Seizure &

Epilepsy

Definitions

Seizure A sudden surge of electrical

activity in brain that usually affects how a person feels or acts for a short time.

Some seizures can hardly be noticed, while others are totally disabling.

Epilepsy A condition that affects central

nervous system (CNS) had at least 2 seizures not caused by some known

medical condition like alcohol withdrawal or extremely low blood sugar.

not indicate anything about the cause of the seizures, what type they are, or how severe they are.

Momentary loss of consciousness

Fit Faint Fake

Transient loss of consciousness

Déjà vuJamais vuAphasiaOlfactory auraEpigastric sensationTongue bitingPost event deliriumFocal neurodeficit

Light-headednessSweatingProlonged standingPrecipitants eg.micturitionChest painPalpitationSlow heart rateLow blood pressure

History and Physical Witness account

AphasiaDeliriumHead turnAutomatismPosturingConvulsionPostictal delirium

Myoclonus or convulsionafter pallor,sweating and collapse

PallorSweatingSlow pulseLow BP

Syncope Seizure

Convulsive syncopeSyncope Seizure

Character Syncope Epileptic seizure

Position

usually upright any

Time daytime day or nighttime

Color pallor normal or cyanotic

Aura dizziness, visual blurring

possible specificaura

Autonomic common uncommon

Duration brief brief or prolonged

Incontinence rare more common

Character Syncope Epileptic seizure

Motor activity occasionally brief tonic seizure or

clonic jerks

variable

Automatism none absence,CPS

Disorientation, posictal

rare can occur withGTC,CPS

Nonepileptic causes for spells

Physiologic Tremor Vasovagal syncope Cardiac arrhythmias Migraine Medication adverse effects Transient ischemic attacks Autonomic dysfunction

Nonepileptic causes for spells

Psychologic Anxiety Panic attacks Mood disorder Personality disorder Psychosis Somatiform illness Psychogenic seizures

Phase of seizures

Preictal phase or aura or warning Ictal phase : simple or complex partial or

generalized tonic-clonic seizure Postictal phase or recovery period : last

from seconds to minutes to hours

Precipitants of seizure

Sleep and lack of sleep

Drugs and alcohol

Intercurrent illness : infection,

electrolyte imbalance

Menstruation

Stress and worry

Other precipitants-reflex epilepsy

Classification of seizure

Partial (focal, localized) seizures

Generalized seizures (convulsive or non-convulsive)

Unclassified epileptic seizures

Partial (focal, localized)seizures

1. Simple partial seizures (preserved consciousness)

2. Complex partial seizures (impaired

consciousness)

3. Partial seizures evolving to secondarily

generalized seizures

1. Simple partial seizures

(preserved consciousness)

With - motor signs

- somatosensory or special

sensory systems

- autonomic symptoms or signs

- psychic symptoms

2. Complex partial seizures (impaired

consciousness)

- Simple partial onset followed by

impairment of conscious

- With impairment of consciousness at

onset

3. Partial seizures evolving to

secondarily generalized seizures

- Simple partial seizures evolving to

generalized seizures

- Complex partial seizures evolving to

generalized seizures

- Simple partial seizures evolving to complex

partial seizures evolving to generalized

seizures

Generalized seizures (convulsive

or nonconvulsive)

- Absence seizures

Typical absences

Atypical absences

- Myoclonic seizures

- Clonic seizures

- Tonic seizures

- Tonic-clonic seizures

- Atonic seizures (astatic seizures)

Unclassified epileptic seizures - Neonatal seizures

- Recurrent status epilepticus

- Rare or ‘isolated’ seizures

Epileptic seizure

Seizuretype (s)

Etiology

All clinical andlaboratory dataneuroimaging

Seizuredescription and EEG

Seizure

Idiopathic Generalized

epilepsy likely

Features of focal epilepsy

Epilepsy or PNES

Provoked seizures

EEGEEG

MRI/CT brain

Video EEG

Treat cause +/- AED

PNES=psychogenic non-epileptic seizures

AED=antiepileptic drug

Laboratory investigation

CBC

FBS, BUN, Creatinine

Electrolyte , Liver function test , Ca+2 Mg+2

Electro-encephalography (EEG)

Video EEG

Neuroimaging : CT Scan, MRI, MR Spect, PET

Special investigation : ammonia, lactate , pyruvate etc.

Electroencephalogram

What value is the EEG?

Add weight to the clinical diagnosis

Aid classification of epilepsy

Detection of the structural brain lesion.

EEG

30 minute interictal EEG –useful when clinical suspicion of epilepsy

Timing is important Within 24 hr of generalized convulsion: 50%

have abnormal EEG First 48 hr: 21-34% have epileptiform activity

Sleep EEG or sleep-deprived EEG might increase diagnostic yield

Normal EEG

Primary generalized epilepsy—ictal EEG

Primary generalized epilepsy- interictal EEG

Burst of generalized spike and wave discharges—typical absence seizure

EEG monitoring

Video Monitoring

Helpful in determining nature of seizure disorder (epilepsy, convulsive syncope, or psychogenic seizures)

Indication for neuroimaging in patients with seizures

Partial seizure

Late onset unprovoked seizure (age > 25)

Unexplained neurological signs

Focal slow waves EEG

poor control or new symptoms / signs

Neuroimaging

In the absence of trauma: CT and MRI brain for patients presenting with suspected first unprovoked seizure or with a focal neurological deficit.

MRI is preferable for looking for neuronal migrational disorders, major malformations, vascular anomalies, tumors

The causes of epilepsy Genetic factor Congenital abnormalities Trauma and the effect of craniotomy CNS infection Cerebrovascular disease Cerebral tumors Alzheimer’s disease and other degenerative

disease Others

Neurocysticercosis

Cerebral infarction

Intracerebral hemorrhage

Brain tumor or metastasis

Lt mesial temporal sclerosis

Cortical dysplasia

52 year old woman with intractable seizure

PET scan

PET using F-18 FDG-- Decreased FDG uptake in both temporal lobes, right worse then left but otherwise relatively symmetric

What to do?Generalized seizure

Loosening the patient’s clothing Lower the patient gently to the floor, turn them

onto their side and cushion head Nothing is put into the mouth Remove any items that could cause injury

What to do? ---Generalized seizure

When the seizure is over, allow the patient to rest or sleep

If they are able to return to their feet, help them home

Obtain medical help if they continue to experience breathing problems once the seizure is over, or if the seizure lasts a long time(over 10 mins), or when another attack quickly follows the first

What to do?

Partial seizures Stay with the patients throughout the seizure Protect them from any dangerous object Taking care not to restrain them in anyway

First aids

Treatment

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Choose a drug : considering the following factors The seizure type and prognosis Age The possibility of pregnancy Toxicity Drug interaction Price

The recurrence risk follow a first unprovoked seizure

27%-52%

50% recurrence occur within 6 months

over 80% within 2 years of initial seizures

twice as likely to have another seizure if you have a

known brain injury or brain abnormality.

RISK OF RECURRENT SEIZURE

RISK OF RECURRENT SEIZURE (cont)

If you do have two seizures, there's about 80% chance that you'll have more.

Factors predictive of a high rate of seizure recurrence after the first

unprovoked seizure

Abnormal neurologic status by NE or imaging

EEG abnormalities (especially epileptiform)

Partial seizures

Counseling before treatment

1. Aims of treatment

2. Prognosis and duration of the

expected treatment

3. Importance of compliance

4. Side effects

Starting antiepileptic treatment Prospective risks Usual clinical

Factors that may modify of epilepsy practice usual practice Single seizure No treatment Progressive cerebral disorder (clinically Dx) Clearly epileptic EEG

2 or more seizure Monotherapy Seizures widely separated (clinically Dx) in time (> 1 year)

Identified precipitating, factors (eg, drugs,

alcohol,reflex stimuli)

Probability of poor compliance (eg, personality disorder) Attitude of patients/parents

Antiepileptic Drug Development

1840 1860 1880 1900 1920 1940 1960 1980 20000

5

10

15

20

BromidePhenobarbital

Phenytoin Primidone

Ethosuximide

Sodium Valproate

BenzodiazepinesCarbamazepine

VigabatrinZonisamide

LamotrigineFelbamate

GabapentinTopiramate Fosphenytoin

OxcarbazepineTiagabine

Levetiracetam

More

Calendar year

Antiepileptic drugs

Pregabalin

First-line choice of AEDs according to seizure type

Seizure type First line

Absence (typical and atypical)

VPA, LTG

Myoclonic VPA

Tonic-clonic VPA, CBZ, PHT, PB

Atonic VPA

Simple and complex partial, with or without secondary generalization

CBZ, PHT, PB,OXC,LTG,TPM, GBP

Unclassifiable VPA

Advantages of Monotherapy

Better seizure controlReduced side effectsAbsence of drug interactionsReduced teratogenic effectsBetter complianceReduced cost of medication Improved quality of life

Expected outcomes of AED therapy

Well controlled

65%

Unsatisfactorilycontrolled

35%

Well controlled

10%

Unsatisfactorilycontrolled

25%

Well controlled

5%

Unsatisfactorilycontrolled

20%

Monotherapy

Add-on therapy

Multiple drug therapy

Managing newly diagnosed epilepsy

Newly diagnosed epilepsy

Seizure freeFirst drug

Second drug

Refractory

Surgical assessmentRational duotherapy

Seizure free

47%

13%

Adverse effect of AED

Dose related Idiosyncratic / allergic Chronic toxicity Teratogenicity

Older AEDs

Drugs Side effects

CBZ Diplopia, headache, dizziness, N/V, rash, mild leukopenia, mild hyponatremia

PHT Ataxia,nystagmus, dysarthria, somnolence,gingival hyperplasia, hirsutism, acne, facial coarsening, folate, deficiency, osteopenia, peripheral neuropathy, cerebellar atropy

VPA Dose-related tremor, weight gain,loss of hair, menstrual irregularities, PCOS, stupor and encephalopathy(rare), hepatotoxicity

PB Sedation and behavioral problem(depression, agitation, hyperactivity)

CZP Sedation, ataxia, behavioral changes(depression)

AED interactions

CBZ : autoinduction, VPA, PHT, -PB PHT : CBZ, VPA, PB PB : CBZ, VPA, PHT VPA : CBZ, PB, PHT

AEDs Drug interaction with AED and other drugs: via

effect on hepatic CYP450 enzyme system PB, primidone, PHT, CBZ induce CYP enz. : Accelerate breakdown of many prescribed

lipid-soluble drugs metabolized by the same system: OCP, cytotoxic, antiarrythmic, warfarin

VPA is a weak CYP enz. Inhibitor: Slow clearance of other AEDs such as PHT,

LTG. Newer AEDs : less likely to interfere with

hepatic metabolism. GBP, LEV,PGB,VGB do not undergo hepatic

metabolism

Newer AEDs

Adjunctive treatment of refractory epilepsy

Some of these AEDs: LTG, GBP, OXC, TPM have also demonstrated efficacy as monotherapy

Effects of phenytoin levels

Level (mg/ml) Effect

0-10 Subtherapeutic

10-20 Therapeutic

20-30 Mild toxicity; nystagmus, mild ataxia

30-40 Moderate toxicity ; ataxia prominent

> 40 Severe toxicity; ataxia, conscious -

ness, encephalopathy

Potential Causes of Treatment Resistant Epilepsy

Diagnostic errors: Non-epileptic events   Wrong diagnosis of seizure types/ epileptic

syndrome   Missing of underlying causes/lesions

Patient’s errors: Non-compliance   Inappropriate life style, inappropriate metabolism

Potential Causes of Treatment Resistant Epilepsy

Treatment errors: Wrong choice of drugs Less optimal doses of drugs   Inadequate dosing schedules Antiepileptic drug toxicity

Disease itself: Treatment resistant epilepsy metabolic disorder

Absolute

requirement 2-3 years free of all

seizures

Patient’s informed

agreement

Stopping antiepileptic treatment

Factors in favour Childhood epilepsy Primary generalized epilepsy

Absence of cerebral disorder

Short duration of epilepsy

Normal EEG Non-driver

Adverse prognostic factors

Symptomatic etiology, identifiable brain pathology Partial-onset seizures or Atonic seizures Late-onset or first-year epilepsy Specific epilepsy syndrome (particularly JME) Abnormal EEGs Multiple seizure types in the same patient Additional mental or motor handicap Long duration or severe epilepsy prior to treatment Poor initial response to treatment

Features common to the surgically privileged seizure disorders

Presence of a well-circumscribed structural lesion on the MRI (lesional epilepsy)

Presence of well-localized interictal epileptiform discharged on the EEG

Clinical features of habitual seizures indicating focal onset

Absence of discordance between above feature

Focus localized by above features is surgically accessible and involves little or no eloquent cortex

Absence of other potentially epileptogenic abnormalities

Status epilepticus

A condition in which epileptic activity

persists for 30 minutes or more

Common etiologies for status epilepticus in children and adolescents

Idiopathic Acute symptomatic

Electrolyte disturbance Encephalitis Head trauma

Remote symptomatic Past stroke CNS infection Cerebral palsy

Progressive encephalopathy Tuberous sclerosis Other neurodegeneration

Febrile

Status epilepticus management

Epilepsy and pregnancy

Seizure control Obstetric complication

Neonatal outcome

Neonatal outcome Risk of seizure

(3 times > normal population)

developmental outcome

congenital anomalies 4-8%

(2-3 times > normal population)

The most common malformation

Congenital heart disease

orofacial cleft

neural tube defect

intestinal atresia

urogenital defects

Neural tube defect

Fetal antiepileptic drug syndrome (minor anomalies)

Facial dysmorphism

Distal digital hypoplasia

Developmental delay

Mental deficiency

Factors affecting neonatal outcome

AED

genetics

folic acid

socioeconomic

maternal health

Recommendations for managing Women With Epilepsy

Before Conception

Educate the family regarding risks

Review classification of epilepsy

Determine most appropriate medicine for

seizure control

Determine need for continued medication

- may discontinue if seizure-free for 2 or more

years

- do not discontinue medication if epilepsy

syndrome

suggests continued need for treatment

Reduce medicines to monotherapy, lowest dose

possible

Start folic acid 1 mg/day

Eliminate other risk factors – smoking, drugs,

alcohol

After conception

Do not change antiepileptic medication Refer for prenatal care Prescribe vitamins, including folic acid Check ‘free’ drug levels every trimester and change

doses as needed Evaluate for neural tube defects at 12 to 16 weeks

(ultrasound, alpha-fetoprotein, amniocentesis)

Consider vitamin K predelivery Check antiepileptic drug levels prior to

delivery and increase doses if needed

After Delivery

Check levels

Examine infant

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