A Practical Approach to A Practical Approach to The Diagnosis and The Diagnosis and Evaluation of SeizuresEvaluation of Seizures

Prof. Dr. Alaa H. AlwanProf. Dr. Alaa H. Alwan TUCOM/ 2015TUCOM/ 2015

Three basic questionsThree basic questions 1. Is it a seizure?1. Is it a seizure?

– If so, what kind?If so, what kind? 2. What caused it?2. What caused it? 3. What should be done?3. What should be done?

SeizureSeizure

A seizure is a set of A seizure is a set of clinical symptomsclinical symptoms associated with associated with abnormal electrical abnormal electrical activityactivity in neurons in the cortex of the in neurons in the cortex of the brain.brain.

The clinical characteristics of a seizure are The clinical characteristics of a seizure are the result of the area of the brain that is the result of the area of the brain that is abnormally stimulated.abnormally stimulated.

Epilepsy is a Epilepsy is a clinical condition in which there clinical condition in which there are multiple seizures that are unprovoked.are multiple seizures that are unprovoked.

Types of seizuresTypes of seizures Generalized seizuresGeneralized seizures

Focal (or partial seizures)Focal (or partial seizures)

Generalized seizuresGeneralized seizures

– Generalized seizures arise from both Generalized seizures arise from both sides of the brain simultaneously. sides of the brain simultaneously. Motor activity is symmetrical and Motor activity is symmetrical and alteration of consciousness occurs.alteration of consciousness occurs.

– Ex. Ex. Primary generalized seizures (grand Primary generalized seizures (grand mal)mal)

Absence seizures (petit mal)Absence seizures (petit mal) Myoclonic seizures, atonic seizuresMyoclonic seizures, atonic seizures

Focal (Partial seizures)Focal (Partial seizures) Arise from one area of the cortex and Arise from one area of the cortex and

may spread to involve adjacent areas or may spread to involve adjacent areas or distant areasdistant areas

Examples:Examples:– Simple partial seizuresSimple partial seizures

Symptoms are referable to the area of the brain Symptoms are referable to the area of the brain involved, no alteration of consciousnessinvolved, no alteration of consciousness

– Complex partial seizuresComplex partial seizures Partial seizures with alteration of consciousnessPartial seizures with alteration of consciousness

– Partial seizures with secondary generalizationPartial seizures with secondary generalization Partial seizure at onset (aura) followed by Partial seizure at onset (aura) followed by

generalized convulsive activitygeneralized convulsive activity

Seizure like episodesSeizure like episodes SyncopeSyncope

– Syncopal seizures may have tonic Syncopal seizures may have tonic stiffening, clonic jerking and/or post-ictal stiffening, clonic jerking and/or post-ictal confusionconfusion

ParasomniasParasomnias– Sleepwalking, night terrorsSleepwalking, night terrors

HyperventilationHyperventilation Stereotypies/TicsStereotypies/Tics Staring spellsStaring spells

Diagnosis is largely Diagnosis is largely based on the history of based on the history of the event*the event*

Precipitating factorsPrecipitating factors– Position, activity, intercurrent illness, medicationsPosition, activity, intercurrent illness, medications

Description of the episodeDescription of the episode– Eye movements, body movements, one sided or Eye movements, body movements, one sided or

both sides, loss of consciousness or alteration of both sides, loss of consciousness or alteration of consciousness, incontinence, duration, consciousness, incontinence, duration, aftereffectsaftereffects

Predisposing factorsPredisposing factors– Past medical history, recent illness or Past medical history, recent illness or

neurological symptoms, family historyneurological symptoms, family history

*Is it a seizure, if so what kind?*Is it a seizure, if so what kind?

Etiology of SeizureEtiology of Seizure– Symptomatic seizuresSymptomatic seizures

Acute/subacuteAcute/subacute– Metabolic causes Metabolic causes

Hypoglycemia, hypo or hypernatremia, Hypoglycemia, hypo or hypernatremia, hypocalemiahypocalemia

Intoxications/ toxins (lead)Intoxications/ toxins (lead)– Infectious/InflammatoryInfectious/Inflammatory

Meningitis, encephalitis, sepsisMeningitis, encephalitis, sepsis Post-infectious or autoimmune causesPost-infectious or autoimmune causes

– Fever*Fever*– TraumaTrauma– Vascular accidentsVascular accidents

Symptomatic seizures, Symptomatic seizures, part 2part 2

Chronic/ ProgressiveChronic/ Progressive– Remote insultsRemote insults

Perinatal asphyxia or vascular insultPerinatal asphyxia or vascular insult Past head injuryPast head injury

– Developmental brain abnormalitiesDevelopmental brain abnormalities Agenesis of the corpus callosum, Agenesis of the corpus callosum,

schizencephaly, cortical dysplasia schizencephaly, cortical dysplasia – Inborn errors of metabolismInborn errors of metabolism

Storage disorders, amino acid disorders, Storage disorders, amino acid disorders, organic acid disordersorganic acid disorders

– Neurocutaneous disordersNeurocutaneous disorders– Cerebral degenerative diseasesCerebral degenerative diseases

Idiopathic seizuresIdiopathic seizures The cause of the seizure can not be The cause of the seizure can not be

determined by conventional testing determined by conventional testing oror

Seizures of genetic origin in which Seizures of genetic origin in which seizures are the only manifestation.seizures are the only manifestation.

This category may comprise as This category may comprise as much as 60% of all childhood much as 60% of all childhood seizure disorders.seizure disorders.

Determining the cause Determining the cause of a child’s seizure(s) *of a child’s seizure(s) * HistoryHistory

– Associated symptoms, intercurrent illness, recent Associated symptoms, intercurrent illness, recent medications, exposures (drugs,toxins, pets), past medical medications, exposures (drugs,toxins, pets), past medical history ( birth history, developmental history, family history ( birth history, developmental history, family history)history)

ExaminationExamination– Fever or other abnormal vital signsFever or other abnormal vital signs– Head size, skin abnormalities (hypo/hyperpigmented Head size, skin abnormalities (hypo/hyperpigmented

areas) ,menigismus, asymmetry of the face or the areas) ,menigismus, asymmetry of the face or the extremities, enlarged organs, dysmorphic featuresextremities, enlarged organs, dysmorphic features

– Alteration of mental status, cranial nerve abnormalities, Alteration of mental status, cranial nerve abnormalities, motor tone or strength or reflex changes, gait motor tone or strength or reflex changes, gait abnormalities,ataxia, sensory abnormalities.abnormalities,ataxia, sensory abnormalities.

*What caused it?*What caused it?

Diagnostic StudiesDiagnostic Studies BloodworkBloodwork - - electrolytes, Ca, glucoseelectrolytes, Ca, glucose UrineUrine- - toxicology, amino acid and organic acid toxicology, amino acid and organic acid

measurement*measurement* EEGEEG

– Useful for evaluating interictal abnormalitiesUseful for evaluating interictal abnormalities– Occasionally useful for determining nature of a Occasionally useful for determining nature of a

clinical symptom (absence seizures, tics or clinical symptom (absence seizures, tics or other frequent movements)other frequent movements)

– Helpful in predicting recurrence of seizures.Helpful in predicting recurrence of seizures.– A normal EEG does not exclude a diagnosis of A normal EEG does not exclude a diagnosis of

seizureseizure..

Diagnostic studies #2Diagnostic studies #2 Ambulatory EEGAmbulatory EEG

– Allows for Ictal recording- ie, EEG activity Allows for Ictal recording- ie, EEG activity during a suspected episodeduring a suspected episode

Drawbacks- technical, availability, depends on Drawbacks- technical, availability, depends on patient/parent to indicate when the episodes are patient/parent to indicate when the episodes are occurringoccurring

VideotelemetryVideotelemetry– Simultaneous recording of EEG and video of Simultaneous recording of EEG and video of

patient. patient. – Can be done as a day procedure or as Can be done as a day procedure or as

inpatientinpatient– Episodes must occur with some frequencyEpisodes must occur with some frequency

Diagnostic Studies#3Diagnostic Studies#3 Imaging proceduresImaging procedures

– CTT is not the procedure of choice but is CTT is not the procedure of choice but is appropriate in emergencies, especially appropriate in emergencies, especially traumatrauma

– MRI is the imaging procedure of choiceMRI is the imaging procedure of choice Abnormal neurological examinationAbnormal neurological examination Focal seizure activityFocal seizure activity Focal findings on EEGFocal findings on EEG

– PET scanning is a specialized procedure done PET scanning is a specialized procedure done in limited circumstances (usually as part of in limited circumstances (usually as part of evaluation of intractable seizures or when a evaluation of intractable seizures or when a surgical treatment is proposed.surgical treatment is proposed.

Treatment Decisions*Treatment Decisions* The decision to treat depends on The decision to treat depends on

evaluation of risks and benefitsevaluation of risks and benefits– Risk of subsequent seizuresRisk of subsequent seizures– Risk of treatmentRisk of treatment– Particular circumstances of patientParticular circumstances of patient

– *What to do about it?*What to do about it?

Risks of further Risks of further seizuresseizures Risk of a second seizure is 20-30% if:Risk of a second seizure is 20-30% if:

– Examination, EEG and CTT (imaging study) Examination, EEG and CTT (imaging study) is normal (and careful review of history is normal (and careful review of history discloses no other events)discloses no other events)

– Exceptions: Absence seizures. Myoclonic Exceptions: Absence seizures. Myoclonic seizuresseizures

Risk of a second seizure if EEG is Risk of a second seizure if EEG is abnormal is 60%abnormal is 60%

Risk of a third seizure is 70% Risk of a third seizure is 70%

Risk of having another Risk of having another seizureseizure Most seizures do not produce Most seizures do not produce

injury to the brain.injury to the brain. Seizures in a bad place- bath, driving a Seizures in a bad place- bath, driving a

car, climbing, riding a bicycle etc.car, climbing, riding a bicycle etc. Prolonged seizure which can lead to Prolonged seizure which can lead to

hypoxia or secondary complications.hypoxia or secondary complications. Sudden unexplained death- a very rare Sudden unexplained death- a very rare

complication of seizures, particularly in complication of seizures, particularly in children. children.

Risk of treatmentRisk of treatment Medication side effectsMedication side effects

– Severe- liver failure, aplastic Severe- liver failure, aplastic anemia, severe allergic reaction anemia, severe allergic reaction (Stevens-Johnson syndrome)(Stevens-Johnson syndrome)

– Decreased alertness, Decreased alertness, personality/behavior changes, personality/behavior changes, weight loss/gainweight loss/gain

Social stigmaSocial stigma

TreatmentTreatment Discuss risks and benefits with patient and Discuss risks and benefits with patient and

parent based on available statisticsparent based on available statistics If 1st seizure with lower risk of recurrence, If 1st seizure with lower risk of recurrence,

consider no treatment. consider no treatment. Use of rectal valium as a “rescue measure”Use of rectal valium as a “rescue measure” If decision to treat, choose a medication If decision to treat, choose a medication

based on seizure type, age of patient and based on seizure type, age of patient and side effect profile.side effect profile.

Monotherapy is generally preferable, Monotherapy is generally preferable, especially in first line treatment.especially in first line treatment.

Anticonvulsant Anticonvulsant medicationsmedications Generalized Generalized

seizuresseizures Divalproex sodiumDivalproex sodium ZonisamideZonisamide TopiramateTopiramate LamotrigineLamotrigine LevetiracetamLevetiracetam RufinamideRufinamide Ethosuximide*Ethosuximide*

Partial SeizuresPartial Seizures– CarbamazepineCarbamazepine– OxycarbazepineOxycarbazepine– ZonisamideZonisamide– TopiramateTopiramate– LevetiracetamLevetiracetam– LamotrigineLamotrigine– PhenytoinPhenytoin– Phenobarbital*Phenobarbital*

Other Treatment Other Treatment AlternativesAlternatives Dietary treatmentDietary treatment

– Ketogenic dietKetogenic diet– Modified Atkins dietModified Atkins diet

Surgical treatmentSurgical treatment– Vagal nerve stimulatorVagal nerve stimulator– Surgical removal of seizure focusSurgical removal of seizure focus

Historical CluesHistorical Clues Precipitating factorsPrecipitating factors

– Seizures may be precipitated by flashing Seizures may be precipitated by flashing lights, hyperventilation, illness or being lights, hyperventilation, illness or being overtired (stress?)overtired (stress?)

– Syncope is precipitated by standing up, Syncope is precipitated by standing up, being overheated, sight of blood, being overheated, sight of blood, frightening eventfrightening event

State of alertness-State of alertness- syncope doesn’t occur in syncope doesn’t occur in sleep, Seizures may occur in sleep or sleep, Seizures may occur in sleep or wakefulness. Parasomnias only occur in sleep.wakefulness. Parasomnias only occur in sleep.

Further historical cuesFurther historical cues Position- Position- seizures may occur in any position, seizures may occur in any position,

syncope usually occurs when sitting or standingsyncope usually occurs when sitting or standing Eye movements- Eye movements- eyes are usually closed or eyes are usually closed or

partially open during a syncopal episode, more partially open during a syncopal episode, more likely to be open during a seizure. The presence likely to be open during a seizure. The presence of deviation of the eyes to one side or another of deviation of the eyes to one side or another suggests a partial seizure.suggests a partial seizure.

Seizures Seizures that affect one side of the body more that affect one side of the body more than the other are likely to be focal in origin. than the other are likely to be focal in origin. Syncopal episodes are usually symmetricalSyncopal episodes are usually symmetrical..

Staring vs. Absence Staring vs. Absence vs. Partial Complex vs. Partial Complex seizuresseizures Staring spells are more apt to occur when the Staring spells are more apt to occur when the

patient is passive, listening to a teacher, or parent patient is passive, listening to a teacher, or parent or watching TV. They can be of indeterminate or watching TV. They can be of indeterminate length and are interruptible by voice or touch.length and are interruptible by voice or touch.

Absence seizures can occur in the midst of activity, Absence seizures can occur in the midst of activity, usually brief 10-20 seconds. There may be eye usually brief 10-20 seconds. There may be eye blinking/fluttering or subtle head movements. The blinking/fluttering or subtle head movements. The patient recovers very quickly. Incontinence may patient recovers very quickly. Incontinence may occur.occur.

Partial complex seizures are usually 1-2 minutes in Partial complex seizures are usually 1-2 minutes in length, and can not be interrupted. There are often length, and can not be interrupted. There are often stereotypic movements and postictal confusion is stereotypic movements and postictal confusion is common.common.

Generalized seizures vs Generalized seizures vs Partial Seizures Partial Seizures Generalized seizures have sudden onset Generalized seizures have sudden onset

without warning. Motor symptoms are without warning. Motor symptoms are symmetrical. Postictal state is common symmetrical. Postictal state is common when there is convulsive activity but not when there is convulsive activity but not for absence or myoclonic seizuresfor absence or myoclonic seizures

Partial seizures may begin with localized Partial seizures may begin with localized symptoms that the patient is aware of symptoms that the patient is aware of (aura) and may have asymmetric motor (aura) and may have asymmetric motor symptoms. Postictal state is common, symptoms. Postictal state is common, even without convulsive activity.even without convulsive activity.

AlgorithmAlgorithmAlgorithmAlgorithmInitial Event

History- eyewitness report if possible

Physical Examination

EEG, imaging study if EEG focal

If isolated event, no treatment or Rectal valium

If multiple episodes discuss medication

Normal Abnormal

Probable seizure Other Another lecture

EEG,Imaging study, consider more emergent evaluation

Neonatal seizuresNeonatal seizures Subtle seizuresSubtle seizures

– Deviation of the eyesDeviation of the eyes– Eyelids are flickeringEyelids are flickering– Swimming or pedaling movementsSwimming or pedaling movements– Apnoeic spellsApnoeic spells

TonicTonic ClonicClonic MyoclonicMyoclonic Seldom tonic clonic seizuresSeldom tonic clonic seizures

Aetiology of neonatal Aetiology of neonatal seizuresseizures

Perinatal:Perinatal:– HIEHIE

MetabolicMetabolic– Hypoglycemia, Hypoglycemia,

hypocalcemiahypocalcemia– hypomagnesemiahypomagnesemia– OtherOther

InfectionsInfections Structural Structural

abnormalitiesabnormalities

Treatment of neonatal Treatment of neonatal seizuresseizures Optimize ventilation, cardiac output, Optimize ventilation, cardiac output,

BP, glucose, electrolytes and pH.BP, glucose, electrolytes and pH. Treat the underlying diseaseTreat the underlying disease Intravenous line is essentialIntravenous line is essential Treat the seizures promptly and Treat the seizures promptly and

vigorouslyvigorously PhenobarbitonePhenobarbitone PhenytoinPhenytoin

Febrile seizuresFebrile seizures Definition:Definition:

– Seizure in children between the age of 6 Seizure in children between the age of 6 months and 3-4(5) years in association with months and 3-4(5) years in association with fever but without evidence of an intracranial fever but without evidence of an intracranial infectioninfection

Majority occurs before the age of 3 yearsMajority occurs before the age of 3 years Average age of onset: 18 months to 22 Average age of onset: 18 months to 22

monthsmonths Boys more than girlsBoys more than girls

PathophysiologyPathophysiology Seizure threshold is low in childrenSeizure threshold is low in children Susceptible to infections i.e urti, Susceptible to infections i.e urti,

LRTILRTI Possible role of endogenous Possible role of endogenous

pyrogens IL1pyrogens IL1– May increase neuronal activityMay increase neuronal activity

Probable role of cytokinesProbable role of cytokines

2 Types2 Types Simple febrile seizuresSimple febrile seizures

– GeneraliseGeneralise– <15min duration<15min duration– Do not recur within 24hrsDo not recur within 24hrs

ComplexComplex– Prolonged seizuresProlonged seizures– Usually more than one in a 24hr periodUsually more than one in a 24hr period– Or may be focalOr may be focal– Indicative of a more serious conditionIndicative of a more serious condition

Febrile seizuresFebrile seizures RecurrenceRecurrence

– 1/3 may have at least one recurrence1/3 may have at least one recurrence– The younger the age of onset the greater the risk of The younger the age of onset the greater the risk of

recurrencerecurrence– Low fever at first seizureLow fever at first seizure– Family hxFamily hx

Risk of developing epilepsyRisk of developing epilepsy– 2% (vs 1% in gen pop)2% (vs 1% in gen pop)– Risk increases with:Risk increases with:

ComplexComplex Abnormal neurological stateAbnormal neurological state

Investigation of febrile Investigation of febrile seizuresseizures Lab investigations, although routine, usually unhelpful, in Lab investigations, although routine, usually unhelpful, in

the evaluation of first time seizure – possible just a Na the evaluation of first time seizure – possible just a Na and Glucoseand Glucose

CT is not warranted in the evaluation of simple febrile CT is not warranted in the evaluation of simple febrile convulsions but considered for complex convulsions but considered for complex – Study of 71 patient with complex seizures Study of 71 patient with complex seizures

None had an intracranial condition requiring treatementNone had an intracranial condition requiring treatement Routine EEG is seldom necessaryRoutine EEG is seldom necessary ??LP??LP

– Simple febrile seizure probable not indicatedSimple febrile seizure probable not indicated Probable those with prolonged post-ictal phaseProbable those with prolonged post-ictal phase

– Current recommendation should be routine in the under 12 month Current recommendation should be routine in the under 12 month group group

Treatment of febrile Treatment of febrile convulsionconvulsion Oxygen and supportive careOxygen and supportive care BenzodiazapinesBenzodiazapines AntipyreticsAntipyretics

– Do not appear to prvent recurrenceDo not appear to prvent recurrence Councel parentsCouncel parents

Treatment of EpilepsyTreatment of Epilepsy– Drug treatment should be regularDrug treatment should be regular– Simple as possibleSimple as possible– Minimum of side effectsMinimum of side effects– MonotherapyMonotherapy– Changes should be made graduallyChanges should be made gradually– High initial dosages increases side effectsHigh initial dosages increases side effects– Rapid withdrawal carries the risk of provoking Rapid withdrawal carries the risk of provoking

statusstatus– Always calculate the dosage according to the Always calculate the dosage according to the

weightweight

Treatment of EpilepsyTreatment of Epilepsy Drugs commonly usedDrugs commonly used

– CarbamazepineCarbamazepine– Sodium valproateSodium valproate– ClonazepamClonazepam– PhenobarbitonePhenobarbitone– PhenytoinPhenytoin

Newer drugsNewer drugs– ClobazamClobazam– OxcarbazepineOxcarbazepine– GabapentinGabapentin– VigabatrinVigabatrin– LamotrigineLamotrigine

Treatment of EpilepsyTreatment of Epilepsy Antiepileptics can cause convulsionsAntiepileptics can cause convulsions

– Benzodiazepines can induce TC seizures in LGSBenzodiazepines can induce TC seizures in LGS– Carbamazepine may exacerbate absence Carbamazepine may exacerbate absence

seizuresseizures What is used as first line treatment.What is used as first line treatment.

– Absence:Absence: Sodium valproateSodium valproate

– Focal and Generalized TC:Focal and Generalized TC: CarbamazepineCarbamazepine

Status epilepticus (SE) presents in a Status epilepticus (SE) presents in a multitude of formsmultitude of forms, dependent on , dependent on aetiology and patient age aetiology and patient age (myoclonic, tonic, subtle, tonic-(myoclonic, tonic, subtle, tonic-clonic, absence, complex partial etc.)clonic, absence, complex partial etc.)

Generalized, tonic-clonic SE (GCSE) Generalized, tonic-clonic SE (GCSE) is the most common form of SEis the most common form of SE

DefinitionDefinition Conventional “textbook” Conventional “textbook”

definition of status epilepticus:definition of status epilepticus:

– Single seizure > 30 minutesSingle seizure > 30 minutes

– Series of seizures > 30 minutes Series of seizures > 30 minutes without full recoverywithout full recovery

Why 30 minutes ?Why 30 minutes ?Animal experiments in the 1970s and Animal experiments in the 1970s and 1980s had shown that ...1980s had shown that ...

… … neuronal injury could be demonstrated neuronal injury could be demonstrated after 30 min of seizure activity, even after 30 min of seizure activity, even while maintaining respiration and while maintaining respiration and circulationcirculation

Nevander G. Ann Neurol 1985;18(3):281-90.Nevander G. Ann Neurol 1985;18(3):281-90.

More practical: More practical: Mechanistic definitionMechanistic definition

GCSE is a condition which most likely will GCSE is a condition which most likely will not terminate rapidly and / or not terminate rapidly and / or spontaneouslyspontaneously

GCSE is a condition which requires prompt GCSE is a condition which requires prompt interventionintervention

Lowenstein DH. Epilepsia 1999Lowenstein DH. Epilepsia 1999

The longer SE persists,The longer SE persists,

–the lower is the likelihood of spontaneous cessationthe lower is the likelihood of spontaneous cessation–the harder it is to controlthe harder it is to control–the higher is the risk of morbidity and mortality the higher is the risk of morbidity and mortality

Bleck TP. Epilepsia 1999;40(1):S64-6Bleck TP. Epilepsia 1999;40(1):S64-6The Status Epilepticus Working Party. Arch Dis Child 2000;83(5):415-9.The Status Epilepticus Working Party. Arch Dis Child 2000;83(5):415-9.

Typical seizure Typical seizure durationduration Children > 5 years:Children > 5 years:

Typical, generalized tonic-clonic seizure Typical, generalized tonic-clonic seizure lasts < 5 minuteslasts < 5 minutes

Young children and infants:Young children and infants:little data. latsts < 10-15 minuteslittle data. latsts < 10-15 minutes

Reviewed in: Lowenstein DH. It's time to revise the definition of status epilepticus. Reviewed in: Lowenstein DH. It's time to revise the definition of status epilepticus. Epilepsia 1999;40(1):120-2.Epilepsia 1999;40(1):120-2.

Revised DefinitionRevised Definition Generalized, convulsive Generalized, convulsive status status

epilepticusepilepticus in older children (> 5 in older children (> 5 years) refers to years) refers to > 5 minutes of > 5 minutes of continuous seizurecontinuous seizure or or >>2 discrete 2 discrete seizures with incomplete recovery seizures with incomplete recovery of consciousnessof consciousness

CausesCauses FeverFever Medication changeMedication change UnknownUnknown MetabolicMetabolic CongenitalCongenital AnoxicAnoxic Other Other (trauma, vascular, (trauma, vascular,

infection, tumor, drugs)infection, tumor, drugs)

36%36%20%20% 9%9% 8%8% 7%7% 5%5%15%15%

\\

MortalityMortality AdultsAdults ChildrenChildren

15 to 22%15 to 22% 3 to 15%3 to 15%

Reviewed in: Fountain NB. Epilepsia 2000;41 Suppl 2:S23-30

MortalityMortality The primary determinant of mortality The primary determinant of mortality

and morbidity of SE in children is its and morbidity of SE in children is its aetiologyaetiology

With the highest mortality rates With the highest mortality rates caused by an acute neurological caused by an acute neurological condition (infection, trauma, stroke)condition (infection, trauma, stroke)

Mitchell WG. J Child Neurol 2002;17 Suppl 1:S36-43.Mitchell WG. J Child Neurol 2002;17 Suppl 1:S36-43.

Prolonged seizuresProlonged seizures

Duration of seizureDuration of seizure

Life Life threateningthreatening

systemicsystemicchangeschanges

DeathDeathTemporaryTemporary

systemicsystemicchangeschanges

RespiratoryRespiratory Hypoxia and hypercarbiaHypoxia and hypercarbia

– Ventilation Ventilation (chest rigidity from muscle spasm)(chest rigidity from muscle spasm)

– Hypermetabolism Hypermetabolism (( O O22 consumption, consumption, CO CO22

production)production)– Poor handling of secretionsPoor handling of secretions– Neurogenic pulmonary oedemaNeurogenic pulmonary oedema

HypoxiaHypoxia Hypoxia/anoxia markedly Hypoxia/anoxia markedly

increase (triple?) the risk of increase (triple?) the risk of mortality in SEmortality in SE

Seizures (without hypoxia) are Seizures (without hypoxia) are much less dangerous than much less dangerous than seizures and hypoxiaseizures and hypoxia

Towne AR. Epilepsia 1994;35(1):27-34Towne AR. Epilepsia 1994;35(1):27-34

AcidosisAcidosis RespiratoryRespiratory LacticLactic

– Impaired tissue Impaired tissue oxygenationoxygenation

– Increased energy Increased energy expenditureexpenditure