EpilepsyEpilepsy

Medicine internationalMedicine international

Definition Definition

Defined as 2 or more unprovoked Defined as 2 or more unprovoked seizuresseizures

Not a single disease, but a Not a single disease, but a manifestation of underlying brain manifestation of underlying brain dysfunctiondysfunction

Single or occasional seizures (eg: Single or occasional seizures (eg: febrile fits) and those occuring during febrile fits) and those occuring during acute illness should not be acute illness should not be considered as epilepsyconsidered as epilepsy

Epidemiology Epidemiology

Epilepsy is the most common serious Epilepsy is the most common serious neurological disease neurological disease

The lifetime prevalence of a single The lifetime prevalence of a single non-febrile seizure is 2–5%non-febrile seizure is 2–5%

The prevalence is slightly higher in The prevalence is slightly higher in males and in those in lower males and in those in lower socioeconomic groupssocioeconomic groups

AetiologyAetiology

The causes of epilepsy vary worldwide and The causes of epilepsy vary worldwide and with age. with age.

The aetiology may be multifactorial, and is The aetiology may be multifactorial, and is unknown in about two- thirds of patientsunknown in about two- thirds of patients

Community-based surveys in the UK show Community-based surveys in the UK show the following common aetiologies:the following common aetiologies:• cerebrovascular disease (15%)cerebrovascular disease (15%)• cerebral tumours (6%)cerebral tumours (6%)• alcohol-related (6%) alcohol-related (6%) • post-traumatic (2%)post-traumatic (2%)

In the UK, refractory epilepsy is most In the UK, refractory epilepsy is most commonly caused by commonly caused by • hippocampal sclerosishippocampal sclerosis• malformations of cortical developmentmalformations of cortical development• small foreign tissue lesions (vascular small foreign tissue lesions (vascular

malformations, hamartomata and low-grade malformations, hamartomata and low-grade gliomas) gliomas)

Neurocysticercosis and other infectious Neurocysticercosis and other infectious causes are common in developing worldcauses are common in developing world

More than 200 disorders showing a More than 200 disorders showing a Mendelian pattern of inheritance feature Mendelian pattern of inheritance feature epilepsy among their manifestations, but epilepsy among their manifestations, but these account for only about 1% of casesthese account for only about 1% of cases

Pathology and pathogenesisPathology and pathogenesis Reciprocal corticothalamic interaction is Reciprocal corticothalamic interaction is

probably important in the generation of probably important in the generation of generalized seizuresgeneralized seizures

Local excitation–inhibition imbalance is the Local excitation–inhibition imbalance is the likely basis of partial seizureslikely basis of partial seizures

Modern pathological studies are beginning Modern pathological studies are beginning to define the structural limits of such to define the structural limits of such changeschanges

Functional imaging studies will also con- Functional imaging studies will also con- tribute, with the eventual aim of rational tribute, with the eventual aim of rational drug designdrug design

DiagnosisDiagnosis

The first step is to establish the The first step is to establish the diagnosis of epilepsy. diagnosis of epilepsy.

Type of seizure, syndromic Type of seizure, syndromic classification and aetiology must classification and aetiology must then be determined for then be determined for complete characterization and optimcomplete characterization and optimum managementum management

Establishing the diagnosisEstablishing the diagnosis

Epileptic seizures are paroxysmal events, Epileptic seizures are paroxysmal events, often with impairment of awarenessoften with impairment of awareness

Symptoms may include generalized con- Symptoms may include generalized con- vulsive movements, drop attacks, vulsive movements, drop attacks, transient focal motor or sensory attacks transient focal motor or sensory attacks (including facial and eye movements), (including facial and eye movements), pychic experiences, episodic phenomena pychic experiences, episodic phenomena in sleep and prolonged confusional statesin sleep and prolonged confusional states

Diagnosis of epilepsy is clinical Diagnosis of epilepsy is clinical

An eyewitness account is almost essential An eyewitness account is almost essential – there is no substitute for a detailed – there is no substitute for a detailed history from the patient and a witness, nor history from the patient and a witness, nor for direct observation of an attack when for direct observation of an attack when possiblepossible

Ask specifically about: Ask specifically about: • the circumstances of the episodethe circumstances of the episode• patterns of occurrencepatterns of occurrence• preceding symptoms that may localize preceding symptoms that may localize

seizure origin or suggest other conditions seizure origin or suggest other conditions• timing, pattern and tempo of evolution of timing, pattern and tempo of evolution of

symptoms symptoms • reported behaviour before, during and after reported behaviour before, during and after

the eventthe event Investigations are needed only Investigations are needed only

occasionally to establish the diagnosis, but occasionally to establish the diagnosis, but help in managementhelp in management

Differential diagnosis of epilepsyDifferential diagnosis of epilepsy

SyncopeSyncope (secondary anoxic movements which (secondary anoxic movements which may be brief, small or irregular may occur)may be brief, small or irregular may occur)• Vasovagal Vasovagal • Micturition Micturition • Postural Postural • Vascular disordersVascular disorders• Respiratory Respiratory • Cardiac Cardiac

Cardiac disordersCardiac disorders • ArrhythmiasArrhythmias• Aortic or mitral stenosisAortic or mitral stenosis• Cardiomyopathies Cardiomyopathies • Other obstructive conditions (e.g. myxoma)Other obstructive conditions (e.g. myxoma)

Metabolic or Metabolic or endocrineendocrine • HypoglycaemiaHypoglycaemia• PhaeochromocytomaPhaeochromocytoma• Carcinoid syndromeCarcinoid syndrome• Porphyria Porphyria

NeurologicalNeurological • Transient ischaemic Transient ischaemic

attack attack • Cataplexy–narcolepsyCataplexy–narcolepsy• Basilar migraineBasilar migraine• Third ventricular cystThird ventricular cyst• Ménière’s diseaseMénière’s disease• Episodic ataxiasEpisodic ataxias• Movement and sleep Movement and sleep

disordersdisorders

Psychological or Psychological or psychiatricpsychiatric • hyperventilation hyperventilation • Panic attacks Panic attacks • Non-epileptic attack Non-epileptic attack

disorder disorder • EpisodicEpisodic• dyscontrol syndrome dyscontrol syndrome • MalingeringMalingering• Münchausen’s Münchausen’s

syndromesyndrome

Type of seizureType of seizure

Partial seizuresPartial seizures begin focally in the begin focally in the cortex. Such seizures may cortex. Such seizures may secondarily become generalized, secondarily become generalized, involving the whole of the cortexinvolving the whole of the cortex

Generalized seizuresGeneralized seizures, in contrast, , in contrast, involve much of the cortex bilaterally involve much of the cortex bilaterally from the outset, and usually cause from the outset, and usually cause immediate loss of consciousnessimmediate loss of consciousness

Generalized tonic-clonic seizureGeneralized tonic-clonic seizure • May occur spontaneously or following a partial May occur spontaneously or following a partial

seizureseizure• May be heralded by a cry, followed by loss of May be heralded by a cry, followed by loss of

consciousnessconsciousness• Falling to the ground with spasm of limbsFalling to the ground with spasm of limbs• Deepening cyanosis in the tonic phaseDeepening cyanosis in the tonic phase• Subsequent clonic phase is marked by Subsequent clonic phase is marked by

Stertorous breathingStertorous breathing Jerky limb convulsion of increasing amplitude and Jerky limb convulsion of increasing amplitude and

decreasing frequencydecreasing frequency• Tongue biting, incontinence of urine and faeces Tongue biting, incontinence of urine and faeces

may occurmay occur• The seizure is typically followed by coma with The seizure is typically followed by coma with

an ascending consciousness level, then by an ascending consciousness level, then by confusion, headache, aching limbs and a desire confusion, headache, aching limbs and a desire to sleep, before complete recoveryto sleep, before complete recovery

Absences:Absences:• Generalized seizuresGeneralized seizures• May be simply a May be simply a sudden, brief cessation sudden, brief cessation

or slowing of activity, with rapid return or slowing of activity, with rapid return to normalityto normality

• Accompanied by 3Hz spike and wave Accompanied by 3Hz spike and wave EEG activityEEG activity

• Atypical absences show slower or poorly Atypical absences show slower or poorly formed spike-wave EEG activity; they formed spike-wave EEG activity; they may be more prolonged than typical may be more prolonged than typical absencesabsences

Epileptic myoclonic jerksEpileptic myoclonic jerks • usually a sudden flexion movement of usually a sudden flexion movement of

the armsthe arms• generalized seizuresgeneralized seizures• occur in various syndromesoccur in various syndromes• They are not usually associated with They are not usually associated with

loss of consciousness, unless loss of consciousness, unless accompanied by absencesaccompanied by absences

Partial seizures:Partial seizures:• occur in a wide variety of formsoccur in a wide variety of forms• Consciousness is not impaired in simple Consciousness is not impaired in simple

partial seizurespartial seizures• Complex partial seizures are defined by Complex partial seizures are defined by

impaired consciousness, which may impaired consciousness, which may occur from the outset or may evolve occur from the outset or may evolve from a simple partial seizurefrom a simple partial seizure

• automatisms may also occurautomatisms may also occur

Partial seizuresPartial seizures

• temporal lobe origin temporal lobe origin abnormal taste or smell experiencesabnormal taste or smell experiences rising epigastric sensationrising epigastric sensation autonomic changes autonomic changes psychic phenomena such as fear, psychic phenomena such as fear, déjà vudéjà vu and and jamais jamais

vuvu

• Frontal seizuresFrontal seizures frequent, bizarre and brief with rapid recovery of frequent, bizarre and brief with rapid recovery of

consciousnessconsciousness commonly, version of eyes or head and unilateral or commonly, version of eyes or head and unilateral or

bilateral limb movement or posturing occurbilateral limb movement or posturing occur may be mistaken for non-epileptic attacks or may be mistaken for non-epileptic attacks or

paroxysmal movement disordersparoxysmal movement disorders

Partial seizuresPartial seizures

• Parietal seizuresParietal seizures characterized by positive sensory or characterized by positive sensory or

paraesthetic symptoms, or by pain paraesthetic symptoms, or by pain

• Occipital seizures:Occipital seizures: positive, possibly coloured visual positive, possibly coloured visual

phenomena in the contralateral visual field, phenomena in the contralateral visual field, or loss of visionor loss of vision

AutomatismsAutomatisms • semi-purposeful release phenomenasemi-purposeful release phenomena• can occur in complex partial seizures or can occur in complex partial seizures or

prolonged absencesprolonged absences• clinical differentiation is therefore clinical differentiation is therefore

difficultdifficult• They include They include

lip-smackinglip-smacking SwallowingSwallowing fidgeting with the handsfidgeting with the hands more complex behaviours including more complex behaviours including

vocalization, speech and wanderingvocalization, speech and wandering

Status epilepticusStatus epilepticus• occur in series, or without interruption occur in series, or without interruption • Any recognized seizure type may occur in Any recognized seizure type may occur in

series or status, usually in patients known to series or status, usually in patients known to have epilepsyhave epilepsy

• Generalized tonic-clonic status epilepticus is Generalized tonic-clonic status epilepticus is the most dramatic, and is a medical the most dramatic, and is a medical emergencyemergency

• the most common causes the most common causes anti-epileptic drug withdrawal anti-epileptic drug withdrawal non-compliancenon-compliance MeningitisMeningitis EncephalitisEncephalitis cerebral tumor cerebral tumor abscess (particularly frontal) abscess (particularly frontal) alcohol withdrawalalcohol withdrawal

• Complex partial status epilepticus may Complex partial status epilepticus may manifest with pro- longed periods of manifest with pro- longed periods of confusion and disorientation, associated confusion and disorientation, associated with automatic activity for which there is with automatic activity for which there is amnesiaamnesia

• Absence status epilepticus often occurs in the Absence status epilepticus often occurs in the context of learning disability or context of learning disability or de novode novo in in older individualolder individual

may be associated with confusion, disorientation may be associated with confusion, disorientation or cognitive slowing or cognitive slowing

• Epileptia partialis continuaEpileptia partialis continua focal (usually motor) status epilepticus, often reflects focal (usually motor) status epilepticus, often reflects

underlying structural abnormalities, and may be underlying structural abnormalities, and may be unremitting for months or years despite treatment unremitting for months or years despite treatment with anti-epileptic drugswith anti-epileptic drugs

ExaminationExamination The presence of neurological signs (e.g. hemiparesis, The presence of neurological signs (e.g. hemiparesis,

dysphasia, field defect, papilloedema) may lateralize or dysphasia, field defect, papilloedema) may lateralize or localize a structural lesionlocalize a structural lesion

Dysmorphism and learning disability may reflect a Dysmorphism and learning disability may reflect a chromosomal disorderchromosomal disorder

progressive features (e.g. dementia, ataxia, worsening progressive features (e.g. dementia, ataxia, worsening myoclonus) suggest a neurodegenerative disordermyoclonus) suggest a neurodegenerative disorder

Cutaneous stigmata of the neurocutaneous disorders Cutaneous stigmata of the neurocutaneous disorders should always be soughtshould always be sought

A cardiovascular examination should be performed at first A cardiovascular examination should be performed at first presentationpresentation

The pupils may dilate during a seizureThe pupils may dilate during a seizure other features may help lateralize the focus other features may help lateralize the focus

• dysphasia indicates dominant hemisphere onsetdysphasia indicates dominant hemisphere onset• Unilateral automatisms are ipsilateral and unilateral dystonia Unilateral automatisms are ipsilateral and unilateral dystonia

contralateral to a temporal lobe focuscontralateral to a temporal lobe focus

Classification of syndromesClassification of syndromes Syndromic classification incorporatesSyndromic classification incorporates

• Seizure typeSeizure type• AetiologyAetiology• PrecipitantsPrecipitants

Sydromic diagnosis may guide treatment and Sydromic diagnosis may guide treatment and prognosisprognosis

International league against epilepsy (ILAE) International league against epilepsy (ILAE) classificationclassification• Two principle categeries are localization related and Two principle categeries are localization related and

generalisedgeneralised• These are subdivided idiopathic, symptomatic These are subdivided idiopathic, symptomatic

(underlying structural abnormality) and cryptogenic (underlying structural abnormality) and cryptogenic (structural abnormalities suggested, but not (structural abnormalities suggested, but not demonstrated)demonstrated)

probably 50% of epilepsies are generalized and probably 50% of epilepsies are generalized and 50% are localization-related, most commonly 50% are localization-related, most commonly temporal in origintemporal in origin

The importance of classification is illustrated by The importance of classification is illustrated by the syndrome of juvenile myoclonic epilepsythe syndrome of juvenile myoclonic epilepsy• This idiopathic generalized epilepsy is characterized by This idiopathic generalized epilepsy is characterized by

myoclonic jerks, tonic- clonic seizures and typical myoclonic jerks, tonic- clonic seizures and typical absencesabsences

• begins in the second decadebegins in the second decade• provoked by sleep deprivation, alcohol and fatigue, and provoked by sleep deprivation, alcohol and fatigue, and

usually occur in the morningusually occur in the morning• EEG in untreated patients is characteristicEEG in untreated patients is characteristic• The condition is lifelong, and though most patients The condition is lifelong, and though most patients

become seizure-free on treatment with valproate, there become seizure-free on treatment with valproate, there is a high risk of recurrence of seizures if treatment is is a high risk of recurrence of seizures if treatment is withdrawnwithdrawn

• Recognition of this syndrome thus has important Recognition of this syndrome thus has important implications, and hence the value of a syndromic implications, and hence the value of a syndromic diagnosis. diagnosis.

Classification of epilepsy (abbreviated Classification of epilepsy (abbreviated

ILAE) ILAE) Generalized epilepsies and Generalized epilepsies and

syndromessyndromes • Idiopathic with age-related onsetIdiopathic with age-related onset

• Benign neonatal familial convulsions • Benign neonatal familial convulsions • Benign neonatal convulsions • Benign neonatal convulsions

• • Benign myoclonic epilepsy in infancy Benign myoclonic epilepsy in infancy • Childhood absence epilepsy • Childhood absence epilepsy

• • Juvenile myoclonic epilepsy Juvenile myoclonic epilepsy • • Epilepsy with generalized tonic-clonic Epilepsy with generalized tonic-clonic

seizures on awakeningseizures on awakening

Generalized epilepsies and Generalized epilepsies and syndromessyndromes• Symptomatic or cryptogenicSymptomatic or cryptogenic

West syndrome West syndrome Lennox–Gastaut syndrome Lennox–Gastaut syndrome Epilepsy with myoclonic-astatic Epilepsy with myoclonic-astatic

seizures seizures Epilepsy with myoclonic absences Epilepsy with myoclonic absences

• SymptomaticSymptomatic Early myoclonic encephalopathy Early myoclonic encephalopathy Early infantile myoclonic Early infantile myoclonic

encephalopathy with burst suppression encephalopathy with burst suppression OthersOthers

Localization-related epilepsies and Localization-related epilepsies and syndromessyndromes • Idiopathic with age-related onsetIdiopathic with age-related onset

Benign childhood epilepsy with centrotemporal spikes Benign childhood epilepsy with centrotemporal spikes Childhood epilepsy with occipital paroxysms Childhood epilepsy with occipital paroxysms Primary reading epilepsy Primary reading epilepsy

• SymptomaticSymptomatic Epilepsy with simple partial, complex partial or Epilepsy with simple partial, complex partial or

secondarily generalized seizures arising from the secondarily generalized seizures arising from the frontal, parietal, temporal or occipital lobe or from frontal, parietal, temporal or occipital lobe or from multiple lobes, or of unknown lobe of onset multiple lobes, or of unknown lobe of onset

Epilepsia partialis continua Epilepsia partialis continua Syndromes characterized by specific modes of Syndromes characterized by specific modes of

activation activation

• Unknown whether idiopathic or symptomaticUnknown whether idiopathic or symptomatic

Epilepsies and syndromes Epilepsies and syndromes undetermined (focal orundetermined (focal or generalized)generalized)• Severe myoclonic epilepsy in Severe myoclonic epilepsy in

infancy infancy • Epilepsy with continuous spike-and-Epilepsy with continuous spike-and-

wave activity in sleep wave activity in sleep • Acquired epileptic aphasiaAcquired epileptic aphasia

Special syndromesSpecial syndromes

Investigations Investigations All patients with a diagnosis, or possible All patients with a diagnosis, or possible

diagnosis of epilepsy should undergo full blood diagnosis of epilepsy should undergo full blood count, electrolytes (including calcium), glucose, count, electrolytes (including calcium), glucose, liver function tests and 12-lead ECGliver function tests and 12-lead ECG

ECG is important to detect rare cases of ECG is important to detect rare cases of prolonged QT interval presenting as seizures prolonged QT interval presenting as seizures (often morning generalized tonic- clonic seizures)(often morning generalized tonic- clonic seizures)

In most patients, relevant abnormalities can be In most patients, relevant abnormalities can be detected only by high-resolution MRI detected only by high-resolution MRI • MRI reveals the cause of epilepsy in 30% of patients MRI reveals the cause of epilepsy in 30% of patients

with generalized epilepsies and in 70% of those with with generalized epilepsies and in 70% of those with localization-related epilepsieslocalization-related epilepsies

EEGEEG • role of EEG is often misunderstoodrole of EEG is often misunderstood• Detection of EEG abnormalities does not equate to Detection of EEG abnormalities does not equate to

epilepsy, unless the clinical context is appropriate epilepsy, unless the clinical context is appropriate• Conversely, absence of interictal EEG abnormalities does not Conversely, absence of interictal EEG abnormalities does not

exclude a diagnosis of epilepsyexclude a diagnosis of epilepsy• In a single awake recording, only one-third of patients In a single awake recording, only one-third of patients

consistently show epileptiform changesconsistently show epileptiform changes• The yield can be improved by repeating recordings in sleep or The yield can be improved by repeating recordings in sleep or

by specific activating methods (hyperventilation, photic by specific activating methods (hyperventilation, photic stimulation)stimulation)

• In certain conditions, EEG may be diagnostic; for example, In certain conditions, EEG may be diagnostic; for example, generalized 3 Hz spike-and-wave activity is characteristic of generalized 3 Hz spike-and-wave activity is characteristic of some primary generalized epilepsiessome primary generalized epilepsies

• About 5% of patients with epilepsy are photosensitive. Specific About 5% of patients with epilepsy are photosensitive. Specific photoparoxysmal findings have implications with respect to photoparoxysmal findings have implications with respect to lifestyle and must be notedlifestyle and must be noted

• Ictal recordings are seldom made in routine practice, unless a Ictal recordings are seldom made in routine practice, unless a seizure occurs by chanceseizure occurs by chance

• In some seizures, there may be no ictal changes; this does In some seizures, there may be no ictal changes; this does not exclude a diagnosis of epilepsy, particularly in simple not exclude a diagnosis of epilepsy, particularly in simple partial seizures and frontal lobe epilepsy.partial seizures and frontal lobe epilepsy.

EEG telemetryEEG telemetry• Indications: Indications:

Diagnosis remains in doubt despite Diagnosis remains in doubt despite apparently frequent seizuresapparently frequent seizures

if surgical treatment is consideredif surgical treatment is considered

• If necessary, presurgical investigations If necessary, presurgical investigations (e.g. intracarotid amytal testing to (e.g. intracarotid amytal testing to determine lateralized memory function determine lateralized memory function and language dominance, intracranial and language dominance, intracranial EEG to determine the seizure focus) are EEG to determine the seizure focus) are undertaken in specialist centresundertaken in specialist centres

More detailed investigationsMore detailed investigations • Hypoglycaemia may need to be excluded, Hypoglycaemia may need to be excluded,

particularly in patients with early morning particularly in patients with early morning seizures. seizures.

• Echocardiography, ambulatory ECG, urinalysis Echocardiography, ambulatory ECG, urinalysis for catecholamine metabolites and porphyrin for catecholamine metabolites and porphyrin determination may be requireddetermination may be required

Neuropsychometric, psychological and Neuropsychometric, psychological and psychiatric assessmentpsychiatric assessment • may be required in patients being considered may be required in patients being considered

for surgery, when there is concern about for surgery, when there is concern about cognitive decline, or when a non-epileptic cognitive decline, or when a non-epileptic attack disorder is diagnosedattack disorder is diagnosed

Non-epileptic attack disorderNon-epileptic attack disorder

most commonly comprise either most commonly comprise either • Prolonged motionlessness with preserved Prolonged motionlessness with preserved

background EEG rhythms, or background EEG rhythms, or • Prominent, often waxing and waning Prominent, often waxing and waning

movements including asynchronous limb movements including asynchronous limb flailing, pelvic thrusting and opisthotonus flailing, pelvic thrusting and opisthotonus

Salivation, incontinence and injury may Salivation, incontinence and injury may occur, but hypoxia does notoccur, but hypoxia does not

These patients usually have underlying These patients usually have underlying psychological or psychiatric problemspsychological or psychiatric problems

Diagnosis of non-epileptic attack disorder may Diagnosis of non-epileptic attack disorder may require prolonged observation and EEG monitoringrequire prolonged observation and EEG monitoring

Prolactin levels rise immediately after generalized Prolactin levels rise immediately after generalized tonic- clonic seizures and some complex partial tonic- clonic seizures and some complex partial seizures, and return to baseline within 50 minutesseizures, and return to baseline within 50 minutes

This does not occur after absence seizuresThis does not occur after absence seizures Serum prolactin concentrations do not generally Serum prolactin concentrations do not generally

rise significantly after non-epileptic attacks, but rise significantly after non-epileptic attacks, but may rise after severe syncopal episodes, or on may rise after severe syncopal episodes, or on physical exertionphysical exertion

Ictal EEG recording may be obscured by movement Ictal EEG recording may be obscured by movement artefact, but the typical EEG changes that may artefact, but the typical EEG changes that may precede or succeed epileptic seizures are not seenprecede or succeed epileptic seizures are not seen

Iatrogenic complications may ensue from Iatrogenic complications may ensue from inappropriate treatment, particularly in inappropriate treatment, particularly in ‘pseudostatus’, which is found in 25% of referrals ‘pseudostatus’, which is found in 25% of referrals of patients with apparent status epilepticus to of patients with apparent status epilepticus to specialist unitsspecialist units

PrognosisPrognosis

In most (70%), remits over a period of In most (70%), remits over a period of years years

The risk of recurrence is greatest in the The risk of recurrence is greatest in the first few months after a first seizure. first few months after a first seizure.

~1/3rd of who suffer a single unprovoked ~1/3rd of who suffer a single unprovoked seizure have a further seizure within 5 seizure have a further seizure within 5 years years

~ 3/4 of those with two unprovoked ~ 3/4 of those with two unprovoked seizures suffer further seizures within 4 seizures suffer further seizures within 4 yearsyears

The most important predictor of The most important predictor of natural history is the type (or natural history is the type (or syndrome) of epilepsy, particularly if syndrome) of epilepsy, particularly if the cause is identified or presumedthe cause is identified or presumed

Patients with malformations, Patients with malformations, congenital abnormalities, progressive congenital abnormalities, progressive myoclonic epilepsies, syndromes with myoclonic epilepsies, syndromes with atypical absence or atonic/tonic atypical absence or atonic/tonic seizures, or localization- related seizures, or localization- related epilepsy with underlying structural epilepsy with underlying structural abnormalities are least likely to remitabnormalities are least likely to remit

Those with juvenile myoclonic epilepsy Those with juvenile myoclonic epilepsy generally do well if kept on treatmentgenerally do well if kept on treatment

Most patients with childhood absence Most patients with childhood absence epilepsy, epilepsy with tonic-clonic epilepsy, epilepsy with tonic-clonic seizures on awakening, or nonspecific seizures on awakening, or nonspecific generalized tonic-clonic seizures who are generalized tonic-clonic seizures who are otherwise neurologically normal may be otherwise neurologically normal may be successfully weaned from drugs once successfully weaned from drugs once remission is achievedremission is achieved

Some types of epilepsy (e.g. benign Some types of epilepsy (e.g. benign neonatal convulsions, fifth-day seizures, neonatal convulsions, fifth-day seizures, benign myoclonic epilepsy of infancy, benign myoclonic epilepsy of infancy, some benign partial epilepsies, epilepsies some benign partial epilepsies, epilepsies precipitated by a specific mode of precipitated by a specific mode of activation) may not need drug treatmentactivation) may not need drug treatment

MortalityMortality epilepsy is often assumed to be benign, but epilepsy is often assumed to be benign, but

population-based studies show an increased population-based studies show an increased standardized mortality ratio (SMR) of 2–3 standardized mortality ratio (SMR) of 2–3

Seizure type may be important in determining Seizure type may be important in determining SMRSMR

Mortality is greatest in the first year after Mortality is greatest in the first year after diagnosis because of the mortality associated diagnosis because of the mortality associated with the underlying causewith the underlying cause

Other causes of increased SMR are epilepsy-Other causes of increased SMR are epilepsy-related accidents, suicide, non-cerebral cancers related accidents, suicide, non-cerebral cancers and ‘sudden unexpected death in epilepsy’ (non-and ‘sudden unexpected death in epilepsy’ (non-traumatic and unwitnessed death in an individual traumatic and unwitnessed death in an individual with epilepsy who had otherwise been previously with epilepsy who had otherwise been previously well, and in whom no cause of death is well, and in whom no cause of death is established even after post mortem). established even after post mortem).

Incidence of sudden unexpected death is Incidence of sudden unexpected death is 1/200/year in refractory epilepsy and is pr1/200/year in refractory epilepsy and is probably seizure relatedobably seizure related

effective treatment (including surgical) effective treatment (including surgical) of epilepsy may reduce this risk. of epilepsy may reduce this risk.

It is important to diagnose the underlying It is important to diagnose the underlying syndrome and aetiology correctly, to syndrome and aetiology correctly, to ensure that the most appropriate ensure that the most appropriate treatment option can be initiated promptlytreatment option can be initiated promptly