Epilepsy

1. Epilepsy Dr. Suhail Al-Shammari Associate Professor of neurology and consultant neurologist

2. Epilepsy: Objectives • To provide definition of epilepsy-ILAE • Explain classification of epilepsy, semiology and differential diagnosis of epilepsy • Describe epileptic syndromes • Evaluation and diagnosis • Treatment

3. Classification of Epilepsy • The International League Against Epilepsy (ILAE) have classified epileptic seizures into groups using clinical data and electroencephalography (EEG) evidence • They have also produced a classification of epilepsy syndromes

4. Practical definitions: Seizure • Is a transient behavioral, somatosensory, motor, or visual symptom or sign and caused by abnormally excessive, synchronous neuronal activity in the brain • Provoked : trauma, brain hemorrhage, metabolic dyscrasias or drug exposure • Spontaneous • Some patients may have recurrent provoked seizures without having epilepsy

5. Practical definitions: Epilepsy-ILAE-2014 • A disease with either recurrent unprovoked seizures : • 2 or more seizures occurring at least 24 hours apart • A single seizure accompanied by evidence of heightened risk for future seizures exist • Diagnosis of epilepsy syndrome • Seizure type and epilepsy syndrome diagnosis: • Description of seizure behavior • EEG pattern • Aided by neuroimaging, and genetics

6. Incidence and Prevalence • Incidence: 50 - 120 per 100 000 per year • Prevalence: 5 - 8 per 1000 • 3 - 5% of the population will experience at least one seizure in their lifetime • Greatest risk at extremes of life • Nearly 75% of first seizures are in those under the age of 20

7. Incidence of Seizures

8. First Time Seizure: Five-Step Approach • Ictal semiology • Is it really a seizure? • Is it the first seizure? • Determine whether treatment is needed • What agents are appropriate?

9. Classification of Epilepsy: Causation • Idiopathic epilepsy: is not associated with an identifiable cause often presumed genetic • Cryptogenic: unknown, but with a likely causative pathology has not yet been identified • Symptomatic epilepsy: The etiology is known and the brain is disordered or diseased before or between seizure episodes . • e.g. a tumour, a stroke, traumatic brain injury, developmental abnormality, metabolic abnormality etc.

10. Epilepsy - ILAE Classification • Generalised Seizures: • Absence seizures e.g. petit mal • Atypical absence • Myoclonic seizures • Clonic seizures • Tonic seizures • Tonic-clonic seizures • Atonic seizures

11. Epilepsy - ILAE Classification • Partial Seizures (seizures beginning focally) • Simple - these may have motor features, sensory symptoms etc but consciousness is not impaired • Complex - at some point consciousness is impaired and the seizure may become generalised

12. First Time Seizure: Five-Step Approach • Ictal semiology • Is it really a seizure? • Is it the first seizure? • Determine whether treatment is needed • What agents are appropriate?

13. Ictal Semiology • Generalized tonic-clonic seizures • Most easily recognized • Most frequently leads to emergency consultations • Eye witness account often unreliable • Usually lasts for about 1-3 minutes

14. Generalized tonic-clonic seizures (GTCS): Phases • Partial seizure: Secondary generalization • The patient may have a recollection of the aura • No recollection of aura, GTCS of generalized onset or develop from complex partial seizure • Onset of generalization: Heralded by a forced head movement to one side (versive) or by brief vocalization • Pretonic clonic phase: Generalization begins with irregular, asymmetric clonic jerking of the extremities

15. Generalized tonic-clonic seizures (GTCS): Phases • Tonic phase: Generalized and sustained contraction of all the muscles in the body • Clonic phase: Slower muscle jerking, decreases in frequency before stopping • Postictal state: The patient lies limp in deep sleep • After several minutes awakens confused and may have headache and muscle pain

16. Temporal lobe Seizure - Generalization

17. Gelastic Seizure

18. Generalized Seizures: Absence • Onset in childhood or adolescence • Typical Absence: • Last for few seconds with abrupt onset and termination • Characterized by unresponsiveness, a fixed blank stare, eye fluttering and facial twitching • Increased or decreases in postural tone • Brief clonic jerks • Automatism • The patient may or may not be aware of the attack • Resume pre-ictal activity as soon as seizure is over

19. Absence seizures

20. Generalized Seizures: Myoclonic • Myoclonus: Sudden involuntary brief jerk of a muscle or a group of muscles • Tends to occur in children, may also begin in adolescents or young adults in juvenile myoclonic epilepsy

21. Generalized Myoclonic Seizure

22. Generalized Tonic Seizure

23. Generalized Seizures: Atonic • Sudden drop attacks: • The patient suddenly loses tone and falls to the ground • Associated with: • Mental retardation • Lennox-Gastaut syndrome

24. Partial Seizures • Begins in focal area of the brain • The most common seizure type in adults • Produces vast array of manifestation: • Motor • Sensory • Perceptual • Behavioral

25. Simple Partial seizure (SPZ): Motor • Arises from motor cortex • Forced head deviation to one side • Speech arrest or vocalization • Stereotyped limb or facial movements • Twitching or jerking or coordinated almost purposeful appearing movements • Jacksonian marsh: Sequential spread of the seizure into the ipsilateralface, arm and leg occurs over seconds • Todd’s paralysis: Muscle weakness persists for several minutes-hours

26. Simple Partial seizure: Sensory • May affect any sensory modality • Visual: • Seeing spots, stars, bright light • Auditory: ringing, buzzing, musical sounds • Somesthetic: tingling, numbness, electrical sensation • Olfactory: burning rubber. Other foul odors • Gustatory: acidic. Bitter, sweet taste • Vestibular: vertigo • Epigastric: sensation of rising in abdomen, descending a rollercoaster, butterflies in the stomach • Primary sensory cortex: unformed and primitive • Higher level association/mesial temporal: detailed

27. Simple Partial seizure: Behavioral and Psychic • Produces a wide variety of psychic or behavioral phenomena • Déjà vu: the sensation of visual familiarity • Déjà vu entendu: auditory familiarity • Jamais vu/ Jamais entendu: sense of unfamiliarity • Temporal lobe: a dreamlike, sense of watching themselves (autoscopy) • Depersonalization, fear, pleasure, religious ecstasy and forced thinking

28. Complex Partial seizure (CPZ): • Partial seizures characterized by impairment of consciousness • Frequently arise from SPS and may progress to GTCS • Often accompanied by automatic repetitive stereotyped behaviors: • Temporal: simple • Lip smacking, chewing, swallowing, grasping, fumbling • Frontal: More complex: orbitofrontal • Bicycling, pelvic thrusting

29. Frontal lobe seizure

30. Epileptic Syndromes

31. Lennox-Gastaut Syndrome • Occurs in children • Multiple seizure types: • Generalized tonic clonic • Atypical absence • Atonic • EEG: slow spike and wave discharges • Impaired cognitive function • Associated with CNS disease • Poor prognosis

32. Juvenile Myoclonic Epilepsy - An example of an epilepsy syndrome • 3 - 11% of all patients with epilepsy • onset between 6 and 22 years • characterised by myoclonic jerks, worst in the morning • generalised tonic-clonic seizures, mainly in the morning • 40% also have absence attacks

33. Differential Diagnosis of Epilepsy • Syncope - postural, cardiac etc • Non - epileptic or psychogenic attacks • Migraine: history of headache, aura develop over minutes • Transient ischemic attacks; risk factors, maximum, negative symptoms at onset • Sleep disorders • Metabolic disorders e.g. hypoglycaemia • Narcolepsy

35. Syncope vs Seizures • Syncope • upright posture • pallor common • gradual onset • injury rare • incontinence rare • rapid recovery • precipitants common • Seizure • any posture • pallor uncommon • sudden onset • injury quite common • incontinence common • slow recovery • precipitants rare

36. Diagnostically Relevant Factors • Age • Sex • Social history • Past medical history including head injury, birth trauma and febrile convulsions • Past psychiatric history • Alcohol and drug use • Family history

37. Determining Seizure Etiology • History • From patient • From witness • Laboratory studies • Neuroimaging • Electroencephalography (EEG)

38. History from the Patient • Frequency of attacks • Circumstances and trigger factors • Symptoms before, during and after attack • Duration of attacks • injury, tongue biting or incontinence

39. History from Witness • Frequency of attacks • Detailed description of observations before and during attacks - including level of responsiveness, motor phenomena, pulse, colour, breathing, vocalisation • Detailed description of behaviour following attacks

40. Laboratory Testing • Complete blood count • Chemistry studies: • Electrolytes, calcium. magnesium, phosphorus • Renal and liver function tests • Urinalysis • Toxicology screen • Therapeutic drug levels • Lumbar puncture • Fever or suspicion of meningitis or encephalitis • Immunosuppression

41. EEG • The EEG is not a diagnostic test for epilepsy • It will be abnormal in only about 50% of those with clinically definite epilepsy • It can be abnormal in those with no history of seizures • It may help to define the type of epilepsy

42. Figure 1-1. Scalp-recorded EEG change during a habitual event showing the onset of a left temporal lobe seizure. This study was performed in the epilepsy monitoring unit with video-EEG recording. Bipolar montage.

43. Figure 1-2. EEG of a patient with focal seizures of right frontal lobe origin that reveals right superior frontal (F4) and midfrontal (Fz) spike discharges during sleep.

44. Figure 1-3. EEG during photic stimulation of a patient with a generalized seizure disorder showing a photoparoxysmal response. Ipsilateral ear reference montage.

45. Figure 1-4. EEG during a psychogenic nonepileptic seizure. A, EEG during psychogenic nonepileptic seizure revealing a prominent artifact related to muscle activity and movement during the “convulsive” behavior. B- EEG immediately after the motor activity has ceased showing a normal awake background without epileptiform activity. The patient appeared unresponsive at this time. This study was performed in the epilepsy monitoring unit with video-EEG recording. Bipolar montage.

46. Neuroimaging in Epilepsy • NOT essential in all cases e.g. juvenile myoclonic epilepsy, • Useful to exclude underlying lesion e.g tumour in older individuals and those with clear-cut history of seizure of focal onset • MRI is increasing used to assess patients for epilepsy surgery • Slowly growing tumour • Encephalitis • Ischemic stroke

47. Bottom-of-Sulcus Dysplasia

48. Transmantle Sign in Cortical Dysplasia

49. Treatment

50. Drug Treatment of Epilepsy • Select AED according to seizure type (s) and to a patient specific characteristics • Use a single drug if possible (monotherapy) • Use multiple drugs (polytherapy) if necessary • When adding an AED start slow and go slow, titrate to maximum tolerated dose if necessary • Consider changing timing of dosing to reduce toxicity • Use pharmacokinetic principles to adjust doses • Adjust dose for drug-drug interactions • Beware interactions with other drugs including oral contraceptive pill