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

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,AEDs

Update on newer AEDs

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 mg/kg ;may repeat in minutes Phenytoin 10-20mg/kg Phenobarbital 5-20mg/kg

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