Is a group of chronic syndromes characterized by recurrent seizures with periods of consciousness

Balance between Inhibitory and Excitatory Transmitting Messages

Glutamate GABA

Excitatory messages from the cerebral cortex are modulated by deeper structures

Bursts of activity from the cortex are not modulated and these bursts spread

Is an abnormal, synchronized, electrical depolarization of neurons in the CNS

Is accompanied by characteristic changes in the EEG (electroencephalogram)

Major causes: Idiopathic CNS infections Fever Metabolic defects Cerebral trauma

Categories of Seizures

Partial (focal) Seizures

Partial seizure with secondary generalization

Primarily generalized Seizures

Partial (focal) Seizures Arise in one cerebral hemispheres

Simple partial seizure (Jacksonian epilepsy) Loses voluntary control of the affected parts

of the body but no alteration of consciousness Consisting of repetitive jerking of a

particular muscle groups which spreads, involving much of the body within about 2 minutes before dying out

Complex partial seizure (Psychomotor epilepsy) Altered consciousness, automatisms (rubbing or

patting movements), and behavioral changes (dressing, walking or hair-combing)

Partial seizure with secondary generalized seizure Focal seizures become generalized and is accompanied

by loss of consciousness

Generalized Seizures Arise in both cerebral hemispheres accompanied by loss of

consciousness Tonic-clonic (grand mal) seizure – increased muscle tone,

followed by spasms of muscle contraction and relaxation Absence (petit mal) seizures – brief loss of consciousness,

with minor muscle twitches and eye blinking Myoclonic seizures – rhythmic, jerking spasms Atonic seizure – sudden loss of all muscle tone Febrile (infantile) seizures

Status Epilepticus Is a condition in which patients experience

recurrent episodes of tonic-clonic seizure without regaining consciousness

Drugs Effective in Tonic-Clonic Seizures (Grand Mal) and Complex Partial Seizures Hydantoin derivatives

Phenytoin Mephenytoin

Barbiturate derivatives Mephobarbital Phenobarbital Primidone

Iminostilbene derivatives Carbamazepine

Drugs Effective in absence (Petit Mal) Seizures Succinamide

derivatives Ethosuximide

Oxazolidine derivatives Trimethadione Paramethadione

Propylpentanoic acid derivatives Valproic acid

Drugs Effective in Seizure disorders including Status Epilepticus Benzodiazepine derivatives

Diazepam Clorazepate Clonazepam

Hydantoin derivatives

Partial Seizure TreatmentSeizure TypeSeizure Type ProtocolsProtocolsSimpleSimpleComplexComplexPartial with 2° Partial with 2° generalizationgeneralization

Carbamazepine (iminostilbene) Carbamazepine (iminostilbene) –– DOCDOCPhenytoin (hydantoin)Phenytoin (hydantoin)Valproate (propylpentanoic acid)Valproate (propylpentanoic acid)PhenobarbitalPhenobarbitalPrimidonePrimidoneAdjuncts (used only if Adjuncts (used only if monotherapy is unsuccessful): monotherapy is unsuccessful): Lamotrigine, Gabapentin, Lamotrigine, Gabapentin, tiagabine, topiramatetiagabine, topiramate

Generalized Seizure TreatmentSeizure TypeSeizure Type ProtocolsProtocolsGrand MalGrand Mal Same as in Tx of partial seizures except Same as in Tx of partial seizures except

valproate is the DOCvalproate is the DOCPetit MalPetit Mal Ethosuximide (succinamide)Ethosuximide (succinamide)

Valproate - DOCValproate - DOCClonazepamClonazepamAdjunct: LamotrigineAdjunct: Lamotrigine

Myoclonic Myoclonic SeizuresSeizures

ValproateValproateSome benzodiazepinesSome benzodiazepines

Infantile SpasmsInfantile Spasms PrednisonePrednisoneVigabatrineVigabatrine

Status Status EpilepticusEpilepticus

Phenytoin with benzodiazepinePhenytoin with benzodiazepine

MOA : Suppress the Formation or Spread of Abnormal Electrical Discharges in the Brain

Reduces NMDAReceptor activation

Affect GABA Reduce Na+

conductance inhyperactive

neurons

Reduce Ca2+

currentthrough

T-channels

Felbamate

DiazepamVigabatrinTopiramateTiagabineGabapentin

Phenobarbital Carbamazepine PhenytoinFosphenytoinLamotriginePrimidone

Ethosuximide

Valproate

Toxic Effects of Phenytoin

What is the advantage of Phenytoin over other Antiepileptic drugs?

nonsedating

Toxic Effects of Phenytoin Megaloblastic anemia

Secondary to interference with folate metabolism Diminished deep tendon reflexes in extremities CNS depression Endocrine disturbances

Diabetes insipidus Hyperglycemia Glycosuria Osteomalacia

Hydantoin syndrome Teratogenic effects

What is the Drug of Choice for Trigeminal Neuralgia?Carbamazepine Adverse effects: Acute intoxication

Respiratory depression Stupor Coma

Severe liver toxicity Aplastic anemia Agranulocytosis Drowsiness Ataxia Nystagmus Vomiting

Most effective agent in Treating Myoclonic Seizures Valproic Acid

Broadest spectrum Also used in bipolar disorder and migraine Side effects

Hepatotoxicity Nausea and vomiting Sedation Tremor High incidence of neural defects during the first

trimester of pregnancy.

What is the Drug of Choice for Febrile Seizure? Phenobarbital

Which antiepileptic drug is chemically related to Phenobarbital? Primidone

Alternative choice for adults who have partial and generalized seizures

What are the 2 active metabolites of Primidone?

Phenobarbital

Phenylethylmalonamide (PEMA)

Which Antiepileptic is the Drug of choice for Absence Seizure?

Ethosuximide Toxic effects

Dizziness Agitation GI distress Confusion Blood dyscrasias Leukopenia Aplastic anemia Thrombocytopenia Skin reactions

Stevens-Johnson syndrome

END OF ANTIEPILEPTICS