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EpilepsyKey slides

Saint Valentine- Patron Saint of Epilepsy, martyred for the

sake of love

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What is epilepsy?CKS PRODIGY Guidance. February 2006; NICE CG 20, October 2004

• Epilepsy– Characterised by recurrent, unprovoked seizures– Should be viewed as a symptom of an underlying

neurological disorder and not as a single disease entity

• Epileptic seizure– Brief disturbance of consciousness, behaviour, emotion,

motor function, or sensation that is due to abnormal electrical discharge in the brain

• Classification– Epileptic seizure type (clinical presentation)– Epileptic syndrome (underlying neurological disorder)

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Epilepsy seizure typesNICE CG 20, October 2004; National Society for Epilepsy

www.epilepsynse.org.uk (accessed March 2008)

• Generalised– Tonic-clonic– Absence– Atonic– Myoclonic

• Partial (focal)– Simple partial– Complex partial

• Mixed

• Status epilepticus

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Epidemiology CKS PRODIGY Guidance, February 2006; NICE CG 20, October 2004

• Most common serious neurological condition in UK– Prevalence on treatment 1 in 200

– Lifetime prevalence 2–5% of population

– Annual incidence rate 50/100,000 (highest in children and the elderly)

• Up to one-third of people with learning disability have epilepsy

• Cause often unknown

• Seizure type and frequency– 60% tonic-clonic

– 20% complex partial

– 12% mixed tonic-clonic and partial

– 3% simple partial

– <5% absence, myoclonic and others

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PrognosisCKS PRODIGY Guidance, February 2006; SIGN 2003

• Recurrence risk after a first seizure varies greatly – Overall risk of recurrence 30–40% – 13%–40% if normal EEG– Up to 90% if abnormal EEG, or with congenital neurological

defects– Recurrence is most likely in the first 12 months, and falls to less

than 10% after 2 years – Treatment with AEDs halves the recurrence risk

• Remission of seizures is common – 9 years after diagnosis ~ 70% of people will have been seizure-

free for the preceding 3 years and only ~ 30% will still be on medication

– Of those who continue to have seizures, some will have recognisable cerebral abnormalities and severe and persistent types of epilepsy

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General principles of epilepsy management NICE Clinical Guideline (adults and children)

NICE CG 20, October 2004

• Information for patients and families/carers

• Diagnosis and investigations

• Management– Initial and ongoing drug treatment (Technology Appraisals)– Withdrawal of drug treatment– Referral for surgery– Status epilepticus– Special groups and consideration– Patient review

• Implementation and audit

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Initial treatmentNICE CG 20, October 2004

• Initiation of AED therapy only when diagnosis confirmed - generally after second epileptic seizure (A)

• AED therapy after first unprovoked seizure if: (B)– Neurological deficit

– EEG indicates unequivocal epileptic activity

– Risk of further seizure considered unacceptable

– Brain imaging shows structural abnormality

• The decision to start an AED should be made by the patient and an epilepsy specialist (largely decided by risk of further seizures) (GPP)– Overall, recurrence risk after first seizure is 30–40%

– Greatest risk in first 12 months

– Risk falls to <10% after 2 years

• Some patients will continue to have seizures despite treatment• Some patients may decide not to undergo treatment following a

discussion of the risks and benefits

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Initial treatmentNICE CG 20, October 2004

• Prescribers should establish base-line biochemistry and full blood count prior to commencing AED therapy (GPP)

• Monotherapy wherever possible (A)– If initial therapy unsuccessful, monotherapy with another

drug can be tried (caution needed in change over) (A)– Second drug can be another first-line or second-line drug– Initiate second drug and increase to adequate or maximum

tolerated dose before tapering off first-line drug (GPP)

• Combination therapy should only be considered where no seizure freedom with monotherapy (A)

• Continuing AED therapy should be planned by the specialist (GPP)

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NICE guidance: Newer AEDsNICE TA 76 & 79, 2004

• Newer AEDs (gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tigabine, topiramate▼ and vigabatrin*) within their licensed indications are recommended in those who have not benefited from treatment with older agents such as carbamazepine or sodium valproate, or for whom older drugs are unsuitable because:– Contraindications– Possible interactions with other drugs– Known to be poorly tolerated by the individual– Females of childbearing potential

(* vigabatrin: adjunct in partial seizures, 1st line monotherapy in infantile spasm)Topiramate is a ‘black triangle’ drug Ref. SPC Topiramate accessed March 2008

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Seizure type 1st Line drug 2nd Line drug Other drugs to consider

Drugs to avoid (worsen seizures)

Generalised tonic-clonic

CBZ, SVP

LTG*, TOP*

CLB, LEV, OXC ACZ, CLN, PHE, PHY, PRI

TIG, VIG

Absence ETS, SVP

LTG*

CLB, CLN, TOP - CBZ, GBP, OXC, TIG, VIG

Myoclonic SVP

(TOP in child/adolescent)

CLB, CLN, LTG, LEV, PIR, TOP

- CBZ, GBP, OXC, TIG, VIG

Tonic SVP

LTG*

CLB, CLN, LEV, TOP

ACZ, PHE, PHY, PRI

CBZ, OXC

Atonic SVP

LTG*

CLB, CLN, LEV, TOP

ACZ, PHE, PRI CBZ, OXC, PHY

Focal + secondary generalisn

CBZ, SVP

LTG*, TOP*, OXC*

CLB, GBP, LEV, PHY, TIG

ACZ, CLN, PHE, PRI

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KEY: CBZ=carbamazepine; SVP=sodium valproate; LTG=lamotrigine; TOP=topiramate; ETS=ethosuximide; OXC=oxcarbazepine; CLB=clobazam; CLN=clonazepam; LEV=levetiracetam; PIR=piracetam; GBP=gabapentin; ACZ=acetazolamide; PHE=phenobarbital; PHY=phenytoin; PRI=primidone; TIG=tiagabine; VIG=vigabatrin

*=under circumstances outlined in NICE TAs of AEDs.

NICE guidance: Drug options by seizure typeNICE CG 20, 2004

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Withdrawal of drug treatmentNICE CG 20, October 2004

• Patients should be seizure free for at least 2 years (A)

• Decision to withdraw treatment taken with individual (family/carers) and specialist (A)– Risks and benefits of continuing or withdrawing treatment – Individual risk of seizure recurrence on and off treatment

(prognostic index of seizure recurrence act as a guide only)

• Withdrawal must be managed by/under supervision of specialist (GPP)

• Withdrawal should be slow (at least 2–3 months) and one drug at a time if on combination therapy (D)

• Plan needed in case of seizure recurrence (GPP)

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Epilepsy Summary

• Epilepsy is the most common serious neurological condition in the UK, and can have profound psychological and physical effects

• Correct diagnosis is essential, but can be very difficult

• Most patients have potential to be seizure free but some patients will continue to have seizures

• Little evidence that newer AEDs offer benefits over older, more established medicines but costs often higher

• All patients should have a comprehensive care plan and regular review

• There is a long history of deficiencies in the standards of care for patients with epilepsy, and on a population level there is evidence of waste of NHS resources