Epilepsy

1. Epilepsy Jesan Benjamin

2. Epilepsy “the recurrent tendency for spontaneous, intermittent, abnormal electrical activity in the brain”

3. Seizure “spontaneous, intermittent, abnormal electrical activity in the brain”

4. Epilepsy “the recurrent tendency for spontaneous, intermittent, abnormal electrical activity in the brain”

5. Epilepsy ≠ single disease Epilepsy = symptom that can result from a number of different disorders

6. PAROXYSMAL DISORDER short, frequent and stereotyped Sx

7. Clinically – What will you see? An alteration in one or more of a pt’s: • Consciousness • Motor Function • Sensory Function • Behaviour • Emotion

8. Epidemiology • Has always been stigmatised, overlooked and misunderstood • Most common serious neurological disease • Over 1.5 million in UK will have an epileptic seizure at some time • 370000 are affected by it in the UK • 75-80% become seizure free with treatment • M=F

9. Dr obliged to contact DVLA • Epileptics cannot fly (impact on job choice) • Cant drive HGVs (if had seizure in past 10 years) • Army can refuse to employ someone with epilepsy

10. Prevalence = 5-8 / 1000 (Age adjusted) • Incidence = 30-50 / 100,000 person years • Incidence peaks in childhood and in the elderly

11. Pathology • Abnormal synchronised discharge of many neurons – many millions fire at the same time • Normal inhibitory mechanisms are lost • Glutamate is main excitatory neurotransmitter, whilst GABA is inhibitory Seizure Threshold • Neurons in epilepsy are hyperexcitable • Seizures occur when neurons breach the seizure threshold • Every patient has their own individual seizure threshold

12. What causes epilepsy? • Can have a familial tendency • Can be related to trauma/physiological underlying cause • Usually NO CAUSE FOUND (70%)

13. Idiopathic 70% Cerebrovascular disease 13% Head Trauma 4% Tumours 3.6% Infection 2.6% Idiopathic Tumours Hd Injury Infection CVD

14. What causes epilepsy? Anybody will have a seizure if physiology is changed sufficiently. Including: • Metabolic disturbances • Hyponatraemia and hypoglycaemia • Drugs (recreational and anti-psychotics) • Alcohol (particularly withdrawal) • Cerebrovascular disease • Tumours • CNS infections • Cerebral anoxia • Development brain abnormalities • Degenerative brain disease Treat underlying cause – if none found then maintenance with anti-epileptic drugs (AEDs)

15. One seizure • About 50% who have their first seizure (without a cause) will have another within six months • Twice as likely to have a seizure if brain abnormality (trauma, stroke, meningitis) • If two seizures 80% will have others in future

16. Classifying seizures Symptoms of underlying brain dysfunction • Specific place: focal epilepsy • Widespread:generalised epilepsy

19. General seizures Tonic / clonic ( formally grand mal ) • Prior = dizziness/irritability • Sudden ‘epileptic cry’ (loud vocalisation – expulsion of air against closed glottis) • Loss of consciousness – falls to ground • Body stiffens ( tonic) – muslce spasms lasting seconds • Body jerks and convulses ( clonic ) • May turn blue / mouth froths • Tongue biting / incontinence • Confused drowsy during postictalstage • Recovery = ?headache, injury from fall

20. General seizures Absence seizures ( formally petit mal ) • Suddenly go blank, trance like state • Clouded consciousness • Unable to absorb and memorise information • Often in children (peak : 4-8)/ difficult to recognise

21. Partial ( focal ) seizures • Pattern demonstrates focal involvement of the brain • Focus in brain which functions abnormally • May have several foci or may develop secondary generalisation very rapidly • Described as point of origin in the brain

23. Todd’s Paresis • Focal weakness in part of the body after a seizure (13% seizures) • Typically affects limbs • Usually subsides completely within 48 hours • Can also affect speech, eye position and/or vision

24. Epilepsy following head trauma • Development of epilepsy depends on many factors: • Age : children > adults • Force of trauma • Identifiable damage (eg depressed skull # 80%)

25. Ix – diagnose, classify and find a cause • Good history from patient and witnesses • Neurological Exam • EEG • Blood Tests – to determine cause • MRI/CT – especially for epilepsy of later onset

26. DDx • non-epileptic attack disorder • difficult to prove • normal EEG during attack • asyncronous limb movements • due to psychological reasons • can co-exist with true epilepsy

27. DDx Syncope (fall in bp = cerebral hypoperfusion) • Often mis-diagnosis in young • Usually precipitant situation • Preceded by lightheadedness, sweaty feeling (prodrome longer than seizure – 30s to 5mins) • Usually unconscious for <30 seconds • Can get brief tonic-clonicactivity

28. DDx Febrile Convulsions • Seizures associated with fever • 3% normal children aged 3 months – 5 years • Usually brief and generalised • But does have risk of subsequent epilepsy of (2-5%)

29. Conservative Management • Avoid triggers (alcohol, drug misuse, exhaustion) • For generalised seizures – avoid the trigger of flashing lights • Studies have shown conservative management to be as good as pharmacologic management

30. Medical Management • Benefits: Diminished risk of injury/ death Reduces psychosocial consequences • Risks: Medication side effects Who should be treated after 1 fit? EEG/ Structural Deficit Who should be treated after 2 or more fits? Most (especially if within 2 years) Who should NOT be treated after 2 or more fits? Pregnant women

31. Medications • Partial Seizures in Adults • Carbamazepine • Phenytoin (Longer half life) • Partial Seizures in children • Carbamazepine or Valproate • Generalised Seizures in adults • Valproate • Generalised Seizures in Children • Valproate COMPLIANCE *****

32. Carbamazepine/ Lamotrigine = lower risk of teratogenicity (suitable for young women – also folic acid usually prescribed alongside) but increases metabolism of the OCP so must adjust dose • Sodium Valproate = lower risk of ataxia and falls (favoured in elderly) – BUT very teratogenic

33. Principles of medical management • Use one drug • Titrate drug UP against response and adverse effects • Ensure compliance • Only in refractory cases should more than one drug be trialed

34. 75% of all incidence patients will enter remission (seizure free  5yrs) • If seizures ongoing at 1 year after onset then <60% remit • If seizures ongoing for >4 years then <10% will remit • Early use of anticonvulsants does not influence the prognosis for seizure control!

35. Sclerotic Hippocampus Surgery • Intractable Drug Resistant Epilepsy • Best Results in Complex Partial Epilepsy with Mesial Temporal Sclerosis ( 80% cure)

36. Evidence Based Review of surgery 1975-97 (n=1100) • 70% seizure free on long term follow up (80-90%) • 10-14% unimproved • Surgical risk is comparable to risk of prolonged pharmacotherapy • Mortality in the Surgical group is less • Surgery is cost effective over a lifetime

37. STATUS EPILPETICUS • MEDICAL EMERGENCY (as can lead to permanent brain damage/death) Either: One continuous, unremitting seizure lasting > 30 minutes OR Recurrent seizures without regaining consciousness between seizures for > 30 minutes

38. ABC • Control seizure and then find out what is going wrong • 1st line: 10mg diazepam IV or rectally • Urgent blood, glucose and toxicology screen • 2nd line: phenytoin infusion • 3rd line: general anaesthesia (if seizures persist despite 1st and 2nd line treatment)

39. If you see a seizure • Remove objects on which the individual may harm themselves • Do not restrain convulsion • If convulsion lasts >10 minutes then call an ambulance • Do not restrain patient after a convulsion