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 - Ethosuximide Gitanjali-3: History of AED therapy 1974 – Carbamazepine, Oxcarbazepine 1975 - Clonazepam 1978 - Valproate 1993 - Felbamate, Gabapentin 1995 – Lamotrigine, Levetiracetam 1997 - Topiramate, Tiagabine Gitanjali-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 Principles of AED Selection…cont. 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. • 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.