Epilepsy and seizure

1. Epilepsy and seizure Specialty Clerkship Student Seminar Group B2 Chan Ying Ting, Purdy Siu Lok Man, Joanne Lee Wai Yip, Jacky

2. OUTLINE • Prevalence and genetics • Etiology • Terminology • Classification of seizure • Epilepsy syndromes • Case studies • General management of seizures

3. PREVALENCE IN CHILDHOOD • 75% with onset before age of 20 years • Prevalence: • 4.1/1000 in children up to 11 years old(National Child Development study,1983); • 4.71/1000 in children up to 19 years old(Oklahoma study,1989) • Incidence: 49/100,000 population

4. Offspring risk for epilepsy to age 20 • General population:1% • Mother with epilepsy: 6% • Father with epilepsy: 2.4% • Sibling risk for epilepsy to age 20 • General population: 1% • Proband with epilepsy: 3% • Proband with 1 parent affected: 8%

5. ETIOLOGY Febrile • Febrile convulsion • Convulsion with fever • Intracranial infection Non-febrile • Metabolic disturbance • Trauma • Poisons / toxins / recreational drugs • Cerebral dysgenesis / malformation • Cerebral damage / cerebral tumor • Neurocutaneous syndromes

6. TERMINOLOGY • Seizure—transient involuntary alteration of consciousness, behavior, motor activity, sensation and/or autonomic function due to abnormal discharge of cortical neurons; an episodic event, may have provoking factors, e.g. anoxia, alcohol, drugs • Convulsion– seizure with prominent alteration of motor activity • Epilepsy—a disorder with recurrent seizures(2 or more), unprovoked by a specific event such as fever, trauma, infection, or chemical change, stereotypic • Aura—a component of seizure which occurs before consciousness is lost and for which memory is retained afterwards; it localizes attack to the point of origin in the CNS • Automatisms--coordinated adapted involuntary motor activity occurring during the state of clouding of consciousness; usually followed by amnesia of the event

7. Tonic seizure: excessive motor outflow, giving rise to a tetanic state of the muscles involved. • Atonic seizure: muscle tone drops to a very low values resulting in a sudden fall of the body • Clonic seizure: a tonic seizure with periodic interruptions • Tonic-clonic seizure: starts as a generalized tonic seizure and then interrupted during clonic phase and ending in complete relaxation. • Myoclonic seizure: short involuntary contraction of one or more muscles (local or generalized)

8. CLASSIFICATION OF SEIZURE Seizures Partial Generalized Absence seizures Myoclonic seizures Clonic seizures Tonic seizures Tonic-clonic seizures Atonic seizures Simple Complex Partial with secondary generalization * ILAE classification of seizures 1981

9. Partial vs Generalized • Partial: if only one hemisphere is involved • Simple—no impairment of consciousness, features depend on the region of the brain that is affected • Complex—consciousness impaired, may have automatisms e.g. chewing, wandering off, dressing, undressing • Generalized: most or both hemispheres are involved, loss of consciousness • Primary VS secondary

10. Simple Partial Seizures • Preserved consciousness (“aura”) • Symptoms related to involved brain regionsa • Frontal lobe: movement, thought, speech • Temporal lobe: memory, speech, smell, taste, abdominal sensations • Parietal lobe: body sensations • Occipital lobe: vision

12. Complex Partial Seizures • Altered consciousness • Unresponsive or less responsive, staring • Impaired memory after seizure -Automatisms: hand and mouth movements (lip smacking, grabbing) • Hypermotor: wild flailing movements (frontal)

13. Generalized Seizures • Most have abnormal, unnatural movements • Tonic (stiffening) • Clonic (repetitive jerking) • Tonic-clonic (“grand mal”) • Atonic (limp) • Myoclonic (irregular jerking, may retain awareness) • Atonic (falling suddenly) • Absence (“petit mal”): staring, may blink, arrest of activity

14. EPILEPSY SYNDROMES • Genetic causes: • Familial neonatal convulsions • Benign familial convulsions of infancy • Benign partial seizures of infancy • Febrile seizures • Epilepsy syndromes: • Infantile spasms(West syndrome) • Lennox-Gastaut syndrome • Absence epilepsies • Juvenile myoclonic epilepsy • Benign rolandic epilepsy

16. (1)Infantile spasms (West syndrome) • Onset: between 4 and 6 months of age • ‘salaam spasms’ • Flexor spasms last 1-2 s and are often multiple, occurring in bursts of 20-30 spasms, frequently on waking • Infants will have developmental delay and later learning disability or epilepsy. • Treatment: vigabatrin or corticosteroids.

17. (2)Lennox-Gastaut Syndrome • Affects children of 2-5 years old • Multiple presentation of seizures • Later, neuro-developmental arrest or regression and behaviour disorder • Treatment: Sodium valproate • Poor prognosis

18. (3)Childhood Absence Epilepsy • Onset at 3-12 years • Peak at 6-7 years • Second peak at 11-12 years • Females more than males • Family history in 15-44% • Rarely associated with developmental problems. • Can be induced by hyperventilation.

19. Treatment: Sodium valproate • Good prognosis with 95% remission in adolescence. • Risk of generalized TC seizures is 30-40%(increased risk if begin after the age of 8 years)

20. (4)Juvenile Myoclonic Epilepsy (JME) • Autosomal dominance with variable penetrance • A common cause of tonic-clonic seizures in teenagers and young adults(myoclonus paricularly in morning) • Myoclonic seizures precede tonic-clonic seizures by 2-3 years; tonic-clonic seizures typically occur when patient reaches 10-17 years • Prognosis excellent but requires lifelong treatment

21. (5)Benign Rolandic Epilepsy • Most common partial epilepsy • Onset 2-12 years • M:F 1.5:1 • Usually occuring in sleep-wake transition states • 10-13% have a single seizure • 20% have frequent seizures • 65% nocturnal • 15% nocturnal or diurnal • 10-20% waking state only

22. Typical presentation: • On waking, fully conscious, mouth to one side, salivating and focal twitching of one side of the face • Duration 1-2 mins; • Child may recall a sensation of numbness, pins and needles or “electricity” in the tongue, gums or cheeks; • Remains conscious but aphasic post-ictally • Secondary generalization may be seen • Remits spontaneously in adolescence; no sequelae • No medication if infrequent seizures.

23. CASE STUDIES

24. History • M/9 • Normal development until 9 years old • Encephalitis at age 9 with coma and 2 generalized seizures • P/E: stupor, ?visual hallucinations, ataxia • CT and MRI normal • Medullobastoma discovered at age 11, died at age 16

25. Complex partial seizure evolving into secondary generalized seizure • Seizure started as complex partial motor seizure because there is impaired consciousness • Classical Jacksonian march is observed but it’s not a Jacksonian seizure since it’s not a simple partial seizure • Then evolves into a generalized tonic-clonic seizure

26. History • M/20 • Caesarian section, anoxia, hemiconvulsions at birth, normal development • Seizure onset again at 9 years old • CT atrophic parieto-occipital zone; MRI large right parieto-occipital lesion probably due to birth trauma • Tx: carbamazepine, clobazam, vigabatrin, clorzepate, lamotrigine • Lives independently with a job

27. Complex partial seizure with automatisms • Aura (secs-mins): unresponsive, dreamy (may also have hallucinations, affect changes, déjà vu) • Automatism (occur in 90%): turning head to left, lip smacking (basically any continuation of an activity that was going on when the seizure occurred) • Alterations of mood, memory, perception (hence complex partial) • Posticteral drowsiness: confused and disoriented for minutes afterwards

28. History • F/28 • Previously healthy, no neurologically relevant diseases or family history • Age of onset 7 • MRI shows slight dilatation of R lateral ventricle; discrete hyperintense signals in frontal lobes • SPECT: low-flow area in L temporal and frontal lobes and R temporal lobe

29. Simple then complex seizure with secondary generalization • Starts off as simple partial seizure with autonomic involving ie. epigastric rising sensation • Although she is unable to speak, she raises as left hand as if to signal that she can understand • This is followed by a complex partial seizure as there is automatism (hand-rubbing and lip smacking) and unresponsiveness • Finally there is a tonic-clonic generalized seizure

30. History • F/8 • Previously health, no neurologically relevant diseases, remote family history of epilepsy • P/E normal, neruoimaging not done • Frequent daily spells with LOC since 8 • interictal EEG: generalized regular 3Hz spike with some polyspikes; normal background activity

31. Absence seizure - typical • Onset in childhood • Child stops activity, stares, blink/roll eyes, unresponsive • Usually lasts 5-10 secs but may occur hundreds of times/day • Usually there is an additional feature like automatism, mild clonus, or change in tone (eg. drop attacks) • May be induced by hyperventilation

32. History • M/17 • Newphew of father and son of the newphew both have epilepsy • Onset of seizure at age 15, treated with carbamazepine but still has daily convulsions

33. Myoclonic – juvenile myoclonic epilepsy • Sudden, brief, generalized muscle contractions • Most common type is the juvenile myoclonic epilepsy (Janz syndrome) which occurs after puberty and doesn’t remit with age • Also occurs in degenerative and metabolic disease • Another type is themyoclonic absence type

34. History • M/6 • Good past health and no family history • P/E: hypotonic muscles • CT showed mild diffuse cerebral atrophy • Refractory to all available antiepileptic drugs

35. Generalized clonic seizure • Clonic seizure is quite rare, even in this caes there is a very short tonic start • Differentiate from myoclonic seizures by the sustained rhythmical nature of the jerks

36. History • M/14 • Good past health, no family history • Onset at 2 years 9 months • One month before onset, he had severe measles • Refractory to all available antiepileptic drugs

37. Generalized tonic seizure • This particular case is unusual in that despite the tonic bending posture, the boy keeps on walking without falling

38. History • M/7 • Normal pregnancy and delivery and no family history • P/E: marked ataxia, severe MR, dull, protruded tongue, hypertonia, hyper-reflexia, spontaneous mild jerks of limbs • CT showed central and peripheral cerebral atrophy

39. Generalized tonic-clonic seizure • Many generalized tonic-clonic seizure have more than one tonic and clonic phase • Tonic phase: contraction of muscles – flexion/extension of limbs, twitching of eyelids, respiratory muscles in spasm (cyanosis), LOC • Clonic phase: violent jerking of face and limbs, tongue biting, incontinence • In this case there is a pronounced tonic stretching of the limbs follow by a clonic phase

40. History • M/4 • Premature birth with injury • Febrile convulsions in paternal cousin • P/E: sever MR • CT showed moderate diffuse cerebral atrophy

41. Generalized Atonic seizure • Many seizures in this type of children are a mixture of atonic, tonic, and myoclonic elements • Differentiation depends on analysis by combine EEG and EMG to see which element is more predominate

42. GENERAL MANAGEMENT OF SEIZURES

43. Aim • To confirm it is a genuine seizure attack • Etiology of the seizure attack • Epilepsy + classification • Convulsion with a febrile illness • Simple febrile convulsion • CNS infection • Severity of the attack / any associated injury • Management plan • Prognosis

44. Is it a genuine seizure attack? • Symptoms before onset of seizure (prodrome) • Aura (sensation / motor) • Behavioural change (mood / behaviour) Presence of prodrome strongly suggest partial onset seizures

45. Symptoms during the seizure • Loss of consciousness? • Temporal relationship with other symptoms • LOC right from the beginning? • Secondary generalization? • Other symptoms • Vocal symptoms • Motor symptoms • Respiration • Autonomic symptoms

46. Symptoms following seizure • Amnesia of the event • Confusion / lethargy / sleepiness • Headache or muscle ache • Transient focal weakness (Todd’s paresis) • Nausea or vomiting

47. The child is febrile • Simple febrile convulsion? • Check for the criteria • CNS infection? • Ask more on associated symptoms of meningitis / encephalitis • Epilepsy? • Any provoking factors • Trauma • Toxin / drug / alcohol consumptions • Flashes / sleep deprivation / physical exhaustion • Causes • Previous CNS insult / developmental milestones • Preceding neurological deficits • Intracranial SOL / increased ICP • Associated symptoms of neurocutaneous syndrome • Family history

48. Systemic screening • Pediatric history • Past health • Drug history • Birth history • Immunization history • Developmental history • Social history

49. Known history of epilepsycurrently on medication • Possible causes of breakthrough seizure • Poor drug compliance • Sleep deprivation • Infection / fever • Recent change of drug regimen

50. Physical examination • Febrile • General condition / vital signs  septic? • Anterior fontonelle pressure / GCS / neck stiffness / kernig’s sign / papilloedema  CNS infection? • Rash / focal signs of infection  source of febrile illness • Epilepsy • Dysmorphism / head circumference • Skin features (adenoma sebaceum / shagreen patch / multiple cafe-au-lait spots / nevus flammeus) • Neurological examination  any focal neurological deficits