Inconsistency between prospectively and retrospectively reported febrile seizures

This study compared the incidence of febrile seizures (FS) reported prospectively up to 5 years of age, with the prevalence of FS by parental recall in the same cohort using the same questionnaire at 12 years of age. Both prospective and retrospective data were available for 807 children (389 males, 418 females). The number of children reported to have experienced FS in the prospective study was 57, and in the retrospective study was 45, yielding a cumulative incidence of 7.1 and 5.6% respectively. In the retrospective study there was an under-reporting of 19 children, over-reporting of eight children, and one child misreported by age at onset. Overall sensitivity of the retrospective approach was 65% and specificity was 99%. Positive predictive value was 82% and negative predictive value was 97%. Retrospective data underestimate the frequency of FS with high specificity but low sensitivity. Recall data suggest that some children with FS were not reported in the prospective data. These biases should be considered when evaluating the value of FS as a predictor of future health effects.

Paroxysmal eyelid movements: A confusing feature of generalized photosensitive epilepsy

BACKGROUND

Persistent, frequent, nonepileptic paroxysmal eyelid movements were observed in 19 children and adults with well-controlled generalized epilepsy.

METHODS

Patients were identified from five epilepsy centers.

RESULTS

Seventeen patients were female and two male. All had generalized photosensitive epilepsy requiring antiepileptic drugs (AEDs). In two children, paroxysmal eyelid movements began 2 to 4 years before their epilepsy was noted; in the remainder, it was noted when epilepsy was first diagnosed. Age at last follow-up was 8 to 38 years (average 21 years) with average follow-up of 9 years. All patients showed photosensitive generalized spike-wave discharges on EEG. Paroxysmal eyelid movements were a source of diagnostic confusion, but direct examination and video during EEG recording distinguished the attacks from absence seizures. In all cases, the epilepsy is completely or nearly completely controlled with AEDs, but the paroxysmal eyelid movements have not resolved with age. In 12 cases, there was a family history of the eyelid disorder without epilepsy. Videos of patients and an affected parent are available on the Neurology Web site.

CONCLUSION

There is an association between paroxysmal eyelid movements and photosensitive generalized epilepsy, creating diagnostic confusion.

Botulinum toxin A as a treatment for excessive drooling in children

Drooling is problematic for some neurologically impaired children. Botulinum toxin A injection to salivary glands has effectively reduced drooling in adults but has only recently been used to treat children. This was a preliminary study to determine the efficacy and safety of botulinum toxin in children. Children identified as having severe daily drooling were enrolled. The preinjection assessment included measurement of the amount and frequency of drool. Each parotid gland was injected with 5 U of botulinum toxin A. Follow-up was for a minimum of 16 weeks. Nine children were enrolled, 4-17 years of age. All children had moderate or severe mental retardation. At week 4, all patients had a reduced drooling frequency and eight of nine patients had a reduction in the weight of saliva. Overall, five of nine parents (55%) deemed the treatment successful. This preliminary study demonstrates that botulinum toxin A is a relatively effective treatment for some children with significant drooling without serious side effects.

Duchenne muscular dystrophy--parental perceptions

Quality of life and availability of services are important for boys with Duchenne muscular dystrophy (DMD) and their families. Families attending our neuromuscular clinic completed a questionnaire on parental perception regarding the importance of services, health issues, and quality of life issues both "now" and "in the future." Eighty-nine percent of the families (31/35) completed questionnaires. Services and health issues related to prolonging ambulation were most important, especially for the parents of younger boys. Mental health issues such as social isolation, anger, and depression were very important, particularly for the families of older boys and were anticipated to be more important in the future. Pediatricians should be aware of both the immediate needs of families to meet the physical and emotional challenges of DMD and the increasing requirement to address the social needs of these patients and their families as the boys become older.

Treatment of febrile seizures: the influence of treatment efficacy and side-effect profile on value to parents

OBJECTIVES

We examined parents' perception of the value of treatments designed to reduce the risk of febrile seizure recurrence.

STUDY DESIGN

The families of 42 children with febrile seizures were recruited after pediatric or neuropediatric consultation. A mail questionnaire addressed the family's willingness to pay for a hypothetical treatment for febrile seizures with risk reductions for future febrile seizures of 25%, 50%, 75%, and 100%. The hypothetical clinical scenario was then modified to include the side- effect profiles of either daily phenobarbital or valproic acid, or intermittent diazepam prophylaxis. Covariates included the nature of the child's febrile seizure(s), parents' familiarity with febrile seizures, experiences at the time of febrile seizures or with medication side effects, education and income, and mastery and trait anxiety.

RESULTS

Thirty-eight parents, representing 22 of 42 families, completed questionnaires. There was a dramatic inflection in parents' willingness to pay for 100% risk reduction as opposed to 75% or lower risk reductions. Introduction of side effects dramatically reduced the value attached to each level of treatment benefit. Nevertheless, a few parents (3/38) would pay "as much as it takes" to be rid of their child's recurrence risk.

CONCLUSIONS

Given the range of value assigned to prophylactic medication for febrile seizures, management strategies for children with febrile seizures must be responsive to the needs and values of individual families.

Irritability in Krabbe's disease: dramatic response to low-dose morphine

Krabbe's disease is characterized by normal neonatal development with subsequent regression and profound, medically intractable irritability. Two female infants presented at 5 months of age with increasing irritability, abnormal motor control, and developmental regression. Investigations confirmed the diagnosis of Krabbe's disease. Maximal treatment of gastroesophageal reflux and nitrazepam 0.1 mg/kg by mouth three times daily were unsuccessful in controlling irritability. Morphine was initiated and titrated to 0.06 mg/kg by mouth every 6 hours in Patient 1 and 0.1 mg/kg by mouth every 8 hours in Patient 2, resulting in remarkably successful control of irritability. The diagnosis of Krabbe's disease is devastating for families and is compounded by the marked irritability. Management is difficult, but in these two infants, irritability was successfully controlled with low-dose morphine.

Population study of benign rolandic epilepsy: is treatment needed?

Forty-three of 79 children (54%) with benign rolandic epilepsy from a regional population were treated with antiepileptic drugs (AED); 36 (46%) were not. Physician advice was a major determinant of treatment choice. AED significantly reduced generalized seizures (p = 0.001) but did not reduce partial seizures. After 4 to 14 years and >900 seizures, all patients were in remission without medication or injury. Physicians may confidently offer a no-AED treatment strategy.

Children with febrile seizures do not consume excess health care resources

BACKGROUND

Febrile seizures are benign but so terrifying for parents that they may subsequently view their affected children as "vulnerable". Children viewed as vulnerable may be brought to medical attention more frequently. We examined subsequent hospitalizations and physician visits during a 6- to 7 1/2-year period for a group of children who had participated in a case-control study of initial febrile seizures.

METHODS

Individual data from a regional cohort of 75 children with a first febrile seizure and 150 febrile and 150 afebrile controls were linked to 2 comprehensive provincial health services databases-a hospital admissions/ separations database and a physician services database.

RESULTS

Linkage was achieved for 98% of the study cohort, with heath care utilization data for 6 to 7 1/2 years available for 96%. Children with febrile seizures had nearly identical rates of subsequent hospitalization compared with age-matched controls (chi2 test, P = .88). An excess of day-surgery visits for primarily otolaryngologic procedures was seen for the febrile seizure patients 0 to 12 months after their initial febrile seizure (chi2 test, P < .001). During the next 6 to 7 1/2 years, the febrile seizure patients had nearly identical rates of physician visits (chi2 test, P = .15); however, they had more visits to otolaryngologists in the first 3 to 9 months after the febrile seizure (chi2 test, P < .001), but fewer visits to pediatricians during the next 1 to 4 years (chi2 test, P < .001).

CONCLUSIONS

Children with febrile seizures have nearly identical rates of hospital and physician services utilization compared with controls. This supports the hypothesis that febrile seizures are benign, and that parents recover from their initial anxiety and do not consider their children vulnerable to additional illness in the years that follow.

Treatment of children with "ordinary" epilepsy

Many children with epilepsy have a relatively benign clinical course with eventual remission of their seizures and no further need for medication. It is not easy to be sure who these children are at the time of diagnosis, but they do not have catastrophic epilepsy. Epilepsy is best defined as two unprovoked seizures. Not all of these children require treatment and treatment is motivated by fear of brain damage, injury, death, kindling of additional seizures, and social consequences. None of these fears provides an absolute indication for treatment. The decision to start medication should be considered on an individual basis. The choice of a first AED is arbitrary with most AEDs having equal efficacy. Follow-up schedules have not been well studied. However, there is fairly convincing evidence that routine blood and urine screening for toxicity is of no benefit, if the child is asymptomatic. Serum drug levels are of little clear benefit. Once the child has been seizure-free for 6 months to 12 months, it is reasonable to consider stopping medication. Only rarely does seizure control fail to return if there are recurrences without medication.

Double-blind methylphenidate trials: practical, useful, and highly endorsed by families

OBJECTIVE

To evaluate a 3-week, randomized, double-blind, methylphenidate placebo-controlled trial (MPT) in routine practice for children with attention-deficit disorder.

PATIENTS AND METHODS

School-aged children with attention-deficit/hyperactivity disorder (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) who enrolled an "N of 1" trial at a pediatric tertiary care center were eligible. Families (n = 50) with a child eligible for the MPT were given 3 bottles of identical capsules. The capsules contained, in random order: placebo of the prescribed dose of methylphenidate (Ritalin) hydrochloride (0.3 mg/kg or 0.6 mg/kg). Families gave the child 1 capsule at 8 AM and 1 capsule at noon. The family, teacher, and physician were blinded for the order of medication. Conners questionnaires (Conners Parent Questionnaire and Conners Teacher Questionnaire) and written comments were completed by parents and teachers at baseline and at the end of each week. Once MPT results were known and following discussion with the physician, families decided whether to continue methylphenidate therapy. Families were interviewed by telephone 14 to 21 months after the MPT.

RESULTS

Forty-three (86%) of the 50 eligible children (mean age, 129 months) were contacted. No family found the MPT difficult, but 6 trials were incomplete, usually because of side effects. All families used the MPT to decide if methylphenidate was the correct treatment choice for their child and 68% (34 of 50 families) used the results exclusively. The remaining 16 families believed the MPT was helpful. Overall, 31 (72%) of the 43 children had a good response to methylphenidate treatment--20 (47%) continued to use it for longer than 12 months and 8 (26%) for 2 to 12 months; 3 responders chose not to use it after the MPT. Nine of the 43 families chose not to use methylphenidate treatment; however, all indicated that participating in the MPT helped them to make that decision. In follow-up interviews, the same proportion of methylphenidate users and nonusers reported improvement in many areas of function including significantly less time spent doing homework. Users reported reduced aggression (P<.001) and fewer discipline problems (P<.01) compared with nonusers.

CONCLUSIONS

An "N of 1" MPT was easily performed and permitted families to decide whether to use methylphenidate for long-term treatment of attention-deficit disorder or attention-deficit/hyperactivity disorder. Regardless of methylphenidate use or lack of use, the condition of all of these children was improved at follow-up.

Topiramate in intractable childhood onset epilepsy--a cautionary note

OBJECTIVES

To study the effectiveness and safety of topiramate in clinical practice, for a group of patients with childhood onset epilepsy.

METHODS

All patients treated with topiramate at the three study centers between November 1995 and December 31, 1997 were analyzed retrospectively, using a standardized study protocol. Data were gathered on demographic features, seizures response and medication related adverse events.

RESULTS

Eighty-seven patients were treated with topiramate. Over 90% seizure reduction was achieved in 8 (9%) patients, 50%-90% in 21 (24%), < 50% in 54 (62%) patients. Four patients (5%) had a deterioration in seizure control. Adverse events required topiramate discontinuation in 36 (41%). Of these 27 (31%) complained of unacceptable cognitive dulling. The rate of dose escalation and final dose in mg/kg were similar in those who remained on topiramate and those who were intolerant because of cognitive side effects.

CONCLUSIONS

Although topiramate resulted in > 50% seizure reduction in 29 (33%) of this group of patients with difficult epilepsy, its usefulness was limited by a high incidence of adverse effects. Adverse events prevented ongoing therapy for 36 (41%) and cognitive dulling resulted in topiramate discontinuation by 27 (31%) of the group.

The cognitive and behavioural effects of clobazam and standard monotherapy are comparable. Canadian Study Group for Childhood Epilepsy

PURPOSE

To compare the cognitive and behavioural effects of clobazam versus standard monotherapy in the treatment of childhood epilepsy.

METHODS

A randomized, double-blind, prospective design was carried out at three Canadian pediatric epilepsy centres. This study was part of a larger multi-centre study on the efficacy of clobazam. Children with newly diagnosed epilepsy were assigned randomly to receive clobazam or carbamazepine. Children who had failed previous treatment with carbamazepine were assigned randomly to clobazam or phenytoin. Children who had failed on any other antiepileptic drug were assigned randomly to receive clobazam or carbamazepine. In a subset of patients neuropsychological assessments were carried out at 6 weeks and 12 months after initiation of medication. Intelligence, memory, attention, psychomotor speed, and impulsivity were assessed.

RESULTS

There were no differences between the clobazam and standard monotherapy groups on any of the neuropsychological measures obtained at 6 weeks or 12 months. There was no evidence for a deterioration in performance for those children who remained on clobazam for the entire 12-month study period.

CONCLUSION

The cognitive and behavioural effects of clobazam appear to be similar to those of standard monotherapy.

A multicenter study of the efficacy of the ketogenic diet

OBJECTIVE

To determine the efficacy of the ketogenic diet in multiple centers.

DESIGN

A prospective study of the change in frequency of seizures in 51 children with intractable seizures who were treated with the ketogenic diet.

SETTING

Patients were enrolled from the clinical practices of 7 sites. The diet was initiated in-hospital and the patients were followed up for at least 6 months.

PATIENTS

Fifty-one children, aged 1 to 8 years, with more than 10 seizures per week, whose electroencephalogram showed generalized epileptiform abnormalities or multifocal spikes, and who had failed results when taking at least 2 appropriate anti-epileptic drugs.

INTERVENTION

The children were hospitalized, fasted, and a 4:1 ketogenic diet was initiated and maintained.

MAIN OUTCOME MEASURES

Frequency of seizures was documented from parental calendars and efficacy was compared with prediet baseline after 3, 6, and 12 months. The children were categorized as free of seizures, greater than 90% reduction, 50% to 90% reduction, or lower than 50% reduction in frequency of seizures.

RESULTS

Eighty-eight percent of all children initiating the diet remained on it at 3 months, 69% remained on it at 6 months, and 47% remained on it at 1 year. Three months after initiating the diet, frequency of seizures was decreased to greater than 50% in 54%. At 6 months, 28 (55%) of the 51 initiating the diet had at least a 50% decrease from baseline, and at 1 year, 40% of those starting the diet had a greater than 50% decrease in seizures. Five patients (10%) were free of seizures at 1 year. Age, sex, principal seizure type, and electroencephalogram were not statistically related to outcome.

CONCLUSION

The ketogenic diet is effective in substantially decreasing difficult-to-control seizures and can successfully be administered in a wide variety of settings.

Outcome of neonatal stroke in full-term infants without significant birth asphyxia

Seven children with neonatal stroke were identified and six were followed for 13 months to 5 years (mean 28 months). Gestational age ranged between 39 and 42 weeks and none had hypoxic ischaemic encephalopathy. Focal clonic seizures were the presenting feature in six, and one presented with apnoea. The age of the first seizure ranged between 8 and 48 h (mean 26). The total number of seizures ranged between 3 and 10 (mean 5), and all seizures resolved by day 3 in all cases. CT scan showed an ischaemic infarct in six cases, and one child had a haemorrhagic infarct in the right anterior cerebral artery distribution. Phenobarbital was maintained for 3 weeks to 6 months (mean 11 weeks). None had recurrent seizures beyond the 3rd day of life and all were developing normally with no significant focal neurological deficits on follow up assessment.

CONCLUSIONS

Full-term infants with neonatal stroke unrelated to significant birth asphyxia have a favourable neurological outcome. Seizures appear to be restricted to the first 3 days of life. We recommend short-term treatment with anticonvulsants.

Children with familial cryptogenic epilepsy have a favorable seizure prognosis

We examined the prognosis for children with epilepsy not conforming to a genetic syndrome, who also had close relatives with epilepsy. Probands, with no identified cause for epilepsy except a first-degree relative with epilepsy, were identified from a population-based cohort of 504 children in Nova Scotia, with onset of seizures between 1977 and 1985. The primary outcome measure was seizure remission after an average of 15 years follow-up for probands (n = 27) and 26 years for their affected relatives (n = 32). Of probands, 92% were seizure free for 3 or more years at the end of follow-up, compared with 76% of relatives. When seizures began before age 12 years, 96% of probands and 94% of affected relatives were seizure free at the end of follow-up. There was little concordance for the details of the clinical course between probands and affected family members. This high level of remission was considerably better than for similar patients from the original Nova Scotian cohort (P < .02). We conclude that children with epilepsy not conforming to a well-defined genetic syndrome, but with an affected first-degree relative, have a remarkably good prognosis.

Peer relationship problems in children with Tourette's disorder or diabetes mellitus

Peer relationships, social skills, self-esteem, parental psychopathology, and family functioning of children with Tourette's disorder and a chronic disease control group of children with diabetes mellitus were compared. Children with Tourette's disorder had poorer peer relationships than their classmates and were more likely to have extreme scores reflecting increased risk for peer relationship problems than children with diabetes mellitus, but did not report self-esteem problems or social skills deficits. Measures of peer relationships were not related to severity or duration of tics. Children with Tourette's disorder and Attention Deficit Hyperactivity Disorder were at increased risk for poor peer relationships. The psychosocial problems of children with Tourette's disorder do not appear to be the generic result of having a chronic disease.

Nova Scotia Niemann-Pick disease (type D): clinical study of 20 cases

Patients with Niemann-Pick type D have been traced to a single Acadian ancestor in Nova Scotia. The objective of this study was to describe the clinical course. A cohort of children with Niemann-Pick type D was identified by chart review. Some children were seen and a telephone interview with the remaining parents was conducted. Twenty children with Niemann-Pick type D were identified. The female to male ratio was 2:1. Five children had severe neonatal jaundice. Early milestones were normal in the majority. Neurologic symptoms generally developed between 5 and 10 years of age with a mean age of 7.2 years at diagnosis. Seizures developed in all between 4.5 and 16 years of age (mean, 10.5 yr), and were followed by significant physical and mental deterioration. The age at death ranged between 11 and 22.5 years (mean, 14.8 yr). In 61%, bronchopneumonia was the cause of death. There is significant variability in the presentation and clinical course of Niemann-Pick type D.

Localization of the giant axonal neuropathy gene to chromosome 16q24

Giant axonal neuropathy (GAN) is a degenerative disorder of the peripheral nerves that is inherited as an autosomal recessive trait, presenting in early childhood and progressing to death, usually by late adolescence. Diagnosis is made by peripheral nerve biopsy, in which a striking pathological finding is seen--fibers distorted by giant axonal swellings filled with densely packed bundles of neurofilaments (the primary intermediate filament in neurons), with segregation of other axoplasmic organelles. In addition to disorganized neurofilaments in nerve, disorganization of other members of the intermediate filament family of proteins is seen in other tissues; this implies that the underlying defect is one of generalized intermediate filament organization, with neurofilaments predominantly affected. We have pursued a genomewide search for regions of homozygosity of descent in 5 consanguineous families. A 5.3-cM region of homozygosity, shared in all 5 families, was found on chromosome 16q24, and linkage was established to this locus with a LOD score of 4.18 at theta = 0.00 at the most tightly linked marker, D16S3098. Determination of this locus is the first step toward characterizing the gene responsible for a fundamental property of intermediate filament organization and may shed light on other disorders (such as amyotrophic lateral sclerosis) in which neurofilament pathology is prominent.

If a first antiepileptic drug fails to control a child's epilepsy, what are the chances of success with the next drug?

OBJECTIVE

This study was carried out to determine how often a child's epilepsy is controlled and remits if a first antiepileptic drug (AED) fails to control seizures.

STUDY DESIGN

We used the Nova Scotia population-based epilepsy study, which identified children between 1977 and 1985 who had two or more unprovoked seizures without progressive cause and followed them up for at least 4 years. Seizure types were partial, primary, and secondarily generalized (excluding absence seizures). The study documented success or failure of the initial AED in the first year of treatment, as well as long-term seizure control and remission.

RESULTS

The number of eligible children was 417, with an average follow-up period of 8 years. The initial prescribed AEDs were phenobarbital (48%), carbamazepine (38%), and phenytoin (11%). Overall, 345 (83%) children received only one AED in the first year of treatment; 61% became free of seizures and no longer required AED treatment at the end of follow-up (remission). Only 4% of those treated with a single AED during the first year later experienced intractable epilepsy. In contrast, 72 of 417 (17%) had inadequate seizure control with their first AED and received a second AED, with only 42% having complete remission of their epilepsy. The 72 children in whom seizures were not controlled with the first AED were more likely to have neurologic deficits (p = 0.01) and complex partial seizures (p = 0.01), and 29% had intractable epilepsy (p < 0.0001).

CONCLUSIONS

If the first AED is not efficacious, the outcome is less favorable, although many children will have remission of their epilepsy. Invasive or complex treatments for epilepsy with partial and generalized tonic-clonic seizures should not be used until at least two AEDs have failed to control seizures.

Long-term psychosocial outcome in typical absence epilepsy. Sometimes a wolf in sheeps' clothing

OBJECTIVES

To determine whether young adults in whom typical absence epilepsy has been diagnosed in childhood have greater psychosocial difficulties than those with a non-neurologic chronic disease and to decide which seizure-related factors predict poor psychosocial outcome.

DESIGN

Population-based, inception cohort study.

SETTING

The only tertiary care pediatric hospital in the province of Nova Scotia.

PATIENTS

All children in whom typical absence epilepsy or juvenile rheumatoid arthritis (JRA) was diagnosed between January 1, 1997, and December 31, 1985, who were aged 18 years or older at follow-up in March 1994 to April 1995. Patients with typical absence epilepsy were identified from centralized electroencephalographic records for Nova Scotia, and those with JRA were identified from discharge diagnoses from the only children's hospital in Nova Scotia.

MAIN OUTCOME MEASURE

Patients participated in a structured interview that assessed psychosocial function.

RESULTS

Fifty-six (86%) of the 65 patients with absence epilepsy and 61 (80%) of the 76 patients with JRA participated in the interview. The mean age of the patients at the interview was 23 years. Terminal remission occurred in 32 (57%) of the patients with typical absence epilepsy but in only 17 (28%) of the patients with JRA. Factor analysis identified 5 categories of outcome: academic-personal, behavioral, employment-financial, family relations, and social-personal relations. Patients with typical absence epilepsy had greater difficulties in the academic-personal and in the behavioral categories (P < .001) than those with JRA. Those with ongoing seizures had the least favorable outcome. Most seizure-related factors showed minimal correlation with psychosocial functioning.

CONCLUSION

Young adults with a history of typical absence epilepsy, particularly those without remission of their seizures, often have poor psychosocial outcomes, considerably worse than those with JRA.

Vomiting after mild head injury is related to migraine

OBJECTIVE

To determine whether vomiting after mild head injury in children is related to migraine and to identify predictors of vomiting after head injury.

METHODS

A series of consecutive children admitted to the observation unit of an emergency department after mild head injury was identified by chart review. A telephone interview with the parents or child or both was then conducted by using a structured questionnaire.

RESULTS

Of 47 eligible children with acute head injury, 44 (94%) were contacted. The mean age at head injury was 7.4 years. Twenty-nine children (66%) vomited after the head injury. The likelihood of vomiting was increased if the child had a history of recurrent headache (p = 0.05). If the headaches were migrainous, the likelihood of vomiting increased further (p <0.002). All 15 children with a history of motion sickness vomited after the head injury. Family history of migraine, particularly maternal (n = 21), also predicted recurrent vomiting (p <0.001). If more than one of these predictive variables was present, the likelihood of vomiting was 100%.

CONCLUSIONS

History of motion sickness, migraine headaches, and family history of migraine are highly predictive of vomiting after a mild head injury.

Long-term prognosis of typical childhood absence epilepsy: remission or progression to juvenile myoclonic epilepsy

OBJECTIVE

To determine the proportion and characteristics of children presenting with childhood absence epilepsy (CAE) who were not taking anti-epileptic drugs (AEDs) and were seizure-free over the last year of long-term follow-up.

METHODS

For case finding, centralized EEG records for the province of Nova Scotia allowed identification of all children with typical CAE diagnosed between 1977 and 1985. Follow-up was done in 1994 to 1995.

RESULTS

Of 81 children with CAE, 72 (89%) were contacted for follow-up. Mean age at seizure onset was 5.7 years (range, 1 to 14 years) and at follow-up was 20.4 years (range, 12 to 31 years). Forty-seven (65%) were in remission. Twelve others (17%) were not taking AEDs but continued to have seizures. Thirteen (18%) were taking AEDs; five were seizure-free over the last year (in four of these a trial without AEDs had previously failed). Fifteen percent of the total cohort had progressed to juvenile myoclonic epilepsy (JME). Multiple clinical and EEG factors were examined as predictors of outcome. Factors predicting no remission (p < 0.05) included cognitive difficulties at diagnosis, absence status prior to or during AED treatment, development of generalized tonic clonic or myoclonic seizures after onset of AEDs, abnormal background on initial EEG, and family history of generalized seizures in first-degree relatives.

CONCLUSIONS

Only 65% of children presenting with CAE had remission of their epilepsy. Forty-four percent of those without remission had developed JME. At the time of diagnosis, remission is difficult to predict accurately in most patients. However, development of generalized tonic-clonic seizures or myoclonic seizures during AED treatment is ominous, predicting both lack of remission of CAE and progression to JME.

Accidental injury is a serious risk in children with typical absence epilepsy

OBJECTIVES

To determine if young adults with a history of typical absence epilepsy (AE) in childhood have a greater risk of accidental injury than controls with juvenile rheumatoid arthritis (JRA). To assess the nature and severity of these injuries.

METHODS

All patients with AE or JRA diagnosed between 1977 and 1985, who were 18 years or older at the onset of the study, were identified from review of pediatric electroencephalographic records for the province of Nova Scotia (AE) or review of the medical records database at the only tertiary care pediatric center for the province (JRA). Fifty-nine (86%) of 69 patients with AE and 61 (80%) of 76 patients with JRA participated in an interview in 1994 or 1995, assessing nature, severity, and treatment of prior accidental injuries. Patients with AE were further questioned about injuries sustained during an absence seizure.

RESULTS

Sixteen (27%) of 59 patients with AE reported accidental injury during an absence seizure, with risk of injury being 9% per person-year of AE. Most injuries (81%) occurred during anti-epileptic drug therapy. Although the majority of injuries did not require treatment, 2 (13%) of 16 patients required minor treatment and 2 (13%) of 16 were admitted to hospital. The risk of accidental injury resulting from an absence seizure in person-years at risk was highest in juvenile myoclonic epilepsy (45%), moderate in juvenile AE (14%), and lowest in childhood AE (3%). Patients with AE had a greater number of overall accidental injuries than those with JRA (P<.04), but these differences were particularly marked for bicycle (P<.003) and car accidents (P<.05) and for mild head injuries (P=.05).

CONCLUSIONS

Accidental injury is common in AE and usually occurs after anti-epileptic drug treatment is started. Injury prevention counseling is indicated both at diagnosis and follow-up. Bicycle accidents pose a special risk and helmet use should be mandatory.

Will a critical level of hyperventilation-induced hypocapnia always induce an absence seizure?

We wished to determine if the degree of hypocapnia correlates with increased frequency of absence seizures and if there is a critical pCO2 at which absence seizures are reliably provoked. Twelve untreated children with newly diagnosed absence epilepsy were continuously monitored by EEG and end-expiratory CO2 recording during quiet respiration and hyperventilation (to absence seizure or exhaustion) while breathing four gas mixtures: (a) room air, (b) 100% O2, (c) 4% CO2 in room air, or (d) 4% CO2 + 96% O2). In quiet respiration, a reduction in number of spike and wave bursts and total seconds of spike and wave was noted in children breathing supplemental CO2 (gases c and d vs. gases a and b), p < 0.05. Supplemental O2 had no effect. Eight subjects had absence seizures elicited with each trial of hyperventilation. All subjects had their own critical pCO2, ranging from 19 to 28 mmHg. Three children had no seizures, two despite hypocapnia to pCO2 of 19 and 21 and 1 who achieved a pCO2 of only 25. In 1, absence seizures were provoked in only six of nine hyperventilation trials to pCO2 of 17-23. In 67% of subjects, absence seizures were reliably provoked by hypocapnia. Critical pCO2 varied among children with absence. Determination of whether variation in sensitivity to hypocapnia may be helpful in determining response to antiepileptic drugs (AEDs) or remission of seizures will require further study.

Antiepileptic drug therapy: when is epilepsy truly intractable?

We define intractable in the first 5 years of epilepsy treatment as an average of at least one seizure every 2 months. For the longer term, we define intractable as at least one seizure per year. Population studies from Chicago, IL, U.S.A., Finland, and Nova Scotia, Canada indicate that with long follow-up, many children with intractable epilepsy eventually have remission of their seizure disorder. Epilepsy is no longer intractable when the seizures stop completely. How often does a new antiepileptic drug (AED) render a child seizure-free when one or more AEDs have failed? Literature on adults with epilepsy suggests that few with chronic epilepsy who have not achieved seizure control with several AEDs will achieve complete seizure control with additional AEDs. The Nova Scotia study suggests that if a child's seizure fails to be controlled with a first AED, there is an increased risk of intractable epilepsy. Nonetheless, the chance of eventual, complete remission of epilepsy (seizure-free without AED treatment) is approximately 40%. We conclude that intractability should not be considered until there has been failure of at least three first-line AEDs. Intractable epilepsy is rare. Careful definition of the characteristics of children with intractable epilepsy who do respond completely to new AEDs will likely provide the only rational approach to treatment of children with three drug failures. Collaboration by multiple epilepsy centers will be required to gain this information.

Incidence of epilepsy in childhood and adolescence: a population-based study in Nova Scotia from 1977 to 1985

Data from a regional EEG laboratory allowed us to identify almost all children in Nova Scotia (population 85,000) with one or more unprovoked, afebrile seizures from 1977 through 1985. We then reviewed hospital and pediatric neurology physician charts to limit cases to those with two or more definite afebrile seizures between the ages of 1 month and 16 years. In all, 693 children developed epilepsy: typical childhood absence seizures (AS) (97), either generalized tonic-clonic (GTCs) or partial seizures either secondarily generalized or not (511), and other generalized seizure types, including infantile spasms (IS) as well as myoclonic, akinetic, tonic, and atypical AS (85). The incidence of epilepsy was 118 in 100,000 for children aged less than 1 year, 48 in 100,000 for those aged 1-5 years, 43 in 100,000 for those aged 6-10 years, and 21 in 100,000 for those aged 11-15 years. The incidence for each year of age between 1 and 10 years was remarkably constant (mean 46 in 100,000 +/- 7 SD). Comparison of the incidence rates showed significant differences for those aged less than one year as compared with all others, and for those aged greater than 10 years as compared with those aged 1-10 years. We conclude that the incidence of epilepsy is highest in the first year of life, plateaus in early childhood, and decreases markedly after age 10 years. The overall incidence of epilepsy in childhood is lower than that reported in previous studies.

Benign rolandic epilepsy: atypical features are very common

The objective of this study was to determine the frequency of atypical clinical and electrographic features in children with benign rolandic epilepsy. A retrospective case series design was employed in the setting of a tertiary care pediatric hospital. Forty-two children with benign rolandic epilepsy were seen through our neurology department between January 1, 1991, and December 31, 1993. Their charts were reviewed for atypical clinical features, imaging studies and results, total number of seizures at initial presentation and last follow-up, and use of anticonvulsants. Atypical clinical features included status epilepticus, developmental delay, daytime-only seizures, screaming as a seizure component, and postictal Todd's paresis. All children had at least one electroencephalogram, and these records were reviewed for atypical electrographic features such as unusual location, atypical spike morphology, and abnormal background. Atypical clinical features were seen in 50% of patients and atypical electrographic features in 31%. Computed tomographic scans were performed in 15 patients and were consistently normal. Treatment with anticonvulsant medication was initiated in 40%. Although patients with atypical features did not have an increased seizure frequency, they were more likely to undergo imaging studies (P < .01) and to be commenced on anticonvulsant medication (P < .02). Our experience suggests that atypical clinical and electrographic features are the rule rather than the exception in benign rolandic epilepsy. Further work must be done to develop a reliable definition of this common entity.

Lamotrigine analysis in serum by high-performance liquid chromatography

Lamotrigine is an anticonvulsant drug soon to be introduced to the North American market. It is chemically unrelated to any currently available antiepileptic drug. The objective of this study was to develop a quantitative high-performance liquid chromatography assay for lamotrigine in serum. Lamotrigine was extracted from serum at alkaline pH into ethyl acetate after addition of the internal standard (BW725C78). After mixing, the organic layer was evaporated to dryness before dissolving the residue in methanol for isocratic separation on a RP-8 column (5 microns) with a mobile phase of water/0.5 M phosphate buffer at pH 6.5/acetonitrile (790/10/200) with eluant monitoring at 306 nm. Calibration was performed with five serum standards (2-32 microM and recovery averaged 88% at 25 microM. Between-run precision was 4.1 and 2.5% C.V. at 13.6 and 31.6 microM, respectively. At room temperature, lamotrigine was stable for a minimum of 7 days. Interference studies were performed on serum specimens containing commonly monitored drugs. The only potentially interfering drug was carbamazepine, which elutes 2.5 times longer than lamotrigine. We conclude that this is a reliable method for quantitation of lamotrigine in serum.

The use of antiepileptic drug levels in children: a survey of Canadian pediatric neurologists

There are 60 pediatric neurologists in Canada. Replies were received from 56 in response to a survey regarding the use and perceived value of antiepileptic drug (AED) levels. AED levels are frequently ordered and influence clinical care. There were, however, discrepancies among pediatric neurologists regarding the upper and lower limits of the "therapeutic ranges" and the clinical application of levels. We suggest that both the value and use of AED levels needs further study.

Reversal of brain atrophy with biotin treatment in biotinidase deficiency

Two children with biotinidase deficiency presented with seizures at 2 months of age. The first child had a fluctuating course with continual developmental progress and cessation of seizures despite symptoms of chronic neurologic dysfunction until he was diagnosed at 17 months. The second child had a progressive course with uncontrolled seizures leading to an unresponsive state until she was diagnosed at 6 1/2 months. Neither child had dermatologic symptoms until shortly before the time of diagnosis. Both children improved markedly with biotin treatment. Serial CT-scan and MRI studies of the brain showed a distinct pattern of changes. Shortly after initial presentation, diffuse low attenuation of the white matter was seen followed by progressive marked cerebral atrophy, which was reversed following biotin treatment. Because this is a reversible condition, clinicians should screen for biotinidase deficiency in all children with symptoms of chronic neurologic dysfunction, especially when radiologic findings of low attenuation of the white matter are followed by cerebral atrophy.

Multiple circumferential skin folds and other anomalies: a problem in syndrome delineation

Three patients with multiple ring creases of the extremities are reported. Evidence to date points to aetiological heterogeneity. The skin folds may occur as an isolated abnormality or together with other patterns of malformation, making-up various syndromes that need to be further delineated. One type is associated with autosomal dominant inheritance. This striking abnormality usually resolves with time.

Aspartame exacerbates EEG spike-wave discharge in children with generalized absence epilepsy: a double-blind controlled study

There are anecdotal reports of increased seizures in humans after ingestion of aspartame. We studied 10 children with newly diagnosed but untreated generalized absence seizures. Ambulatory cassette recording of EEG allowed quantification of numbers and length of spike-wave discharges in a double-blind study on two consecutive days. On one day the children received 40 mg/kg aspartame and on the other day, a sucrose-sweetened drink. Baseline EEG was the same before aspartame and sucrose. Following aspartame compared with sucrose, the number of spike-wave discharges per hour and mean length of spike-wave discharges increased but not to a statistically significant degree. However, the total duration of spike-wave discharge per hour was significantly increased after aspartame (p = 0.028), with a 40% +/- 17% (SEM) increase in the number of seconds per hour of EEG recording that the children spent in spike-wave discharge. Aspartame appears to exacerbate the amount of EEG spike wave in children with absence seizures. Further studies are needed to establish if this effect occurs at lower doses and in other seizure types.

Benign familial neonatal convulsions are epileptic

An infant with benign familial neonatal convulsions fortuitously had a clinical seizure during a routine EEG. The seizures had started on day 2 of life, and the EEG recording was performed on day 6. The EEG, although not complete, did show a simultaneous electrographic seizure. Our finding establishes that benign familial neonatal convulsions are indeed epileptic.

Peer problems in Tourette's disorder

To explore the social adjustment and peer relationships of children with Tourette's disorder, 29 patients with mild to moderate Tourette's disorder were studied. Children underwent neuropsychological testing. The patients completed self-esteem scales and their parents and teachers completed behavior rating scales. Peer relationships were examined with the Pupil Evaluation Inventory, which is a sociometric questionnaire completed by the child's classmates and provides measures of aggression, withdrawal, and likability. As a group, Tourette's disorder patients were significantly more withdrawn, more aggressive, and less popular than their classmates. Thirty-five percent of the children with Tourette's disorder received the lowest rating in the class on one or more of the Pupil Evaluation Inventory factors. These social problems were not predicted by the frequency or duration of tics. A clinical diagnosis of attention-deficit hyperactivity disorder and teachers' ratings on the summary scale of the Child Behavior Checklist and the Pupil Evaluation Inventory did predict poor adjustment. It is concluded that social adjustment is a major difficulty for many children with Tourette's disorder, irrespective of tic severity.

The value of CT scans for children with headaches

We studied the value of CT scans for all children referred because of headache to one secondary and one tertiary pediatric centre during a 1 year period. Of 117 children who were seen by the Pediatric Neurology Service, at the I.W.K. Children's Hospital, 4 had CT scans and only 1 of these was abnormal. The consultant Pediatrician saw 40 children because of headache. CT scans were done on 3 of these patients and all were normal. None of the children who had a clinical assessment alone had unrecognized neurological disease during 20 months of follow-up. Therefore only 1 of 157 children had significant intracranial pathology. We conclude that CT scans have a limited role in the management of children with headache.

Syncope in childhood: a case control clinical study of the familial tendency to faint

We investigated the possibility of an inherited tendency to faint by studying 30 consecutively referred well children with vasodepressor or vasovagal syncope. The family history of each patient was reviewed for syncope and for 24 cases was compared with the family history of the child's best friend. None of the best friends had syncope. 27/30 cases and 8/24 best friends had at least one first degree relative with syncope (p less than 0.01). Of the 8 best friend controls with a parent or sibling with syncope, the mother was affected in 7; 4/7 of these mothers had first degree relative(s) with syncope. In 11/30 patients both a sibling and parent had syncope compared with 1/24 of control families (p less than .01). We conclude that there is an inherited tendency to faint since most children who faint have a first degree relative who faints, a useful fact in differential diagnosis. This inherited tendency may be multifactorial but requires an environmental stimulus for expression.

Stretch syncope in adolescence

We describe 6 adolescents with syncope induced by stretching with the neck hyperextended. Studies of the cardiovascular responses to stretching and Valsalva in these patients were the same as controls, indicating that the mechanism is not simply Valsalva but may also involve vertebral artery compression coupled with a familial tendency to faint.

Once-daily ethosuximide in the treatment of absence epilepsy

Once-daily ethosuximide was used to treat 10 consecutive children with typical absence seizures. Three patients had gastrointestinal side effects which resolved when the same total daily dose was divided into 2 doses. Two other patients continued to have seizures on ethosuximide, whether given once or twice daily. Five patients had complete seizure control without adverse effects on once-daily ethosuximide.

Home use of rectal diazepam to prevent status epilepticus in children with convulsive disorders

Thirty families were taught to administer rectal liquid diazepam to their children to stop a seizure at home. Twelve children had previous prolonged afebrile seizures, and 18 had either prolonged or repeated febrile seizures. During follow-up, 17 of the 30 families administered the rectal diazepam an average of three times per child with no complications. Fifteen of 17 families reported prompt cessation of the seizure, while in two the rectal diazepam was unsuccessful and hospital treatment was needed. We conclude that rectal diazepam is a useful adjunctive home treatment for children at risk for prolonged seizures. Hospitalization is decreased and parental confidence increased. Without our knowledge, twelve families taught others how to give the rectal diazepam, a practice that might be hazardous and should be anticipated.

Changes in serum anticonvulsant levels with febrile illness in children with epilepsy

Changes in anticonvulsant serum levels during intercurrent illness may cause toxicity or decreased seizure control in children with epilepsy. We studied prospectively the effect of intercurrent illness and its treatment in 111 children being treated with AC monotherapy. Free fraction and total serum AC levels were determined when the child was well, on the fifth day of any illness with fever and one month after recovery. There were 55 episodes of febrile illness in 39 children during the study period. Twelve illnesses were associated with significant increases or decreases in serum AC levels; 7 children became clinically toxic; 1 child had increased seizures during illness. The mechanisms of AC level changes appeared to include interaction with antibiotics, with antipyretics or with viral illness. Amoxycillin and acetaminophen did not appear to interact with the AC's used. Physicians caring for children with epilepsy should be aware of the frequency and complexity of potential interactions between intercurrent febrile illness and anticonvulsant medication.

Neonatal seizures: a commentary on selected aspects

Despite the immaturity of the newborn brain, the neonatal period is reported to have a very high frequency of seizures. This review concludes that many of the neonatal events that are called seizures probably originate from subcortical structures, have little in common with cortical seizures seen in older individuals, and may not benefit from conventional anticonvulsant treatment. Many studies of anticonvulsants in the newborn have important methodologic problems, compounded by the fact that the seizures tend to spontaneously remit with the resolution of the acute hypoxic-ischemic encephalopathy that is most often the cause. Randomized trials of anticonvulsants in this setting have not been carried out. Even in many of these seizures do not originate in the cortex, they still imply profound cortical disturbance and are associated with high mortality and morbidity. It is unknown if the type and duration of treatment influence the long-term, overall outcome. The seizures usually stop in the newborn period, and anticonvulsants beyond hospital discharge seem unwarranted because they are unlikely to prevent subsequent epilepsy. Newer investigations, including video-EEG and nuclear magnetic resonance studies, may clarify the real significance of neonatal seizures.

Clinical valproate toxicity induced by acetylsalicylic acid

We report three patients with serious clinical valproate (VPA) toxicity induced by interaction with acetylsalicylic acid (ASA). Two patients had a documented rise in VPA free level, and the third showed only clinical signs of toxicity. Symptoms resolved in all three when the ASA was stopped. This interaction has been previously documented under experimental conditions, and is due to displacement of VPA from plasma protein binding sites and a probable interference in metabolism. This is the first report of the clinical significance of this interaction.

Effects of phenobarbital on early intellectual and behavioral development: a concordant twin case study

A Monozygotic twin pair had febrile seizures, only one was treated with phenobarbital from 17-30 months of age. Standard intellectual and behavioral assessments were conducted during Treatment (30 months of age), and Post-Treatment (32, 41, 48, 66 months of age). Both twins showed normal global intelligence at all assessments, however, the phenobarbital twin scored lower at all assessments. Differences in specific abilities were also seen during Post-Treatment. When phenobarbital was withdrawn, the treated twin's behavior showed immediate improvement. This experience suggests that early phenobarbital treatment may affect global intelligence through the preschool period, but that the effect is not severe. Phenobarbital also may adversely affect behavior, although the effect disappears with termination of the drug.