Transcript Document
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
Is it a seizure?
Yes
Is it symptomatic of an acute illness
No
What is the probable cause?
natural history investigation treatment Yes Diagnose and Treat No
Treatment of epilepsy
Therapeutic principle drugs (AEDs) of ntiepilepsy
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,AEDs
drug VPA Dosage mg/kg Effective blood level ug/ml 15-50 50-120 T1/2 8h CBZ PHT PB ESX CZP ACTH 15-30 4-8 4-6 20 0.01-0.2 25-40u 4-12 10-20 20-40 40-120 20-80 15h 22h 4d 55h 55h Side effect Ganstric discomfort, sthenic apptite , hepatic dysfunction Drowsiness, Skin rash, WBC decrease, hepatic dysfunction Skin rash,ataxia, WBC decrease, unsteady gait Hyperkinesia, inattention, Skin rash Gastrointestinal disorder, headache , WBC decrease, Drowsiness, Skin rash, unsteady gait, ataxia, salivate Hyperfuction of the adrenal cortex
Update on newer AEDs
drug TMP LTG GBP Dosage mg/kg 3-10 5-15 (used with VPA 1-5) Effective blood level ug/ml 1.1-3.0 T1/2 Side effect 20-30h infant 15h Drowsiness, inattention, slow reaction, lose appetite, weight lose 20-30h Drowsiness, Skin rash, ataxia, headache, gastric discomfort 20-50 2-3 5-7 Drowsiness, ataxia, nystagmus, personality and behavioral changes
Treatment of epilepsy
1 種抗癲癇藥物 30% 難以控制 2 種抗癲癇藥物 70% 控制良好 25% 難以控制 3 種抗癲癇藥物 20% 難以控制 5% 5% 控制良好 控制良好 10% 難以控制 試用新藥 10% 難以控制 3% 控制良好 VNS 7% 難以控制 3% 控制良好 10% 手術治療 3% 難以控制 7% 控制良好
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