Anti-myelin basic protein (MBP) antibodies in pediatric-onset MS and controls were characterized. Serum samples were obtained from 94 children with MS and 106 controls. Paired CSF and serum were obtained from 25 children with MS at time of their initial episode of acute demyelinating syndrome (ADS). Complementary assays were applied across samples to evaluate the presence, and the physical binding properties, of anti-MBP antibodies. While the prevalence and titers of serum anti-MBP antibodies against both immature and mature forms of MBP were similar in children with MS and in controls, binding characteristics and formal Surface Plasmon Resonance (SPR) studies indicated surprisingly high binding affinities of all pediatric anti-MBP antibodies. Serum levels of anti-MBP antibodies correlated significantly with their CSF levels, and their presence in children with MS was associated with significantly increased risk of an acute disseminated encephalomyelitis-like initial clinical presentation. While antibodies to both immature and mature forms of MBP can be present as part of the normal pediatric humoral repertoire, these anti-myelin antibodies are of surprisingly high affinity, can access the CNS during inflammation, and have the capacity to modulate disease expression. Our findings identify an immune mechanism that could contribute to the observed heterogeneity in spectrum of clinical presentations in early-onset MS.
OBJECTIVE:To accurately define the electroclinical features of absence seizures in children with newly diagnosed, untreated childhood absence epilepsy (CAE). METHODS:The authors searched an EEG database for absence seizures in normal children with new onset untreated absence epilepsy. Seventy consecutive children were classified into IGE syndromes. The clinical and EEG features of the seizures in the children with CAE were analyzed using video-EEG recordings. RESULTS:The authors analyzed 339 absence seizures in 47 children with CAE. The average seizure duration was 9.4 seconds and clinical features consisted of arrest of activity, loss of awareness, staring, and 3-Hz eyelid movements, but there was individual variation. Ictal EEG predominantly showed regular 3-Hz generalized spike and wave (GSW) with one or two spikes per wave; however, disorganization of discharges was common and three or more spikes per wave occurred rarely. Postictal slowing was frequent. Interictal abnormalities included fragments of GSW, posterior bilateral delta activity, and focal discharges. Although all 47 children met the current criteria for CAE, only 5 fulfilled the recently proposed criteria for CAE. CONCLUSION:The heterogeneous nature of each clinical and EEG feature of untreated absence seizures is of critical importance when determining criteria for childhood absence epilepsy.
The diagnosis of mitochondrial encephalomyopathies is complex and a system for classification of the diagnosis as definite, probable, and possible has been proposed. The objective of this study was to explore the spectrum of epileptic disorders associated with probable and definite mitochondrial disease in children using this classification system. The patient population with mitochondrial disease and epilepsy was selected from a tertiary care children's hospital. Interictal electroencephalograms and video-EEG recordings were used to characterize seizure types. Ten children fulfilled the criteria for probable or definite mitochondrial disease and had epilepsy. Four had siblings with a similar clinical phenotype. Spasms were the most common seizure type and were the initial seizure type in seven patients and two siblings. Four patients had only partial seizures, with or without generalization, and one patient had seizures that were difficult to classify. Blood lactate concentrations were elevated consistently in patients with partial seizures alone but were occasionally normal in children with spasms. Spasms were the most common presenting seizure type in children with probable and definite mitochondrial disease.
In this study, spectroscopic and chromatographic evidence is presented for the identification and characterization of the metabolites, valproyl glutamate (2-propylpentanoyl glutamate, VPA-GLU) and valproyl glutamine (2-propylpentanoyl glutamine, VPA-GLN) in the urine, serum, and cerebrospinal fluid (CSF) of patients on valproic acid (VPA) therapy. Moreover, the identification of valproyl glycine (2-propylpentanoyl glycine, VPA-GLY) in the serum and urine of patients on VPA, albeit in trace concentrations, is also reported here. The three amino acid conjugates excreted in urine accounted for about 1% of the VPA dose in four patients who were on VPA therapy chronically and had reached steady state. VPA-GLU was quantitatively the most prominent metabolite (0.66-13.1 microg/mg creatinine) compared with VPA-GLN (0.78-9.93 microg/mg creatinine) and VPA-GLY (trace-1.0 microg/mg creatinine) in overnight urine samples of all patients studied (n = 29). The relatively low serum concentrations of the three amino acid conjugates of VPA in six patients suggest that the metabolites are readily excreted once formed. In contrast, whereas VPA GLY was absent in the CSF of one patient on VPA, the concentrations of VPA-GLU and VPA-GLN in this CSF sample were 9 and 5 times, respectively, their corresponding serum concentrations.
Purpose: Valproic acid (VPA) is an antiepileptic drug (AED) used for generalized and absence seizures. It has a rare but potentially fatal hepatotoxicity side effect, and many researchers believe that reactive metabolites of VPA could be involved. We demonstrated here that the thiol conjugates of (E)-2,4-diene VPA were significantly elevated in a high-risk group of patients.Methods: Thirty-four patients with seizures were divided into three groups. Group A (n = 14) were being treated with VPA; group B (n = 12) received VPA as well as other AEDs that do not induce P450-VPA metabolism; and group C (n = 8) received VPA and AEDs that induce P450-VPA metabolism. The NAC conjugates of (E)-2,4-diene VPA (NAC I and NAC II) were identified in the urine of patients by gas chromatography/mass spectrography NICI analysis.Results: VPA monotherapy (group A) or VPA polytherapy with non-P450-enzyme-inducing drugs (group B), showed that patients younger than 7.5 years excreted significantly higher concentrations of the two conjugates compared with older patients (older than 7.5 years) in the same groups (p < 0.05). Patients receiving VPA polytherapy with P450-enzyme-inducing drugs were all older than 7.5 years (group C). They excreted significantly higher concentrations of NAC I and NAC II compared with patients in groups A and B who were older than 7.5 years (p < 0.05).Conclusions: There were no significant differences in the excretion of NAC I and NAC II between patients in group C and those who were 7.5 years or younger in groups A and B. High doses of VPA also were a significant factor associated with elevated NAC I and NAC II among young patients and in polytherapy patients.
Prior studies have found no adverse effects of pediatric epilepsy surgery on IQ. However, empirical techniques such as regression models. designed to account for confounding factors such as practice effects and test-retest reliability and able to provide a standardized method for evaluating outcome, have not been used in studying change after pediatric epilepsy. The goal of this study was to demonstrate the regression technique while empirically measuring the effect of epilepsy surgery on IQ in a group of pediatric patients. Predictors of retest IQ (e.g., baseline IQ, retest interval. demographics, epilepsy severity) were evaluated in a control group with intractable seizures (N = 23) assessed twice with the WISC-III. The resulting equation was used to evaluate IQ changes in a second group of children who underwent epilepsy surgery (N = 22). In controls, baseline IQ was a strong predictor of retest IQ. Number of AEDs was inversely related to retest IQ. Based on the control regression, four children (18%) in the surgical sample obtained significantly higher than expected postsurgical IQ scores and one child (5%) obtained a lower than expected IQ score. This study demonstrates that regression-based techniques yield informative estimates on outcome and may be an improvement over prior methods of measuring change after pediatric epilepsy surgery.
Purpose: Hyperventilation-induced high-amplitude rhythmic slowing (HIHARS) in children may be associated with clinical episodes of altered awareness. The presence of automatisms has been proposed as a distinguishing feature that helps to differentiate absence seizures from nonepileptic causes of decreased responsiveness. This retrospective, controlled, video-EEG study compared the clinical characteristics of episodes of HIHARS with loss of awareness with those of absence seizures.Methods: The database of a tertiary Children's Hospital was searched for patients studied between April 1993 and April 1997 who had at least one episode of HIHARS with loss of awareness. The absence control group was obtained by selecting the next patient, after an HIHARS study subject, who met the following criteria: (a) had at least one absence seizure occurred during hyperventilation in the EEG recording, and (b) had a diagnosis of idiopathic generalized epilepsy. The video-EEG and medical histories of all patients were reviewed and summarized.Results: We reviewed video-EEG recordings of 77 episodes of HIHARS with loss of awareness from 22 children and 107 absence seizures during hyperventilation from 22 children. Eye opening and eyelid flutter were seen more frequently in absence seizures, whereas fidgeting, smiling, and yawning occurred more frequently during HIHARS episodes. Arrest of activity, staring, and oral and manual automatisms were observed in both groups.Conclusions: Automatisms are common in both HIHARS and absence seizures. Yawning, smiling, and particularly fidgeting occur more commonly and eye opening and eyelid flutter less commonly in HIHARS. However, episodes of HIHARS with loss of awareness clinically mimic absence seizures, and these conditions can be distinguished reliably only by EEG.
PURPOSE:Validity studies on health-related quality of life (HRQOL) scales for pediatric epilepsy are few, and cross-validation with other samples has not been reported. This study was designed to assess the validity of three parent-rated measures of HRQOL in pediatric epilepsy: (a) the Impact of Childhood Illness Scale (ICI), (b) the Impact of Child Neurologic Handicap Scale (ICNH), and (c) the Hague Restrictions in Epilepsy Scale (HARCES).METHODS:Retrospective data were examined for 44 children with intractable epilepsy. Validity was assessed by evaluating differences across epilepsy severity groups as well as correlations between HRQOL scales and neurologic variables (seizure severity, epilepsy duration, current/prior antiepileptic medications) and psychosocial measures (emotional functioning, IQ, social skills, adaptive behavior). Scale overlap with a global QOL rating also was assessed.RESULTS:The HRQOL measures were moderately to highly intercorrelated. The scales differed in terms of their associations with criterion measures. The HARCES was related to the highest number of neurologic variables and the ICNH to the fewest. All three scales were related to psychosocial functioning and to global quality of life.CONCLUSIONS:The results of this study suggest that the three measures are likely adequate measures of HRQOL for use in intractable childhood epilepsy. The measures were highly intercorrelated, and they were all broadly related to criterion measures reflecting specific domains of HRQOL as well as global QOL. Some differences between scales emerged, however, that suggest care in choosing HRQOL instruments for children with epilepsy.
The objective of this study was to examine the factors associated with the occurrence of behavioral and cognitive abnormalities in children treated with topiramate. A retrospective chart review of patients up to 18 years of age who had been treated with topiramate at a tertiary epilepsy center was performed. Behavioral or cognitive abnormalities were observed in 11 (14.6%) of 75 children between 2 weeks and 4 months after initiation of therapy. The mean dosage (4.6 mg/kg daily) at which these abnormalities were observed was similar to the mean final dose (5.8 mg/kg daily) in children without abnormalities. The mean rate of dosage increase was 0.72 mg/kg weekly and 0.7 mg/kg weekly in those with and without abnormalities, respectively. Five of the 11 children with behavioral or cognitive abnormalities had a previous history of behavioral or cognitive abnormalities, but only nine of the 64 children without abnormalities had a previous history of behavioral or cognitive abnormalities (P = 0.03). Lamotrigine was used concurrently in four of the 11 children with behavioral or cognitive abnormalities but in only seven of the 64 children without abnormalities (P = 0.05). Behavioral and cognitive abnormalities in children treated with topiramate do not appear to be related to the rate of dosage increase. A previous history of behavioral problems and the concurrent use of lamotrigine may be predisposing factors.
This retrospective study documents the clinical features, electroencephalographic data, and outcome of 50 children with a history of seizures with fever that occurred after 5 years of age. Children with afebrile seizures before the onset of febrile seizures were excluded. Outcome was based on a cross-sectional survey and the follow-up period was 1-13 years. Of the 50 children, 40 had two or fewer febrile seizures after 5 years of age, and febrile seizures did not occur after 10 years of age. Twenty had complex febrile seizures, and 16 had a first-degree relative with febrile seizures. Five developed afebrile seizures, and 18 had educational difficulties. Epileptiform electroencephalographic abnormalities were observed in 22 but were not predictive of later afebrile seizures. Febrile seizures that occur after 5 years of age recur infrequently and cease by 10 years of age. The risk of developing afebrile seizures in this group is small.
1. Rob Forsyth, MD* 2. Kevin Farrell, MD* 1. 2. *Division of Neurology, Department of Pediatrics, University of British Columbia; British Columbia Children’s Hospital, Vancouver, British Columbia, Canada. After completing this article, readers should be able to: 1. Describe what most parents who want help for a child who has a headache are seeking. 2. List the most common cause of severe headache in children. 3. Describe what tests must be performed prior to lumbar puncture in any patient who has a headache. 4. Determine common causes of chronic daily headache. Chronic or recurrent headache is common in children, occurring in approximately 40% of children by 7 years of age and 75% of children by 15 years. Most parents who seek help for a child who has headaches are looking for reassurance that the headache is not due to a serious cause. Pain referred to the head can arise from the following structures: 1) intracranial or extracranial arteries, large intracranial veins, or venous sinuses; 2) cranial or spinal nerves; 3) basal meninges; 4) cranial and cervical muscles; and 5) extra-cranial structures such as the nasal cavity and sinuses, teeth, mucous membranes, skin, and subcutaneous tissues. The brain, most of the meninges overlying the convexity, and the bony skull are not sensitive to pain. Pain arising from the cranial circulation and supratentorial structures travels primarily via the trigeminal nerve and is referred to the anterior part of the head. Pain arising from posterior fossa structures travels mainly via the first three cervical nerves, resulting in pain in the back of the head and neck as well as the forehead. The glossopharyngeal and vagal nerves innervate part of the posterior fossa, and pain is referred to the ear and throat. There are two major hypotheses regarding the pathogenesis of migraine. The vascular hypothesis proposes that vasoconstriction results in aura or focal neurologic signs and is followed by painful vasodilatation. The neurogenic hypothesis proposes that afferent inputs to the brainstem result in a slowly spreading …
The role of lamotrigine (LTG) in childhood epilepsy is emerging. We evaluated the efficacy and adverse effects of LTG in an open, prospective study of 56 children with generalized epilepsies. Six (11%) children became seizure-free, and 24 (43%) had greater than 50% reduction in seizure frequency. LTG was effective against a broad range of generalized seizure types. Three of 15 patients with Lennox-Gastaut syndrome achieved complete seizure control and eight demonstrated 50 to 99% improvement in seizure control. Increase in seizures (7) and rash (5) were the most common side effects. After valproate was discontinued, LTG therapy was resumed, with no recurrence of rash in any patient. This study suggests that LTG may be a useful drug in the treatment of generalized epilepsies in children.
Most reports of supplementary sensorimotor seizures have been of adults with medically refractory epilepsy. Typically, supplementary sensorimotor seizures have onset in childhood. We describe the electroclinical features in 12 children. Cases were selected from an EEG laboratory population in whom video-EEG was performed routinely on all children. Supplementary sensorimotor seizures were diagnosed when there was bilateral tonic posturing of the upper or lower extremities, preserved consciousness, and lack of postictal confusion. Sensory auras were reported by 8 of 9 children aged > 3 years who had daytime seizures. Speech arrest occurred in all patients in whom it could be assessed, and abnormal vocalization was observed in 7 children. Interictal EEGs were often normal (49% of recordings), and ictal EEG changes could be subtle. An etiology was demonstrated in only 2 children, and brain imaging studies were normal in the other 10 patients. Seizures were controlled with antiepileptic drugs (AEDs) in 6 of the 12 children. The clinical manifestations of supplementary sensorimotor seizures in children are similar to those reported in adults; misdiagnosis is common at all ages.