TYPES OF EPILEPSY AND THEIR MANAGEMENT

1. DR MUHAMMAD OMAR JAMIL MD TYPES OF EPILEPSY AND THEIR MANAGEMENT

2. Definition of Seizures • Seizures are sudden, transitory, and uncontrolled episodes of brain dysfunction resulting from abnormal discharge of neuronal cells with associated motor, sensory or behavioral changes • Seizures are usually unpredictable • Seizures are usually brief (< 5 minutes) • They usually stop spontaneously

3. Cellular Electrophysiology • Selectively Permeable Membrane - Channels • Depolarising Shift • Epileptic Focus

4. Cellular Electrophysiology Membrane Potential The Na+ / K+ Pump http://www.biologymad.com/NervousSystem/nerveimpulses.htm

6. Classification of Seizures

7. Types of s (focal) Primary

8. ILAE Classification of Seizures

9. Partial (Focal) Seizures I. Simple Partial Seizures (Jacksonian) • Involves one side of the brain at onset. • Focal w/motor, sensory or speech disturbances. • Confined to a single limb or muscle group. • Seizure-symptoms don’t change during seizure. • No alteration of consciousness. EEG: Excessive synchronized discharge by a small group of neurons. Contralateral discharge.

10. Partial (focal) Seizures II. Complex Partial Seizures(Temporal Lobe epilepsy or Psychomotor Seizures) • Produces confusion and inappropriate or dazed behavior. • Motor activity appears as non-reflex actions. Automatisms (repetitive coordinated movements). • Wide variety of clinical manifestations. • Consciousness is impaired or lost. EEG: Bizarre generalized EEG activity with evidence of anterior temporal lobe focal abnormalities. Bilateral.

11. Tonic-Clonic seizures Absence Seizures Atonic Seizures Tonic Seizures Clonic and Myoclonic Seizures Infantile Spasms Generalized Seizures

12. Neuronal Correlates of Paroxysmal Discharges Generalized Seizures

13. Generalized Tonic-Clonic Seizures Recruitment of neurons throughout the cerebrum Major convulsions, usually with two phases: 1) Tonic phase 2) Clonic phase

14. Generalized Tonic-Clonic Seizures Tonic phase: - sustained powerful muscle contraction (involving all body musculature) which arrests ventilation. EEG: Rythmic high frequency, high voltage discharges with cortical neurons undergoing sustained depolarization, with protracted trains of action potentials.

15. Generalized Tonic-Clonic Seizures Clonic phase: - alternating contraction and relaxation, causing a reciprocating movement which could be bilaterally symmetrical or “running” movements. EEG: Characterized by groups of spikes on the EEG and periodic neuronal depolarizations with clusters of action potentials.

16. Neuronal Correlates of Paroxysmal Discharges

17. General Seizures II. Absence Seizures (Petite Mal) • Brief and abrupt loss of consciousness. • Sometimes with no motor manifestations. • Usually symmetrical clonic motor activity varying from occasional eyelid flutter to jerking of the entire body. • Typical 2.5 – 3.5 Hz spike-and-wave discharge. • Usually of short duration (5-10 sec), but may occur dozens of times a day.

18. II. Absence Seizures (Petite Mal) (con’t) • Often begin during childhood (daydreaming attitude, no participation, lack of concentration). • A low threshold Ca2+ current has been found to govern oscillatory responses in thalamic neurons (pacemaker) and it is probably involve in the generation of these types of seizures. EEG: Bilaterally synchronous, high voltage 3-per-second spike-and-wave discharge pattern. spike phase: neurons generate short duration depolarization and a burst of action potentials. No sustained depolarization or repetitive firing.

19. III. Atonic Seizures (atypical) • Loss of postural tone, with sagging of the head or falling. • May loose consciousness. IV. Tonic Seizures • Opisthotonus, loss of consciousness. • Marked autonomic manifestations.

20. V. Clonic Seizures • Rhythmic clonic contractions of all muscles, loss of consciousness, and marked autonomic manifestations. VI. Myoclonic Seizures • Isolated clonic jerks associated with brief bursts of multiple spikes in the EEG. VII. Infantile Spasms • An epileptic syndrome. • Attacks although fragmentary, are often bilateral. • Characterized by brief recurrent myoclonic jerks of the body with sudden flexion or extension of the body and limbs.

21. Cellular and Synaptic Mechanisms of Epileptic Seizures (From Brody et al., 1996)

22. What is epilepsy? “A disorder of the brain characterized by an enduring predisposition to generate epileptic seizures and by the neurobiologic, cognitive, psychological, and social consequences of this condition. The definition of epilepsy requires the occurrence of at least two epileptic seizures.” -International League Against Epilepsy, 2005

23. Epilepsy • A disease characterized by spontaneous recurrence of unprovoked seizures (at least 2) • Seizures are symptoms, while epilepsy is a disease, so those terms should not be used interchangeably • Epilepsy = “seizure disorder” • Epilepsy is a syndromic disease • Each epilepsy syndrome is determined based on; Type of seizures, age at seizure onset, family history, physical exam, EEG findings, and neuroimaging

24. Epidemiology • Peaks in incidence in childhood and later life. Late adulthood is now the most common time to develop new-onset seizures.

25. What is an epileptic seizure? • A transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. • Commonly generated in cortex and hippocampus, may also be subcortical

26. Classification of Epilepsy • ILAE classification of epilepsy and epileptic seizures in 1989 • Depends on 2 distinctions; • Location of pathology (Localized or generalized) • Know or presumed etiology • Idiopathic • Symptomatic • Cryptogenic

27. ILAE Classification of Epilepsy

28. Evaluation - Differential Diagnosis • When a paroxysmal event occurs, especially if associated with loss of consciousness; • Is this event (spell) a seizure ? • If it is a seizure, is it provoked or unprovoked? • If it is an unprovoked seizure, what is the chance of recurrence? (making decision about treatment) • Does this patient have epilepsy? What type? • What is the appropriate treatment? • “Diagnosis of epilepsy is a clinical one” • History is the key

29. Common differential diagnoses of seizures • Neurological • TIA • Migraine • Cardiac • Vasovagal syncope • Arrhythmias • Metabolic • Hypoglycemia • Psychiatric • Non-epileptic seizures

30. Helpful elements of history • Childhood seizures including febrile seizures • Head trauma • Symptoms of infection • Sleep deprivation • Family history of epilepsy • Drug and Alcohol use

31. Helpful elements of history • Before the event • Provoking factors • Preceding symptoms • Duration of symptoms

32. Helpful elements of history • During the event • Motor symptoms • Level of consciousness • Injury • Incontinence • Duration

33. Helpful elements of history • After the event • Confusion • Focal neurologic signs • Duration

34. Physical examination • General examination • Injury • Signs of infection • Neurological examination • Assess mental status • Post-ictal state • Any evidence of ongoing seizures • Look for focality, may be indicative of an underlying lesion or a Todd’s paralysis

35. Clinical Characteristics of Pseudoseizures • Strongly Suggest • Prolonged duration of the event (10-30 minutes) • Preservation of consciousness despite whole body jerking • Bizarre and asynchronous motor movements • Pelvic thrusting movements • Not stereotyped • Strongly Against • Injuries sustained during spells • Tongue laceration (especially the sides of the tongue) • Incontinence

36. Establishing a Diagnosis • Could be very challenging • Tests (EEG, MRI) may help • Diagnosis is established clinically • Consider seizures even if not sure • Initiate treatment

37. Approach to Diagnosis • Was the episode a seizure? • Is so, what type of seizure? • What is the underlying etiology? • What is the best management?

38. Classification of seizures • Divided according to the origin of the seizure: • Generalized • Partial (aka focal) • Described by clinical manifestation

39. Approach to Diagnosis • Was the episode a seizure? • Is so, what type of seizure? • What is the underlying etiology? • What is the best management?

40. Underlying etiology: provoked vs. unprovoked • A provoked seizure is one that occurs in the setting of a medical condition known to cause seizures and is not necessarily indicative of a predisposition to further seizures • The treatment is to correct the underlying abnormality

41. Underlying etiology: provoked vs. unprovoked • An unprovoked seizure has no clear underlying cause, and increases the risk of further seizures • Caveat: The same “provokers” that cause seizures may also unmask a seizure disorder by lowering the seizure threshold

42. Conditions that provoke seizures • Metabolic abnormalities • Hypoglycemia • Hypo and hypernatremia • Hypo and hypercalcemia • Hypomagnesemia • Uremic encephalopathy • Hepatic encephalopathy • Systemic infection

43. Conditions that provoke seizures • Sleep deprivation • Drugs • Intoxication with stimulants • Amphetamines • Cocaine • Withdrawal from sedatives • Alcohol • BZD • Barbiturate

44. 0 1 5 10 20 60 Etiologies of Epilepsy by Age Congentital Anomalies TS Storage diseases Cerebral Tumors Febrile seizures Head Injury Birth trauma ICH Hypoxia Hypoglycemia Hypocalcemia Genetic Epilepsies Drugs and Alcohol Cerebrovascular Disease Age (years)

45. Diagnostic evaluation • Routine lab work: CBC, electrolytes, LFTs • Neuroimaging: MRI brain (with contrast if malignancy suspected or immunocompromised) • EEG

46. MRI • Used to rule out mass lesion (especially in middle-aged patients) • May show chronic microvascular ischemic change

47. EEG • Routine recording is 30 minutes • Rare to capture a seizure • Looking for: • Background rhythm. May be generally slow in dementia. Focally slow with tumor or stroke • “Epileptogenic” features, like sharp waves or spikes • May be normal or non-specific in ~50% of seizure patients

48. EEG

49. EEG

50. Approach to Diagnosis • Was the episode a seizure? • Is so, what type of seizure? • What is the underlying etiology? • What is the best management?