Definition

The epilepsies are a group of

disorders characterized by chronic

recurrent paroxysmal changes in

neurologic function caused by

abnormalities in the electrical activity

of the brain

SELECTED EPILEPSY TERMS

Epilepsy A clinical paroxysmal disorder of recurring seizures

Seizure A transient dysfunction of brain

due to an abnormal firing of cerebral

neurons, which may or may not have a

clinical manifestation.

Myoclonus A single abrupt shock like extensor movement of a limb. myoclonic seizures.

Petit Mal Used to describe absence seizures as well as atypical absence.

Tonic Sustained contraction of one or more muscle groups, independent of position (i.e. can be flexed, extended, or opisthotonic).

Aura A generic term for a warning. A colloquial term for simple partial seizure.

Convulsion Tonic, clonic or tonic-clonic seizure

Status

A pathological state different from a single seizure

by the Epilepticus (absence or reduction of

inhibitory processes to terminate the seizure).

Applies to any seizure type. The length of time

required to differentiate seizure from status is both

empirical and practical.

Convulsive, myoclonic status: 10-30 minutes.

Differential diagnosis of seizures

Syncope

Drop attacks

Narcolepsy-Cataplexy

Pseudoseizures

Panic attacks

Hypoglycemia

Migraine

Epidemiology

Incidence:

Developed countries: 40-70 per one lakh

Developing countries: 100-190 per one lakh

Prevalence:

Developed countries: 4-10 per 10,000

Developing countries: 57 per 10,000

Partial seizures with or without generalization is most common

Bimodal age distribution:

< 1 and > 60. Less sharp in developing

countries

Common causes: Perinatal disorders

associated with cerebral palsy & mental

retardation, Head trauma, CNS infections,

Stroke, Brain tumours, Alcohol and other

drugs

Men affected 1-2.4 times compared

to women

Revised ILAE (International League Against Epilepsy) Seizure Classification

I. PARTIAL (FOCAL, LOCAL) SEIZURES

A. Simple partial seizures

B. Complex partial seizure

C. Partial seizures evolving to generalized tonic-clonic convulsions (GTC)

II. GENERALIZED SEIZURES

A. 1. Absence seizures

2. Atypical absence

B. Myoclonic seizures, Myoclonic jerks (simple or multiple)

C. Clonic seizures

D. Tonic seizures

E. Tonic-clonic seizures

F. Atonic seizures (astatic)

III. UNCLASSIFIED EPILEPTIC SEIZURES

Includes all seizures that cannot be

classified because of inadequate or

incomplete data and some that defy

classification in hitherto described

categories. This includes some neonatal

seizures, e.g., rhythmic eye movements,

chewing, and swimming movements.

Antiepileptic drug (AED)

A drug which decreases the frequency and /or severity of seizures in people with epilepsy.

Treats the symptom of seizures, not the underlying epileptic condition.

Improves quality of life by minimizing seizures.

Gitanjali-2:

History of Antiepileptic Drug Therapy

1857 - Bromides

1912 - Phenobarbitone

1937 - Phenytoin

1944 - Trimethadione

1954 - Primidone

1960 - EthosuximideGitanjali-3:

History of AED therapy

1974 – Carbamazepine, Oxcarbazepine

1975 - Clonazepam

1978 - Valproate

1993 - Felbamate, Gabapentin

1995 – Lamotrigine, Levetiracetam

1997 - Topiramate, TiagabineGitanjali-4:

Principles of AED Selection

Correct diagnosis of the type of epilepsy influences treatment, prognosis and genetic counseling.

One best drug to fit the fit, fit the patient; Sequential monotherapy

Use the least expensive AED (all things being equal, like efficacy).

Prefer AEDs which can be taken od over bid / tid.

AEDs almost never need qid dosing

Newer is not better, and almost certainly more expensive

Start with one AED and push the dose to clinical toxicity or seizure control.

Withdraw AEDs that are not effective.

Never have a patient on more than three (3)

AED's.

Principles of AED Selection…cont.

Principles of AED Selection…cont.

• Don't use combination medications (e.g., phenytoin with phenobarbital).

• No proof that multiple AEDs are synergistic in the treatment of epilepsy.

• Polypharmacy is expensive, increases side effects and increases the complexity of adjusting AEDs in the refractory patient.

Therapeutic Drug Monitoring

Use AED levels to assess:

i. Poor clinical control (compliance, metabolism)

ii. Dose-related side effect

iii. Drug or disease interaction

iv. "Routine" levels on controlled, nontoxic patients are not indicated.