.B. Saunders Company; 1994. 52. Lemoh JN, Brooke OG. Frequency and weight of normal stools in infancy. Arch Dis Child 1979;54:719–20. 53. Weaver LT, Streiner H. The bowel habits of young children. Arch Dis Child 1984;59:649–52. 54. Colon AR, Jacob LJ. Defecation patterns in American infants and children. Clin Pediatr 1977;16(10):999–1000. 55. Fontana M, Bianchi C, Cataldo F, et al. Bowel frequency in healthy children. Acta Pediatr Scand 1989;78:682–4. 56. Loening-Baucke V. Chronic constipation in children. Gastroenterology 1993;105(5):1557–64. 57. Rockney RM, McQuade WH, Days AL. The plain abdominal roentgenogram in the management of encopresis. Arch Pediatr Adolesc Med 1995;149:623–7. 58. Blethyn AJ, Jones KV, Newcombe R, et al.Radiological assessment of constipation. Arch Dis Child 1995;73:532–3. 226 Evidence-Based Pediatrics 59. Barr RG, Levine MD, Wilkinson RH, Mulvihill D. Chronic and occult stool retention. Clin Pedi- atr 1979;18(11):675–86. 60. Starrveld JS, Pols MA, Van Wijk HJ, et al. The plain abdominal radiograph in the assessment of constipation. Z Gastroenterology 1990;28:335–8. 61. Bewley A, Clancy MJ, Hall JRW. The erroneous use by an accident and emergency department of plain abdominal radiographs in the diagnosis of constipation. Arch Emerg Med 1989;6:257–8. 62. Benninga MA, Buller HA, Staalman CR, et al. Defecation disorders in children, colonic transit time versus the Barr-score. Eur J Pediatr 1995;154:277–84. 63. Berg I, Forsythe I, Holt P, Watts J. A controlled trial of `senekot’ in fecal soiling treated by behavioural methods. J Child Psychiatry Psychol 1983;24(4):543–9. 64. Halpern WI. The treatment of encopretic children. Am Acad Child Psychol 1977;16:478–99. 65. Perkin JM. Constipation in childhood: a controlled comparison between lactulose and standard- ized senna. Curr Med Res Opin 1977;4(8):540–3. 66. Staiano A, Cucchiara S, Andreotti MR, et al. Effect of cisapride on chronic idiopathic constipation in children. Digest Dis Sci 1991;36(6):733–6. 67. Nolan F, Debrelle G, Oberklaid F, Coffey C. Randomised trial of laxatives in treatment of childhood encopresis. Lancet 1991;338:523–7. 68. Sondheimer JM, Gervaise EP. Lubricant versus laxative in the treatment of chronic functional constipation in children: a comparative study. J Pediatr Gastroenterol Nutrition 1982;1(2):223–6. 69. Davidson M, Kugler MM, Bauer CH. Diagnosis and management of children with severe and pro- tracted constipation and obstipation. J Pediatr 1963;62(2):261–75. 70. Gleghorn EE, Heyman MB, Rudolph CD. No-enema therapy for idiopathic constipation and encopresis. Clin Pediatr 1991;30(12):669–72. 71. Sprague-McRae JM, Lamb W, Homer D. Encopresis: a study of treatment alternatives and his- torical and behavioural characteristics. Nurse Practitioner 1993;18:52–3, 56–63. 72. Beach RC. Management of childhood constipation. Lancet 1996;348:766–7. 73. Fleischer DR. Encopresis, enemas and gold stars. Pediatrics 1978;61:155–6. 74. Martin RR, Lisehora GR, Braxton M. Fatal poisoning from sodium phosphate enema. JAMA 1987;257:2190–2. 75. Clayden GS, Lawson JON. Investigation and management of long-standing chronic constipation in childhood. Arch Dis Child 1976;51:918–23. 76. Snape WJ. The effect of methylcellulose on symptoms of constipation. Clin Thera 1989;11(5):572–9. 77. Muller-Lissner SA. Effect of wheat bran on weight of stool and gastrointestinal transit time: a meta-analysis. Br Med J 1988;296:615–7. 78. Dwyer JT. Dietary fibre for children: how much? Pediatrics 1995;96(Suppl 5):1019–22. 79. Clark JH, Russell GJ, Fitzgerald JF, Nagamori KE. Serum beta-carotene, retinol and alpha-toco- pherol levels during mineral oil therapy for constipation. Am J Dis Child 1987;141:1210–2. Abdominal Pain in Children 227 CHAPTER 12 Seizure Disorders Peter Camfield, MD, FRCPC Carol Camfield, MD, FRCPC  Seizures in children are common and have many causes. This chapter concentrates on spon- taneous, unprovoked seizures that tend to recur, as well as febrile seizures. Seizures can be provoked by nearly any acute disturbance to the cerebral neocortex. Provoked seizures, irre- spective of the cause, have a very low rate of recurrence, provided that the provoking factor can be treated or avoided. For example, only about 10 percent of people who have seizures provoked by a major head injury will later develop epilepsy. 1 The decision that a child has had a seizure is almost always based on the history since most seizures are brief and have stopped by the time the child is seen by a physician. Only the history can exclude such disorders as syncope, breath-holding, or vertigo. Even experts interpreting the same history may have difficulty, on occasion, in agreeing on the nature of a child’s “event” 2 (level II-2). In our opinion, if the history is unclear, it is less harmful to await a recurrent event than to falsely label a child as having an epileptic disorder. There are different kinds of seizures, and if seizures are recurrent, there are different types of epilepsy. Seizures can be categorized into partial (or focal) and generalized types. Partial seizures begin in one part of the brain. They are subdivided into simple partial, if consciousness is retained, or complex partial, if consciousness is altered or lost. Generalized seizures arise diffusely all over the brain at once; they can be thought of as a “system failure” or “system overload.” The main types of generalized seizures are generalized tonic-clonic, absence, and myoclonic seizures. If a seizure begins in one part of the brain and spreads to involve the entire brain, a partial seizure with secondary generalization is said to have occurred. The patient may have an “aura” followed by a generalized tonic-clonic seizure. The aura is really a simple partial seizure. Therefore, a child with a “grand mal” or generalized tonic-clonic seizure may have had a primarily generalized seizure or a partial seizure with secondary generalization. When all of the details of a child’s seizure disorder are combined with the electroencephalography (EEG), an epilepsy syndrome can usually be defined. The diagnosis of an epilepsy type may assist in understanding the cause and in defining the prognosis. Table 12–1 outlines the main epilepsy syndromes and serves to emphasize the variety of types of epilepsy. 3 The clinician is urged to consider seizures as the result of many different brain processes. FEBRILE SEIZURES About 3 to 4 percent of children will have one or more febrile convulsions, making this the most common convulsive event in humans. 4 The usual age range is 6 months to 5 years with a peak age at 18 to 22 months. To make the diagnosis, there must be documented fever and a clear history of a convulsion. It is important to note that syncope in small children may be precipitated by fever 5 (level III). When a child presents with an ongoing febrile seizure, the first task is to stop the seizure. Intravenous diazepam or lorazepam appear to be roughly equivalent 6 (level I, recommendation A). Although rectal diazepam has not been subjected to a randomized controlled trial 230 Evidence-Based Pediatrics Table 12–1 International classification of epilepsies and epileptic syndromes and related seizure disorders I. Localization-related (local, focal, partial) epilepsies and syndromes 1.1 Idiopathic (with age-related onset) Benign childhood epilepsy with centro-temporal spikes Childhood epilepsy with occipital paroxysms Primary reading epilepsy 1.2 Symptomatic Chronic progressive epilepsia partialis continua Syndromes characterized by seizures with specific modes of precipitation Temporal lobe epilepsies Frontal lobe epilepsies Parietal lobe epilepsies Occipital lobe epilepsies 1.3 Cryptogenic II. Generalized epilepsies and syndromes 2.1 Idiopathic (with age-related onset) Benign neonatal familial convulsions Benign neonatal convulsions Benign myoclonic epilepsy in infancy Childhood absence epilepsy Juvenile myoclonic epilepsy Epilepsy with grand mal seizures (GTCS) on awakening Other generalized idiopathic epilepsies Epilepsies with seizures precipitated by specific modes of activation 2.2 Cryptogenic or symptomatic West syndrome Lennox-Gastaut syndrome Epilepsy with myoclonic-astatic seizures Epilepsy with myoclonic seizures 2.3 Symptomatic 2.3.1 Non-specific etiology Early myoclonic encephalopathy Early infantile epileptic encephalopathy with suppression burst Other symptomatic generalized epilepsies 2.3.2 Specific syndromes Epileptic seizures complicating other disease states III. Epilepsies and syndromes undetermined whether focal or generalized 3.1 With both generalized and focal seizures Neonatal seizures Severe myoclonic epilepsy of infancy Epilepsy with continuous spike waves during slow wave sleep Acquired epileptic epilepsies Other undetermined epilepsies 3.2 Without unequivocal generalized or focal features IV. Special syndromes 4.1 Situation-related seizures Febrile convulsions Isolated seizures or isolated status-epilepticus Seizures occurring only with acute metabolic or toxic events (RCT), the nature of status epilepticus and the prompt response to rectal diazepam convince us that it is effective to stop seizures at a dose of 0.5 mg/kg 7 (level III, recommendation B). Rectal lorazepam has been less studied but is apparently effective at 0.1 mg/kg 8 (level III). Once the seizure has stopped, it is very unlikely that it will start again (level III); therefore, we do not usually give further acute medications (recommendation D). After the seizure has stopped, the physician must take the necessary steps to exclude meningitis. Almost all children with seizures and meningitis have important clinical features that allow them to be distinguished. 9,10 A child with a febrile seizure and who quickly returns to neurologic well-being does not have meningitis and need not be subjected to a lumbar puncture (LP) (recommendation D). Children less than 1 year of age or with suspicious neurologic or physical findings should have an LP done (recommendation A), although the yield is still only about 15 percent 11 (level II-2). There is good evidence that complete blood count (CBC), electrolytes, and serum glucose provide insufficient yield to be worth measuring (level II-2 11–13 and level III, 14 recommendation D). There is some evidence that children with a first febrile seizure are more likely to have a recurrence within that illness if the serum sodium is lowered 15 (level II-2). This makes a case for checking electrolytes in children with a first febrile seizure, not to help with the acute management but rather to help with prediction of recurrence within that illness (recommendation B). Neuroimaging studies (CT and MRI) and skull radiography have no value in children with febrile seizures, even complex febrile seizures 14 (level III, recommendation E). The EEG is also of no predictive value in this setting and is not recommended (level III, 14 level II-2, 16 recommendation E). Families of patients get very upset by febrile seizures, and most parents indicate that they thought that their child was dying during the event 17,18 (level III). Since the child will recover unscathed, much of the acute management must be devoted to parental reassurance. There is no data to indicate the value of admitting the child to the hospital; however, if admission is contemplated, the rationale would be reassurance of parents or further investigation/treatment of the fever. The febrile seizure is no longer an issue. The value of an admission for parental reassurance has not been studied, but the expense of admission and lack of benefit to the child strongly suggest that admission is usually not of value (recommendation D). Following the febrile seizure, there are two possible sequellae—recurrence of febrile seizures in 30 to 40 percent 19 and epilepsy in 2 to 4 percent. 20 Recurrent febrile seizures can be reasonably predicted by the following risk factors: age of seizure <14 months, low fever at the time of the seizure, a short duration of illness prior to the seizure, and family history of febrile seizures. A child with all four factors has about an 80 percent chance of recurrence, while a child with no risk factors has only about 10 to 15 percent of recurrence. 19,21 Rigorous antipyretic use does not prevent recurrent febrile seizures. This might sound ridiculous, since fever is a necessary ingredient; however, the literature is very consistent 22–25 (level I, recommendation E). The most rigorous studies of daily phenobarbital or valproic acid suggest that these medications can reduce recurrences 22,26,27 (level I); however, there is rarely a convincing reason to prescribe daily medication for febrile seizures (recommendation E). A meta-analysis of randomized trials of phenobarbital or valproate disputes their efficacy, 28 although the trials with the most rigorous methodology and compliance are at odds with this conclusion. Compliance is a major confounder. Daily phenobarbital has a high rate of severe behavioral reactions, and there is some evidence that the child’s learning abilities may be affected. 26,27 Valproic acid has been associated with fatal hepatitis in small children, possibly at a rate of 1:500. 29 The importance of these side effects and the uncertainty of the efficacy of these medications mean that there is rarely a convincing reason to prescribe daily medication (recommendation D). Seizure Disorders 231 Diazepam can be used intermittently in children with febrile seizures. One approach is to use liquid injectable diazepam in a dose of 0.5 mg/kg up to 20 mg given rectally during an actual seizure 30,31 (levels II-2 and II-3). The medication can be drawn up in a small syringe, the needle removed, and the syringe inserted into the rectum, thus obviating the need for a rectal tube. The medication is quickly absorbed, and the seizure stops promptly. Parents using this approach need careful instruction, as an overdose can cause apnea. This approach will prevent prolonged febrile seizures but requires a well-organized family for the child. It may be of some use for those living in very remote areas (recommendation B). The other approach is to use diazepam at the time of a fever to prevent recurrent febrile seizures. Since a febrile seizure is frequently the initial manifestation of the illness, clearly this approach will never be completely successful. Rectal liquid diazepam 0.5 mg/dose given every 12 hours during the illness is as effective as daily phenobarbital 30 (level I). Oral diazepam at a dose of 0.3 mg/kg every 8 hours during the illness is associated with a modest reduction in febrile seizure recurrence 31 (level I). However, it is necessary to treat 14 children to prevent 1 febrile seizure recurrence. 32 Twenty-five percent of children have side effects from 0.3 mg/kg oral diazepam. In Uhari’s study, a lower dose of 0.2mg/kg was shown to be ineffective 23 (level I). We do not recommend this approach to treatment because the rate of seizure reduction is very low and the incidence of side effects very high (recommendation E). It is fortunate that only 2 to 4 percent of children with a febrile seizure later develop epilepsy. 20 There is no evidence that the febrile seizures actually cause the subsequent epilepsy and likewise no evidence that prevention of febrile seizures prevents subsequent epilepsy. 33 Risk factors noted at the time of a first febrile seizure are associated with an increased risk of subsequent epilepsy. These factors include focal seizure, prolonged febrile seizure, ≥ 2 seizures within an illness, developmental abnormalities at the time of the febrile seizure, and family history of epilepsy. Each of these factors increases the risk of subsequent epilepsy to about 4 to 6 percent. Combinations of the factors increase the risk to about 10 to 15 percent. Thus even in the “high-risk” group, 85 percent of children will not develop epilepsy 20,21 (level II- 2). This reassuring information should be kept in mind because as many as 40 percent of children with a first febrile seizure will have a risk factor for subsequent epilepsy 19,20 (level II-2). AFEBRILE SEIZURES This section is divided into two parts. The first deals with types of epilepsy that can present with a single seizure. When a child is seen after a first seizure, there are special issues con- cerning evaluation and treatment. The second part of this section deals with epilepsies that virtually always present with multiple seizures. The issues for evaluation of these are some- what different, but treatment decisions are usually more straightforward. Evaluation of a Child with a Single Seizure Most children presenting with a single seizure have had a generalized tonic-clonic, partial with secondary generalization, or a dramatic complex partial seizure. Simple partial seizures and many complex partial seizures are initially not recognized by parents to be very significant. Once the child has been stabilized, the clinician must decide if a seizure has occurred and if the seizure was provoked by factors such as CNS infection, head injury, electrolyte disturbance, and hypoglycemia. Usually, the history and physical examination will determine provoking factors, and treatment will flow directly from the diagnosis. A conundrum occurs when there are no clear provoking factors: how much acute investigation is needed? Lumbar Puncture and Blood Tests In the absence of fever, there is no clear value for a lumbar puncture 34 (level III). Aside from the detection of meningitis/encephalitis, the LP cannot provide any useful diagnostic information in this setting. If the child is completely well, the chance of CNS infection must be very 232 Evidence-Based Pediatrics remote, and therefore there is no need for an LP (recommendation D). Blood work, includ- ing electrolytes, calcium, glucose, and urea, rarely gives useful results; however, the literature on children studied with these routine tests is not very extensive 35–37 ) (level III). In a well child, there does not seem to be much justification for routine blood work (recommendation D). Neuroimaging Studies Brain tumors in children virtually never present with a first unprovoked seizure. After a first unprovoked seizure, brain imaging studies, especially MRI, are abnormal in about 15 percent 38 (level III). Fortunately, most of these abnormalities do not require direct treatment. Their value is a fuller understanding of the cause of the seizure, but their significance in pre- dicting recurrent seizures is unstudied. Conditions that might require immediate neurosur- gical intervention, such as intracerebral hemorrhage from an arteriovenous malformation or acute hydrocephalus, are expected to manifest significant clinical findings. It is safe to con- clude that a child with a first seizure who has recovered completely rarely benefits from an emergency imaging study (recommendation E). If an imaging study is to be carried out, it can be done electively. In addition, when the EEG (see below) shows evidence of an idiopathic epilepsy, there is no need for an imaging study. If the EEG is normal or shows a focal abnormality, an elective MRI is the best imaging study, although CT will detect most major abnormalities 39 (level II-2). If the child has not recovered from the seizure or there are new neurologic abnormalities on examination, clearly an urgent imaging study is required to exclude such disorders as intracranial hemorrhage, hydrocephalus, or other acute processes. A CT scan is adequate in this acute assessment. Electroencephalography Following a first unprovoked seizure, an EEG is always recommended (recommendation A). A single study in adults suggested that the sooner the EEG is performed, the higher the yield will be, with the greatest yield within 24 hours of the seizure 40 (level III). Nonetheless, an EEG should be regarded as an elective investigation. Its role is to help classify the seizure disorder and assist in the prediction of recurrence. The possible increased yield from very early EEG must be balanced with the fact that early EEG recordings may be contaminated by transient postictal slow-wave abnormalities. Such findings may require another later EEG to determine the significance of the slow waves. In most clinical settings, especially outside of normal working hours, emergency EEG is not available. Until there is more evidence for the optimal timing of the EEG, our preference is to delay it until the postictal changes are likely gone, perhaps in 48 hours (recommendation B). The EEG can give clear evidence of an idiopathic epilepsy, that is, the etiology is genetic and no further work-up is needed. The two most important disorders to consider are benign focal epilepsy of childhood with centro-temporal spikes (benign rolandic epilepsy) and juvenile myoclonic epilepsy. The presence of spike discharge on EEG after a first seizure increases the risk of recurrence from about 20 percent to about 70 percent 41 (level II-2). Treatment after a first seizure After a first unprovoked seizure, about 50 percent of children will never have another seizure 37 (level II-2). The diagnosis of epilepsy is reserved for those with two seizures because the recurrence risk after two seizures is about 80 percent 42,43 (level II-2). Factors that help predict further seizures are neurologic abnormality (or remote symptomatic etiology) and focal seizure and epileptic (spike) discharge on EEG. Remote symptomatic etiology means that the child has a longstanding brain abnormality that has now caused a seizure (for example, a brain malformation or previous severe head injury). With all of these factors, the recurrence risk is about 75 percent; with none, it is about 15 percent. 41,42 Seizure Disorders 233 There is little reason to offer antiepileptic medication after a first seizure in childhood (recommendation E). In population-based studies, the rate of recurrence is not altered by the prescription of medication, presumably because of compliance issues 42,44 (level II-2). In randomized trials, the rate of recurrence is decreased but not enough to be medically significant 45,46 (level I). For example, in the largest trial, the recurrence risk for those treated was still 25 percent, compared with 51 percent for the untreated over a 2-year period. 46 This means that treated patients continue to have a high rate of recurrence and must make the same adjustments to lifestyle as those not treated. Those not treated after a first seizure have the same rate of long-term remission as those treated after repeated seizures 47 (level I). Par- ents need to know that most recurrences happen within a few months of the first seizure and recurrence after 6 months is very uncommon. 42 No studies have addressed the value of restrictions in the child’s daily activities; after a first seizure, we do not usually recommend any change 48 (level III, recommendation D). Approach after Two or More Seizures When a child presents with a possible first seizure, there is often a history of other more minor but convincing events. Partial seizures may be dismissed by the family as unimpor- tant, until there is a secondarily generalized seizure. A history of less severe events means that the child has epilepsy. Alternatively, a true first seizure may be followed by a second. Once the diagnosis of epilepsy has been made, there are several important considerations that con- cern investigation and management. The first and most critical decision must be the definition of the child’s epilepsy syndrome. The approach to a benign focal epilepsy may be much more relaxed than that to a symptomatic partial epilepsy. To come to a syndrome diagnosis, the history must be evaluated by an expert (recommendation B). The success of an expert in assigning a correct diagnosis of a syndrome has not been compared with the skills of other physicians; however, given that the current classification of epilepsy includes >100 syndromes, it would seem likely that an expert would be more accurate. The EEG and imaging studies must be interpreted in the context of the history. The evaluation of a child who has had two or more seizures is essentially the same as after the first seizure. If the clinical history and examination, supplemented by the EEG, yield a diagnosis of idiopathic epilepsy, there is no need for brain imaging studies. This means that children with disorders such as benign Rolandic epilepsy or juvenile myoclonic epilepsy do not derive any additional benefit from a CT scan or MRI. Once there have been two or more seizures, prescription of an antiepileptic drug (AED) may be considered. These medications do not “cure” epilepsy but do suppress seizures. The rate of long-term remission of the epilepsy is the same if treatment is delayed for up to at least 10 seizures 49 (level II-2). Many experts suggest starting medication after two seizures. It is acceptable to wait longer, provided there is no clear “down side” to the child, in terms of excessive supervision or exclusion from normal activities 49 (level II-2, recommendation B). Initial Medication for Epilepsies that may present with a Single Seizure (once further seizures have occurred) There is good evidence that carbamazepine and valproic acid are equally effective on the basis of the British “Epiteg” study, an open-label but randomized, multi-centered trial of newly treated children 50 (level I). Phenytoin, valproate, and carbamazepine were equivalent in another randomized trial; however,phenobarbital was inferior because of a much higher rate of unacceptable side effects 51 (level I). The only large, double-blind, comparative trial of antiepileptic drugs (AEDs) in childhood epilepsy is the Canadian Clobazam Trial 52 (level I). This study randomized children in double-blind fashion to clobazam, phenytoin, and carbamazepine. Each drug was equally efficacious as measured by the time retained on medication, although the data for carbamazepine and clobazam were most secure. 234 Evidence-Based Pediatrics Studies in adults suggest that lamotrigine is roughly equivalent to carbamazepine 53 (level I) and vigabatrin is equivalent to carbamazepine 54 (level I). The bottom line is that many medications are interchangeable at the beginning of treatment. On the basis of relative lack of side effects and ease of use, our personal preference is to use carbamazepine or clobazam first for children with partial epilepsies (partial seizures or partial with secondary generalization) (recommendation B). Although there are no randomized trials, there is a very wide consensus that valproate is best for juvenile myoclonic epilepsy and carbamazepine may exacerbate this disorder (level III, recommendation B). Evaluation of Epilepsies that Always Present with Multiple Seizures A variety of epilepsies always present with multiple seizures. The seizure types in these epilepsies include infantile spasms, generalized absence, akinetic (drop) seizures, and myoclonus. The most common epilepsy types are West’s syndrome, typical childhood absence, and Lennox-Gastaut syndrome. If the child is intellectually normal and has absence seizures from the history confirmed by EEG, then there is no need for further evaluation (level III, recommendation A). Absence epilepsy is dealt with separately below. If the epilepsy with many seizures at presentation is of any other type, a careful search for etiology is needed. Nearly all of these epilepsies have an underlying etiology; they are considered “remote symptomatic,” meaning that there is a pre-existing brain problem. Etiolo- gies include diffuse brain injury from neonatal or postnatal hypoxia, developmental brain abnormalities such as neuronal migration problems, or neurocutaneous syndromes such as tuberous sclerosis. Evaluation must include a very careful history and physical examination. A brain imaging study and consultation with an expert are always indicated because the causes may be subtle, the treatment difficult, and there is a high rate of either long-term intractable epilepsy and/or mental handicap (level III, recommendation B). Treatment depends on the epilepsy type. Perhaps the most complex is infantile spasm. This devastating disorder has its onset in the first year of life. The spasms usually appear in clusters, but the child becomes dull, withdrawn and less interested in life between the seizures. The EEG shows a special pattern called hypsarrhthymia with a chaotic continuous electrical disaster—the spasms are the tip of the iceberg for a very serious condition, and rapid treatment is indicated, even though the long-term mental outcome is nearly always unfavorable. There is evidence from a large open case series 55 (level III), a small randomized placebo-controlled trial 56 (level I), and a comparative trial that vigabatrin is often effective within 1 to 2 days 57 (level I). It is not as powerful as adrenal corticotrophic hormone (ACTH) treatment, where the response rate is >80 percent. 57 Because of the side effects of ACTH, most experts suggest initial treatment with vigabatrin. If it fails to stop the spasms after 48 to 72 hours, then ACTH can be started (recommendation B). The dose of ACTH and length of treatment varies; a low dose of 4 to 5 units/kg/day for a month seems to be as effective as higher doses for most patients. 58 Oral prednisone may also be effective 59 (level III); however, there have not been definitive randomized trials comparing prednisone with ACTH. 58 For other epilepsies always presenting with repeated seizures, valproic acid is usually the first drug, even though there are no comparative drug trials. Open-label case series have con- sistently shown reasonable efficacy (level III, recommendation B). Ethosuximide is very effective for absence seizures but has no action against generalized tonic-clonic seizures (level III). A benzodiazepine such as clobazam or nitrazepam, is often started first. GENERALIZED ABSENCE EPILEPSY About 10 percent of children with epilepsy have absence seizures (“petit mal”). There are several different types of absence epilepsy but the most common is typical childhood absence epilepsy with onset between ages 3 to 10 years. The children have many seizures a Seizure Disorders 235 day, and virtually all will have an actual seizure during EEG, which confirms the diagnosis. The ictal EEG pattern is typically generalized 3 Hz spike and wave. The cause of typical childhood absence epilepsy appears to be genetic, although the specific inheritance pattern remains unknown. Once EEG indicates this diagnosis, there is no value in further work-up. Specific medications may be effective for this disorder. Ethosuximide is equivalent to valproic acid for absence epilepsy, although valproate has additional efficacy against generalized tonic-clonic seizures 60 (level I). Also effective are clobazam 61 (level II-1) and lamotrigine 62 (level I, recommendation A). In our opinion, any of these medications may be used. Routines in Clinical Practice for Antiepileptic Drug Therapy When a medication is started, there is hope that the seizures will be completely suppressed without side effects. In clinical practice, these two issues need to be balanced. For nearly all AEDs, one can usually expect increased seizure control with an increased dose. Determina- tion of serum levels of AEDs has been used to try to optimize treatment. There are no care- fully designed trials to determine the optimal serum level of any AED. In Canada, and likely in all countries, it is possible to have the same level interpreted in one center as subthera- peutic and potentially toxic in another 63 (level III). For patients with controlled seizures, there is evidence that further assessment of serum levels interferes with management. The only randomized trial of this issue indicated that the use of serum levels actually increased side effects without improving seizure control 64 (level I). The “therapeutic range”for all AEDs should be used only as a rough guide for dosing. In general, the dose is correct if there are no seizures and no side effects (recommendation E). Our current practice is to order very few serum levels. If there is an issue of compliance, it seems that direct questioning of the child and family more often gets useful information than checking blood levels 65 (level III). Since there is a lot of individual sensitivity to the behavioral and cognitive side effects of AEDs, asking about these side effects is likely of greater value than measuring serum levels (recommendation B). Clinicians are appropriately concerned about severe catastrophic reactions to AEDs. These include liver failure, aplastic anemia, nephritis, and Stevens-Johnson reaction. These reactions are idiosyncratic and are not related to dose, although they tend to occur early in treatment (first few months). None of these reactions can be predicted in asymptomatic patients from screening blood and urine tests 67 (level II-2). There is an important consensus in Canada that screening tests are of no value and may interfere with treatment 68 (level III). We recommend that patients be warned of these reactions and asked to call the physician immediately if such a reaction is suspected. At that time the child can be investigated, as the clinical situation appears to warrant (recommendation E). Duration of Treatment Epilepsy in children is often outgrown. For only about 40 percent is it a life-long disorder 68,69 (level II-2). Once a child has had 1 to 2 seizure-free years, it is reasonable to consider stopping medication. Overall, such children have a 60 to 70 percent chance of remaining seizure- free. This percentage is about the same if the seizure-free interval has been 1, 2, 4, or 5 years 70 (level II-2). Therefore, in general, consideration of stopping medication is appropriate once a child has been seizure-free for 1 year 71 (level II-2, recommendation A). The group of children with the best chance of remaining seizure-free off medication are those with normal intelligence, normal neurologic examination, generalized epilepsy, and age at onset <12 years. This group has a 80 to 90 percent chance of remaining free of further seizures, once off medication. Those with teenage onset of partial seizures in association with neurologic deficits have only a 10 to 15 percent chance of successfully stopping medication 69,70 These children may be candidates for longer treatment. Recommendations for the treatment of seizure disorders are listed in Table 12–2. 236 Evidence-Based Pediatrics [...]... department, 69 6 had a chief complaint of headache.40 Among a random sample of 288 of these patients, the most common diagnoses were viral illness (39.2 percent), sinusitis ( 16 percent), migraine (15 .6 percent), post-traumatic headache (6. 6 percent), streptococcal pharyngitis (4.9 percent), and tension-type headache (4.5 percent) There were no cases of tumor or bacterial meningitis.40 2 46 Evidence- Based. .. precipitants or self-hypnosis The best abortive medication appears to be ibuprofen.120 Further study is needed to establish the optimal approach to these patients REFERENCES 1 Bille B Migraine in school children Acta Paediatr 1 962 ;51(Suppl 1 36) :1–151 2 Sillanpää M, Antilla P Increasing prevalence of headache in 7-year-old schoolchildren Headache 19 96; 36: 466 –70 258 Evidence- Based Pediatrics 3 deLissovoy... 244 Evidence- Based Pediatrics in case definition, age, and sex of the study populations), 70 percent of the variance among studies was explained.11 Tension-type headache is reported to be uncommon before 7 years of age.12,13 This has been disputed by a Finnish population -based study of 6- year-old children, which found a 14 .6 percent prevalence of headache that disturbed activity within the preceding 6. .. Social environment and headache in 8- to 9-year-old children: a follow-up study Headache 1998;38:222–8 16 Carlsson J, Larsson B, Mark A Psychosocial functioning in schoolchildren with recurrent headaches Headache 19 96; 36: 77–82 17 Wober-Bingol C, Wober C, Wagner-Ennsgraber C, et al IHS criteria for migraine and tensiontype headache in children and adolescents Headache 19 96; 36: 231–8 18 Scheller JM The history,... Dripps RD Long-term follow-up of patients who received 10,098 spinal anesthetics JAMA 19 56; 161 :5 86 91 62 Lynch J, Arthelger S, Krings-Ernst I, et al Whitecare 2-gauge pencil-point needle for spinal anesthesia A controlled trial in 300 young orthopedic patients Anesth Intens Care 1992;20:322–5 63 Jay GW, Tomasi LG Pediatric headaches: a one year retrospective analysis Headache 1981;21:5–9 64 Lee LH, Olness... tension-type headache and 15 percent as having tension-type headache not fulfilling all International Headache Society (IHS) criteria.14 As in migraine, the prevalence of tension-type headache increases with age Tension-type headaches, within the previous month, occurred in 27.3 percent of 8 to 9-year-old Finnish children.15 Clinic -based case studies add more evidence for an increase in tension-type... Neurology 19 86; 36: 838–41 242 Evidence- Based Pediatrics 67 Camfield PR, Camfield CS, Dooley J, et al Routine screening of blood and urine for severe reactions to anticonvulsant drugs in asymptomatic patients is of doubtful value Can Med Assoc J 1989;140:281–5 68 Sillanpaa M Remission of seizures and predictors of intractability in long-term follow-up Epilepsia 1993;34:930 6 69 Camfield CS, Camfield PR, Gordon... were 0.25 mg/kg/d (maximum 2 to 16 mg/d) with ranges of 12 mg/d for 2 to 6- year-olds, 16 mg/d for 7 to 14-year-olds and 32 mg/d for older patients.124 Side effects include sedation and appetite stimulation Beta-adrenergic receptor blockers The mechanism of action of β-blockers in migraine is poorly understood There appears to be no correlation between efficacy and β-receptor selectivity Three controlled... 1981;21:5–9 64 Lee LH, Olness KN Clinical and demographic characteristics of migraine in urban children Headache 1997;37: 269 – 76 Headaches in Childhood 261 65 Lance JW, Anthony M Some clinical aspects of migraine: a prospective study of 500 patients Arch Neurol 1 966 ;15:3 56 61 66 Gallai V, Sarchielli P, Carboni F, et al., on behalf of the Juvenile Headache Collaborative Study Group Applicability of... in juvenile migraine Pediatrics 1979 ;63 :517–9 262 Evidence- Based Pediatrics 88 Dooley J, Gordon K, Camfield P “The rushes.” A migraine variant with hallucinations of time Clin Pediatr 1990;29:5 36 8 89 Shaabat A Confusional migraine in childhood Ped Neurol 19 96; 15:23–5 90 Gascon G, Barlow C Juvenile migraine presenting as acute confusional states Pediatrics 1970;45 :62 8–35 91 Roh JK, Kim JS, Ahn YO Epidemiologic . Practitioner 1993;18:52–3, 56 63 . 72. Beach RC. Management of childhood constipation. Lancet 19 96; 348: 766 –7. 73. Fleischer DR. Encopresis, enemas and gold stars. Pediatrics 1978 ;61 :155 6. 74. Martin RR,. the emergency department. Ann Emerg Med 19 86; 15 :69 –75. 36. Turnbull TL, Vanden Hoek TL, Howes DS, Eisner RF. Utility of laboratory studies in the emergency department patient with a new-onset. headaches into migraine or tension-type. Subsequently, there has been considerable dispute regarding the applicability of the IHS criteria to children. 46 48 2 46 Evidence- Based Pediatrics Table 13–1