Epilepsy The prevalence of active epilepsy is 8

Epilepsy • The prevalence of active epilepsy is 8. 2 per 1 000 of the general population • An annual incidence of epilepsy is 50 per 100 000 of the general population • Around 50 million people in the world (1 % of the general population) have epilepsy at any one time.

Epilepsy is a chronic disorder, or group of chronic disorders, in which the indispensable feature is recurrence of seizures that are typically unprovoked and usually unpredictable.

What causes epilepsy? • Inheritance - genetic low seizure threshold • The injury of the brain (due to a road traffic accident, tumour, stroke or trauma at birth ) • An infection that affects the brain, such as meningitis or encephalitis

How is epilepsy diagnosed? • Unlike most other neurological conditions, there may be no physical sign that a person has epilepsy when they are not having a seizure. • Therefore the diagnosis is based on a history of more than one epileptic seizure. • An eyewitness account may provide useful information in reaching an accurate diagnosis, as the person experiencing the seizure will not usually remember what has happened.

• I. A. General seizures • • initial stage tonic stage clonic stage recovery stage • B. Without seizure attacks (Absentia epileptica) • II. Focal attacks.

Can epilepsy be treated? • With the appropriate drug treatment, seizures can be completely controlled in up to 80% of people • Some people continue to have seizures despite treatment. A small proportion of these people may benefit from neurosurgery (brain surgery).

TREATMENT FOR EPILEPSY § Drug treatment § Surgical treatment § Complementary treatment

• Epilepsy is the most common serious neurological condition. • Anyone can develop epilepsy; it occurs in all ages, races and social classes. • Labelling people as 'epileptics' on the basis of a medical diagnosis of epilepsy ignores the rest of their attributes and characteristics

The Treatment of Epilepsy • The incidence and prevalence • Aetiologies and risk factors • Aims of treatment • Clinical settings • Principles of treatment – Medical treatment – Surgical treatment • Guidelines • Conclusions

Incidence and Prevalence • Incidence of new cases of epilepsy: • 50/100, 000/year • Incidence of single seizures: • 20 - 30/100, 000/year • Prevalence of active epilepsy • 5 - 10/1, 000 (50% because on AEDs) • Severe epilepsy: 1 - 2/1, 000 • Cumulative Incidence (lifetime prevalence): • 2 - 5%

Incidence and Prevalence in the UK • 30 000 new cases a year • 300 000 - 400 000 cases • 72 000 - 80 000 cases of severe epilepsy

Incidence and Prevalence in the UK • GP – 1 - 2 new cases of epilepsy/year – 10 - 12 cases of active epilepsy • Neurologist – 150 cases of epilepsy/single seizures/year – 1, 200 cases of active epilepsy

Epilepsy: Aetiologies and Risk Factors • Risk factors varies with age and geographic location – Congenital, developmental and genetic conditions in childhood, adolescence and young adults – Head trauma, infection and tumours at any age although tumours more likely over age 40 – Cerebrovascular disease common in elderly – Endemic infections are associated with epilepsy in certain areas – malaria, neurocysticercosis, paragonomiasis, – no adequate large scale study of attributable risk yet

Antiepileptic Treatment • AEDs are mainstay treatment • Non-pharmacological options feasible in only few selected cases – Surgery • Curative • Palliative – Ketogenic diet (children) – Behaviour modification – Avoidance therapy in cases with clear precipitants

Aims of Antiepileptic Treatment • Complete seizure freedom • 50% seizure reduction of little benefit • No adverse effects • long term treatment - long term effects ? • cognitive effects debilitating • teratogenicity • Non-obtrusive treatment • once or twice daily • No PK or PD interactions • Maintenance of a normal lifestyle • Reduction in morbidity and mortality

AED Treatment: Clinical Settings • Prophylactic Treatment • Newly Diagnosed Epilepsy • Single seizure • Recurrent seizures • Chronic Epilepsy

Prophylactic use of AEDs • Often advocated after • Head injury • Craniotomy h There are considerable compliance problems • There is no evidence of a protective effect of this policy • No place for this! • Better wait for the event to happen

Is it Epilepsy ? • Newly diagnosed or suspected cases at Primary Care level > 50% not epilepsy commonest differential diagnosis: syncope • Chronic cases 15 - 20% not epilepsy mostly psychological in nature § Careful diagnostic assessment a must in all cases

The Single Seizure • A controversial area! • Single unprovoked attack usually not treated: practice to defer treatment until 2 or more seizures, although patients at high risk may be treated after a first attack • Incidence of epilepsy much greater than of single seizures • Community-based studies show that overall risk of a second seizure greater than previously accepted • selection bias § Patients § Seizure type è time to entry bias

The Single Seizure • AED treatment following a single seizure reduce risk of recurrence in the short term although long term prognosis not changed • This may eventually lead to changes in the way single seizures are managed • treatment after first seizure • - for six months, for a year? • tailored treatment and not symptomatic • Meanwhile, involve patient and or guardians in the decision

Recurrent Seizures • Treatment recommended after two or more seizures v Exceptions: - Long interval between seizures - Clear identifiable precipitant factor - Patient against treatment - Unlikely compliance

Precipitating Factors ü Fever ü Drugs ü Alcohol ü Photo-Sensitivity ü Sleep Deprivation ü Reflex Mechanisms ü Acute Metabolic Stress ü Emotional Stress/Major Life Events

Starting an AED • Starting AED treatment is a major event and should not be undertaken without careful evaluation of all relevant factors • Therapy is a long term prospect • All implications must be fully explained to the individual and or guardian • Paramount that the patient or guardians are kept informed about the treatment process and the rationale behind it

Starting Treatment • Treatment should always be started with a single drug at a small dose • All common side-effects must be discussed • teratogenicity and contraception if applicable • Importance of compliance should be stressed • Careful titration is a must - start low, go slow

Choice of AEDs treatment • Choice of AED influenced by: • • Type of seizure and or epileptic syndrome Individual circumstances of patient Side effect profile of drug Personal preferences • No clear cut evidence based medicine is available! • Clinical practice is based more on dogmatic teaching than on scientific knowledge • Empirical rather than rational

Principles of AED treatment • Diagnosis clearly established • Appropriate first line drug for syndrome and patient • One drug at a time as a rule: – If first drug ineffective add another first line drug and then withdraw first drug • Combination therapy only when single drug ineffective

What Is Chronic Epilepsy ? • Active 2 years after onset • Failed 2 first line AEDs • Great number of seizure in early history

Chronic Epilepsy 1 • Review history of epilepsy - Obtain and review old notes if possible - Interview patient and witness - Classify seizures • Review diagnosis - Non-epileptic events - Identifiable aetiology - High resolution MRI scanning • Question Compliance - Check serum AED levels • Review past and present AED treatment for efficacy and side-effects

Chronic Epilepsy 2 • Select the AED that is most likely to be efficacious and with the least side-effects • Adjust the dose of the selected drug to the optimum • Attempt to reduce and taper other AEDs • If seizures continue despite a maximally tolerated dose of a first-line drug: - Check compliance - tablet count, serum levels, counselling • Commence another first-line AED if there is one that has not been used to its optimum

Chronic Epilepsy 3 • If seizures continue try a combination of two AEDs • If combination unhelpful, AED which appears most effective and with fewer side-effects should be continued and the other AED replaced • If this drug is effective, withdrawal of the initial agent should be considered; if not, it should be replaced by another AED • Consider the possibility of surgical treatment • Consider using an experimental AED

Inappropriate use of AEDs • Inappropriate treatment of people who do not have epilepsy • Inappropriate drug treatment of patients who do have epilepsy • JME easily treated with some AEDs but poorly controlled with others • Partial epilepsies often misdiagnosed as generalised epilepsy • Incorrect dosages or inappropriate use of polytherapy • Overzealous adherance to “therapeutic” AED drug levels

AED drug levels monitoring § Measurement of AED levels: • • • drug toxicity occurs and needs to be documented suspected non-compliance suspected drug interactions during pregnancy (free levels) during systemic illness phenytoin therapy § Not a guide to dosing!

Who Should be Evaluated for Surgery • Partial seizures: simple, complex, sec gen. • Stereotyped onset • No non-epileptic attacks • No contraindication for Neurosurgery • Active epilepsy for >2 -3 yr, despite 3 + AEDs • Inadequate seizure control: > 1 -2 c p s /month • Acceptance of best risk / benefit ratio

Best risk vs benefit ratio of temporal lobe epilepsy surgery Medical Surgical Chance of seizure control 10% 70% Risk Morbidity from seizures 1/100 long-lasting impairment Psychosocial handicap hemiparesis, aphasia 1/100 Annual mortality 1/20 quandrantanopia prevents driving

Range of Epilepsy Surgery • 70% Anterior temporal lobe resection • 20% Extra-temporal cortical resection Lesionectomy • 10% Palliative Procedures » » Hemispherectomy Corpus callosotomy Subpial transection Vagal Nerve Stimulation

Components of Presurgical Evaluation Convergence of data – One epileptogenic & dysfunctional area – Rest of brain normal • • • Clinical Neuro-Imaging EEG Neuropsychology Neuropsychiatry Psychosocial

Psychosocial • • Realistic expectations? Improvement in life from seizure control? Intelligence, memory will not improve Not more attractive, employable Need to continue AEDs after Social support • Family, friends, community, finances

Neuro-imaging • Fundamental • MRI predicts nature and extent of pathology • Unusual to resect area with normal imaging • Poor results if imaging normal

Pathology and Outcome TLE: Anterior Temporal Lobe resection • Focal pathology: 70% seizure free, 25% >90% reduced • DNT, cavernoma>HS>AVM>trauma>MCD • 20% seizure free if no focal pathology Extra Temporal Lobe • Focal pathology: 60% seizure free, 20% >90% reduced • DNT, cavernoma, glioma>AVM>trauma • MCD 20 -30% seizure free, if focal • <20% seizure free if no focal pathology

Treatment Guidelines for Epilepsy • NICE = www. nice. org. uk – National Institute for Clinical Excellence (England Wales) • SIGN = www. sign. ac. uk – Scottish Intercollegiate Guidelines Network (Scotland) • AAN = www. aan. com – American Academy of Neurology (USA)

Primary Care Guidelines for Epilepsy • Referral of ALL who experience a suspected seizure – Seen within 14 days by specialist • • Risk and safety precautions documented Care Plan in place At least a yearly review Early re-referral if – – – Treatment failure Seizures not controlled Diagnostic uncertainty Considering pregnancy Considering drug withdrawal

Managing People With Epilepsy § Holistic issues: - Interest and continuity of care - Clear plan - Information provision - SUDEP - Easy access - Practical Issues: • Cooking, Bathing, Driving, Contraception, Conception - Reasonable Expectations: • Prognosis, Independent Living, Employment

AED Treatment: Conclusions § Correct diagnosis and classification paramount to treatment § AEDs are mainstay treatment § Treatment empirical rather than rational! § > 70% of patients become seizure free § Potential complications: toxicity § Low threshold for s/effects

AED Treatment: Conclusions § Potential for misuse of AEDs not to be dismissed § New AEDs may be better tolerated, but more effective? § Chronic side effect profile of new AEDs not fully known § Surgical treatment very successful but only possible in a few selected cases § Consider stopping AED if seizure free for years § New treatment still needed!