What is EpilepsyWhat is Epilepsy Over-responsiveness to brain state changes Over-responsiveness to brain state changes

and to transient sensory stimuliand to transient sensory stimuli• Seizure triggers:Seizure triggers:

Sleep deprivationSleep deprivation StressStress Drugs or alcoholDrugs or alcohol Menstrual cycleMenstrual cycle Nutritional deficiencies, low blood sugarNutritional deficiencies, low blood sugar Other medsOther meds HyperventilationHyperventilation Flashing lights or sounds Flashing lights or sounds

• (like from a video game or TV – (like from a video game or TV – 1991 Pokemon) 1991 Pokemon)

• i.e., Transitionsi.e., Transitions

Associated with cortical or subcortical Associated with cortical or subcortical hyperexcitabilityhyperexcitability

History of the “Falling Sickness”History of the “Falling Sickness” 44thth century account of epileptic attack differs little century account of epileptic attack differs little

from current textbook description of a from current textbook description of a generalized tonic-clonic seizure: generalized tonic-clonic seizure: • "After various premonitory signs the patient falls down, "After various premonitory signs the patient falls down,

stretched out or twisted, and in this condition he stretched out or twisted, and in this condition he remains for some time. After these tonic convulsions he remains for some time. After these tonic convulsions he passes into the stage of clonic convulsions and a passes into the stage of clonic convulsions and a condition where he appears to be sleeping. The attack is condition where he appears to be sleeping. The attack is followed by complete amnesia." followed by complete amnesia."

Guainerius in 1516 recommended placing an Guainerius in 1516 recommended placing an object between the teeth of a person undergoing object between the teeth of a person undergoing a convulsion. a convulsion.

The Sacred diseaseThe Sacred disease

Mohammed Mohammed is is reported to have reported to have had seizures since had seizures since age 3 and to have age 3 and to have said, "This is a said, "This is a common affliction common affliction of prophets, of of prophets, of whom I wish to be whom I wish to be counted as one." counted as one."

St PaulSt Paul Julius CaesarJulius Caesar NapoleonNapoleon TolstoyTolstoy SocratesSocrates Numerous painters, Numerous painters,

writers, composers, writers, composers, leaders…leaders…

Joan D’ArcJoan D’Arc Joan often felt that the secrets of the universe Joan often felt that the secrets of the universe

were about to be revealed to herwere about to be revealed to her Seizures were triggered by ringing church bells. Seizures were triggered by ringing church bells.

• A musicogenic TLE, with ecstatic aura. A musicogenic TLE, with ecstatic aura.

Musicogenic epilepsy is generally triggered by Musicogenic epilepsy is generally triggered by particular music which has an emotional particular music which has an emotional significance to the individual. significance to the individual.

Joan's voices (St Catherine) and visions propelled Joan's voices (St Catherine) and visions propelled her to become an heroic soldier in the effort to her to become an heroic soldier in the effort to save France from English domination. She was save France from English domination. She was burned at the stake as a heretic when she was 19 burned at the stake as a heretic when she was 19 years old in 1431. years old in 1431.

Fyodor DostoyevskyFyodor Dostoyevsky on TLE 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.'

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Temporal Lobe Epilepsy SxTemporal Lobe Epilepsy Sx

Interictal traitsInterictal traits• HypergraphiaHypergraphia• HyperreligiosityHyperreligiosity• ““Stickiness” or clinginessStickiness” or clinginess• Altered interest in sexAltered interest in sex• Undirected and transient aggressivenessUndirected and transient aggressiveness

Perhaps due to Amygdala overactivation, Perhaps due to Amygdala overactivation, which acts as a brake on engagementwhich acts as a brake on engagement

Common MythsCommon Myths Seizures cause additional brain damage… Not usuallySeizures cause additional brain damage… Not usually

• Single tonic-clonic seizures lasting 5-10 minutes are not Single tonic-clonic seizures lasting 5-10 minutes are not thought to cause brain damage. thought to cause brain damage.

• However, more frequent and prolonged tonic-clonic However, more frequent and prolonged tonic-clonic seizures may in some patients injure the brain. seizures may in some patients injure the brain.

Epilepsy is a life-long disorder for all – not always.Epilepsy is a life-long disorder for all – not always.• Half of childhood epilepsies are outgrown by adulthood. Half of childhood epilepsies are outgrown by adulthood. • When a person has been free of seizures for 1 to 3 years, When a person has been free of seizures for 1 to 3 years,

medications can be slowly withdrawn and discontinued medications can be slowly withdrawn and discontinued under a doctor's supervision.under a doctor's supervision.

Seizure disorder is another term for epilepsy (clarity Seizure disorder is another term for epilepsy (clarity of definition, not a myth per se)of definition, not a myth per se)

Epilepsy CausesEpilepsy Causes 1 in 200 people suffer epilepsy1 in 200 people suffer epilepsy

Many cases have no known cause. Many cases have no known cause. • Head injuries, such as MVA or fall. Head injuries, such as MVA or fall. • Brain tumor or strokeBrain tumor or stroke• Arteriosclerosis (fatty plaque build-Arteriosclerosis (fatty plaque build-

up) up) • Pre/natal brain injury Pre/natal brain injury

(anoxia/hypoxia) (anoxia/hypoxia) • Infections-meningitis or encephalitis Infections-meningitis or encephalitis

Brain damage causes "scar" on Brain damage causes "scar" on brain. This is where a seizure brain. This is where a seizure starts. It is unknown starts. It is unknown whywhy a scar a scar starts a seizure. starts a seizure.

Causes Causes • Genetic factorsGenetic factors• Metabolic abnormalitiesMetabolic abnormalities• Structural damage to brainStructural damage to brain

Types of EpilepsyTypes of Epilepsy Generalized seizuresGeneralized seizures (most common) - (most common) -

uncontrollable neural discharge starts in one area that spreads uncontrollable neural discharge starts in one area that spreads across brain. across brain. • Muscle twitches and convulsions Muscle twitches and convulsions • Loss of consciousness and loss of recall about seizure. Loss of consciousness and loss of recall about seizure.

• Tonic-clonic ("grand mal“ - great sickness) seizure - massive Tonic-clonic ("grand mal“ - great sickness) seizure - massive discharge. Rigidity and violent jerking of body. "Tonic-clonic" discharge. Rigidity and violent jerking of body. "Tonic-clonic" = "stiffness-violent."= "stiffness-violent."

• AbsenceAbsence ("petit mal") seizure - nonconvulsive., person ("petit mal") seizure - nonconvulsive., person unaware of surroundings, may stare off in space or freeze for unaware of surroundings, may stare off in space or freeze for 5 to 10s. 5 to 10s.

• Myoclonic seizure - Seizure involves motor cortex and Myoclonic seizure - Seizure involves motor cortex and causes twitching or jerking of certain parts of the body. causes twitching or jerking of certain parts of the body.

• Status epilepticus – Frequent lengthy seizures without Status epilepticus – Frequent lengthy seizures without regaining consciousness between attacks. Requires regaining consciousness between attacks. Requires immediate medical attention. immediate medical attention.

Example: Absence or Petit MalExample: Absence or Petit Mal

Absence seizures Absence seizures • Loss or diminution of normal activity. Loss or diminution of normal activity. • Staring and loss of responsiveness Staring and loss of responsiveness • Occasionally subtle motor activity – flutters, jerks. Occasionally subtle motor activity – flutters, jerks. • May go unrecognized for years or be mistaken as daydreaming May go unrecognized for years or be mistaken as daydreaming

or ADD.or ADD.

““Spells” (seizures) last ~10 s, dozens of times daily. No Spells” (seizures) last ~10 s, dozens of times daily. No recollection of events during seizures and resumes previous recollection of events during seizures and resumes previous activity without any postictal symptoms.activity without any postictal symptoms.

EEG classically shows intermittent runs of generalizedEEG classically shows intermittent runs of generalized3 cps spike and wave3 cps spike and wave activity which may be precipitated by activity which may be precipitated by hyperventilation.hyperventilation.

Petit Mal: Petit Mal: 3 Hz spike and wave3 Hz spike and wave

VHS Brain #30 – VHS Brain #30 – Another example of Petit MalAnother example of Petit Mal

Types of EpilepsyTypes of Epilepsy Partial SeizuresPartial Seizures - abnormal electrical activity - abnormal electrical activity

involving small part of brain (sometimes speads). involving small part of brain (sometimes speads).

• Simple partial seizures (or "Jacksonian" or "focal" Simple partial seizures (or "Jacksonian" or "focal" seizures) seizures)

Short-lasting seizures without loss of consciousness. Short-lasting seizures without loss of consciousness. Often see, hear or smell something strange. Often see, hear or smell something strange. Part of the body may jerk. Part of the body may jerk.

• Complex partial seizures Complex partial seizures Seizure with a Seizure with a changechange, not loss, in consciousness. , not loss, in consciousness. People may hear or see things, or memories may resurface. People may hear or see things, or memories may resurface.

Feelings of Feelings of deja vudeja vu common. common.

Example: Example: complex partial seizurecomplex partial seizure

SymptomsSymptoms• Staring & guttural vocalizations in 8yStaring & guttural vocalizations in 8y• EEG: Awake and asleep EEG reveals frequent spike-EEG: Awake and asleep EEG reveals frequent spike-

wave discharges localized to left temporal lobe wave discharges localized to left temporal lobe near near T3 electrodeT3 electrode

Diagnosis: Diagnosis: Asymmetric motor manifestations Asymmetric motor manifestations (facial grimace, post-ictal unilateral weakness) (facial grimace, post-ictal unilateral weakness) suggest focal origin. suggest focal origin. • Presence of altered consciousness indicates complex Presence of altered consciousness indicates complex

partial rather than simple partial. partial rather than simple partial.

CComplex partial seizureomplex partial seizure

Focal dischargeFocal discharge

Generalized dischargeGeneralized discharge

HyperventilationHyperventilation is performed over a 3 minute period to is performed over a 3 minute period to induce absence seizures.   Often bilateral slow waves are induce absence seizures.   Often bilateral slow waves are

induced by hyperventilation.induced by hyperventilation.

Attempt to induce seizure with stroboscopic stimulationAttempt to induce seizure with stroboscopic stimulation

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

Photoconvulsive seizuresPhotoconvulsive seizures

Seizures induced by photic stim; more common for generalized Seizures induced by photic stim; more common for generalized epilepsy.  Not time locked to photic stim, may begin later than epilepsy.  Not time locked to photic stim, may begin later than onset and persist after; different frequencyonset and persist after; different frequency

Also possible, photomyoclonic responsesAlso possible, photomyoclonic responses

Epilepsy Treatment and ControlEpilepsy Treatment and Control

• Drugs (first mode of attack - Drugs (first mode of attack - anticonvulsants)anticonvulsants)

• Surgery (“last” resort)Surgery (“last” resort)

• Novel therapiesNovel therapies Neurofeedback (30 y record, not so novel)Neurofeedback (30 y record, not so novel) DietDiet ExerciseExercise Vasal stimulationVasal stimulation

Traumatic Brain Injury (TBI)Traumatic Brain Injury (TBI) Clinical EEG evaluation Clinical EEG evaluation

(subjective & requires extensive (subjective & requires extensive training of the “eyeball”)training of the “eyeball”)• Activity characterized by Activity characterized by

shape and frequencyshape and frequency• Transients & backgroundTransients & background• x2 interhemispheric power x2 interhemispheric power

asymmetry indicates asymmetry indicates abnormality abnormality

Assess severity & depth of coma Assess severity & depth of coma • initial EEG more abnormal, initial EEG more abnormal,

more predictive at 24-48 hrsmore predictive at 24-48 hrs• Reactivity to sound & pain - Reactivity to sound & pain -

somatosensory potentialssomatosensory potentials• Sleep reorganization Sleep reorganization

Cortical potentials are 500-Cortical potentials are 500-1500 uV, but 5-50 uV at scalp 1500 uV, but 5-50 uV at scalp

~1 billion neurons per electrode ~1 billion neurons per electrode

EEG & GCS used to make initial diagnosis and treatment recommendationsEEG & GCS used to make initial diagnosis and treatment recommendations

Frontal intermittent rhythmic delta activityFrontal intermittent rhythmic delta activity

Occipital IRDA in childrenOccipital IRDA in children Normal during hyperventilation, increases with Normal during hyperventilation, increases with

drowsinessdrowsinessImages from http://www.neuro.mcg.edu/amurro/cnphys/

Diffuse slowingDiffuse slowing

cerebral dysfunction from multifocal cerebral dysfunction from multifocal or diffuse brain disease. or diffuse brain disease.

Polymorphic focal slowing (< 8 Hz).Polymorphic focal slowing (< 8 Hz).

Unlike FIRDA, does not change during drowsiness. Unlike FIRDA, does not change during drowsiness. Abnormality indicates structural brain lesion and the site of Abnormality indicates structural brain lesion and the site of

this abnormality localizes the brain lesion. this abnormality localizes the brain lesion.

Closed Head Injury: Closed Head Injury: Coup and ContrecoupCoup and Contrecoup

Prehistoric trephination to Prehistoric trephination to relieve pressurerelieve pressure

TBI: 1 in 400 people in USA TBI: 1 in 400 people in USA Leading cause of children's Leading cause of children's death and 60% of all death and 60% of all traumatic deathstraumatic deaths

Glasgow Coma ScoreGlasgow Coma Score (GCS) (GCS)• Best Eye Response. (4) Best Eye Response. (4)

• 1 No eye opening. 1 No eye opening. • 2 Eye opening to pain. 2 Eye opening to pain. • 3 Eye opening to verbal 3 Eye opening to verbal

command. command. • 4 Eyes open spontaneously.4 Eyes open spontaneously.

• Best Verbal Response. (5) Best Verbal Response. (5) • 1 No verbal response 1 No verbal response • 2 Incomprehensible sounds. 2 Incomprehensible sounds. • 3 Inappropriate words. 3 Inappropriate words. • 4 Confused 4 Confused • 5 Oriented 5 Oriented

• Best Motor Response. (6)Best Motor Response. (6) • 1 No motor response. 1 No motor response. • 2 Extension to pain. 2 Extension to pain. • 3 Flexion to pain. 3 Flexion to pain. • 4 Withdrawal from pain. 4 Withdrawal from pain. • 5 Localizing pain. 5 Localizing pain. • 6 Obeys Commands to act. 6 Obeys Commands to act.

HIGHER IS BETTERHIGHER IS BETTER

GCS 13+ correlates with GCS 13+ correlates with a mild brain injury, a mild brain injury,

9 to 12, moderate injury9 to 12, moderate injury 8 or less, a severe TBI8 or less, a severe TBI

E3V3M5 = GCS 11. E3V3M5 = GCS 11.

Cerebral Cerebral IschemiaIschemia

Occurs when CBF falls below metabolic Occurs when CBF falls below metabolic demands of tissuedemands of tissue

At CBF 15 ml/100g/min, synaptic transmission At CBF 15 ml/100g/min, synaptic transmission ceases and EEG flattens.  ceases and EEG flattens.  • Cellular integrity preserved (membrane ion Cellular integrity preserved (membrane ion

pumps and ion gradients) until lower flows. pumps and ion gradients) until lower flows. • Loss of electrical activity is protective, reduces Loss of electrical activity is protective, reduces

energy expenditure of cell.energy expenditure of cell.

Isoelectric -- CBF must be restored to avoid Isoelectric -- CBF must be restored to avoid neurologic injury. neurologic injury.

• At 6 to 10 ml/100g/min, extracellular potassium At 6 to 10 ml/100g/min, extracellular potassium concentrations increase and cell death followsconcentrations increase and cell death follows

Detected and Detected and classified by EEG classified by EEG • Mild - isolated Mild - isolated

reduction in amplitude reduction in amplitude of fast activity of fast activity

• Moderate - amplitude Moderate - amplitude reduction and reduction and concomitant slowingconcomitant slowing

• Severe - loss of fast Severe - loss of fast activity with activity with predominant delta predominant delta activity or activity or isoelectricityisoelectricity

(Matthew) EEG Grades with TBI(Matthew) EEG Grades with TBI

Grade I - Alpha rhythm with beta and some thetaGrade I - Alpha rhythm with beta and some theta

Grade II - Predominant theta waves with some Grade II - Predominant theta waves with some alpha, beta, and delta waves alpha, beta, and delta waves

Grade III - Predominant delta waves mixed with Grade III - Predominant delta waves mixed with some theta waves some theta waves

Grade IV - Delta waves, occasionally isoelectric Grade IV - Delta waves, occasionally isoelectric

Grade V & VI – Burst-suppression (isoelectric)Grade V & VI – Burst-suppression (isoelectric)

Grade VII - IsoelectricGrade VII - Isoelectric

Grade IVGrade IV

Anterior 8-12 Hz activity unresponsive to stimulationAnterior 8-12 Hz activity unresponsive to stimulation Poor prognosisPoor prognosis

Grade V or VIGrade V or VI

Periodic bursts of high voltage slow waves and spikes that occur between low voltage periods Periodic bursts of high voltage slow waves and spikes that occur between low voltage periods Poor prognosisPoor prognosis

Grade VIIGrade VII

IsoelectricityIsoelectricity

Electrocerebral inactivity: Electrocerebral inactivity: 8+ channels, 30 min recording, proper 8+ channels, 30 min recording, proper

equipment sensitivity. equipment sensitivity. In addition, technician touches each In addition, technician touches each

electrode to verify integrity of recording electrode to verify integrity of recording system and stimulate patient to see if EEG system and stimulate patient to see if EEG activity occurs.  activity occurs. 

• Non-cerebral potentials (pulse and EKG) Non-cerebral potentials (pulse and EKG) may be present.  may be present. 

• Indicates brain death, but also posisble Indicates brain death, but also posisble in drug overdose and hypothermia.in drug overdose and hypothermia.