Epilepsy

Shi Xue Chuan

General Considerations A seizure is a sudden, transient disturbance of brain

function, manifested by involuntary motor, sensory, autonomic, or psychic phenomena, alone or in any combination, often accompanied by alteration or loss of consciousness.

A seizure may occur after a metabolic, traumatic, anoxic, or infectious insult to the brain.

Repeated seizures without evident cause justify the label of epilepsy.

General Considerations Incidence is greatest in early and late

life, with a prevalence of approximately 3 ～ 6 ‰.

Chance of having a second seizure after an initial unprovoked episode is 30%.

Chance of remission from epilepsy in childhood is 80%.

General Considerations Recurrence rate after the withdrawal of

drugs is about 30%. Idiopathic or genetic epilepsy most often

appears between ages 4 and 16 yaers.

General Considerations Factors adversely influencing

recurrence include: Difficulty in getting the seizures

under control Neurologic dysfunction or mental

retardation Age at onset under 2 years Abnormal EEG at the time of

discontinuing medication Type of epilepsy

Etiology Genetic factor Brain damage and

dysmetabolism Inborn Acquired

Causative factor

Classification Classified by etiology

Idiopathic (essential) epilepsy Symptomatic (secondary)

epilepsy Cryptogenic epilepsy

Classification Classified by epileptic

seizures Partial (foal, local) seizures

Simple partial seizures, without impairment of consciousness With motor signs With somatosensory or special-

sensory symptoms With autonomic symptoms or signs With psychic symptoms

Classification Classified by epileptic seizures

Complex partial seizures, with

impairment of consciousness

Partial seizures evolving to

secondarily generalized seizures

Classification Classified by epileptic seizures

Generalized seizures Absence seizures

Typical absence Atypical absence

Myoclonic seizures Clonic seizures Tonic seizures Tonic-clonic seizures Atonic seizures Infant spasm, tonic-spasm

Unclassified epileptic seizures

Classification Classification of epilepsy and epilepsy

syndromes Benign children epilepsy with centrol-

temporal spike Lennox-Gastaut syndrome Infantile spaams Juvenile myoclonic

Clinical manifestation Partial epilepsy

Focal epilepsy may arise from an intracerebral structural defect, causing motor or sensory symptoms localized to one body part, which may then spreads to contiguous regions of the cortex (e.g. jacksonian seizures).

There are simple partial seizures without impairment of consciousness.

Complex partial seizures associated with disturbance of consciousness usually arise in the temporal lobe.

Clinical manifestation Partial epilepsy

Seizures arising in the medial temporal lobe may produce disturbances of smell and taste, visual hallucinations.

These may evolve to a tonic-clonic seizures ( secondary generalization).

Weakness following the event may occur for minutes or hours (todd’s paresis).

Clinical manifestation Generalized seizures

Absence attacks usually consist of a brief interruption of activity, sometimes with complex motor activity (such as fumbling with clothes), but without collapse.

EEG during this event shows a three-per-second spike-and-wave activity.

Clinical manifestation Generalized seizures

In a generalized tonic-clonic seizures, the tonic phase is a sudden tonic contraction of muscles usually with upward eye deviation. The clonic (‘with clonus-type activity’) phase follows.

Initial EEG changes are often bilateral. This condition usually has its onset in

childhood.

Diagnosis of epilepsy The integrate diagnosis should include

seizure type, anatomy, etiology and concomitant mental disorders.

For example: Epilepsy--grand mal—secondary

(symptomatic)— mental retardation Epilepsy—centrotemporal spike wave--

benign childhood epilepsy

Diagnosis of epilepsy Clinical picture

Clinical history Description of Sz Symptomatology Physical/Neurologic

examination Therapy

EEG Background activity Epileptiform activity

Interictal Ictal Postictal

Laboratory tests Neuroimaging

Differenial diagnosis Febrile Seizures

Ages 3 months to 5 years Fever Non-CNS infection Generalized seizures Last less than 5 minutes

Migraine Positive family history. Pulsatile headache Manifestations of autonomic nerve disorder Visual disorder Sensory disturbance

Differenial diagnosis Breath-holding spells

Age 6 months to 3 years, Cry, loss of consciousness Apnea and cyanosis Family historypositive in 30% Normal EEG.

Sleeping disturbance Sleepwalking , Nightmare Night terrors

Differenial diagnosis Masturbation

Consciousness not impaired Normal EEG

Pseudoseizures Effectual Suggestive therapy Normal EEG

Tourette sydrome Simple or complete stereotyped jerks or

movements Cough and grunt Normal EEG Positive Family history

An approach to Seizures

natura l h isto ry

investiga tion

trea tm ent

What is the probable cause?

N o

D iagnose and Treat

Yes

Is it sym ptom atic of an acute illness

Yes N o

Is it a seizure?

Treatment of epilepsy Therapeutic principle of ntiepilepsy

drugs (AEDs) Early treatment Treatment as the types of epileptic seizure Treatment with one drug Individual therapy Long course of treatment Slow drug withdrawal Periodic re-examination

Treatment of epilepsy AEDs selection on types of epileptic seizure

types drugs

Tonic-clonic seizures VPA, PB, CBZ, PRM or PHT

Absence seizures VPA, ES, CNP

Myoclonic seizures VPA, CNP, PRM, Topamax

Partial seizures CBZ, VPA, PB, PHT, PRM, T

Infantile spasms CNP, ACTH, Prednison, VPA

Antiepilepsy drugs,AEDsdrug

Dosage mg/kg

Effective blood level ug/ml

T1/2 Side effect

VPA 15-50 50-120 8h Ganstric discomfort, sthenic apptite , hepatic dysfunction

CBZ 15-30 4-12 15h Drowsiness, Skin rash, WBC

decrease, hepatic dysfunction

PHT 4-8 10-20 22h Skin rash,ataxia, WBC decrease, unsteady gait

PB 4-6 20-40 4d Hyperkinesia, inattention, Skin rash

ESX 20 40-120 55h Gastrointestinal disorder, headache , WBC decrease,

CZP 0.01-0.2 20-80 55h Drowsiness, Skin rash, unsteady gait, ataxia, salivate

ACTH 25-40u Hyperfuction of the adrenal cortex

Update on newer AEDsdrug Dosage

mg/kg Effective blood

level ug/ml T1/2 Side effect

TMP 3-10 20-30h infant 15h

Drowsiness, inattention, slow reaction, lose appetite, weight lose

LTG 5-15 (used with VPA

1-5)

1.1-3.0 20-30h Drowsiness, Skin rash, ataxia, headache, gastric discomfort

GBP 20-50 2-3 5-7 Drowsiness, ataxia, nystagmus, personality and behavioral changes

2 種 抗 癲 癇 藥 物

3 種 抗 癲 癇 藥 物

試 用 新 藥

7% 難 以 控 制 3% 控 制 良 好

VNS

10% 難 以 控 制 3% 控 制 良 好

10% 難 以 控 制

3% 難 以 控 制 7% 控 制 良 好

10% 手 術 治 療

20% 難 以 控 制 5% 控 制 良 好

25% 難 以 控 制 5% 控 制 良 好

30% 難 以 控 制 70% 控 制 良 好

1 種 抗 癲 癇 藥 物Treatment of epilepsy

Status epilepticus Status epilepticus is a clinical or electrical

seizure lasting at least 30 minutes, or a series of seizures without complete recovery over the same period of time.

Emergency Treatment ABC(airway, breathing, circulation) Diazepam 0.3-0.5mg/kg ;may repeat in 15-30 minutes Phenytoin 10-20mg/kg Phenobarbital 5-20mg/kg

Thank you