Epilepsy 2 Notes Lecture 4 PDF

Seizures and epilepsy Part 2 Epilepsy syndromes Eeg status DR KATZ DIVISION OF NEUROLOGY  EPILEPSY SYNDROME Takes into account:- not only SEIZURES types (generalised/partial) But also aetiology (idiopathic / symptomatic)  age of onset...

Seizures and epilepsy Part 2 Epilepsy syndromes Eeg status DR KATZ DIVISION OF NEUROLOGY  EPILEPSY SYNDROME Takes into account:- not only SEIZURES types (generalised/partial) But also aetiology (idiopathic / symptomatic)  age of onset  prognosis  response to treatment Importance of syndrome classification  If part of syndrome – shows same response to treatment and prognosis. JUVENILE MYCOLONIC EPILEPSY Most common Idiopathic Generalised Epilepsy Syndrome Inherited Age of onset : adolescence Myoclonic jerks + GTC * after awakening +/- Absence Precipitated by sleep deprivation, alcohol N intelligence EEG: characteristic: Bursts of fast generalised polyspike and wave Not progressive – but need life long therapy Responds very well to Valproic Acid, Lamotrigine But need life-long treatment LENNOX GASTAUT SYNDROME SEVERE EPILEPSY SYNDROME Symptomatic generalised epilepsy Triad: 1. Multiple seizure types 2. Characteristic EEG 3. Diffuse cognitive dysfunction Age of onset : 1 – 7 years SEIZURES: multiple seizure types usually generalised * Atonic (falling attacks), tonic, tonic clonic, atypical absence Intellectual impairment EEG : characteristic Etiology  symptomatic/secondary to e.g. prematurity, perinatal injury, metabolic disease of infancy  Management and Prognosis  Very poor prognosis  Very difficult to treat  Multiple drugs regimens  EEG Records ELECTRICAL ACTIVITY of brain by means of scalp electrodes  Electrodes are placed on scalp in standard positions. The potential differences recorded  EEG Normal EEG =background activity 8- 12 HZ (alpha rhythm) Drowsy slower Epilepsy-epileptiform activity: sharp or spike and wave activity  In addition to resting record, a number of Activating Procedures usually carried out (procedures which provoke hidden abnormalities) Hyperventilation Photic stimulation Sleep Sleep deprivation  USES OF EEG IN EPILPESY 1.Support diagnosis of epilepsy 2.classify seizures 3.to localise seizure focus pre surgery 4.may assist in prognosis 5.may assist in monitoring management of status  EEG IN EPILEPSY DIAGNOSIS OF EPILEPSY Most useful during actual seizure  Confirms electrographically However, most EEGs are done interictally (between seizures) - Often normal  INTERICTAL EEG ONE EEG in epileptic: Abnormal +/- 55% Can increase yield of abnormal EEG by: - repeated recordings - activation procedures  then abnormal +/- 80%  WHAT TO LOOK FOR ON EEG? EPILEPTIFORM ACTIVITIES: - bursts (paroxysms) of spikes and sharp wave activity - Distinct from background Mostly used: Episode clinically possibly seizures: Epileptiform activity helps suggest diagnosis of epilepsy A NORMAL EEG – does not exclude EPILEPSY  clinical history most important  2.) TO CLASSIFY SEIZURES & EPILEPSY Some epilepsy syndromes – characteristic EEG ? complex partial seizure ? Absence  EEG can make distinction: Typical Absence: characteristic EEG: Generalised, bilaterally symetrical, 3HZ spike and wave vs Complex partial: very different EEG with focal abnormality   USES OF EEG IN EPILPESY 1.Support diagnosis of epilepsy 2.classify seizures 3.to localise seizure focus pre surgery 4.may assist in prognosis 5.may assist in monitoring management of status  STATUS EPILEPTICUS DEFINITION OF GENERALISED STATUS: Continuous seizures or recurrent seizures without recovery of consciousness in between for a duration of 30 minutes. New definition -. ≥5 minutes of –continuous seizures, or –≥2 discrete seizures between which there is incomplete recovery of consciousness Any seizure type can become status GENERALISED TONIC CLONIC STATUS is an EMERGENCY With high MORBIDITY and MORTALITY  COMPLICATIONS STATUS In first 30 minutes seizure Catecholamines increase Heart rate,Blood pressure Temperature Metabolic acidosis White cell count Mild pO2, Pco2 other FRACTURES RHABDOMYOLYSIS renal failure GLUCOSE INCREASES aspiration  AFTER 30 minutes Systemic changes Prolonged electrical activity itself Leads to neuronal injury blood pressure decreases respiratory compromise acidosis decrease glucose Status- Focal impaired awareness Absence…..