Chronic Management of Idiopathic Generalized epilepsies (IGE) Hassan S.Hosny M.D. Prof of Neurology, Cairo University

Transcription

1 Chronic Management of Idiopathic Generalized epilepsies (IGE) Hassan S.Hosny M.D. Prof of Neurology, Cairo University Sanaa 2009

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3 Points of Discussion Prevalence compared to focal epilepsy Adult form Status epilepticus Drug of choice Drug trials of new AEDs Seizure types Misdiagnosis

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5 IGE diagnosis Strict clinical & EEG criteria features proposed by the ILAE (no contamination with 2ry generalized epilepsies Easy to diagnose if clinical & EEG data are available (History) Sometimes diagnosis is made late & retrospectively after the 1 st GTC as in JME IGE encompasses different syndromes & a patient may shift from one phenotype to another Diagnosis of epilepsy can be made after a single seizure Follow up EEGs may reclassify patients as having IGE (Benbadis 2005, Berkovic 1987, Janz 1989,Reutens 1995, Briellmann 2001,Loiseau 1995)

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7 Diagnosis & Treatment of the 1 st Seizure W.G is a 30 year old banker who presented with the 1 st GTCS during a business lunch He was rushed to the hospital where an MRI brain & EEG were done. All investigations were normal His concern was about the risk of recurrent seizures esp at work A two hour EEG recording was done aiming to classify his seizure as partial or generalized

8 IGE with the 1 st Generalized Tonic Clonic Seizure

9 2 hour recording in a 30 y old male with the 1 st GTCS

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11 Defining IGE Overall, there are more similarities than differences in various types of IGE (often impossible, controversial & not necessarily important Same seizure types (3 types) Similar EEG findings Evolution to one another Overlapping genetic origin (ie; family members express different IGE syndrome)

12 Case 2 M.A is a 15 year old male who had a GTC seizure in November MRI brain & routine EEG (20mins) were normal No medication was given Jan 2007 got another GTCS (versive Sz). EEG was normal Was put on a starting dose of OXC 600mg/day He came one month later for a routine follow up visit

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17 Epidemiology of IGE (225/ % ) Clinical criteria as seizure type, age of onset, personal& family background, evolution &EEG are indispensable for diagnosis Some epileptic syndromes are rare & are excluded as BNFS & BMEI Some time elapses between onset of myoclonic seizures & first medical visit General frequency between 15%-20% CAE between 1.5% & 12.1% JAE under diagnosed (phantom absence) JME 10.7% & 11.4% (Jallon 2005,Berg 1999,Oka 1995,Wolf 1986,Obeid 1988)

18 Newly diagnosed patients in children Presentations at diagnosis (Berg,1999) 613 Children 0-15 y over 4 years Mean age 5.3 years 58.6 % localization related: 10% idiopathic, 31% symptomatic localization related, 17% cryptogenic localization related Primary generalized epilepsy 20% 12% Absence Generalized cryptogenic symptomatic epilepsies 8.5% ( 3.9% infantile spasms)

19 Long term prognosis of Seizures with onset in childhood (3 decades) ( Sillanpaa 1998) 245 children (prospective ) mean age 4.3 years 28% idiopathic seizures, 22% cryptogenic seizures, 50% remote symptomatic seizures At end of follow up, 220 patients ( 44 died,39 were not Sz free,33 remote symptomatic Sz) 112 (64%) of surviving patients were seizure free for at least 5 years including 83 (47%) on no AEDs Predicators of being seizure free were rapid response to therapy and a diagnosis of idiopathic seizures

20 Classification & long-term outcome in Idiopathic generalized epilepsies (IGE) (Camfield 2004) 140 IGE patients ( ) 58% had CAE, 65% went into remission 9% had JAE, 60% went into remission 10% had JME, 15% went into remission 23% IGE not otherwise defined children with tonic clonic seizures

21 Management of IGE Making a diagnosis is critical (pseudo-intractability) What s beneficial in focal epilepsy may be deleterious in IGE Efficacy of AEDs differ within the IE seizure types Usually optimistic prognostic implications Awareness that IGE is a childhood as well as an adult syndrome Possibility of discontinuation of medication Preparation for adult life (seizure precipitants, gender issues)

22 22 year old male with intractable seizures Age 17 years had his 1 st GTC. Received a small dose of Valproate 600mg/day. Checking liver enzymes, discovered to have HCV VPA was stopped and switched to CBZ up to 1200mg.Seizures increased in frequency 4/month.Add on Lamotrigine 400mg with no success. Add on Topiramate 300mg/day no success

23 22 year old male with intractable seizures

24 22 year old male with intractable seizures

25 Aggravation of seizures or epilepsy syndrome ((Generalized seizures)) Seizure/syndro me CBZ PHT LTG GBP VGB TGB BDZ Absence seizures Yes Yes Yes Yes Yes Myoclonic seizures Yes Yes Yes Yes JME Yes Yes LGS/MAE Yes Yes Yes Yes Yes Yes BECTS Yes Yes LKS/CSWS Yes Yes Unvericht- Lundberg Yes

26 Do AEDs with one mechanism of action aggravate seizures? Na blockade or increase in GABA transmission!! AEDs Barbiturates Benzodiazepines Carbamazepine, oxcarbazepine, phenytoin Seizures Aggravated Absence, tonic Tonic ( i.v. use, Lennox-Gastaut syndrome and West syndrome) Absence, myoclonic, atonic, (?) tonic Vigabatrin, tiagabine Gabapentin, pregabalin Lamotrigine Absence, myoclonic Myoclonic Many seizure types in SMEI, myoclonic jerks in many syndromes SMEI = severe myoclonic epilepsy of infancy; JME = juvenile myoclonic epilepsy

27 Choice of the 1 st AED in IGE does affect the response (Nicolson et al, 2004) 962 with IGE (mostly adults) comparing VPA,LTG,TPM 285 /549 52% VPA, Dose 1286mg 26 /156 16% LTG Dose 324mg 9 /26 34% TPM Dose 256 VPA failure due to side effects switching to LTG 6/44 (13%) achieved remission (did not receive LTG before) VPA ineffective, none achieved remission Polytherapy VPA + LTG 10/83 12 % achieved remission LTG failure switch to VPA 3/6 remission Conclusion: with VPA failure, Switch to polytherapy?? Use of LTG as polytherapy rather than monotherapy in IGE

28 S.M 19 year old girl. Seizures started age 8 years GTCS,myoclonic jerks (stimulus sensitive), followed by cognitive decline. Positive consanguinity and a younger brother with a similar condition

29 Distribution of IGEs among the study group N: % 2% 17% 46% JME JAE CAE GTCS MAE 20%

30 GENDER

31 Age of onset & Gender Mean age of onset Female Male CAE JAE JME GTCS

32 Different seizure types in IGE syndromes N : 225 Video EEG monitoring (absence & myoclonic jerks are not reported by patient) Epidemiological studies undercount absences & myoclonic jerks and refer to them as GTCS CAE JAE JME GTC Myoclonus Absence

33 Photosensitivity in IGE 8% Photosensitive not Photosensitive 92% 15 females & 3 males

34 Seizure control in 225 IGE patients Controlled Monotherapy 14% uncontrolled 31% Polytherapy 86% 69%

35 Adequacy of control of seizures JME patients who continue to have myoclonus, what is the risk of more GTCS (Mild Myoclonic Jerks Clonazepam is enough??) A Child with CAE controlled on a small dose of AED, is that sufficient to prevent GTCS A child with subclinical generalized spike-wave discharges, is it warranted to increase the dose to suppress the EEG discharges Cognitive functions in IGE in children suggesting long term risk of learning impairment even with a normal IQ & controlled seizures (Henkin,2005 )

36 Seizure control in 36 CAE & 48 JAE patients 16% 50% 17% 55% 8% 17% 8% 18% VPA ESX LTG Poly drug resis 11% VPA cont poly other mono unconrolled

37 Considerations for discontinuation of AEDs (CAE) Remission of CAE in 65% of patients in well defined syndrome If monotherapy is successful for 1-2 years,it is reasonable to try to discontinue medication Look for the next seizure type, even undetected infrequent absence (risk of relapse!) Role of the video EEG monitoring (Wirrel 1997)

38 JME patients N: % 3% 15% VPA poly cont poly uncon other mono 68%

39 IGE with GTCS only Occur during wakefulness & sleep Peak years Incidence range from 0.9%,10%, 15%, 62% In it s pure form CBZ,OXZ PHT can be used Secondarily GTCS may contaminate the selected population Semiological studies showed that focal features are quiet common in GTCS of IGE (unilateral jerks, automatisms with absence, version with GTCS) (Gelisse 2004, Reutens 1995, Roger 1994, Niaz 1999)

40 Seizure control in IGE with GTCS N:34 12% 3% 35% 50% VPA cont poly PHT uncont

41 Adult onset IGE Onset in adults in 15% No clear age boundary where early IGE & late onset IGE starts Often taught that epilepsy in adults should be assumed to have focal epilepsy 13% & 28 % had adult onset IGE mean age 23 Years, 50% had an adult myoclonic epilepsy Behavioral disturbances anxiety & depression despite well control of seizures (Janz,1997 Cutting, 2001 Marini 2003)

42 Early onset versus late onset IGE adult onset early onset 15% 26% JME JAE GTCS 59% 85% 15% Mean age of onset

43 Co-existence of focal and generalized epilepsies P A is 38 year old journalist female 1 st seizure age 26 followed by 2 GTCS in 3 months Remained seizure free for 3 years. Age 33 years recurrent psychomotor seizures followed by GTC. 5 seizures in 1 day. Controlled on Oxcarbazepine 1200mg/day. Non-compliance results in clusters of seizures. MRI normal. EEG showing left temporal slow waves and slowing Age 38 years complaining of frequent myoclonic jerks

44 38 year old female with seizures

45 Dose of VPA & LTG Drug levels??? Dose of VPA when used in monotherapy was mg, while Lamotrigine was 150 mg Dose of VPA when used in polytherapy was 1000mg, while Lamotrigine was 100 mg (Max for VPA 2000 &300mg for LTG) In a RCT, no difference in control of various seizure types could be demonstrated between 1000& 2000mg of VPA (Sundquist, 1999)

46 27 year old female with seizures Onset of seizures age 21 years GTC EEG consistent with generalized discharges No myoclonus or absence On VPA 500 and LTG 75 mg/day Concerned about pregnancy so she stopped VPA and remained on LTG 75 mg/day Remained seizure free for 2 years Husband called his mother in law asking her to come because her daughter is acting in a strange way

47 27 year old female with seizures

48 Status epilepticus in IGE Is it any different from SE in partial complex seizure Absence status epilepticus is the SE encountered 2 females and one male Probable cause: 16 y old female sudden stoppage of VPA 55 y old female seizure free for years 53 y old male who received Quinilones

49 Study of patients & epilepsy variables &their relation to seizure control Age of onset Sex Family history Seizure types Status epilepticus Febrile seizures Photosensitivity

50 Defining Intractability in IGE Once refractory, always refractory?? 2 year period as in partial epilepsy Which seizure type is refractory Response to the 1 st AED (depends on drug of choice) Pseudo-intractability (ill-advised drugs) Appearance of new seizure types Co-existence of IGE & focal epilepsy (9/962 patients) Generalized EEG with focal discharges (Andrew 2004, Kwan &Brodie 2001)

51 Clinical trials in IGE In partial seizures, we ignore etiology& anatomy focusing on final expression (partial Complex Seizure or 2ry GTCS) IGE incorporate more than one seizure type which are electroclinically & probably molecularly distinct Drugs that control GTCS worsen absence! Absence is a component of several syndromes so should we do clinical trials focusing on one seizure type or on one syndrome with several seizure types Infrequent seizure occurrence prolong trials & decreases statistical power Lifelong treatment (knowledge of long term side effects of AEDs)

52 Clinical Trials in well defined Syndromes Hardly any data on relatively uncommon IGE Most reviewers suggest Valproate (class III evidence) little evidence from RCT JAE (VPA extrapolated experience from its efficacy in control of the component seizure type CAE: Double blind parallel trial VPA vs ESM equally effective in 80% (verifying seizure count was manual), LTG Enrichment design study Trials in Primary GTCS, TPM Recent trials of LEV appear to be impressive (duration of trial??) (Suzuki 1972, Sato 1982, Frank 1999, Biton 1999, La Neve 2004)

53 Conclusions A majority of IGE still receive ill-advised drugs,one of the reasons for pseudo-intractability A drug efficacious in one type of seizure may be ineffective or exaggerate another type of seizure Small dose of the appropriate drug is as good as a large dose VPA still has superior efficacy in all seizure types When VPA fails, a combination of VPA + Lamotrigine appears to be the most effective

54 Conclusions IGE syndrome are probably lifelong with the exception of CAE Non-convulsive status epilepticus occurs particularly in patients with JAE It is still uncertain how effective are the new AEDs in controlling IGEs

55 Thank you