What is Epilepsy

1. Over-responsiveness to brain state changes and to transient sensory stimuli Seizure triggers: Sleep deprivation Stress Drugs or alcohol Menstrual cycle Nutritional deficiencies, low blood sugar Other meds Hyperventilation Flashing lights or sounds (like from a video game or TV – 1991 Pokemon) i.e., Transitions Associated with cortical or subcortical hyperexcitability What is Epilepsy

2. History of the “Falling Sickness” • 4th century account of epileptic attack differs little from current textbook description of a generalized tonic-clonic seizure: • "After various premonitory signs the patient falls down, stretched out or twisted, and in this condition he remains for some time. After these tonic convulsions he passes into the stage of clonic convulsions and a condition where he appears to be sleeping. The attack is followed by complete amnesia." • Guainerius in 1516 recommended placing an object between the teeth of a person undergoing a convulsion.

3. Mohammed is reported to have had seizures since age 3 and to have said, "This is a common affliction of prophets, of whom I wish to be counted as one." St Paul Julius Caesar Napoleon Tolstoy Socrates Numerous painters, writers, composers, leaders… The Sacred disease

4. Joan D’Arc • Joan often felt that the secrets of the universe were about to be revealed to her • Seizures were triggered by ringing church bells. • A musicogenic TLE, with ecstatic aura. • Musicogenic epilepsy is generally triggered by particular music which has an emotional significance to the individual. • Joan's voices (St Catherine) and visions propelled her to become an heroic soldier in the effort to save France from English domination. She was burned at the stake as a heretic when she was 19 years old in 1431.

5. Fyodor Dostoyevsky on TLE      'You are all healthy people, but you have no idea what joy that joy is which we epileptics experience the second before a seizure... I do not know whether this joy lasts for seconds or hours or months, but believe me, I would not exchange it for all the delights of this world.' » continue...

6. Temporal Lobe Epilepsy Sx • Interictal traits • Hypergraphia • Hyperreligiosity • “Stickiness” or clinginess • Altered interest in sex • Undirected and transient aggressiveness • Perhaps due to Amygdala overactivation, which acts as a brake on engagement

8. Common Myths • Seizures cause additional brain damage… Not usually • Single tonic-clonic seizures lasting 5-10 minutes are not thought to cause brain damage. • However, more frequent and prolonged tonic-clonic seizures may in some patients injure the brain. • Epilepsy is a life-long disorder for all – not always. • Half of childhood epilepsies are outgrown by adulthood. • When a person has been free of seizures for 1 to 3 years, medications can be slowly withdrawn and discontinued under a doctor's supervision. • Seizure disorder is another term for epilepsy (clarity of definition, not a myth per se)

9. 1 in 200 people suffer epilepsy Many cases have no known cause. Head injuries, such as MVA or fall. Brain tumor or stroke Arteriosclerosis (fatty plaque build-up) Pre/natal brain injury (anoxia/hypoxia) Infections-meningitis or encephalitis Brain damage causes "scar" on brain. This is where a seizure starts. It is unknown why a scar starts a seizure. Causes Genetic factors Metabolic abnormalities Structural damage to brain Epilepsy Causes

10. Types of Epilepsy • Generalized seizures (most common) - uncontrollable neural discharge starts in one area that spreads across brain. • Muscle twitches and convulsions • Loss of consciousness and loss of recall about seizure. • Tonic-clonic ("grand mal“ - great sickness) seizure - massive discharge. Rigidity and violent jerking of body. "Tonic-clonic" = "stiffness-violent." • Absence ("petit mal") seizure - nonconvulsive., person unaware of surroundings, may stare off in space or freeze for 5 to 10s. • Myoclonic seizure - Seizure involves motor cortex and causes twitching or jerking of certain parts of the body. • Status epilepticus – Frequent lengthy seizures without regaining consciousness between attacks. Requires immediate medical attention.

11. Example: Absence or Petit Mal • Absence seizures • Loss or diminution of normal activity. • Staring and loss of responsiveness • Occasionally subtle motor activity – flutters, jerks. • May go unrecognized for years or be mistaken as daydreaming or ADD. • “Spells” (seizures) last ~10 s, dozens of times daily. No recollection of events during seizures and resumes previous activity without any postictal symptoms. • EEG classically shows intermittent runs of generalized 3 cps spike and wave activity which may be precipitated by hyperventilation.

12. Petit Mal: 3 Hz spike and wave

13. VHS Brain #30 – Another example of Petit Mal

14. Types of Epilepsy • Partial Seizures - abnormal electrical activity involving small part of brain (sometimes speads). • Simple partial seizures (or "Jacksonian" or "focal" seizures) • Short-lasting seizures without loss of consciousness. • Often see, hear or smell something strange. • Part of the body may jerk. • Complex partial seizures • Seizure with a change, not loss, in consciousness. • People may hear or see things, or memories may resurface. Feelings of deja vu common.

15. Example: complex partial seizure • Symptoms • Staring & guttural vocalizations in 8y • EEG: Awake and asleep EEG reveals frequent spike-wave discharges localized to left temporal lobe near T3 electrode • Diagnosis: Asymmetric motor manifestations (facial grimace, post-ictal unilateral weakness) suggest focal origin. • Presence of altered consciousness indicates complex partial rather than simple partial.

16. Complex partial seizure

17. Focal discharge

18. Generalized discharge

19. Hyperventilation is performed over a 3 minute period to induce absence seizures.   Often bilateral slow waves are induced by hyperventilation.

20. Attempt to induce seizure with stroboscopic stimulation NORMAL: Small evoked occipital potentials.  Photic driving responses are time locked to each flash of light at same frequency or half the frequency (subharmonic).  Photic driving responses begin and end simultaneously with the onset and cessation of photic stimulation.

21. Photoconvulsive seizures • Seizures induced by photic stim; more common for generalized epilepsy.  Not time locked to photic stim, may begin later than onset and persist after; different frequency • Also possible, photomyoclonic responses

22. Epilepsy Treatment and Control • Drugs (first mode of attack - anticonvulsants) • Surgery (“last” resort) • Novel therapies • Neurofeedback (30 y record, not so novel) • Diet • Exercise • Vasal stimulation

23. Clinical EEG evaluation (subjective & requires extensive training of the “eyeball”) Activity characterized by shape and frequency Transients & background x2 interhemispheric power asymmetry indicates abnormality Assess severity & depth of coma initial EEG more abnormal, more predictive at 24-48 hrs Reactivity to sound & pain - somatosensory potentials Sleep reorganization Cortical potentials are 500-1500 uV, but 5-50 uV at scalp ~1 billion neurons per electrode Traumatic Brain Injury (TBI) • EEG & GCS used to make initial diagnosis and treatment recommendations

24. Frontal intermittent rhythmic delta activity • Occipital IRDA in children • Normal during hyperventilation, increases with drowsiness Images from http://www.neuro.mcg.edu/amurro/cnphys/

25. Diffuse slowing • cerebral dysfunction from multifocal or diffuse brain disease.

26. Polymorphic focal slowing (< 8 Hz). • Unlike FIRDA, does not change during drowsiness. • Abnormality indicates structural brain lesion and the site of this abnormality localizes the brain lesion.

27. Closed Head Injury: Coup and Contrecoup • Prehistoric trephination to relieve pressure TBI: 1 in 400 people in USA Leading cause of children's death and 60% of all traumatic deaths

28. Best Eye Response. (4) 1 No eye opening. 2 Eye opening to pain. 3 Eye opening to verbal command. 4 Eyes open spontaneously. Best Verbal Response. (5) 1 No verbal response 2 Incomprehensible sounds. 3 Inappropriate words. 4 Confused 5 Oriented Best Motor Response. (6) 1 No motor response. 2 Extension to pain. 3 Flexion to pain. 4 Withdrawal from pain. 5 Localizing pain. 6 Obeys Commands to act. HIGHER IS BETTER GCS 13+ correlates with a mild brain injury, 9 to 12, moderate injury 8 or less, a severe TBI E3V3M5 = GCS 11. Glasgow Coma Score (GCS)

29. Occurs when CBF falls below metabolic demands of tissue At CBF 15 ml/100g/min, synaptic transmission ceases and EEG flattens.  Cellular integrity preserved (membrane ion pumps and ion gradients) until lower flows. Loss of electrical activity is protective, reduces energy expenditure of cell. Isoelectric -- CBF must be restored to avoid neurologic injury. At 6 to 10 ml/100g/min, extracellular potassium concentrations increase and cell death follows Detected and classified by EEG Mild - isolated reduction in amplitude of fast activity Moderate - amplitude reduction and concomitant slowing Severe - loss of fast activity with predominant delta activity or isoelectricity Cerebral Ischemia

30. (Matthew) EEG Grades with TBI • Grade I - Alpha rhythm with beta and some theta • Grade II - Predominant theta waves with some alpha, beta, and delta waves • Grade III - Predominant delta waves mixed with some theta waves • Grade IV - Delta waves, occasionally isoelectric • Grade V & VI – Burst-suppression (isoelectric) • Grade VII - Isoelectric

31. Grade IV • Anterior 8-12 Hz activity unresponsive to stimulation • Poor prognosis

32. Grade V or VI • Periodic bursts of high voltage slow waves and spikes that occur between low voltage periods • Poor prognosis

33. Grade VII

34. Isoelectricity • Electrocerebral inactivity: • 8+ channels, 30 min recording, proper equipment sensitivity. • In addition, technician touches each electrode to verify integrity of recording system and stimulate patient to see if EEG activity occurs.  • Non-cerebral potentials (pulse and EKG) may be present.  • Indicates brain death, but also posisble in drug overdose and hypothermia.