sign in sign up
<<
Home , Absence seizure, Aura (symptom), Dravet syndrome, Epilepsy in children, Epilepsy syndromes, Focal seizure

• THEME in children

Patrick W Carney BACKGROUND Understanding the common childhood epilepsy syndromes is valuable when approaching BSc, BMed, is a the diagnosis and management of a child presenting with . registrar, Austin Health, OBJECTIVE This article discusses the common epilepsy syndromes in children and provides a guide Melbourne, Victoria. to appropriate investigation and management of these syndromes. patrick.carney@ austin.org.au DISCUSSION A careful history and examination, supported by an electroencephalogram, are the cornerstones of epilepsy syndrome diagnosis. This, in turn, guides the need for further investigation such as magnetic Michael A Prowse resonance imaging, optimisation of therapy and prognostic counselling. Understanding the implications MBBS, FRACGP, is a of a specific syndrome diagnosis helps support families who are frequently overwhelmed by a diagnosis general practitioner, of epilepsy in their child. Berwick, Victoria.

Ingrid E Scheffer PhD, FRACP, is pilepsy is defined as more than one unprovoked child, and Professor and E paediatric neurologist, 1 and is essentially a clinical diagnosis based on • symptomatic – epilepsy occurs in the setting of Departments of an eye witness account of the attacks. When a child or a known or suspected abnormality of the central Medicine and Paediatrics, The adolescent presents with their first seizure, a detailed (Table 3).2,3 University of history should be sought for other that For example, a child with developmental delay has Melbourne, Austin may not have previously been appreciated (Table 1, symptomatic epilepsy, as does an individual with Health and Royal Children’s Hospital, 2). For example, an adolescent presenting with their . Melbourne, Victoria. first generalised tonic-clonic seizure (GTCS) may have The are further subdivided into: had subtle absence or myoclonic seizures; diagnosis • generalised – seizures arise from both hemispheres of these seizure types is critical to diagnosis of the simultaneously, and specific epilepsy syndrome. An electroencephalogram • partial (or focal) epilepsy – which begins in one part of (EEG) provides supporting evidence for diagnosis the and may secondarily generalise. of a specific epilepsy syndrome; if a routine EEG is normal, a sleep deprived study should be considered. Generalised epilepsies In individuals with focal epilepsy not classified as idiopathic partial epilepsy, magnetic resonance Idiopathic generalised epilepsies Absence seizures are the hallmark of childhood imaging (MRI) should be performed. Investigations may be initiated by a general practitioner, but more absence epilepsy (CAE) and juvenile absence epilepsy sophisticated syndrome diagnosis would usually be (JAE) (Table 3). Typical absence seizures, or ‘staring made by a paediatrician or neurologist. spells’, have an abrupt onset without warning and rapid offset with resumption of previous activities (Table 1, Classification of the epilepsies 2). The events are brief, lasting less than 20 seconds, The International League Against Epilepsy (ILAE) and awareness is impaired. Other features may include classifies epilepsy syndromes as: mild clonic, myoclonic, atonic or tonic movements, and • idiopathic – epilepsy develops in an otherwise normal oral and manual automatisms.4,5

Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 4 1009 Theme: Epilepsy syndromes in children

Table 1. Common generalised seizure types

Seizure type Clinical features Postictal Duration Usual epilepsy syndrome Absence Abrupt onset of staring Abrupt return to <30 seconds CAE, JAE with cessation of normal motor activity

Myoclonic Brief contraction of Abrupt return to <5 seconds IGE, Lennox- muscle/muscle groups normal Gastaut, progressive, either singularly or epilepsies repetitively

Tonic-clonic seizure May begin with a cry Drowsiness may Usually <5 minutes May be generalised or fall to the ground be prolonged with from onset, secondarily followed by tonic recovery taking generalised with flexion. This is followed minutes to hours. focal onset or occur by a clonic phase Postictal confusion and due to an acute involving symmetrical agitation is common metabolic disturbance. movement of all limbs. Associated with Autonomic features a broad range of are common as are epilepsies including incontinence and IGE and SGE tongue biting

Tonic Tonic extension of 10 seconds SGE especially the all limbs with semi- Lennox-Gastaut flexed arms (bear syndrome hug). Patients often fall backward

Atonic Classic drop attacks Few seconds SGE including Lennox- with sudden loss Gastaut syndrome of postural tone

Table 2. Common partial (focal) seizure types and adversely affect school performance. Absence seizures may be triggered by stress, fatigue, and Location Clinical features . The EEG shows bilaterally synchronous Temporal may involve epigastric sensation, olfactory 3 Hz spike and wave discharges (generalised spike or gustatory , autonomic features, wave [GSW]) on a normal background. Trains of 3 Hz dysmnestic changes such as followed by loss GSW correlate with a clinical on EEG; of awareness and automatisms involving the mouth hyperventilation is used to trigger GSW and absence or upper limbs. Duration 30–300 seconds with a brief period of postictal confusion seizures during an EEG (Figure 1). Childhood absence epilepsy may be accompanied by GTCS, which tend to Frontal May be hyperkinetic with motor automatisms or an asymmetric tonic seizure depending on the location occur later in adolescence. Seizures resolve in 60% of in the frontal cortex; may be incontinent children by mid adolescence.4,5 Occipital Visual symptoms including hallucinations, field Juvenile absence epilepsy defects, and flashing lights; may vomit Juvenile absence epilepsy differs from CAE not only Childhood absence epilepsy because of a later age of onset (after the age of 10 Childhood absence epilepsy begins between 3 and years and occasionally as late as 20 years), but also 12 years of age with peak onset at 6 years. Absence because of the seizure pattern. Absence seizures seizures occur frequently, often 20 times per day,5 are less frequent, perhaps once per week, and less

1010 3Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 Theme: Epilepsy syndromes in children

severe impairment of awareness may occur. Other Table 3. ILAE classification of epilepsy syndromes2 seizure types, such as GTCS, are more common. The EEG shows faster GSW, usually at 3.5–4.0 Hz and Generalised occasionally faster, and generalised polyspike wave Idiopathic generalised epilepsy syndromes with age related onset is often seen.6 (in order of age) Juvenile Benign neonatal – sporadic and familial forms Childhood absence epilepsy Juvenile myoclonic epilepsy (JME) accounts for up to Juvenile absence epilepsy a quarter of idiopathic generalised epilepsies (IGE). Juvenile myoclonic epilepsy Onset is in adolescence (8–20 years of age) and is Epilepsy with generalised tonic-clonic seizures alone characterised by isolated myoclonic seizures, especially Symptomatic generalised epilepsies (in order of age) after awakening (see Case study 1). Other seizure West syndrome types are common including GTCS in up to 80% of Lennox-Gastaut syndrome patients and absence seizures in 30%. Seizures often Epilepsy with myoclonic-astatic seizures occur following sleep deprivation, fatigue and alcohol use.8 The EEG shows 4–6 Hz polyspike wave and Focal/partial seizure disorders photosensitivity is common; occurring in more than Idiopathic focal epilepsies 30% of individuals.7 Benign epilepsy with centro-temporal spikes Treatment of IGE Childhood epilepsy with occipital paroxysms is the drug of first choice for IGE.8 Although Symptomatic focal epilepsies generally well tolerated, common side effects include Temporal epilepsy weight gain and fatigue. Another concern for teenage epilepsy girls is teratogenesis, as valproate is associated epilepsy with an increased incidence of neural tube defects. epilepsy Contraceptive advice should be provided and specialist advice sought before conception. is an Epilepsies or syndromes undetermined as to whether focal effective second line agent, especially in combination or generalised with valproate. The principal side effect of lamotrigine Neonatal seizures is rash, which is more likely when on valproate co- (severe myoclonic epilepsy of infancy therapy. Therefore, lamotrigine should be started at a Epileptic- syndromes low dose and slowly increased over several months. Other medications include , and Special syndromes .9,10 Febrile seizures Isolated seizures or isolated Symptomatic generalised epilepsies Acute symptomatic seizures (associated with acute metabolic or toxic event) The symptomatic generalised epilepsies are characterised by multiple seizure types and other neurological deficits including intellectual . West syndrome

West syndrome usually begins at 6 months of age (range 3–12 months years) and is sometimes mistaken for infantile colic. The baby has clusters of , developmental arrest or regression. The EEG shows with continuous multifocal epileptiform activity. Cerebral malformations are an important cause but often no aetiology is apparent. Seizures generally respond to corticosteroid treatment, Figure 1. EEG showing typical 3 Hz generalised spike and wave which should be initiated as early as possible.11 associated with childhood absence epilepsy

Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 4 1011

Theme: Epilepsy syndromes in children

Lennox-Gastaut syndrome Case study 1 – Chloe Lennox-Gastaut syndrome (LGS) begins between 1 and Chloe, 15 years of age, partied late into the night. At 6 am her mother 8 years of age; 20% of infants with West syndrome found her in the middle of a 2 minute generalised tonic-clonic seizure. evolve to LGS.12 The key seizure type is the tonic When asked specifically, Chloe admitted to noticing sudden ‘jerks of her seizure but atonic drop attacks, atypical absence, GTCS arms’ when eating her cereal at breakfast time – she had even dropped and myoclonic seizures may also occur. The EEG shows her grandmother’s antique butter dish. Her sleep deprived EEG showed slow 1.0–2.5 Hz sharp and slow activity that can be fast generalised polyspike-wave activity with photosensitivity. Chloe’s myoclonic seizures and convulsions were fully controlled with valproate virtually continuous.13 Lennox-Gastaut syndrome has 200 mg twice per day. many aetiologies including cortical malformations, The diagnosis of epilepsy and its implications were discussed with Chloe and acquired causes such as trauma. and her parents. Chloe has juvenile myoclonic epilepsy, which means Lennox-Gastaut syndrome accounts for up to 10% that although she may require long term treatment, her epilepsy should of childhood epilepsy. Lennox-Gastaut syndrome be well controlled with the appropriate medication. It was emphasised children have variable intellect, however most that sleep deprivation and fatigue were potent triggers of seizures, even commonly display intellectual disability. Cognition with medication compliance. This is often an issue for adolescents, but strategies such as having a nap in the afternoon before a late night, and may be normal before development of the syndrome, limiting alcohol to one drink per night lessens the risk. Another issue however few maintain normal intellect with frequent is compliance and it is important for adolescents to take responsibility poorly controlled seizures.12,13 Treatment is difficult, for this as they become independent. The appropriate age depends on but the combination of valproate and lamotrigine is the the adolescent. Often they become more interested in compliance when most effective regimen.10 they wish to sit for their driver learner’s permit. For Chloe’s epilepsy syndrome, she requires 3 months without seizures to drive a vehicle. Partial seizure disorders Chloe presented again at the age of 18 years following a generalised tonic-clonic seizure, the first in over 2 years. She said that she had been A partial, or arises in one part of the having some late nights, as she had just finished her final exams, and cerebral cortex and may generalise to involve the entire was not taking her medications as reliably. She also stated that she was brain.14 Clinical features of partial seizures reflect the worried about the effects of her medication and what effect they would cortical origin of the seizure (Table 2). Seizures may have on a baby if she were to fall pregnant. Chloe was told that it would arise from normal brain tissue or specific lesions. be best to plan a pregnancy and talk to her doctors well in advance. Some antiepileptic drugs are not safe in pregnancy, so this needs to be Advances in imaging have highlighted the importance carefully planned with specialist consultation. Chloe was encouraged to of cortical developmental malformations in focal become more adherent so that she could continue to drive a vehicle. epilepsies.15 If a child has focal epilepsy (focal features clinically or on EEG) not falling into the recognised idiopathic partial epilepsy syndromes, then a MRI brain scan is indicated to exclude a structural lesion. A Case study 2 – Jack computerised tomography (CT) scan is rarely useful. Jack, 8 years of age, awakens half an hour after falling asleep with Idiopathic partial epilepsies tingling in his tongue and gums. He finds himself unable to speak and is drooling. He alerts his parents by banging on the wall and they find Benign epilepsy with centro-temporal spikes him having a secondarily generalised tonic-clonic seizure. Jack had an Benign epilepsy with centro-temporal spikes (BECTS), EEG performed the following day which showed frequent right centro- also known as benign or benign temporal spikes when drowsy. focal epilepsy of childhood, is the most common Jack’s parents were worried about him going on medication but equally worried about the risks of further seizures. They also asked whether he childhood epilepsy syndrome.16,17 Nocturnal seizures needed a brain scan to ‘rule out a brain tumour’. His parents were told begin at 3–13 years of age and stop by 16 years of that Jack’s seizures were a common, benign form of childhood epilepsy age. Seizures occur shortly after falling asleep or just called ‘benign childhood epilepsy with centro-temporal spikes’ (BECTS). before awakening. It is worth asking the child if he/she Medication would generally be considered after three seizures as many experiences a warning, or aura, of perioral or gum children with this syndrome only have 1–2 seizures and never require treatment. In view of Jack’s typical clinical history and EEG pattern, the paraesthesia. Other common features include speech diagnosis could be made with relative certainty and a scan would not arrest, drooling, and tonic or clonic involvement of the be required. Jack’s parents were initially distressed with the diagnosis face or upper limb. Alternatively parents may be alerted of epilepsy and required reassurance and a detailed explanation of the by gurgling or grunting noises, and find their child excellent prognosis of BECTS. Jack had no further seizures and never having a secondarily GTCS. The EEG shows a spike over required medication. the rolandic or centro-temporal area.2 If not present

Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 4 1013 Theme: Epilepsy syndromes in children

awake, the rolandic spike is brought out in sleep, so a should be considered with appropriate evaluation by a sleep deprived EEG may help (see Case study 2). comprehensive epilepsy program. When indicated for Benign epilepsy with centro-temporal spikes has hippocampal sclerosis, anterior temporal lobectomy is an excellent prognosis even in patients with frequent successful in at least 60% of patients who are rendered seizures. Controversy surrounds the neuropsychological seizure free or experience a substantial reduction in findings in children with BECTS with some studies seizure frequency.23 suggesting mild limitations in memory and phonologic skills while others show no difficulties.16 Overall, Conclusion intellectual and language ability is consistent with peers. A range of epilepsy syndromes develop in childhood No treatment is required for the first few seizures but if and adolescence. Accurately identifying the seizure seizures are frequent, or valproate type and correlating this with the EEG findings provides should be considered. The decision to start treatment important prognostic and management information needs to be balanced between the risks of medication for families with a child with epilepsy. Many childhood side effects and the social and learning implications of epilepsy syndromes are readily treated and have an untreated seizures.17 excellent prognosis. Accurate and early diagnosis may ameliorate the psychosocial impact of these disorders Benign occipital epilepsies of childhood on children and their families. The benign occipital epilepsies of childhood comprise early and late onset syndromes with overlapping age Conflict of interest: none declared. ranges of onset between 3–14 years; they generally resolve by the mid teens.18 The early Panayiotopoulos References syndrome is characterised by rare prolonged nocturnal 1. Fisher RS, Boas W, Blume W, Elger C, Genton P, Lee P, Engel J. Epileptic seizures and epilepsy: definition proposed by the attacks with eye deviation, vomiting and autonomic International League Against Epilepsy and the International features. The later Gastaut syndrome has frequent, Bureau for Epilepsy. Epilepsia 2005;46:420–2. brief, elementary visual auras, prominent and 2. Commission on Classification and Terminology of the transient visual impairment. The EEG in both syndromes International League Against Epilepsy. Proposal for Revised Clinical and Electroencephalographic Classification of Epileptic shows interictal occipital rhythmic activity brought out by Seizures. Epilepsia 1989;30:389–99. eye closure. Symptomatic may present 3. Engel J. A proposed diagnostic scheme for people with similarly so MRI of the brain is indicated to exclude an epileptic seizures and epilepsy: report of the ILAE Taskforce on occipital malformation.19,20 Classification and Terminology. Epilepsia 2001;42:796–803. 4. Loiseau P. Childhood absence epilepsy epileptic syndromes in Symptomatic partial epilepsies infancy, childhood and adolescence. 2nd ed. In: Roger J, et al, editors. UK: John Libbey & Co. 1992;135–50. epilepsy 5. Panayiotopoulus CP. Typical absence seizures and their treatment. (TLE) is the most common Arch Dis Child 1999;81:351–5. form of refractory partial and 6. Wolf P. Juvenile absence epilepsy. Epileptic syndromes in infancy, childhood and adolescence. 2nd ed. In: Roger J, et al, editors. 21 adults. Temporal lobe auras comprise olfactory or John Libbey & Co. 1992;307–12. gustatory hallucinations or perceptual phenomena 7. Zifkin B, Andermann E, Andermann F. Mechanisms, genetics, such as déjà vu. Seizures typically consist of ‘staring and pathogenesis of juvenile myoclonic epilepsy. Curr Opin spells’ with psychomotor arrest with loss of awareness Neurol 2005;18:147–53. 8. Avoli M, Rogawski MA, Avanzini G. Generalised epileptic and automatisms involving the perioral region or upper disorders: an update. Epilepsia 2001;42:445–57. limbs. Seizures last 30 seconds to a few minutes, 9. French JA, Kanner AM, Bautista J, et al. Efficacy and tolerability with postictal confusion, drowsiness and headache. of the new antiepileptic drugs. I: Treatment of new onset epilepsy: Features that differentiate temporal lobe seizures report of the TTA and QSS Subcommittees of the American Academy of Neurology and the American Society of Epilepsy. from absence seizures include an aura, duration and Epilepsia 2004;45:401–9. postictal changes. 10. French JA, Kanner AM, Bautista J, et al. Efficacy and tolerability The most common aetiology of refractory TLE of the new antiepileptic drugs. I: Treatment of new onset epilepsy: is hippocampal sclerosis,21 often associated with a report of the TTA and QSS Subcommittees of the American Academy of Neurology and the American Society of Epilepsy. history of prolonged febrile seizures.22 Management Epilepsia 2004;45:410–23. may require more than one drug to achieve seizure 11. Nabbout R, Dulac O. Epileptic : a brief control. Where seizures persist, overview. J Clin Neurophysiol 2003;20:393–7.

1014 3Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 Theme: Epilepsy syndromes in children

12. Beaumanoir A, Dravet C. The Lennox-Gastaut syndrome. Epileptic syndromes in infancy, childhood and adolescence. 2nd ed. In: Roger J, et al, editors. John Libbey & Co. 1992;135–150. 13. Markand ON. Lennox-Gastaut syndrome (childhood epileptic ). J Clin Neurophysiol 2003;20:426–41. 14. Dalla Bernadina B, Sgro V, Fejerman N. Epilepsy with centro- temporal spikes and related syndromes. Epileptic syndromes in infancy, childhood and adolescence. 3rd ed. In: Roger J, et al, editors. John Libbey & Co. 2002;181–202. 15. Sisodiya SM. Malformations of cortical development: burdens and insights from important causes of human epilepsy. Lancet Neurol 2004;3:29–38. 16. Northcott E, Connolly AM, Berroya A, et al. The neuropsychological and language profile of children with benign rolandic epilepsy. Epilepsia 2005;46:924–30. 17. Peters JM, Camfield CS, Camfield PR. Population study of benign rolandic epilepsy: is treatment needed? Neurology 2001;57:537–9. 18. Bouma PA, Bovenkerk AC, Westendorp RG, Brouwer OF. The course of benign partial epilepsy of childhood with centro- temporal spikes: a meta-analysis. Neurology 1997;48:430–7. 19. Taylor I, Scheffer IE, Berkovic SF. Occipital epilepsies: identification of specific and newly recognised syndromes. Brain 2003;126:753–69. 20. Kanazawa O, Tohyama J, Akasaka N, Kamimura T. Magnetoencephalographic study of patients with . Epilepsia 2005;46:1106–13. 21. Cendes F. Febrile seizures and mesial temporal sclerosis. Curr Opin Neurol 2004;17:161–4. 22. Baulac S, Gourfinkel-An I, Nabbout R, Huberfeld G, Serratosa J, LeGuern E, Baulac M. , , and epilepsy. Lancet Neurol 2004;3:421–30. 23. Wiebe S, Blume WT, Girvin JP, Eliasziw M. Effectiveness and efficiency of surgery for temporal lobe epilepsy study group. A randomised, controlled trial of surgery for temporal-lobe epilepsy. N Engl J Med 2001;345:311–8.

Email: [email protected] AFP

Reprinted from Australian Family Physician Vol. 34, No. 12, December 2005 4 1015